scripts/explorer_app.py

"""
Interactive SAE Feature Explorer - Bokeh Server App.

Visualizes SAE features with:
  - UMAP scatter plot of features (activation-based and dictionary-based)
  - Click a feature to see its top-activating images with heatmap overlays
  - Patch explorer: click patches of any image to find active SAE features
    (uses live GPU inference via the backbone + SAE loaded from --sae-path)
  - Feature naming: assign names to features, saved to JSON, searchable
  - CLIP text search, Gemini auto-interp, DynaDiff brain steering panel
  - Optional NSD brain MEI dataset (--brain-data) shown in the dataset dropdown

Launch: see run_explorer.sh
"""

import argparse
import os
import io
import json
import base64
import random
import threading
from collections import OrderedDict

import cv2
import numpy as np
import torch
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import matplotlib.colors as mcolors
from PIL import Image
import sys
sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'src'))
from clip_utils import load_clip, compute_text_embeddings

from bokeh.io import curdoc
from bokeh.layouts import column, row
from bokeh.events import MouseMove
from bokeh.models import (
    ColumnDataSource, HoverTool, Div, Select, TextInput, Button,
    DataTable, TableColumn, NumberFormatter, NumberEditor,
    Slider, Toggle, RadioButtonGroup, CustomJS,
)
from bokeh.plotting import figure
from bokeh.palettes import Turbo256
from bokeh.transform import linear_cmap


# ---------- Parse args ----------
parser = argparse.ArgumentParser()
parser.add_argument("--data", type=str, required=True)
parser.add_argument("--image-dir", type=str, required=True,
                    help="Primary image directory used during precompute")
parser.add_argument("--extra-image-dir", type=str, default=[], nargs="*",
                    help="Additional image directories used during precompute")
parser.add_argument("--thumb-size", type=int, default=256)
parser.add_argument("--inference-cache-size", type=int, default=64,
                    help="Number of images to keep in the patch-activations LRU cache")
parser.add_argument("--names-file", type=str, default=None,
                    help="Path to JSON file for saving feature names "
                         "(default: <data>_feature_names.json)")
parser.add_argument("--primary-label", type=str, default="Primary",
                    help="Display label for the primary --data file")
parser.add_argument("--clip-model", type=str, default="openai/clip-vit-large-patch14",
                    help="HuggingFace CLIP model ID for free-text search "
                         "(only loaded on first out-of-vocab query)")
parser.add_argument("--google-api-key", type=str, default=None,
                    help="Google API key for Gemini auto-interp button "
                         "(default: GOOGLE_API_KEY env var)")
parser.add_argument("--sae-url", type=str, default=None,
                    help="Download URL for the SAE weights — shown as a link in the summary panel")
parser.add_argument("--phi-dir", type=str, default=None,
                    help="Directory containing Phi_cv_*.npy, phi_c_*.npy, voxel_coords.npy "
                         "(brain-alignment data; enables cortical profile and brain leverage features)")
parser.add_argument("--phi-model", type=str, default=None,
                    help="Model name substring to match phi files (e.g. 'dinov3', 'dinov2', 'clip_encoder'). "
                         "Default: pick largest Phi_cv_*.npy by file size.")
parser.add_argument("--dynadiff-dir", type=str, default=None,
                    help="Path to the local dynadiff repo. "
                         "When provided (with --phi-dir), enables the brain steering panel.")
parser.add_argument("--dynadiff-checkpoint", type=str,
                    default="dynadiff_padded_sub01.pth",
                    help="Checkpoint filename or path (relative to --dynadiff-dir or absolute).")
parser.add_argument("--dynadiff-h5", type=str,
                    default="extracted_training_data/consolidated_sub01.h5",
                    help="Path to fMRI H5 (relative to --dynadiff-dir or absolute).")
parser.add_argument("--brain-data", type=str, default=None,
                    help="Path to brain_meis.pt produced by precompute_nsd_meis.py. "
                         "Adds 'NSD Brain (DINOv2 L11)' as a selectable dataset in the "
                         "dataset dropdown, using NSD images and NSD-based UMAPs.")
parser.add_argument("--brain-thumbnails", type=str, default=None,
                    help="Directory containing NSD JPEG thumbnails (nsd_XXXXX.jpg). "
                         "Required with --brain-data if image_paths are not absolute paths.")
parser.add_argument("--brain-label", type=str, default="NSD Brain (DINOv2 L11)",
                    help="Dataset label shown in the dropdown for --brain-data.")
parser.add_argument("--sae-path", type=str, default=None,
                    help="Path to SAE state-dict .pth file. When provided the backbone + SAE "
                         "are loaded on GPU so any image can be explored without pre-computed "
                         "patch activations.")
parser.add_argument("--backbone", type=str, default="dinov2",
                    help="Backbone name matching the SAE (default: dinov2).")
parser.add_argument("--layer", type=int, default=11,
                    help="Backbone layer used during SAE training (default: 11).")
parser.add_argument("--top-k", type=int, default=100,
                    help="SAE top-k sparsity (default: 100).")
args = parser.parse_args()


# ---------- Lazy CLIP model (loaded on first free-text query) ----------
_clip_handle = None   # (model, processor, device), set on first use

def _get_clip():
    """Load CLIP once and cache it."""
    global _clip_handle
    if _clip_handle is None:
        _dev = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
        print(f"[CLIP] Loading {args.clip_model} on {_dev} (first free-text query)...")
        _m, _p = load_clip(_dev, model_name=args.clip_model)
        _clip_handle = (_m, _p, _dev)
        print("[CLIP] Ready.")
    return _clip_handle


# ---------- GPU backbone + SAE runner (optional, lazy-loaded) ----------
# Tuple of (forward_fn, sae, transform_fn, n_reg, extract_tokens_fn, backbone_name, device)
_gpu_runner = None

def _get_gpu_runner():
    """Load backbone + SAE on GPU once; return the runner tuple or None."""
    global _gpu_runner
    if _gpu_runner is not None:
        return _gpu_runner
    if not args.sae_path:
        return None
    if not torch.cuda.is_available():
        print("[GPU runner] No CUDA device — on-the-fly inference disabled.")
        return None
    import sys, os as _os
    sys.path.insert(0, _os.path.abspath(_os.path.join(_os.path.dirname(__file__), '..', 'src')))
    from backbone_runners import load_batched_backbone
    from precompute_utils import load_sae, extract_tokens as _et
    _dev = torch.device("cuda:0")
    print(f"[GPU runner] Loading {args.backbone} layer {args.layer} + SAE on {_dev} ...")
    _fwd, _d_hidden, _n_reg, _tfm = load_batched_backbone(args.backbone, args.layer, _dev)
    _sae = load_sae(args.sae_path, _d_hidden, d_model, args.top_k, _dev)
    _gpu_runner = (_fwd, _sae, _tfm, _n_reg, _et, args.backbone, _dev)
    print("[GPU runner] Ready.")
    return _gpu_runner


def _run_gpu_inference(pil_img):
    """Run pil_img through backbone→SAE; return (n_patches, d_sae) float32 numpy or None."""
    runner = _get_gpu_runner()
    if runner is None:
        return None
    _fwd, _sae, _tfm, _n_reg, _et, _bname, _dev = runner
    tensor = _tfm(pil_img).unsqueeze(0).to(_dev)   # (1, C, H, W)
    with torch.inference_mode():
        hidden = _fwd(tensor)                        # (1, n_tokens, d_hidden)
        tokens = _et(hidden, _bname, 'spatial', _n_reg)  # (1, n_patches, d_hidden)
        flat   = tokens.reshape(-1, tokens.shape[-1])    # (n_patches, d_hidden)
        _, z, _ = _sae(flat)                         # (n_patches, d_sae)
    return z.cpu().float().numpy()


# ---------- Brain alignment (Phi) data ----------
# Loaded once from --phi-dir; None when not provided.
# Phi_cv: (C, V) concept-by-voxel alignment matrix (mmap)
# phi_c:  (C,)  per-concept cortical leverage scores
# _voxel_coords: (V, 3) MNI coordinates of each voxel
# _voxel_to_vertex: (V,) mapping from fsaverage vertices → voxel indices (surface-space phi only)

_phi_cv         = None
_phi_c          = None
_voxel_coords   = None
_voxel_to_vertex = None

_N_VOXELS_DD   = 15724   # DynaDiff voxel count
_N_VERTS_FSAVG = 37984   # fsaverage vertex count

if args.phi_dir:
    _pdir = args.phi_dir
    _phi_model_key = (args.phi_model or "").lower()

    def _pick_phi_file(candidates, model_key):
        """Pick best phi file: model_key substring match, else largest by size."""
        if not candidates:
            return None
        if model_key:
            matched = [f for f in candidates if model_key in f.lower()]
            if matched:
                return sorted(matched)[0]
            print(f"[Phi] WARNING: --phi-model '{model_key}' matched no files in {candidates}; "
                  "falling back to largest file")
        # Fall back to largest file by size
        return max(candidates, key=lambda f: os.path.getsize(os.path.join(_pdir, f)))

    # --- Phi_cv matrix ---
    _phi_mat_files = [f for f in os.listdir(_pdir)
                      if f.lower().startswith('phi_cv') and f.endswith('.npy')]
    _phi_mat_pick = _pick_phi_file(_phi_mat_files, _phi_model_key)
    if _phi_mat_pick:
        _phi_path = os.path.join(_pdir, _phi_mat_pick)
        _phi_cv = np.load(_phi_path, mmap_mode='r')
        print(f"[Phi] Loaded {_phi_mat_pick}: shape {_phi_cv.shape}, dtype {_phi_cv.dtype}")
        if _phi_cv.shape[1] == _N_VERTS_FSAVG:
            _v2v_path = os.path.join(_pdir, 'voxel_to_vertex_map.npy')
            if os.path.exists(_v2v_path):
                _voxel_to_vertex = np.load(_v2v_path)
                print(f"[Phi] Surface-space phi; loaded voxel_to_vertex_map: {_voxel_to_vertex.shape}")
            else:
                print("[Phi] WARNING: surface-space phi but voxel_to_vertex_map.npy not found")
        elif _phi_cv.shape[1] == _N_VOXELS_DD:
            print("[Phi] Voxel-space phi detected.")
        else:
            print(f"[Phi] WARNING: unexpected phi dimension {_phi_cv.shape[1]}")
    else:
        print(f"[Phi] WARNING: no Phi_cv_*.npy found in {_pdir}")
    # --- phi_c leverage scores ---
    _phi_c_files = [f for f in os.listdir(_pdir)
                    if f.lower().startswith('phi_c')
                    and not f.lower().startswith('phi_cv')
                    and f.endswith('.npy')]
    _phi_c_pick = _pick_phi_file(_phi_c_files, _phi_model_key)
    if _phi_c_pick:
        _phi_c = np.load(os.path.join(_pdir, _phi_c_pick))
        print(f"[Phi] Leverage scores {_phi_c_pick}: shape {_phi_c.shape}, "
              f"range [{_phi_c.min():.4f}, {_phi_c.max():.4f}]")
    else:
        print(f"[Phi] No phi_c_*.npy found in {_pdir} — leverage scores unavailable")
    # --- Voxel coordinates ---
    _coords_path = os.path.join(_pdir, 'voxel_coords.npy')
    if os.path.exists(_coords_path):
        _voxel_coords = np.load(_coords_path)
        print(f"[Phi] Voxel coordinates: {_voxel_coords.shape}")
    else:
        print("[Phi] voxel_coords.npy not found — cortical scatter unavailable")

HAS_PHI = _phi_cv is not None


# ---------- DynaDiff steering (in-process) ----------
# Enabled when --dynadiff-dir is provided and --phi-dir is also set.
_dd_loader = None
HAS_DYNADIFF = False

if args.dynadiff_dir and os.path.isdir(args.dynadiff_dir):
    if not HAS_PHI:
        print("[DynaDiff] WARNING: --phi-dir not set; steering panel requires Phi data. Disabling.")
    else:
        try:
            sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
            from dynadiff_loader import get_loader

            _h5 = args.dynadiff_h5
            if not os.path.isabs(_h5):
                _h5 = os.path.join(args.dynadiff_dir, _h5)

            _dd_loader = get_loader(
                dynadiff_dir   = args.dynadiff_dir,
                checkpoint     = args.dynadiff_checkpoint,
                h5_path        = _h5,
                nsd_thumb_dir  = args.brain_thumbnails,
                subject_idx    = 0,
            )
            HAS_DYNADIFF = True
            print(f"[DynaDiff] In-process loader ready (checkpoint: {args.dynadiff_checkpoint})")
        except Exception as _dd_err:
            print(f"[DynaDiff] WARNING: Could not start in-process loader ({_dd_err}). "
                  "Steering panel will be disabled.")


