"""
benchmark_interaction.py — Interactive cross-modal visualization for the benchmark tab.

Creates a self-contained HTML component that shows:
- Image with real UnSAM segment outlines (clickable via hidden canvas label map)
- Caption tokens below the image (clickable, colored by Shapley value)
- Arrows/lines connecting image regions to their most interacting tokens
- Click a region → highlights linked tokens; click a token → highlights linked regions
"""

from __future__ import annotations

import json
import uuid
from html import escape
from typing import Any, Dict, List, Optional, Sequence, Tuple


def _value_to_color(value: float, max_abs: float, single_color: bool = False) -> str:
    if max_abs <= 0:
        return "rgb(225, 225, 223)"
    norm = min(1.0, abs(value) / max_abs)
    if single_color:
        base = (225, 225, 223)
        target = (52, 102, 177)  # influence neutral blue
    elif value >= 0:
        base = (225, 225, 223)
        target = (1, 109, 1)
    else:
        base = (225, 225, 223)
        target = (221, 19, 19)
    r = int(round(base[0] + (target[0] - base[0]) * norm))
    g = int(round(base[1] + (target[1] - base[1]) * norm))
    b = int(round(base[2] + (target[2] - base[2]) * norm))
    return f"rgb({r}, {g}, {b})"


def _value_to_rgba(value: float, max_abs: float, alpha: float = 0.5) -> str:
    if max_abs <= 0:
        return "rgba(200, 200, 200, 0.1)"
    norm = min(1.0, abs(value) / max_abs)
    if value >= 0:
        return f"rgba(1, 109, 1, {alpha * norm:.2f})"
    else:
        return f"rgba(221, 19, 19, {alpha * norm:.2f})"


def create_benchmark_interaction_html(
    image_b64: str,
    clip_summary: Optional[Dict[str, Any]],
    vllm_logprob: Optional[Dict[str, Any]],
    caption: str = "",
    all_cross_modal_pairs: Optional[List[Dict[str, Any]]] = None,
    segmap_b64: str = "",
    overlay_b64: str = "",
    segment_bboxes: Optional[List[Optional[Dict[str, float]]]] = None,
    label_map_b64: str = "",
    image_width: int = 0,
    image_height: int = 0,
    title: str = "Cross-Modal Interaction View",
    method_label: str = "Shapley",
) -> str:
    """
    Build a self-contained HTML + JS component for the benchmark tab.

    Shows:
    - Image panel (left) with real UnSAM segment outlines and clickable regions
    - Token panel (right) with clickable colored tokens
    - SVG arrow layer connecting regions to tokens on click
    - Cross-modal interaction list

    When segment_bboxes and label_map_b64 are provided, uses canvas-based
    pixel-level click detection for accurate segment selection matching
    the real UnSAM segmentation. Falls back to horizontal strips otherwise.
    """
    if not image_b64 and not clip_summary:
        return "<div style='padding:20px;color:#888;'>No data available. Select an example.</div>"

    view_id = f"bm-{uuid.uuid4().hex[:8]}"
    is_influence = (method_label or "").lower() == "influence"

    # Prepare image URL
    img_url = image_b64
    if img_url and not img_url.startswith("data:"):
        img_url = f"data:image/png;base64,{img_url}"

    # Extract CLIP data
    regions = []  # {index, label, value}
    tokens = []   # {index, label, value}
    cross_interactions = []  # {seg, tok, value}
    n_segs = 0

    if clip_summary:
        raw_items = clip_summary.get("image_region_values", [])
        total_regions = len(raw_items)
        grid_guess = int(round(total_regions ** 0.5))
        looks_like_patch_grid = (grid_guess * grid_guess == total_regions) and all(
            str(it.get("label", "")).startswith("patch_")
            or str(it.get("label", "")).isdigit()
            for it in raw_items
        )
        for item in raw_items:
            # Resolve the segment number:
            #   seg_6       → 6           (UnSAM)
            #   patch_1_2   → 1*grid+2    (raw patch-grid; assumes grid=sqrt(n))
            #   "7"         → 7 - 1 = 6   (post-rename patch-grid)
            raw_label = str(item["label"])
            seg_num = n_segs  # fallback: sequential
            if raw_label.startswith("seg_"):
                try:
                    seg_num = int(raw_label.split("_", 1)[1])
                except (ValueError, IndexError):
                    pass
            elif raw_label.startswith("patch_"):
                try:
                    _, r_str, c_str = raw_label.split("_", 2)
                    seg_num = int(r_str) * grid_guess + int(c_str)
                except (ValueError, IndexError):
                    pass
            elif raw_label.isdigit():
                try:
                    seg_num = int(raw_label) - 1
                except ValueError:
                    pass
            # Display label: in patch-grid mode always show "1".."N" in reading
            # order so the overlay doesn't leak raw "patch_r_c" text.
            display_label = str(seg_num + 1) if looks_like_patch_grid else raw_label
            regions.append({
                "index": seg_num,
                "label": display_label,
                "value": item["value"],
                "type": "segment",
            })
            n_segs += 1

        # Build a lookup from CLIP token labels to values.
        # Also build a ##-stripped version for subword matching.
        clip_tok_values: Dict[str, float] = {}
        for item in clip_summary.get("token_values", []):
            tok_label = item["label"].replace("tok:", "")
            clip_tok_values[tok_label] = item["value"]

        # Collect tokens with ## stripped for substring matching
        clip_tok_set = set(clip_tok_values.keys())

        # Include ALL words from the full caption, not just CLIP's top-k
        if caption:
            words = caption.replace(".", " .").replace(",", " ,").replace("(", " (").replace(")", " )").split()
            for i, word in enumerate(words):
                value = clip_tok_values.get(word, 0.0)
                matched_tok = word if value != 0.0 else None
                if value == 0.0:
                    value = clip_tok_values.get(word.lower(), 0.0)
                    matched_tok = word.lower() if value != 0.0 else None
                if value == 0.0:
                    # Sum all matching subword tokens (strip ## before matching)
                    total = 0.0
                    for tok in clip_tok_set:
                        tok_clean = tok.lstrip("#")
                        if len(tok_clean) >= 3 and tok_clean.lower() in word.lower():
                            total += clip_tok_values[tok]
                            matched_tok = tok
                    value = total
                tokens.append({
                    "index": i,
                    "label": word,
                    "value": value,
                    "_matched_tok": matched_tok,
                })
        else:
            for i, item in enumerate(clip_summary.get("token_values", [])):
                tok_label = item["label"].replace("tok:", "").lstrip("#")
                tokens.append({
                    "index": i,
                    "label": tok