# ---------- Load all datasets into a unified list ----------

def _load_dataset_dict(path, label, sae_url=None):
    """Load one explorer_data.pt file and return a unified dataset dict."""
    print(f"Loading [{label}] from {path} ...")
    d = torch.load(path, map_location='cpu', weights_only=False)
    cs = d.get('clip_text_scores', None)
    names_file = (args.names_file if path == args.data and args.names_file
                  else os.path.splitext(path)[0] + '_feature_names.json')
    feat_names = {}
    if os.path.exists(names_file):
        with open(names_file) as _nf:
            feat_names = {int(k): v for k, v in json.load(_nf).items()}
    auto_interp_file = os.path.splitext(path)[0] + '_auto_interp.json'
    auto_interp = {}
    if os.path.exists(auto_interp_file):
        with open(auto_interp_file) as _af:
            auto_interp = {int(k): v for k, v in json.load(_af).items()}
        print(f"  Loaded {len(auto_interp)} auto-interp labels from "
              f"{os.path.basename(auto_interp_file)}")
    entry = {
        'label':             label,
        'path':              path,
        'image_paths':       d['image_paths'],
        'd_model':           d['d_model'],
        'n_images':          d['n_images'],
        'patch_grid':        d['patch_grid'],
        'image_size':        d['image_size'],
        'token_type':        d.get('token_type', 'spatial'),
        'backbone':          d.get('backbone', 'dinov3'),
        'top_img_idx':       d['top_img_idx'],
        'top_img_act':       d['top_img_act'],
        'mean_img_idx':      d.get('mean_img_idx', d['top_img_idx']),
        'mean_img_act':      d.get('mean_img_act', d['top_img_act']),
        'p75_img_idx':       d['p75_img_idx'],
        'p75_img_act':       d['p75_img_act'],
        'nsd_top_img_idx':   d.get('nsd_top_img_idx', None),
        'nsd_top_img_act':   d.get('nsd_top_img_act', None),
        'nsd_mean_img_idx':  d.get('nsd_mean_img_idx', None),
        'nsd_mean_img_act':  d.get('nsd_mean_img_act', None),
        'feature_frequency': d['feature_frequency'],
        'feature_mean_act':  d['feature_mean_act'],
        'feature_p75_val':   d['feature_p75_val'],
        'umap_coords':       d['umap_coords'].numpy(),
        'dict_umap_coords':  d['dict_umap_coords'].numpy() if 'dict_umap_coords' in d else np.full((d['d_model'], 2), np.nan, dtype=np.float32),
        'clip_scores':       cs,
        'clip_vocab':        d.get('clip_text_vocab', None),
        'clip_embeds':       d.get('clip_feature_embeds', None),
        'nsd_clip_embeds':   d.get('nsd_clip_feature_embeds', None),
        'clip_scores_f32':   cs.float() if cs is not None else None,
        'inference_cache':   OrderedDict(),
        'names_file':        names_file,
        'auto_interp_file':  auto_interp_file,
        'feature_names':     feat_names,
        'auto_interp_names': auto_interp,
    }
    # Load pre-computed heatmaps sidecar if present
    sidecar = os.path.splitext(path)[0] + '_heatmaps.pt'
    if os.path.exists(sidecar):
        print(f"  Loading pre-computed heatmaps from {os.path.basename(sidecar)} ...")
        hm = torch.load(sidecar, map_location='cpu', weights_only=True)
        entry['top_heatmaps']      = hm.get('top_heatmaps')
        entry['mean_heatmaps']     = hm.get('mean_heatmaps')
        entry['p75_heatmaps']      = hm.get('p75_heatmaps')
        entry['nsd_top_heatmaps']  = hm.get('nsd_top_heatmaps')
        entry['nsd_mean_heatmaps'] = hm.get('nsd_mean_heatmaps')
        # patch_grid stored in sidecar may differ from data (e.g. --force-spatial on CLS SAE)
        entry['heatmap_patch_grid'] = hm.get('patch_grid', d['patch_grid'])
        has_hm = 'yes (no GPU needed for heatmaps)'
    else:
        entry['top_heatmaps']      = None
        entry['mean_heatmaps']     = None
        entry['p75_heatmaps']      = None
        entry['nsd_top_heatmaps']  = None
        entry['nsd_mean_heatmaps'] = None
        entry['heatmap_patch_grid'] = d['patch_grid']
        has_hm = 'no'

    entry['sae_url'] = sae_url

    print(f"  d={entry['d_model']}, n={entry['n_images']}, token={entry['token_type']}, "
          f"backbone={entry['backbone']}, clip={'yes' if (cs is not None or entry.get('clip_embeds') is not None) else 'no'}, "
          f"heatmaps={has_hm}")
    return entry


_all_datasets = []


# ---------- Mutable session state ----------
class _S:
    """Mutable module-level state shared by all Bokeh callbacks.

    Using a plain-class namespace avoids the ``[value]`` mutable-list idiom;
    attributes can be read and written by any function without ``global`` statements.
    """
    active: int = 0              # index into _all_datasets for the current view
    render_token: int = 0        # incremented on each feature selection; stale renders bail out
    search_filter = None         # set of feature indices matching the current name search, or None
    color_by: str = "Log Frequency"   # which field drives UMAP point colour
    hf_push = None               # active Bokeh timeout handle for debounced HuggingFace upload
    patch_img = None             # image index currently loaded in the patch explorer
    patch_z = None               # cached (n_patches, d_model) float32 for the loaded image


def _ds():
    """Return the currently-active dataset dict."""
    return _all_datasets[_S.active]


# Primary dataset — always loaded eagerly
_all_datasets.append(_load_dataset_dict(args.data, args.primary_label, sae_url=args.sae_url))

def _load_brain_dataset_dict(path, label, thumb_dir):
    """Load a brain_meis.pt file and return a dataset entry dict.

    Brain MEI files share the same entry schema as regular explorer_data.pt files
    but have a different on-disk layout (NSD image indices, no CLIP embeddings, etc.)
    and may store only basenames in image_paths (resolved via thumb_dir at load time).
    Returns None on failure.
    """
    print(f"[Brain] Loading NSD dataset from {path} ...")
    try:
        bd = torch.load(path, map_location='cpu', weights_only=False)
    except Exception as err:
        print(f"[Brain] WARNING: Failed to load NSD dataset: {err}")
        return None

    # Resolve image_paths: prepend thumb_dir when paths are stored as basenames,
    # or when stored as absolute paths that don't exist on this machine.
    raw_paths = bd.get('image_paths', [])
    if raw_paths and thumb_dir and (
        not os.path.isabs(raw_paths[0]) or not os.path.exists(raw_paths[0])
    ):
        bd_paths = [os.path.join(thumb_dir, os.path.basename(p)) for p in raw_paths]
    else:
        bd_paths = raw_paths

    d_model = bd['d_model']
    nan2    = np.full((d_model, 2), np.nan, dtype=np.float32)
    stem    = os.path.splitext(path)[0]

    entry = {
        'label':             label,
        'path':              path,
        'image_paths':       bd_paths,
        'd_model':           d_model,
        'n_images':          bd.get('n_images', len(bd_paths)),
        'patch_grid':        bd.get('patch_grid', 16),
        'image_size':        bd.get('image_size', 224),
        'token_type':        bd.get('token_type', 'spatial'),
        'backbone':          bd.get('backbone', 'dinov2'),
        'top_img_idx':       bd['top_img_idx'],
        'top_img_act':       bd['top_img_act'],
        'mean_img_idx':      bd.get('mean_img_idx', bd['top_img_idx']),
        'mean_img_act':      bd.get('mean_img_act', bd['top_img_act']),
        'p75_img_idx':       bd.get('p75_img_idx', torch.full((d_model, 1), -1, dtype=torch.long)),
        'p75_img_act':       bd.get('p75_img_act', torch.zeros(d_model, 1)),
        'top_heatmaps':      None,
        'mean_heatmaps':     None,
        'p75_heatmaps':      None,
        'heatmap_patch_grid': bd.get('patch_grid', 16),
        'feature_frequency': bd['feature_frequency'],
        'feature_mean_act':  bd['feature_mean_act'],
        'feature_p75_val':   bd.get('feature_p75_val', torch.zeros(d_model)),
        'umap_coords':       bd['umap_coords'].numpy() if 'umap_coords' in bd else nan2,
        'dict_umap_coords':  bd['dict_umap_coords'].numpy() if 'dict_umap_coords' in bd else nan2,
        'clip_scores':       bd.get('clip_text_scores', None),
        'clip_vocab':        bd.get('clip_text_vocab', None),
        'clip_embeds':       bd.get('clip_feature_embeds', None),
        'clip_scores_f32':   bd['clip_text_scores'].float() if 'clip_text_scores' in bd else None,
        'inference_cache':   OrderedDict(),
        'names_file':        stem + '_feature_names.json',
        'auto_interp_file':  stem + '_auto_interp.json',
        'feature_names':     {},
        'auto_interp_names': {},
        'sae_url':           None,
    }

    # Load pre-computed heatmaps sidecar if present.
    sidecar = stem + '_heatmaps.pt'
    if os.path.exists(sidecar):
        print(f"[Brain] Loading heatmaps sidecar: {os.path.basename(sidecar)} ...")
        bhm = torch.load(sidecar, map_location='cpu', weights_only=False)
        entry['top_heatmaps']       = bhm.get('top_heatmaps')
        entry['mean_heatmaps']      = bhm.get('mean_heatmaps')
        entry['p75_heatmaps']       = bhm.get('p75_heatmaps')
        entry['heatmap_patch_grid'] = bhm.get('patch_grid', bd.get('patch_grid', 16))

    print(f"[Brain] Added '{label}' dataset: "
          f"d_model={d_model}, n_images={entry['n_images']}, backbone={entry['backbone']}")
    return entry


# NSD brain dataset — loaded as a regular dataset entry so it appears in the
# dataset dropdown and drives both the MEI image views and the UMAP.
if args.brain_data and os.path.exists(args.brain_data):
    _brain_entry = _load_brain_dataset_dict(
        args.brain_data, args.brain_label, args.brain_thumbnails or '')
    if _brain_entry is not None:
        _all_datasets.append(_brain_entry)
elif args.brain_data:
    print(f"[Brain] WARNING: --brain-data file not found: {args.brain_data}")


def _ensure_loaded(idx):
    """Load dataset at idx if it is still a lazy placeholder."""
    ds = _all_datasets[idx]
    if ds.get('_lazy', False):
        print(f"[Lazy load] Loading '{ds['label']}' on first access ...")
        _all_datasets[idx] = _load_dataset_dict(ds['path'], ds['label'], sae_url=ds.get('sae_url'))


_basename_to_idx = {}   # rebuilt by _apply_dataset_globals; basename/stem → image index


def _build_basename_index(paths):
    """Build stem→idx and full-basename→idx lookup for fast filename search."""
    d = {}
    for i, p in enumerate(paths):
        base = os.path.basename(p)
        stem = os.path.splitext(base)[0]
        d[base] = i
        d[stem] = i
    return d


def _apply_dataset_globals(idx):
    """Swap every module-level data alias to point at dataset[idx].

    Bokeh callbacks capture module-level names at import time, so the
    simplest way to support dataset switching is to rebind these aliases
    each time the active dataset changes.  All callbacks read these names;
    only this function and the initialisation below may write them.
    """
    global image_paths, d_model, n_images, patch_grid, image_size, heatmap_patch_grid
    global top_img_idx, top_img_act, mean_img_idx, mean_img_act
    global p75_img_idx, p75_img_act
    global nsd_top_img_idx, nsd_top_img_act, nsd_mean_img_idx, nsd_mean_img_act, HAS_NSD_SUBSET
    global top_heatmaps, mean_heatmaps, p75_heatmaps
    global nsd_top_heatmaps, nsd_mean_heatmaps
    global feature_frequency, feature_mean_act, feature_p75_val
    global umap_coords, dict_umap_coords
    global freq, mean_act, log_freq, p75_np
    global live_mask, live_indices, dict_live_mask, dict_live_indices
    global umap_backup
    global _clip_scores, _clip_vocab, _clip_embeds, _nsd_clip_embeds, _clip_scores_f32, HAS_CLIP
    global feature_names, _names_file, auto_interp_names, _auto_interp_file
    global _active_feats
    global _basename_to_idx

    ds = _all_datasets[idx]
    image_paths        = ds['image_paths']
    _basename_to_idx   = _build_basename_index(image_paths)
    d_model            = ds['d_model']
    n_images           = ds['n_images']
    patch_grid         = ds['patch_grid']
    image_size         = ds['image_size']
    top_img_idx        = ds['top_img_idx']
    top_img_act        = ds['top_img_act']
    mean_img_idx       = ds['mean_img_idx']
    mean_img_act       = ds['mean_img_act']
    p75_img_idx        = ds['p75_img_idx']
    p75_img_act        = ds['p75_img_act']
    nsd_top_img_idx    = ds.get('nsd_top_img_idx')
    nsd_top_img_act    = ds.get('nsd_top_img_act')
    nsd_mean_img_idx   = ds.get('nsd_mean_img_idx')
    nsd_mean_img_act   = ds.get('nsd_mean_img_act')
    nsd_top_heatmaps   = ds.get('nsd_top_heatmaps')
    nsd_mean_heatmaps  = ds.get('nsd_mean_heatmaps')
    HAS_NSD_SUBSET     = nsd_top_img_idx is not None
    top_heatmaps        = ds.get('top_heatmaps')
    mean_heatmaps       = ds.get('mean_heatmaps')
    p75_heatmaps        = ds.get('p75_heatmaps')
    heatmap_patch_grid  = ds.get('heatmap_patch_grid', patch_grid)
    feature_frequency  = ds['feature_frequency']
    feature_mean_act   = ds['feature_mean_act']
    feature_p75_val    = ds['feature_p75_val']
    umap_coords        = ds['umap_coords']
    dict_umap_coords   = ds['dict_umap_coords']
    _clip_scores       = ds['clip_scores']
    _clip_vocab        = ds['clip_vocab']
    _clip_embeds       = ds['clip_embeds']
    _nsd_clip_embeds   = ds.get('nsd_clip_embeds')
    _clip_scores_f32   = ds['clip_scores_f32']
    HAS_CLIP           = _clip_embeds is not None or (_clip_scores is not None and _clip_vocab is not None)
    feature_names      = ds['feature_names']
    _names_file        = ds['names_file']
    auto_interp_names  = ds['auto_interp_names']
    _auto_interp_file  = ds['auto_interp_file']

    # Derived arrays used by UMAP, feature list, and callbacks
    freq          = feature_frequency.numpy()
    mean_act      = feature_mean_act.numpy()
    log_freq      = np.log10(freq + 1)
    p75_np        = feature_p75_val.numpy()
    live_mask         = ~np.isnan(umap_coords[:, 0])
    live_indices      = np.where(live_mask)[0]
    dict_live_mask    = ~np.isnan(dict_umap_coords[:, 0])
    dict_live_indices = np.where(dict_live_mask)[0]
    umap_backup = dict(
        act_x=umap_coords[live_mask, 0].tolist(),
        act_y=umap_coords[live_mask, 1].tolist(),
        act_feat=live_indices.tolist(),
        dict_x=dict_umap_coords[dict_live_mask, 0].tolist(),
        dict_y=dict_umap_coords[dict_live_mask, 1].tolist(),
        dict_feat=dict_live_indices.tolist(),
    )
    # Features that fired at least once — used by the Random button.
    _active_feats = [int(i) for i in range(d_model) if feature_frequency[i].item() > 0]


# Initialise all globals from the primary dataset
_apply_dataset_globals(0)


def _save_names():
    with open(_names_file, 'w') as _f:
        json.dump({str(k): v for k, v in sorted(feature_names.items())}, _f, indent=2)
    print(f"Saved {len(feature_names)} feature names to {_names_file}")
    _schedule_hf_push(_names_file)


def _save_auto_interp():
    with open(_auto_interp_file, 'w') as _f:
        json.dump({str(k): v for k, v in sorted(auto_interp_names.items())}, _f, indent=2)
    print(f"Saved {len(auto_interp_names)} auto-interp labels to {_auto_interp_file}")
    _schedule_hf_push(_auto_interp_file)


def _schedule_hf_push(names_file_path):
    """Debounce HF dataset upload: waits 2 s after the last save, then pushes in a thread.
    No-op if HF_TOKEN / HF_DATASET_REPO are not set (i.e. running locally)."""
    hf_token = os.environ.get("HF_TOKEN")
    hf_repo  = os.environ.get("HF_DATASET_REPO")
    if not (hf_token and hf_repo):
        return

    # Cancel any already-pending push for this session.
    if _S.hf_push is not None:
        try:
            curdoc().remove_timeout_callback(_S.hf_push)
        except Exception:
            pass

    def _push_thread():
        try:
            from huggingface_hub import upload_file
            upload_file(
                path_or_fileobj=names_file_path,
                path_in_repo=os.path.basename(names_file_path),
                repo_id=hf_repo,
                repo_type="dataset",
                token=hf_token,
                commit_message="Update feature names",
            )
            print(f"  Pushed {os.path.basename(names_file_path)} to HF dataset {hf_repo}")
        except Exception as e:
            print(f"  Warning: could not push feature names to HF: {e}")

    def _fire():
        _S.hf_push = None
        threading.Thread(target=_push_thread, daemon=True).start()

    _S.hf_push = curdoc().add_timeout_callback(_fire, 2000)


def _display_name(feat: int) -> str:
    """Return the label to show in tables: manual label takes priority over auto-interp."""
    m = feature_names.get(feat)
    if m:
        return m
    a = auto_interp_names.get(feat)
    return f"[auto] {a}" if a else ""




def compute_patch_activations(img_idx):
    """Return (n_patches, d_sae) float32 via GPU inference, or None if unavailable.

    Results are cached in a per-dataset LRU cache keyed by image index.
    """
    ds    = _all_datasets[_S.active]
    cache = ds['inference_cache']

    if img_idx in cache:
        cache.move_to_end(img_idx)
        return cache[img_idx]

    try:
        pil  = load_image(img_idx)
        z_np = _run_gpu_inference(pil)
    except Exception as _e:
        print(f"[GPU runner] inference failed for img {img_idx}: {_e}")
        z_np = None

    if z_np is not None:
        cache[img_idx] = z_np
        if len(cache) > args.inference_cache_size:
            cache.popitem(last=False)
    return z_np


# ---------- Alpha colormap ----------
def create_alpha_cmap(base='jet'):
    base_cmap = plt.cm.get_cmap(base)
    colors = base_cmap(np.arange(base_cmap.N))
    colors[:, -1] = np.linspace(0.0, 1.0, base_cmap.N)
    return mcolors.LinearSegmentedColormap.from_list('alpha_cmap', colors)

ALPHA_JET = create_alpha_cmap('jet')


# ---------- Image helpers ----------
THUMB = args.thumb_size


def _parse_img_label(value):
    """Parse an image label into an integer index.

    Accepts:
      - exact filename match: 'nsd_31215.jpg', 'nsd_31215', '000000204103.jpg'
      - bare integer index: '42'
      - ImageNet-style synset: 'n02655020_475' (basename lookup, then trailing-int fallback)

    Basename lookup is tried before integer parsing so that zero-padded COCO
    filenames like '000000204103' are resolved to the correct dataset entry
    rather than being misinterpreted as raw index 204103.
    Raises ValueError on failure.
    """
    val = value.strip()
    # Basename / stem lookup first — handles COCO zero-padded names and any
    # filename where the numeric value differs from the dataset index.
    key = os.path.splitext(val)[0]   # strip extension if given
    if key in _basename_to_idx:
        return _basename_to_idx[key]
    if val in _basename_to_idx:
        return _basename_to_idx[val]
    # Fall back to bare integer index
    try:
        return int(val)
    except ValueError:
        pass
    # Last-resort: extract trailing integer after final underscore
    return int(val.rsplit('_', 1)[-1])


def _resolve_img_path(stored_path):
    """Resolve a stored image path, searching image dirs first. Returns None on failure."""
    if os.path.isabs(stored_path) and os.path.exists(stored_path):
        return stored_path
    basename = os.path.basename(stored_path)
    for base in filter(None, [args.image_dir] + (args.extra_image_dir or [])):
        candidate = os.path.join(base, basename)
        if os.path.exists(candidate):
            return candidate
    if os.path.exists(stored_path):
        return stored_path
    return None


def _load_image_by_path(path):
    """Load a single image, searching args.image_dir / args.extra_image_dir first."""
    resolved = _resolve_img_path(path) or path
    return Image.open(resolved).convert("RGB")


def load_image(img_idx):
    """Load an image by index using the active dataset's image_paths."""
    return _load_image_by_path(image_paths[img_idx])


def render_heatmap_overlay(img_idx, heatmap_16x16, size=THUMB, cmap=ALPHA_JET, alpha=1.0):
    """Render image with heatmap overlay."""
    img = load_image(img_idx).resize((size, size), Image.BILINEAR)
    img_arr = np.array(img).astype(np.float32) / 255.0

    heatmap = heatmap_16x16.numpy() if isinstance(heatmap_16x16, torch.Tensor) else heatmap_16x16
    heatmap = heatmap.astype(np.float32)
    heatmap_up = cv2.resize(heatmap, (size, size), interpolation=cv2.INTER_CUBIC)

    hmax = heatmap_up.max()
    heatmap_norm = heatmap_up / hmax if hmax > 0 else heatmap_up

    overlay = cmap(heatmap_norm)
    ov_alpha = overlay[:, :, 3:4] * alpha
    blended = img_arr * (1 - ov_alpha) + overlay[:, :, :3] * ov_alpha
    blended = np.clip(blended * 255, 0, 255).astype(np.uint8)
    return Image.fromarray(blended)


def render_zoomed_overlay(img_idx, heatmap_16x16, size=THUMB, pg=None, alpha=None,
                          center='peak'):
    """Render heatmap overlay cropped to the zoom window at the current slider level.

    At full zoom (slider == pg) the whole image is returned.  At lower values
    the overlay is cropped to a zoom_patches × zoom_patches patch window and
    upscaled to `size`.

    center='peak'     — window centred on the argmax patch (good for max-ranked images)
    center='centroid' — window centred on the activation-weighted centroid
                        (good for mean-ranked images where activation is diffuse)
    """
    if pg is None:
        pg = heatmap_patch_grid
    if alpha is None:
        alpha = heatmap_alpha_slider.value
    heatmap = heatmap_16x16.numpy() if isinstance(heatmap_16x16, torch.Tensor) else heatmap_16x16

    # Render full overlay at native resolution so the crop is high quality
    overlay = render_heatmap_overlay(img_idx, heatmap, size=image_size, alpha=alpha)

    zoom_patches = int(zoom_slider.value)
    if zoom_patches >= pg:
        return overlay.resize((size, size), Image.BILINEAR)

    # Find crop centre
    if center == 'centroid':
        total = heatmap.sum()
        if total > 0:
            rows = np.arange(pg)
            cols = np.arange(pg)
            peak_row = int(np.average(rows, weights=heatmap.sum(axis=1)))
            peak_col = int(np.average(cols, weights=heatmap.sum(axis=0)))
        else:
            peak_row, peak_col = pg // 2, pg // 2
    else:
        peak_idx = np.argmax(heatmap)
        peak_row, peak_col = divmod(int(peak_idx), pg)

    patch_px = image_size // pg
    half = (zoom_patches * patch_px) // 2
    cy = peak_row * patch_px + patch_px // 2
    cx = peak_col * patch_px + patch_px // 2
    y0 = max(0, cy - half); y1 = min(image_size, cy + half)
    x0 = max(0, cx - half); x1 = min(image_size, cx + half)
    return overlay.crop((x0, y0, x1, y1)).resize((size, size), Image.BILINEAR)


def pil_to_data_url(img):
    buf = io.BytesIO()
    img.save(buf, format="JPEG", quality=85)
    b64 = base64.b64encode(buf.getvalue()).decode("utf-8")
    return f"data:image/jpeg;base64,{b64}"


# ---------- Brain / Phi helpers ----------

def _phi_c_for_feat(feat):
    """Return cortical leverage score φ_c for a feature, or None."""
    if _phi_c is None or feat >= len(_phi_c):
        return None
    return float(_phi_c[feat])


def _phi_voxel_row(feat):
    """Return the phi row in voxel space (15724,) float32, or None."""
    if _phi_cv is None or feat >= _phi_cv.shape[0]:
        return None
    phi_row = np.array(_phi_cv[feat], dtype=np.float32)
    if _voxel_to_vertex is not None:
        return phi_row[_voxel_to_vertex]
    return phi_row


def _render_steering_preview(feats, lams, thresholds):
    """Render the net combined steering direction across all chosen features.

    Computes: sum_i( lam_i * threshold_mask_i * phi_i / max|phi_i| )
    Returns an HTML string with an inline PNG brain map, or "" if no data.
    """
    if not feats or _voxel_coords is None:
        return ""
    combined = np.zeros(_N_VOXELS_DD, dtype=np.float32)
    n_valid = 0
    for f, lam, thr in zip(feats, lams, thresholds):
        phi = _phi_voxel_row(f)
        if phi is None:
            continue
        phi_max = float(np.abs(phi).max())
        if phi_max < 1e-12:
            continue
        norm_phi = phi / phi_max
        if thr < 1.0:
            cutoff = float(np.percentile(np.abs(phi), 100.0 * (1.0 - thr)))
            norm_phi = norm_phi * (np.abs(phi) >= cutoff)
        combined += lam * norm_phi
        n_valid += 1
    if n_valid == 0 or np.abs(combined).max() < 1e-12:
        return ""
    vmax = float(np.abs(combined).max()) or 1e-6
    fig, axes = plt.subplots(1, 2, figsize=(8, 3.2), facecolor='#f8f8f8')
    for ax, (title, xi, yi) in zip(axes, [("Axial (x–y)", 0, 1), ("Coronal (x–z)", 0, 2)]):
        sc = ax.scatter(
            _voxel_coords[:, xi], _voxel_coords[:, yi],
            c=combined, cmap='RdBu_r', s=3, alpha=0.7,
            vmin=-vmax, vmax=vmax, rasterized=True, marker='s',
        )
        ax.set_title(title, fontsize=9)
        ax.set_aspect('equal')
        ax.set_xticks([]); ax.set_yticks([])
        ax.set_facecolor('#f8f8f8')
    fig.subplots_adjust(right=0.88, top=0.85)
    cbar_ax = fig.add_axes([0.91, 0.15, 0.02, 0.65])
    cbar = fig.colorbar(sc, cax=cbar_ax)
    cbar.set_label('Δ fMRI (norm.)', fontsize=8)
    lbl = f'{n_valid} feature{"s" if n_valid != 1 else ""}'
    fig.suptitle(f'Net brain modification — {lbl}', fontsize=10)
    buf = io.BytesIO()
    fig.savefig(buf, format='png', dpi=80, bbox_inches='tight', facecolor='#f8f8f8')
    plt.close(fig)
    b64 = base64.b64encode(buf.getvalue()).decode('utf-8')
    return (
        '<h4 style="margin:6px 0 3px 0;color:#333;font-size:12px">Net Brain Modification</h4>'
        f'<img src="data:image/png;base64,{b64}" '
        'style="max-width:100%;border-radius:4px;border:1px solid #ddd"/>'
    )


def _render_cortical_profile(feat):
    """Render two 2D scatter views of voxel phi values as an inline PNG HTML block.

    Returns empty string when phi data is unavailable for this feature.
    """
    phi_vox = _phi_voxel_row(feat)
    if phi_vox is None or _voxel_coords is None:
        return ""

    vmax = float(np.abs(phi_vox).max()) or 1e-6
    phi_c_val = _phi_c_for_feat(feat)
    phi_c_str = f"φ_c = {phi_c_val:.4f}" if phi_c_val is not None else ""

    fig, axes = plt.subplots(1, 2, figsize=(10, 4.0), facecolor='#f8f8f8')
    view_pairs = [("Axial  (x – y)", 0, 1), ("Coronal  (x – z)", 0, 2)]
    for ax, (title, xi, yi) in zip(axes, view_pairs):
        sc = ax.scatter(
            _voxel_coords[:, xi], _voxel_coords[:, yi],
            c=phi_vox, cmap='RdBu_r', s=4, alpha=0.75,
            vmin=-vmax, vmax=vmax, rasterized=True, marker='s',
        )
        ax.set_title(title, fontsize=10)
        ax.set_aspect('equal')
        ax.set_xticks([]); ax.set_yticks([])
        ax.set_facecolor('#f8f8f8')

    fig.subplots_adjust(right=0.88, top=0.88)
    cbar_ax = fig.add_axes([0.91, 0.15, 0.02, 0.65])
    cbar = fig.colorbar(sc, cax=cbar_ax)
    cbar.set_label('Φ weight', fontsize=9)
    fig.suptitle(
        f'Cortical Profile — Feature {feat}' + (f'  ({phi_c_str})' if phi_c_str else ''),
        fontsize=11,
    )

    buf = io.BytesIO()
    fig.savefig(buf, format='png', dpi=90, bbox_inches='tight', facecolor='#f8f8f8')
    plt.close(fig)
    b64 = base64.b64encode(buf.getvalue()).decode('utf-8')

    return (
        '<h3 style="margin:4px 0 6px 0;color:#333;border-bottom:2px solid #e0e0e0;'
        'padding-bottom:4px">Cortical Profile (Φ)</h3>'
        f'<img src="data:image/png;base64,{b64}" '
        'style="max-width:100%;border-radius:4px;border:1px solid #ddd"/>'
    )


def _status_html(state, msg):
    """Return a styled HTML status banner."""
    styles = {
        'idle':    'background:#f5f5f5;border-left:4px solid #bbb;color:#666',
        'loading': 'background:#fff8e0;border-left:4px solid #f0a020;color:#7a5000',
        'ok':      'background:#e8f4e8;border-left:4px solid #2a8a2a;color:#1a5a1a',
        'dead':    'background:#fce8e8;border-left:4px solid #c03030;color:#8a1a1a',
    }
    style = styles.get(state, styles['idle'])
    return f'<div style="{style};padding:7px 12px;border-radius:3px;font-size:13px">{msg}</div>'


# ---------- DynaDiff steering helpers ----------

def _dynadiff_request(sample_idx, steerings, seed):
    """Run DynaDiff reconstruction.

    steerings: list of (phi_voxel np.ndarray, lam float, threshold float)
    Returns dict with baseline_img, steered_img, gt_img, beta_std.
    """
    status, err = _dd_loader.status
    if status == 'loading':
        raise RuntimeError('DynaDiff model still loading — try again shortly')
    if status == 'error':
        raise RuntimeError(f'DynaDiff model load failed: {err}')
    return _dd_loader.reconstruct(sample_idx, steerings, seed)


def _make_steering_html(resps, concept_name):
    """Build HTML showing GT | Baseline | Steered for one or more trials.

    resps: list of (trial_label, resp_dict) pairs.
    """
    header = (
        f'<h3 style="margin:4px 0 6px 0;color:#333;border-bottom:2px solid #e0e0e0;'
        f'padding-bottom:4px">DynaDiff Steering — {concept_name}</h3>'
    )
    rows_html = ''
    for trial_label, resp in resps:
        parts = []
        for label, key in [('GT', 'gt_img'),
                            ('Baseline', 'baseline_img'),
                            ('Steered', 'steered_img')]:
            b64 = resp.get(key)
            if b64 is None:
                img_html = ('<div style="width:160px;height:160px;background:#eee;'
                            'display:flex;align-items:center;justify-content:center;'
                            'color:#999;font-size:12px">N/A</div>')
            else:
                img_html = (f'<img src="data:image/png;base64,{b64}" '
                            'style="width:160px;height:160px;object-fit:contain;'
                            'border:1px solid #ddd;border-radius:4px"/>')
            parts.append(
                f'<div style="text-align:center;margin:0 4px">'
                f'{img_html}'
                f'<div style="font-size:11px;color:#555;margin-top:3px">{label}</div>'
                f'</div>'
            )
        trial_head = (f'<div style="font-size:11px;font-weight:bold;color:#777;'
                      f'margin:6px 0 3px 4px">{trial_label}</div>')
        rows_html += (trial_head
                      + '<div style="display:flex;align-items:flex-end;margin-bottom:8px">'
                      + ''.join(parts) + '</div>')
    return header + rows_html


def make_image_grid_html(images_info, title):
    if not images_info:
        return (f'<h3 style="margin:4px 0 6px 0;color:#444;border-bottom:2px solid #e8e8e8;'
                f'padding-bottom:4px">{title}</h3>'
                f'<p style="color:#aaa;font-style:italic;margin:4px 0">No examples available</p>')
    thumb_w = min(THUMB, 224)
    html = (f'<h3 style="margin:4px 0 8px 0;color:#333;border-bottom:2px solid #e0e0e0;'
            f'padding-bottom:4px">{title}</h3>')
    html += '<div style="display:flex;flex-wrap:wrap;gap:8px;padding:2px 0 10px 0">'
    for img, caption in images_info:
        url = pil_to_data_url(img)
        parts = caption.split('<br>')
        cap_html = ''.join(f'<div>{p}</div>' for p in parts)
        html += (f'<div style="text-align:center;width:{thumb_w}px">'
                 f'<img src="{url}" width="{thumb_w}" height="{thumb_w}"'
                 f' style="border:1px solid #d0d0d0;border-radius:5px;display:block"/>'
                 f'<div style="font-size:10px;color:#555;margin-top:3px;line-height:1.4">'
                 f'{cap_html}</div></div>')
    html += '</div>'
    return html


def make_compare_aggregations_html(top_infos, mean_infos, feat, n_each=6, model_label=None):
    """Figure-ready side-by-side comparison of the first two aggregation methods.

    Only Top (Max Activation) and Mean Activation are shown so that a screenshot
    of this element stands alone as a clean figure panel.
    """
    col_thumb = min(THUMB, 160)

    # Only the first two methods are shown in the figure
    sections = [
        ("Top Activation",  "#2563a8", top_infos),
        ("Mean Activation", "#1a7a4a", mean_infos),
    ]

    cols_per_row = 2
    strip_w = cols_per_row * col_thumb + (cols_per_row - 1) * 6

    # Outer container — white background, no border decoration so the figure can
    # be cropped cleanly.  A subtle bottom-padding keeps images from being clipped.
    html = (
        '<div style="font-family:Arial,Helvetica,sans-serif;background:#ffffff;'
        'padding:16px 20px 14px 20px;display:inline-block">'
        # Title row
        f'<div style="font-size:13px;font-weight:bold;color:#222;margin-bottom:14px;'
        f'letter-spacing:0.1px">'
        + (f'{model_label} — ' if model_label else '')
        + f'Feature {feat}</div>'
        '<div style="display:flex;gap:24px;align-items:flex-start">'
    )

    for method_name, color, infos in sections:
        shown = (infos or [])[:n_each]

        html += (
            f'<div style="display:inline-flex;flex-direction:column">'
            # Bold, clearly-coloured column header
            f'<div style="background:{color};color:#ffffff;font-size:13px;font-weight:bold;'
            f'text-align:center;padding:6px 0;border-radius:5px;margin-bottom:10px;'
            f'letter-spacing:0.4px;width:{strip_w}px;box-sizing:border-box">{method_name}</div>'
            f'<div style="display:grid;grid-template-columns:repeat({cols_per_row},{col_thumb}px);gap:6px">'
        )
        if not shown:
            html += '<div style="color:#aaa;font-style:italic;font-size:11px;padding:8px">No images</div>'
        for img, caption in shown:
            url = pil_to_data_url(img)
            parts = caption.split('<br>')
            cap_html = '<br>'.join(parts)
            html += (
                f'<div style="text-align:center">'
                f'<img src="{url}" width="{col_thumb}" height="{col_thumb}"'
                f' style="border:1px solid #ccc;border-radius:3px;display:block"/>'
                f'<div style="font-size:9px;color:#555;margin-top:3px;line-height:1.35">'
                f'{cap_html}</div></div>'
            )
        html += '</div></div>'

    html += '</div></div>'
    return html



# ---------- UMAP data source ----------
# live_mask / live_indices / freq / mean_act / log_freq / umap_backup are all
# already set by _apply_dataset_globals(0) above — just build the source from them.

# Helpers to build phi_c and color_val arrays for any set of feature indices.

def _phi_c_vals(indices):
    """Return phi_c leverage values for a list of feature indices (0.0 when unavailable)."""
    if _phi_c is None:
        return [0.0] * len(indices)
    return [float(_phi_c[i]) if i < len(_phi_c) else 0.0 for i in indices]



def _make_point_alphas(n):
    """Return uniform 0.6 alpha for all n UMAP points."""
    return [0.6] * n


def _make_color_vals(indices):
    """Return color values for the UMAP scatter based on current _S.color_by."""
    cb = _S.color_by
    idx_arr = np.array(indices, dtype=int)
    if cb == "Mean Activation":
        return mean_act[idx_arr].tolist()
    elif cb == "Brain Leverage (φ_c)":
        return _phi_c_vals(indices)
    else:  # "Log Frequency"
        return log_freq[idx_arr].tolist()


umap_source = ColumnDataSource(data=dict(
    x=umap_coords[live_mask, 0].tolist(),
    y=umap_coords[live_mask, 1].tolist(),
    feature_idx=live_indices.tolist(),
    frequency=freq[live_mask].tolist(),
    log_freq=log_freq[live_mask].tolist(),
    mean_act=mean_act[live_mask].tolist(),
    phi_c_val=_phi_c_vals(live_indices.tolist()),
    color_val=log_freq[live_mask].tolist(),
    point_alpha=_make_point_alphas(int(live_mask.sum())),
))


# ---------- UMAP figure ----------
_init_log_freq = log_freq[live_mask]
color_mapper = linear_cmap(
    field_name='color_val', palette=Turbo256,
    low=float(np.percentile(_init_log_freq, 2)) if live_mask.any() else 0,
    high=float(np.percentile(_init_log_freq, 98)) if live_mask.any() else 1,
)

def _set_color_mapper_range(color_vals):
    """Update color_mapper low/high to the 2nd–98th percentile of color_vals."""
    if not color_vals:
        return
    arr = np.array(color_vals)
    lo, hi = float(np.percentile(arr, 2)), float(np.percentile(arr, 98))
    if lo == hi:
        hi = lo + 1e-6
    color_mapper['transform'].low  = lo
    color_mapper['transform'].high = hi


umap_fig = figure(
    title="UMAP of SAE Features (by activation pattern)",
    width=700, height=650,
    tools="pan,wheel_zoom,box_zoom,reset,tap",
    active_scroll="wheel_zoom",
)
umap_scatter = umap_fig.scatter(
    'x', 'y', source=umap_source, size=4, alpha='point_alpha',
    color=color_mapper,
    selection_color="#FF2222", selection_alpha=1.0,
    selection_line_color="white", selection_line_width=1.5,
)

# Scale point size with zoom: bigger when zoomed in
_zoom_cb = CustomJS(args=dict(renderer=umap_scatter, x_range=umap_fig.x_range), code="""
    const span = x_range.end - x_range.start;
    if (window._umap_base_span === undefined) {
        window._umap_base_span = span;
    }
    const zoom = window._umap_base_span / span;
    const new_size = Math.min(12, Math.max(3, 3 * Math.pow(zoom, 0.1)));
    renderer.glyph.size = new_size;
    renderer.nonselection_glyph.size = new_size;
    renderer.selection_glyph.size = Math.max(14, new_size * 3);
""")
umap_fig.x_range.js_on_change('start', _zoom_cb)
umap_fig.x_range.js_on_change('end', _zoom_cb)

_phi_hover = [("Brain φ_c", "@phi_c_val{0.0000}")] if HAS_PHI else []
umap_fig.add_tools(HoverTool(tooltips=[
    ("Feature", "@feature_idx"),
    ("Frequency", "@frequency{0}"),
    ("Mean Act", "@mean_act{0.000}"),
] + _phi_hover))


# ---------- Dataset / model selector ----------
dataset_select = Select(
    title="Dataset:",
    value="0",
    options=[(str(i), ds['label']) for i, ds in enumerate(_all_datasets)],
    width=250,
)


def _on_dataset_switch(attr, old, new):
    idx = int(new)
    old_idx = int(old)
    _ensure_loaded(idx)

    # Capture current feature and old d_model before swapping globals
    _prev_feat_str = feature_input.value.strip()
    _old_d_model = _all_datasets[old_idx]['d_model']

    _S.active = idx
    _apply_dataset_globals(idx)  # also resets _active_feats

    # Rebuild UMAP scatter
    _feat_ids = live_indices.tolist()
    _color_vals = _make_color_vals(_feat_ids)
    _phi_c_list = _phi_c_vals(_feat_ids)
    umap_source.data = dict(
        x=umap_coords[live_mask, 0].tolist(),
        y=umap_coords[live_mask, 1].tolist(),
        feature_idx=_feat_ids,
        frequency=freq[live_mask].tolist(),
        log_freq=log_freq[live_mask].tolist(),
        mean_act=mean_act[live_mask].tolist(),
        phi_c_val=_phi_c_list,
        color_val=_color_vals,
        point_alpha=_make_point_alphas(len(_feat_ids)),
    )
    _set_color_mapper_range(_color_vals)
    umap_source.selected.indices = []
    umap_type_select.value = "Activation Pattern"
    umap_fig.title.text = f"UMAP — {_all_datasets[idx]['label']}"

    # Rebuild feature list
    _S.search_filter = None
    _apply_order(_get_sorted_order())

    # Update summary panel
    summary_div.text = _make_summary_html()

    # Show/hide patch explorer depending on token type (spatial required) and GPU availability.
    ds = _all_datasets[idx]
    can_explore = (
        ds.get('token_type', 'spatial') == 'spatial'
        and bool(args.sae_path)
    )
    patch_fig.visible = can_explore
    patch_info_div.visible = can_explore
    if not can_explore:
        reason = "CLS token — no patch grid" if ds.get('token_type') == 'cls' else "no --sae-path provided"
        patch_info_div.text = (
            f'<p style="color:#888;font-style:italic">Patch explorer unavailable: {reason}.</p>')
        patch_info_div.visible = True

    # Update CLIP search hint
    if HAS_CLIP:
        clip_result_div.text = ""
        clip_result_source.data = dict(
            feature_idx=[], clip_score=[], frequency=[], mean_act=[], phi_c_val=[], name=[])

    # If the two datasets share the same feature space, re-display the current feature
    _same_space = (_all_datasets[idx]['d_model'] == _old_d_model)
    _restore_feat = None
    if _same_space and _prev_feat_str:
        try:
            _restore_feat = int(_prev_feat_str)
        except ValueError:
            pass

    if _restore_feat is not None and 0 <= _restore_feat < d_model:
        feature_input.value = str(_restore_feat)
        update_feature_display(_restore_feat)
    else:
        feature_input.value = ""
        stats_div.text = "<h3>Select a feature to explore</h3>"
        brain_div.text = ""
        status_div.text = _status_html('idle', 'Model switched — select a feature to explore.')
        if HAS_DYNADIFF:
            _dd_output.text = ""
            _dd_status.text = ""
        for div in [top_heatmap_div, mean_heatmap_div]:
            div.text = ""


dataset_select.on_change('value', _on_dataset_switch)


# ---------- Detail panels ----------
status_div = Div(
    text=_status_html('idle', 'Select a feature on the UMAP or from the list to begin.'),
    width=900,
)
stats_div = Div(text="<h3>Click a feature on the UMAP to explore it</h3>", width=900)
top_heatmap_div  = Div(text="", width=900)
mean_heatmap_div = Div(text="", width=900)
compare_agg_div = Div(text="", width=1400)   # side-by-side aggregation comparison
brain_div       = Div(text="", width=900)    # cortical profile for selected feature

# ---------- DynaDiff steering panel builder ----------
# Feature list stored in a ColumnDataSource so the DataTable can edit λ and threshold inline.

def _phi_cv_feat_name(feat):
    """Best-effort display name for the feature."""
    if feat is None:
        return 'unknown'
    ds = _all_datasets[_S.active] if _all_datasets else None
    if ds and feat in ds.get('feature_names', {}):
        return ds['feature_names'][feat]
    return f'feat {feat}'

def _build_dynadiff_panel():
    """Build the DynaDiff brain-steering panel widgets and callbacks.

    Returns (panel_body, dd_output, dd_status, dd_feat_input).
    When HAS_DYNADIFF is False, panel_body is None and the divs are 1-pixel stubs.
    dd_feat_input is None when disabled so callers must guard before use.
    """
    if not HAS_DYNADIFF:
        return None, Div(text="", width=1), Div(text="", width=1), None, None

    # ---- ColumnDataSource backing the feature table ----
    dd_source = ColumnDataSource(data=dict(feat=[], name=[], lam=[], threshold=[]))

    dd_table = DataTable(
        source=dd_source,
        columns=[
            TableColumn(field='feat',      title='#',       width=55),
            TableColumn(field='name',      title='Feature', width=190),
            TableColumn(field='lam',       title='λ',       width=60,
                        editor=NumberEditor(),
                        formatter=NumberFormatter(format='0.0')),
            TableColumn(field='threshold', title='Brain%',  width=65,
                        editor=NumberEditor(),
                        formatter=NumberFormatter(format='0.00')),
        ],
        editable=True,
        width=460,
        height=130,
        index_position=None,
    )

    # ---- Brain modification preview div ----
    dd_steer_div = Div(text="", width=460)

    def _update_dd_preview():
        feats = list(dd_source.data['feat'])
        lams  = list(dd_source.data['lam'])
        thrs  = list(dd_source.data['threshold'])
        dd_steer_div.text = _render_steering_preview(feats, lams, thrs)

    dd_source.on_change('data', lambda attr, old, new: _update_dd_preview())

    # ---- "Add feature" row ----
    dd_feat_input     = TextInput(title="Feature index:", placeholder="e.g. 1234", width=120)
    dd_add_lam_input  = TextInput(title="λ:", value="3.0", width=65)
    dd_add_thr_select = Select(
        title="Brain %:",
        options=[('0.05', '5%'), ('0.10', '10%'), ('0.25', '25%'), ('1.0', '100%')],
        value='0.10',
        width=90,
    )
    dd_feat_add_btn    = Button(label="Add",             button_type="success", width=55)
    dd_feat_remove_btn = Button(label="Remove selected", button_type="light",   width=130)
    dd_feat_clear_btn  = Button(label="Clear all",       button_type="light",   width=80)

    # ---- Global run controls ----
    dd_sample_input = TextInput(title="Sample idx", value="0", width=180)
    dd_seed_input   = TextInput(title="Seed:", value="42", width=70)
    dd_btn    = Button(label="Steer & Reconstruct", button_type="primary", width=200)
    dd_status = Div(text="", width=460)
    dd_output = Div(text="", width=460)

    def _on_add_feat():
        try:
            f = int(dd_feat_input.value.strip())
        except ValueError:
            dd_status.text = '<span style="color:#c00">Invalid feature index.</span>'
            return
        if _phi_cv is None or f < 0 or f >= _phi_cv.shape[0]:
            n = _phi_cv.shape[0] if _phi_cv is not None else '?'
            dd_status.text = f'<span style="color:#c00">Feature {f} out of range (0–{n}).</span>'
            return
        try:
            lam = float(dd_add_lam_input.value)
        except ValueError:
            lam = 3.0
        threshold = float(dd_add_thr_select.value)
        new_data = {k: list(v) for k, v in dd_source.data.items()}
        new_data['feat'].append(f)
        new_data['name'].append(_phi_cv_feat_name(f))
        new_data['lam'].append(lam)
        new_data['threshold'].append(threshold)
        dd_source.data = new_data
        dd_status.text = ''

    def _on_remove_feat():
        sel = dd_source.selected.indices
        if not sel:
            dd_status.text = '<span style="color:#888">Select a row first.</span>'
            return
        new_data = {k: [v for i, v in enumerate(vals) if i not in sel]
                    for k, vals in dd_source.data.items()}
        dd_source.data = new_data
        dd_source.selected.indices = []
        dd_status.text = ''

    def _on_clear_feats():
        dd_source.data = dict(feat=[], name=[], lam=[], threshold=[])
        dd_status.text = ''

    dd_feat_add_btn.on_click(_on_add_feat)
    dd_feat_remove_btn.on_click(_on_remove_feat)
    dd_feat_clear_btn.on_click(_on_clear_feats)

    def _reconstruct_thread(sample_idxs, steerings, seed, feat_name, doc):
        try:
            resps = []
            for i, sidx in enumerate(sample_idxs):
                trial_label = f'Trial {i+1} (sample {sidx})'
                resp = _dynadiff_request(sidx, steerings, seed)
                resps.append((trial_label, resp))
            html = _make_steering_html(resps, feat_name)
            def _apply(html=html):
                dd_output.text  = html
                dd_status.text  = ''
                dd_btn.disabled = False
            doc.add_next_tick_callback(_apply)
        except Exception as exc:
            msg = str(exc)
            def _show_err(msg=msg):
                dd_status.text  = f'<span style="color:#c00">Error: {msg}</span>'
                dd_btn.disabled = False
            doc.add_next_tick_callback(_show_err)

    def _on_reconstruct():
        feats = list(dd_source.data['feat'])
        lams  = list(dd_source.data['lam'])
        thrs  = list(dd_source.data['threshold'])
        if not feats:
            dd_status.text = '<span style="color:#c00">Add at least one feature first.</span>'
            return
        steerings = []
        for f, lam, thr in zip(feats, lams, thrs):
            phi = _phi_voxel_row(f)
            if phi is not None:
                steerings.append((phi, float(lam), float(thr)))
        if not steerings:
            dd_status.text = '<span style="color:#c00">No phi data for selected features.</span>'
            return
        _raw = dd_sample_input.value.strip()
        try:
            _parsed = _parse_img_label(_raw)
        except ValueError:
            dd_status.text = '<span style="color:#c00">Invalid sample index.</span>'
            return
        # Check model status before proceeding — _nsd_to_sample is empty while
        # loading, so we must gate on status here rather than letting an empty
        # lookup produce a misleading "no trials for this subject" error.
        _dd_cur_status, _dd_cur_err = _dd_loader.status
        if _dd_cur_status == 'loading':
            dd_status.text = ('<span style="color:#f0a020">'
                              'DynaDiff model still loading — try again shortly.</span>')
            return
        if _dd_cur_status == 'error':
            dd_status.text = (f'<span style="color:#c00">'
                              f'DynaDiff model load failed: {_dd_cur_err}</span>')
            return
        # If input looks like an NSD image label (e.g. "nsd_22910"), extract the
        # NSD stimulus index from the trailing integer.  _parse_img_label returns
        # the union-dataset index (e.g. 1431612) which is wrong for DynaDiff —
        # it needs the NSD image number (22910).
        if '_' in _raw:
            try:
                nsd_img_idx = int(_raw.rsplit('_', 1)[-1])
            except ValueError:
                dd_status.text = '<span style="color:#c00">Could not parse NSD image index.</span>'
                return
            sample_idxs = _dd_loader.sample_idxs_for_nsd_img(nsd_img_idx)
            if not sample_idxs:
                dd_status.text = (
                    f'<span style="color:#c00">NSD image {nsd_img_idx} has no trials '
                    f'for this subject.</span>')
                return
        else:
            sample_idxs = [_parsed]
        _n = _dd_loader.n_samples
        if _n is not None and any(not (0 <= s < _n) for s in sample_idxs):
            dd_status.text = f'<span style="color:#c00">sample_idx must be 0–{_n-1}.</span>'
            return
        try:
            seed = int(dd_seed_input.value)
        except ValueError:
            seed = 42
        names = list(dd_source.data['name'])
        feat_name = ' + '.join(names) if names else 'unknown'
        dd_btn.disabled = True
        n_trials = len(sample_idxs)
        dd_status.text  = (f'<i style="color:#888">Running DynaDiff reconstruction '
                           f'({n_trials} trial{"s" if n_trials > 1 else ""})…</i>')
        doc = curdoc()
        threading.Thread(
            target=_reconstruct_thread,
            args=(sample_idxs, steerings, seed, feat_name, doc),
            daemon=True,
        ).start()

    dd_btn.on_click(_on_reconstruct)

    panel_body = column(
        row(dd_feat_input, dd_add_lam_input, dd_add_thr_select, dd_feat_add_btn),
        row(dd_feat_remove_btn, dd_feat_clear_btn),
        dd_table,
        dd_steer_div,
        row(dd_sample_input, dd_seed_input),
        row(dd_btn, dd_status),
        dd_output,
    )
    return panel_body, dd_output, dd_status, dd_feat_input, dd_sample_input


# ---------- DynaDiff steering widgets ----------
# _dd_feat_input, _dd_status, _dd_output, _dd_sample_input are referenced by
# update_feature_display and _on_dataset_switch — they must be module-level names.
_dd_panel_body, _dd_output, _dd_status, _dd_feat_input, _dd_sample_input = _build_dynadiff_panel()

# Name editing widget (defined here so update_feature_display can reference it)
name_input = TextInput(
    title="Feature name (auto-saved):",
    placeholder="Enter a name for this feature...",
    width=420,
)

# Gemini auto-interp button
_gemini_api_key = args.google_api_key or os.environ.get("GOOGLE_API_KEY")
gemini_btn = Button(
    label="Label with Gemini",
    width=140,
    button_type="warning",
    disabled=(_gemini_api_key is None),
)
gemini_status_div = Div(text=(
    "<i style='color:#aaa'>No GOOGLE_API_KEY set</i>"
    if _gemini_api_key is None else ""
), width=300)

# Zoom slider — controls neighbourhood size in the zoomed-patch view
zoom_slider = Slider(
    title="Zoom (patches)", value=16, start=1, end=16, step=1, width=220,
)

# Heatmap opacity slider — controls alpha of the overlay in render_heatmap_overlay
heatmap_alpha_slider = Slider(
    title="Heatmap opacity", value=1.0, start=0.0, end=1.0, step=0.05, width=220,
)

# View selector: which image ranking to show in the detail panel
_view_options = ["Top (max activation)", "Mean activation", "Compare aggregations"]

view_select = Select(
    title="Image ranking:",
    value="Top (max activation)",
    options=_view_options,
    width=250,
)

nsd_subset_toggle = RadioButtonGroup(
    labels=["All images", "NSD sub01"],
    active=0,
    width=220,
)

N_DISPLAY = 6


def update_feature_display(feature_idx):
    feat = int(feature_idx)
    _S.render_token += 1
    my_token = _S.render_token

    freq_val = feature_frequency[feat].item()
    mean_val = feature_mean_act[feat].item()
    dead = "DEAD FEATURE" if freq_val == 0 else ""

    feat_name = feature_names.get(feat, "")
    auto_name = auto_interp_names.get(feat, "")
    name_parts = []
    if feat_name:
        name_parts.append(
            f'<div style="color:#1a6faf;font-style:italic;margin:2px 0 3px 0">'
            f'&#x1F3F7;&#xFE0E; {feat_name}'
            f'<span style="font-size:10px;color:#999;margin-left:6px">(manual)</span></div>'
        )
    if auto_name:
        name_parts.append(
            f'<div style="color:#5a9a5a;font-style:italic;margin:2px 0 3px 0">'
            f'&#x1F916; {auto_name}'
            f'<span style="font-size:10px;color:#999;margin-left:6px">(auto-interp)</span></div>'
        )
    name_display = "".join(name_parts)

    phi_c_val = _phi_c_for_feat(feat)
    phi_chip = (f' &nbsp;&middot;&nbsp; <b>φ_c:</b> {phi_c_val:.4f}' if phi_c_val is not None else '')
    stats_div.text = (
        f'<h2 style="margin:4px 0">Feature {feat}'
        f'<span style="color:red;margin-left:8px">{dead}</span>'
        f'<span style="font-size:13px;font-weight:normal;color:#555;margin-left:14px">'
        f'<b>Freq:</b> {int(freq_val):,} &nbsp;&middot;&nbsp; '
        f'<b>Mean act:</b> {mean_val:.4f}'
        f'{phi_chip}</span></h2>'
        + name_display
    )
    name_input.value = feat_name

    if freq_val == 0:
        status_div.text = _status_html(
            'dead', f'Feature {feat} is dead — it never activated on the precompute set.')
        brain_div.text = _render_cortical_profile(feat)   # still show cortical profile if available
        for div in [top_heatmap_div, mean_heatmap_div, compare_agg_div]:
            div.text = ""
        return

    status_div.text = _status_html(
        'loading', f'&#x23F3; Rendering heatmaps for feature {feat}...')

    def _render():
        # Bail out if the user has already clicked a different feature.
        if _S.render_token != my_token:
            return

        _SLOT_EMPTY = object()   # sentinel: no more stored slots (img_i < 0)

        def _render_one(img_idx_tensor, act_tensor, ranking_idx, heatmap_tensor=None,
                        center='peak'):
            img_i = img_idx_tensor[feat, ranking_idx].item()
            if img_i < 0:
                return _SLOT_EMPTY   # no more slots stored for this feature
            try:
                # Use pre-computed heatmap
                if heatmap_tensor is not None and heatmap_patch_grid > 1:
                    hmap = heatmap_tensor[feat, ranking_idx].float().numpy()
                    hmap = hmap.reshape(heatmap_patch_grid, heatmap_patch_grid)
                else:
                    hmap = None

                img_label = os.path.splitext(os.path.basename(image_paths[img_i]))[0]
                act_val = float(act_tensor[feat, ranking_idx].item())
                caption = f"act={act_val:.4f}  {img_label}"
                if hmap is None:
                    plain = load_image(img_i).resize((THUMB, THUMB), Image.BILINEAR)
                    return (plain, caption)
                img_out = render_zoomed_overlay(img_i, hmap, size=THUMB, center=center)
                return (img_out, caption)
            except (FileNotFoundError, OSError):
                return None   # image file not available on this machine — skip silently
            except Exception as e:
                ph = Image.new("RGB", (THUMB, THUMB), "gray")
                return (ph, f"Error: {e}")

        def _collect(idx_tensor, act_tensor, hm_tensor, n, center='peak'):
            """Render up to n images, skipping unavailable files but stopping at empty slots."""
            results = []
            for j in range(min(n, idx_tensor.shape[1])):
                hm = _render_one(idx_tensor, act_tensor, j, hm_tensor, center=center)
                if hm is _SLOT_EMPTY:
                    break          # no more stored slots
                if hm is None:
                    continue       # file missing on this machine — try next slot
                results.append(hm)
            return results

        # --- Top images ---
        _use_nsd = nsd_subset_toggle.active == 1 and HAS_NSD_SUBSET
        _top_idx  = nsd_top_img_idx  if _use_nsd else top_img_idx
        _top_act  = nsd_top_img_act  if _use_nsd else top_img_act
        _mean_idx = nsd_mean_img_idx if _use_nsd else mean_img_idx
        _mean_act = nsd_mean_img_act if _use_nsd else mean_img_act
        _top_hm   = nsd_top_heatmaps  if _use_nsd else top_heatmaps
        _mean_hm  = nsd_mean_heatmaps if _use_nsd else mean_heatmaps

        heatmap_infos = _collect(_top_idx, _top_act, _top_hm, N_DISPLAY)

        _subset_label = " [NSD sub01]" if _use_nsd else ""
        top_heatmap_div.text = make_image_grid_html(
            heatmap_infos, f"Top by Max Activation (feature {feat}){_subset_label}")

        # --- Mean-ranked images ---
        mean_hm_infos = _collect(_mean_idx, _mean_act, _mean_hm, N_DISPLAY, center='centroid')

        mean_heatmap_div.text = make_image_grid_html(
            mean_hm_infos, f"Top by Mean Activation (feature {feat}){_subset_label}")

        # Side-by-side aggregation comparison (paper-ready screenshot view)
        compare_agg_div.text = make_compare_aggregations_html(
            heatmap_infos, mean_hm_infos, feat,
            model_label=_all_datasets[_S.active]['label'])

        brain_div.text = _render_cortical_profile(feat)

        # Pre-fill DynaDiff inputs when a feature is selected.
        # Sample input: use the stem of the top NSD MEI when the NSD subset toggle
        # is active (e.g. "nsd_22910"), so the image index passed to DynaDiff
        # refers to the NSD stimulus number, not the union-dataset index.
        if HAS_DYNADIFF:
            _dd_feat_input.value = str(feat)
            _use_nsd_dd = nsd_subset_toggle.active == 1 and HAS_NSD_SUBSET
            if _use_nsd_dd and _dd_sample_input is not None:
                _top_i = nsd_top_img_idx[feat, 0].item()
                if _top_i >= 0:
                    _dd_sample_input.value = os.path.splitext(
                        os.path.basename(image_paths[_top_i]))[0]
            _dd_status.text = (
                '<i style="color:#888">Feature pre-filled → click Add, then Steer & Reconstruct.</i>'
                if _phi_voxel_row(feat) is not None else
                '<span style="color:#c00">No phi data for this feature.</span>'
            )

        status_div.text = _status_html('ok', f'&#x2713; Feature {feat} ready.')
        _update_view_visibility()

    curdoc().add_next_tick_callback(_render)


# ---------- View visibility ----------
def _update_view_visibility():
    v = view_select.value
    is_compare = (v == "Compare aggregations")
    top_heatmap_div.visible  = (v == "Top (max activation)")
    mean_heatmap_div.visible = (v == "Mean activation")
    compare_agg_div.visible  = is_compare

view_select.on_change('value', lambda attr, old, new: _update_view_visibility())
_update_view_visibility()  # set initial state


def _rerender_current_feature(attr, old, new):
    """Re-render the current feature when any display control changes."""
    try:
        feat = int(feature_input.value)
        if 0 <= feat < d_model:
            update_feature_display(feat)
    except ValueError:
        pass

zoom_slider.on_change('value', _rerender_current_feature)
heatmap_alpha_slider.on_change('value', _rerender_current_feature)
nsd_subset_toggle.on_change('active', _rerender_current_feature)


# ---------- Callbacks ----------
def _umap_alphas_for_selection(selected_pos):
    """Return point_alpha list: 0.6 for selected point, 0.2 for all others."""
    n = len(umap_source.data['feature_idx'])
    if selected_pos is None:
        return [0.6] * n
    return [0.6 if i == selected_pos else 0.2 for i in range(n)]


def on_umap_select(attr, old, new):
    if new:
        umap_source.data['point_alpha'] = _umap_alphas_for_selection(new[0])
        feature_idx = umap_source.data['feature_idx'][new[0]]
        feature_input.value = str(feature_idx)
        update_feature_display(feature_idx)
    else:
        umap_source.data['point_alpha'] = _umap_alphas_for_selection(None)

umap_source.selected.on_change('indices', on_umap_select)


# UMAP type toggle
_umap_type_options = ["Activation Pattern", "Dictionary Geometry"]

umap_type_select = Select(
    title="UMAP Type", value="Activation Pattern",
    options=_umap_type_options, width=220,
)

# UMAP color select
_color_options = ["Log Frequency", "Mean Activation"]
if _phi_c is not None:
    _color_options.append("Brain Leverage (φ_c)")

umap_color_select = Select(
    title="Color by:", value="Log Frequency",
    options=_color_options, width=200,
)


def _apply_umap_color(color_by, feat_ids):
    """Update umap_source color_val and color_mapper range for the given indices."""
    _S.color_by = color_by
    new_colors = _make_color_vals(feat_ids)
    umap_source.data['color_val'] = new_colors
    _set_color_mapper_range(new_colors)


def _on_umap_color_change(attr, old, new):
    feat_ids = list(umap_source.data['feature_idx'])
    _apply_umap_color(new, feat_ids)


umap_color_select.on_change('value', _on_umap_color_change)



def on_umap_type_change(attr, old, new):
    color_vals = []
    if new == "Activation Pattern":
        feat_ids = umap_backup['act_feat']
        color_vals = _make_color_vals(feat_ids)
        _phi_c_list = _phi_c_vals(feat_ids)
        umap_source.data = dict(
            x=umap_backup['act_x'],
            y=umap_backup['act_y'],
            feature_idx=feat_ids,
            frequency=freq[live_mask].tolist(),
            log_freq=log_freq[live_mask].tolist(),
            mean_act=mean_act[live_mask].tolist(),
            phi_c_val=_phi_c_list,
            color_val=color_vals,
            point_alpha=_make_point_alphas(len(feat_ids)),
        )
        umap_fig.title.text = "UMAP of SAE Features (by activation pattern)"
    else:
        feat_ids = umap_backup['dict_feat']
        dict_freq = freq[dict_live_mask]
        dict_log_freq = log_freq[dict_live_mask]
        dict_mean_act = mean_act[dict_live_mask]
        color_vals = _make_color_vals(feat_ids)
        _phi_c_list = _phi_c_vals(feat_ids)
        umap_source.data = dict(
            x=umap_backup['dict_x'],
            y=umap_backup['dict_y'],
            feature_idx=feat_ids,
            frequency=dict_freq.tolist(),
            log_freq=dict_log_freq.tolist(),
            mean_act=dict_mean_act.tolist(),
            phi_c_val=_phi_c_list,
            color_val=color_vals,
            point_alpha=_make_point_alphas(len(feat_ids)),
        )
        umap_fig.title.text = "UMAP of SAE Features (by dictionary geometry)"
    _set_color_mapper_range(color_vals)

umap_type_select.on_change('value', on_umap_type_change)


# Direct feature input
feature_input = TextInput(title="Feature Index:", value="", width=120)
go_button = Button(label="Go", width=60)
random_btn = Button(label="Random", width=70)


def _select_and_display(feat):
    """Show the detail panel for feat and sync the UMAP highlight."""
    update_feature_display(feat)
    feat_list = umap_source.data['feature_idx']
    if feat in feat_list:
        umap_source.selected.indices = [feat_list.index(feat)]


def on_go_click():
    try:
        feat = int(feature_input.value)
        if 0 <= feat < d_model:
            _select_and_display(feat)
        else:
            stats_div.text = f"<h3>Feature {feat} out of range (0-{d_model-1})</h3>"
    except ValueError:
        stats_div.text = "<h3>Please enter a valid integer</h3>"

go_button.on_click(on_go_click)


def _on_random():
    if not _active_feats:
        return
    feat = random.choice(_active_feats)
    feature_input.value = str(feat)
    _select_and_display(feat)

random_btn.on_click(_on_random)


# ---------- Sorted feature list ----------

_init_order = np.argsort(-freq)
feature_list_source = ColumnDataSource(data=dict(
    feature_idx=_init_order.tolist(),
    frequency=freq[_init_order].tolist(),
    mean_act=mean_act[_init_order].tolist(),
    p75_val=p75_np[_init_order].tolist(),
    phi_c_val=_phi_c_vals(_init_order.tolist()),
    name=[_display_name(int(i)) for i in _init_order],
))

def _phi_col():
    """Return phi_c column definition list (single element) if phi data is loaded, else []."""
    if not HAS_PHI:
        return []
    return [TableColumn(field="phi_c_val", title="φ_c", width=65,
                        formatter=NumberFormatter(format="0.0000"))]

feature_table = DataTable(
    source=feature_list_source,
    columns=[
        TableColumn(field="feature_idx", title="Feature", width=60),
        TableColumn(field="frequency", title="Freq", width=70,
                    formatter=NumberFormatter(format="0,0")),
        TableColumn(field="mean_act", title="Mean Act", width=80,
                    formatter=NumberFormatter(format="0.0000")),
    ] + _phi_col() + [
        TableColumn(field="name", title="Name", width=200),
    ],
    width=500, height=500, sortable=True, index_position=None,
)

# Search state: None = no filter, otherwise a set of matching feature indices


def _get_sorted_order():
    order = np.argsort(-freq)
    if _S.search_filter is not None:
        mask = np.isin(order, list(_S.search_filter))
        order = order[mask]
    return order


def _apply_order(order):
    feature_list_source.data = dict(
        feature_idx=order.tolist(),
        frequency=freq[order].tolist(),
        mean_act=mean_act[order].tolist(),
        p75_val=p75_np[order].tolist(),
        phi_c_val=_phi_c_vals(order.tolist()),
        name=[_display_name(int(i)) for i in order],
    )


def _update_table_names():
    """Refresh the name column after saving or deleting a feature name."""
    _apply_order(np.array(feature_list_source.data['feature_idx']))


def _on_table_select(attr, old, new):
    if new:
        feat = feature_list_source.data['feature_idx'][new[0]]
        feature_input.value = str(feat)
        _select_and_display(feat)

feature_list_source.selected.on_change('indices', _on_table_select)


# ---------- Auto-save name on typing ----------
def on_name_change(attr, old, new):
    try:
        feat = int(feature_input.value)
    except ValueError:
        return
    name = new.strip()
    if name:
        feature_names[feat] = name
    elif feat in feature_names:
        del feature_names[feat]
    _save_names()
    _update_table_names()

name_input.on_change('value', on_name_change)


# ---------- Gemini auto-interp button ----------
_N_GEMINI_IMAGES    = 6
_GEMINI_MODEL       = "gemini-2.5-flash"
_GEMINI_HM_ALPHA    = 0.25   # heatmap overlay opacity sent to Gemini

def _gemini_label_thread(feat, mei_items, doc):
    """Run in a worker thread: call Gemini and push the result back to the doc.

    mei_items: list of (path_str, heatmap_np_or_None) where heatmap is (H, W) float32.
    """
    try:
        from google import genai
        from google.genai import types

        SYSTEM_PROMPT = (
            "You are labeling features of a Sparse Autoencoder (SAE) trained on a "
            "vision transformer. Each SAE feature is a sparse direction in activation "
            "space that fires strongly on certain visual patterns."
        )
        USER_PROMPT = (
            "The images below are the top maximally-activating images for one SAE feature. "
            "In 2–5 words, give a precise label for the visual concept this feature detects. "
            "Be specific — prefer 'dog snout close-up' over 'dog', or 'brick wall texture' "
            "over 'texture'. "
            "Reply with ONLY the label, no explanation, no punctuation at the end."
        )

        client = genai.Client(api_key=_gemini_api_key)
        parts = []
        for path, _heatmap in mei_items[:_N_GEMINI_IMAGES]:
            resolved = _resolve_img_path(path)
            if resolved is None:
                continue
            try:
                img = Image.open(resolved).convert("RGB").resize((224, 224), Image.BILINEAR)
                buf = io.BytesIO()
                img.save(buf, format="JPEG", quality=85)
                parts.append(types.Part.from_bytes(data=buf.getvalue(), mime_type="image/jpeg"))
            except Exception:
                continue

        if not parts:
            def _no_images():
                gemini_btn.disabled = False
                gemini_status_div.text = "<span style='color:#c00'>No images could be loaded.</span>"
            doc.add_next_tick_callback(_no_images)
            return

        parts.append(types.Part.from_text(text=USER_PROMPT))
        response = client.models.generate_content(
            model=_GEMINI_MODEL,
            contents=parts,
            config=types.GenerateContentConfig(system_instruction=SYSTEM_PROMPT),
        )
        label = response.text.strip().strip(".,;:\"'")

        def _apply_label(feat=feat, label=label):
            auto_interp_names[feat] = label
            _save_auto_interp()
            _update_table_names()
            # Refresh the stats panel so the [auto] label appears immediately
            try:
                update_feature_display(feat)
            except Exception:
                pass
            gemini_btn.disabled = False
            gemini_status_div.text = (
                f"<span style='color:#1a6faf'><b>Labeled:</b> {label}</span>"
            )
            print(f"  [Gemini] feat {feat}: {label}")

        doc.add_next_tick_callback(_apply_label)

    except Exception as e:
        err = str(e)
        def _show_err(err=err):
            gemini_btn.disabled = False
            gemini_status_div.text = f"<span style='color:#c00'>Error: {err[:120]}</span>"
            print(f"  [Gemini] feat {feat} error: {err}")
        doc.add_next_tick_callback(_show_err)


def _on_gemini_click():
    try:
        feat = int(feature_input.value)
    except ValueError:
        gemini_status_div.text = "<span style='color:#c00'>Select a feature first.</span>"
        return

    if feature_frequency[feat].item() == 0:
        gemini_status_div.text = "<span style='color:#c00'>Dead feature — no images.</span>"
        return

    n_top_stored = top_img_idx.shape[1]
    mei_items = []
    for j in range(n_top_stored):
        idx = top_img_idx[feat, j].item()
        if idx >= 0:
            hm = None
            if top_heatmaps is not None:
                hm = top_heatmaps[feat, j].float().numpy().reshape(heatmap_patch_grid, heatmap_patch_grid)
            mei_items.append((image_paths[idx], hm))

    if not mei_items:
        gemini_status_div.text = "<span style='color:#c00'>No MEI paths found.</span>"
        return

    gemini_btn.disabled = True
    gemini_status_div.text = "<i style='color:#888'>Calling Gemini…</i>"

    doc = curdoc()
    t = threading.Thread(
        target=_gemini_label_thread,
        args=(feat, mei_items, doc),
        daemon=True,
    )
    t.start()


if _gemini_api_key:
    gemini_btn.on_click(_on_gemini_click)


# ---------- Search by name ----------
search_input = TextInput(
    title="Search feature names:",
    placeholder="Type to search...",
    width=220,
)
search_btn = Button(label="Search", width=70, button_type="primary")
clear_search_btn = Button(label="Clear", width=60)
search_result_div = Div(text="", width=360)


def _do_search():
    query = search_input.value.strip().lower()
    if not query:
        _S.search_filter = None
        search_result_div.text = ""
        _apply_order(_get_sorted_order())
        return
    matches = {
        i for i, name in feature_names.items() if query in name.lower()
    } | {
        i for i, name in auto_interp_names.items() if query in name.lower()
    }
    _S.search_filter = matches
    _apply_order(_get_sorted_order())
    if matches:
        search_result_div.text = (
            f'<span style="color:#1a6faf"><b>{len(matches)}</b> feature(s) matching '
            f'&ldquo;{query}&rdquo;</span>'
        )
    else:
        search_result_div.text = (
            f'<span style="color:#c00">No features named &ldquo;{query}&rdquo;</span>'
        )


def _do_clear_search():
    search_input.value = ""
    _S.search_filter = None
    search_result_div.text = ""
    _apply_order(_get_sorted_order())


search_btn.on_click(_do_search)
clear_search_btn.on_click(_do_clear_search)


# Summary — regenerated on every dataset switch
def _make_summary_html():
    ds = _all_datasets[_S.active]
    n_umap_act     = int(live_mask.sum())
    n_live_dict    = int(dict_live_mask.sum())
    n_truly_active = int((freq > 0).sum())
    n_dead         = d_model - n_truly_active
    tok_label = ("CLS global" if ds.get('token_type') == 'cls'
                 else f"{patch_grid}×{patch_grid} = {patch_grid**2} patches")
    backbone_label = ds.get('backbone', 'dinov3').upper()
    clip_label = "yes" if (ds['clip_scores'] is not None or ds.get('clip_embeds') is not None) else "no"
    hm_label   = "yes" if ds.get('top_heatmaps') is not None else "no"
    sae_url    = ds.get('sae_url')
    dl_row     = (f'<tr><td><b>SAE weights:</b></td>'
                  f'<td><a href="{sae_url}" download style="color:#1a6faf">⬇ Download</a></td></tr>'
                  if sae_url else '')
    return f"""
<div style="background:#f0f4f8;padding:12px;border-radius:6px;margin-bottom:8px;">
<h2 style="margin:0 0 8px 0">SAE Feature Explorer</h2>
<table style="font-size:13px;">
<tr><td><b>Active model:</b></td><td><b style="color:#1a6faf">{ds['label']}</b></td></tr>
<tr><td><b>Backbone:</b></td><td>{backbone_label}</td></tr>
<tr><td><b>Token type:</b></td><td>{ds.get('token_type','spatial')}</td></tr>
<tr><td><b>Dictionary size:</b></td><td>{d_model:,}</td></tr>
<tr><td><b>Active (fired ≥1):</b></td><td>{n_truly_active:,} ({100*n_truly_active/d_model:.1f}%)</td></tr>
<tr><td><b>Dead:</b></td><td>{n_dead:,} ({100*n_dead/d_model:.1f}%)</td></tr>
<tr><td><b>Images:</b></td><td>{n_images:,}</td></tr>
<tr><td><b>Tokens/image:</b></td><td>{tok_label}</td></tr>
{dl_row}
</table>
</div>"""

summary_div = Div(text=_make_summary_html(), width=700)


# ---------- Patch Explorer ----------
# Click patches of an image to find the top active SAE features for that region.
# Activations are computed on-the-fly via GPU inference (backbone + SAE from --sae-path).

_PATCH_FIG_PX = 400

# Raster-order (row, col) pairs for every patch cell.
# _pr[i] = row index, _pc[i] = col index for flat patch i.
_pr = [r for r in range(patch_grid) for _ in range(patch_grid)]   # 0,0,...,0, 1,1,...,N-1
_pc = list(range(patch_grid)) * patch_grid                         # 0,1,...,N-1, 0,1,...

patch_grid_source = ColumnDataSource(data=dict(
    x=[c + 0.5 for c in _pc],
    y=[patch_grid - r - 0.5 for r in _pr],
    row=_pr,
    col=_pc,
))

patch_bg_source = ColumnDataSource(data=dict(
    image=[], x=[0], y=[0], dw=[patch_grid], dh=[patch_grid],
))

patch_fig = figure(
    width=_PATCH_FIG_PX, height=_PATCH_FIG_PX,
    x_range=(0, patch_grid), y_range=(0, patch_grid),
    tools=["tap", "reset"],
    title="Click or drag to paint patch selection",
    toolbar_location="above",
    visible=False,
)

# Paint-on-drag selection: any patch the mouse passes over while the button
# is held gets added to the selection.  We track button state with a
# document-level mousedown/mouseup listener (set up lazily on first move).
_paint_js = CustomJS(args=dict(source=patch_grid_source, pg=patch_grid), code="""
    if (!window._patch_paint_init) {
        window._patch_paint_init = true;
        window._patch_btn_held  = false;
        document.addEventListener('mousedown', () => { window._patch_btn_held = true;  });
        document.addEventListener('mouseup',   () => { window._patch_btn_held = false; });
    }
    if (!window._patch_btn_held) return;

    const x = cb_obj.x, y = cb_obj.y;
    if (x === null || y === null || x < 0 || x >= pg || y < 0 || y >= pg) return;

    const col       = Math.floor(x);
    const row       = pg - 1 - Math.floor(y);
    const flat_idx  = row * pg + col;

    const sel = source.selected.indices.slice();
    if (sel.indexOf(flat_idx) === -1) {
        sel.push(flat_idx);
        source.selected.indices = sel;
    }
""")
patch_fig.js_on_event(MouseMove, _paint_js)
patch_fig.image_rgba(
    source=patch_bg_source,
    image='image', x='x', y='y', dw='dw', dh='dh',
)
patch_fig.rect(
    source=patch_grid_source,
    x='x', y='y', width=0.95, height=0.95,
    fill_color='yellow', fill_alpha=0.0,
    line_color='white', line_alpha=0.35, line_width=0.5,
    selection_fill_color='red', selection_fill_alpha=0.45,
    nonselection_fill_alpha=0.0, nonselection_line_alpha=0.35,
)
patch_fig.axis.visible = False
patch_fig.xgrid.visible = False
patch_fig.ygrid.visible = False

patch_img_input = TextInput(title="Image Index:", value="0", width=120)
load_patch_btn = Button(label="Load Image", width=90, button_type="primary")
clear_patch_btn = Button(label="Clear", width=60)

patch_feat_source = ColumnDataSource(data=dict(
    feature_idx=[], patch_act=[], frequency=[], mean_act=[], phi_c_val=[],
))
patch_feat_table = DataTable(
    source=patch_feat_source,
    columns=[
        TableColumn(field="feature_idx", title="Feature",   width=65),
        TableColumn(field="patch_act",   title="Patch Act", width=85,
                    formatter=NumberFormatter(format="0.0000")),
        TableColumn(field="frequency",   title="Freq",      width=65,
                    formatter=NumberFormatter(format="0,0")),
        TableColumn(field="mean_act",    title="Mean Act",  width=80,
                    formatter=NumberFormatter(format="0.0000")),
    ] + _phi_col(),
    width=310 + (65 if HAS_PHI else 0), height=350, index_position=None, sortable=False, visible=False,
)
patch_info_div = Div(
    text="<i>Load an image, then click patches to find top features.</i>",
    width=310,
)



def _pil_to_bokeh_rgba(pil_img, size):
    pil_img = pil_img.resize((size, size), Image.BILINEAR).convert("RGBA")
    arr = np.array(pil_img, dtype=np.uint8)
    out = np.empty((size, size), dtype=np.uint32)
    view = out.view(dtype=np.uint8).reshape((size, size, 4))
    view[:, :, :] = arr
    return out[::-1].copy()


def _do_load_patch_image():
    try:
        img_idx = _parse_img_label(patch_img_input.value)
    except ValueError:
        patch_info_div.text = "<b style='color:red'>Invalid image index</b>"
        return
    if not (0 <= img_idx < n_images):
        patch_info_div.text = f"<b style='color:red'>Index out of range (0–{n_images - 1})</b>"
        return

    _S.patch_img = img_idx
    try:
        pil = load_image(img_idx)
        bokeh_arr = _pil_to_bokeh_rgba(pil, _PATCH_FIG_PX)
        patch_bg_source.data = dict(
            image=[bokeh_arr], x=[0], y=[0], dw=[patch_grid], dh=[patch_grid],
        )
    except Exception as e:
        patch_info_div.text = f"<b style='color:red'>Error loading image: {e}</b>"
        return

    # Show spinner immediately, then compute (possibly slow GPU inference) in background.
    load_patch_btn.disabled = True
    patch_info_div.text = (
        "<span style='color:#1a6faf'>&#x23F3; Computing patch activations"
        + (" (running GPU inference — first image may take ~10 s)…"
           if _gpu_runner is None and args.sae_path else "…")
        + "</span>"
    )

    _doc = curdoc()

    def _bg():
        try:
            z_np = compute_patch_activations(img_idx)
        except Exception as e:
            err = str(e)
            def _show_err(err=err):
                load_patch_btn.disabled = False
                patch_info_div.text = f"<b style='color:red'>Error: {err}</b>"
            _doc.add_next_tick_callback(_show_err)
            return

        def _apply(z_np=z_np):
            _S.patch_z = z_np
            load_patch_btn.disabled = False
            patch_fig.visible = True
            patch_grid_source.selected.indices = []
            patch_feat_source.data = dict(feature_idx=[], patch_act=[], frequency=[], mean_act=[], phi_c_val=[])

            if z_np is None:
                patch_feat_table.visible = False
                patch_info_div.text = (
                    f"<b style='color:#888'>GPU inference unavailable for image {img_idx}. "
                    f"Ensure --sae-path is set and the GPU runner loaded successfully.</b>"
                )
                return

            patch_feat_table.visible = True
            patch_info_div.text = (
                f"Image {img_idx} loaded. "
                f"Drag to select a region, or click individual patches."
            )

        _doc.add_next_tick_callback(_apply)

    threading.Thread(target=_bg, daemon=True).start()


load_patch_btn.on_click(_do_load_patch_image)


def _do_clear_patches():
    patch_grid_source.selected.indices = []
    patch_feat_source.data = dict(feature_idx=[], patch_act=[], frequency=[], mean_act=[], phi_c_val=[])
    patch_info_div.text = "<i>Selection cleared.</i>"

clear_patch_btn.on_click(_do_clear_patches)


def _get_top_features_for_patches(patch_indices, top_n=20):
    """Sum SAE activations over selected patches; return top features."""
    z_np = _S.patch_z
    if z_np is None:
        return [], [], [], []

    # z_np: (n_patches, d_model) — vectorized sum over selected patches
    z_selected = z_np[patch_indices]          # (n_sel, d_model)
    feat_sums = z_selected.sum(axis=0)        # (d_model,)

    top_feats = np.argsort(-feat_sums)[:top_n]
    top_feats = top_feats[feat_sums[top_feats] > 0]   # keep only nonzero

    feats = top_feats.tolist()
    acts  = feat_sums[top_feats].tolist()
    freqs = [int(feature_frequency[f].item()) for f in feats]
    means = [float(feature_mean_act[f].item()) for f in feats]
    return feats, acts, freqs, means


def _on_patch_select(attr, old, new):
    if _S.patch_img is None:
        return
    if not new:
        patch_feat_source.data = dict(feature_idx=[], patch_act=[], frequency=[], mean_act=[], phi_c_val=[])
        patch_info_div.text = "<i>Selection cleared.</i>"
        return

    # Convert selected rect indices to flat patch indices
    rows = [patch_grid_source.data['row'][i] for i in new]
    cols = [patch_grid_source.data['col'][i] for i in new]
    patch_indices = [r * patch_grid + c for r, c in zip(rows, cols)]

    feats, acts, freqs, means = _get_top_features_for_patches(patch_indices)
    patch_feat_source.data = dict(
        feature_idx=feats, patch_act=acts, frequency=freqs, mean_act=means,
        phi_c_val=_phi_c_vals(feats),
    )
    patch_info_div.text = (
        f"{len(new)} patch(es) selected → {len(feats)} feature(s) found. "
        f"Click a row below to explore the feature."
    )

patch_grid_source.selected.on_change('indices', _on_patch_select)


def _on_patch_feat_table_select(attr, old, new):
    if not new:
        return
    feat = patch_feat_source.data['feature_idx'][new[0]]
    feature_input.value = str(feat)
    _select_and_display(feat)

patch_feat_source.selected.on_change('indices', _on_patch_feat_table_select)


# ---------- CLIP Text Search ----------
def _build_clip_panel():
    """Build the CLIP text-search panel widgets and callbacks.

    Returns (panel, result_div, result_source).
    When HAS_CLIP is False, result_div and result_source are None and panel is a
    static placeholder Div.
    """
    if not HAS_CLIP:
        panel = Div(
            text="<i style='color:#aaa'>CLIP text search unavailable — "
                 "run <code>scripts/add_clip_embeddings.py</code> to enable.</i>",
            width=470,
        )
        return panel, None, None

    clip_query_input = TextInput(
        title="Search features by text (CLIP):",
        placeholder="e.g. 'dog', 'red stripes', 'water'...",
        width=280,
    )
    clip_search_btn  = Button(label="Search", width=70, button_type="primary")
    result_div       = Div(text="", width=360)
    clip_top_k_input = TextInput(title="Top-K results:", value="20", width=70)

    result_source = ColumnDataSource(data=dict(
        feature_idx=[], clip_score=[], frequency=[], mean_act=[], phi_c_val=[], name=[],
    ))
    clip_result_table = DataTable(
        source=result_source,
        columns=[
            TableColumn(field="feature_idx", title="Feature",    width=65),
            TableColumn(field="clip_score",  title="CLIP score", width=85,
                        formatter=NumberFormatter(format="0.0000")),
            TableColumn(field="frequency",   title="Freq",       width=65,
                        formatter=NumberFormatter(format="0,0")),
            TableColumn(field="mean_act",    title="Mean Act",   width=80,
                        formatter=NumberFormatter(format="0.0000")),
        ] + _phi_col() + [
            TableColumn(field="name",        title="Name",       width=160),
        ],
        width=470 + (65 if HAS_PHI else 0), height=300, index_position=None, sortable=False,
    )

    def _do_search():
        query = clip_query_input.value.strip()
        if not query:
            result_div.text = "<i>Enter a text query above.</i>"
            return
        try:
            top_k = max(1, int(clip_top_k_input.value))
        except ValueError:
            top_k = 20

        # Check if query matches a vocab term exactly (case-insensitive)
        vocab_lower = [v.lower() for v in (_clip_vocab or [])]
        if _clip_vocab and query.lower() in vocab_lower:
            col = vocab_lower.index(query.lower())
            scores_vec = _clip_scores_f32[:, col]
        elif _clip_embeds is not None or _nsd_clip_embeds is not None:
            # Free-text: encode on-the-fly with CLIP, dot with feature image embeds.
            # Use NSD-specific embeds when the subset toggle is active.
            _use_nsd_embeds = nsd_subset_toggle.active == 1 and _nsd_clip_embeds is not None
            _active_embeds  = _nsd_clip_embeds if _use_nsd_embeds else _clip_embeds
            result_div.text = "<i>Encoding query with CLIP…</i>"
            try:
                clip_m, clip_p, clip_dev = _get_clip()
                q_embed = compute_text_embeddings([query], clip_m, clip_p, clip_dev)
                scores_vec = (_active_embeds.float() @ q_embed.T).squeeze(-1)
            except Exception as exc:
                result_div.text = f"<span style='color:#c00'>CLIP error: {exc}</span>"
                return
        else:
            result_div.text = (
                f"<span style='color:#c00'>Query not in vocab and no feature embeddings "
                f"available. Try one of: {', '.join((_clip_vocab or [])[:8])}…</span>"
            )
            return

        # When NSD subset toggle is active, restrict to features with at least one NSD image
        if nsd_subset_toggle.active == 1 and HAS_NSD_SUBSET:
            nsd_mask = nsd_top_img_idx[:, 0] >= 0   # (d_model,) bool
            scores_vec = scores_vec.clone()
            scores_vec[~nsd_mask] = float('-inf')

        top_indices = torch.topk(scores_vec, k=min(top_k, len(scores_vec))).indices.tolist()
        # Drop any -inf results (features with no NSD images when subset is active)
        top_indices = [i for i in top_indices if scores_vec[i] > float('-inf')]
        result_source.data = dict(
            feature_idx=top_indices,
            clip_score=[float(scores_vec[i]) for i in top_indices],
            frequency=[int(feature_frequency[i].item()) for i in top_indices],
            mean_act=[float(feature_mean_act[i].item()) for i in top_indices],
            phi_c_val=_phi_c_vals(top_indices),
            name=[_display_name(int(i)) for i in top_indices],
        )
        _subset_note = " [NSD sub01]" if (nsd_subset_toggle.active == 1 and HAS_NSD_SUBSET) else ""
        result_div.text = (
            f'<span style="color:#1a6faf"><b>{len(top_indices)}</b> features for '
            f'&ldquo;{query}&rdquo;{_subset_note}</span>'
        )

    clip_search_btn.on_click(_do_search)

    def _on_result_select(attr, old, new):
        if not new:
            return
        feat = result_source.data['feature_idx'][new[0]]
        feature_input.value = str(feat)
        _select_and_display(feat)

    result_source.selected.on_change('indices', _on_result_select)

    panel = column(
        row(clip_query_input, clip_top_k_input, clip_search_btn),
        result_div,
        clip_result_table,
    )
    return panel, result_div, result_source


clip_search_panel, clip_result_div, clip_result_source = _build_clip_panel()




# ---------- Layout ----------
controls = row(umap_type_select, umap_color_select, feature_input, go_button, random_btn)

name_panel = column(
    name_input,
    row(gemini_btn, gemini_status_div),
)

search_panel = column(
    row(search_input, search_btn, clear_search_btn),
    search_result_div,
)

feature_list_panel = column(search_panel, feature_table)


def _make_collapsible(title, body, initially_open=False):
    """Wrap a widget in a toggle-able collapsible section."""
    btn = Toggle(
        label=("▼  " if initially_open else "▶  ") + title,
        active=initially_open,
        button_type="light",
        width=500,
        height=30,
    )
    body.visible = initially_open
    btn.js_on_click(CustomJS(args=dict(body=body, btn=btn, title=title), code="""
        body.visible = btn.active;
        btn.label = (btn.active ? '▼  ' : '▶  ') + title;
    """))
    return column(btn, body)


patch_explorer_panel = column(
    row(patch_img_input, load_patch_btn, clear_patch_btn),
    patch_fig,
    patch_info_div,
    patch_feat_table,
)

summary_section     = _make_collapsible("SAE Summary",          summary_div)
patch_section       = _make_collapsible("Patch Explorer",       patch_explorer_panel)
clip_section        = _make_collapsible("CLIP Text Search",     clip_search_panel)

_ds_select_row = ([dataset_select] if len(_all_datasets) > 1 else [])
left_panel = column(*_ds_select_row, controls, umap_fig, feature_list_panel)

middle_panel = column(
    status_div,
    stats_div,
    name_panel,
    row(view_select,
        column(Div(text="<b>Images:</b>", width=60, height=15, styles={"padding-top":"5px"}),
               nsd_subset_toggle),
        column(zoom_slider, heatmap_alpha_slider)),
    compare_agg_div,
    top_heatmap_div,
    mean_heatmap_div,
    brain_div,
)

dd_section = (
    _make_collapsible("DynaDiff Brain Steering", _dd_panel_body, initially_open=True)
    if HAS_DYNADIFF else Div(text="", width=1)
)

right_panel = column(summary_section, patch_section, clip_section, dd_section)

layout = row(left_panel, middle_panel, right_panel)
curdoc().add_root(layout)
curdoc().title = "SAE Feature Explorer"

print("Explorer app ready!")

# Warm up GPU runner in background so the first patch explore request is instant.
if args.sae_path:
    def _warmup_gpu():
        try:
            _get_gpu_runner()
        except Exception as _e:
            print(f"[GPU runner] Warmup failed: {_e}")
    threading.Thread(target=_warmup_gpu, daemon=True).start()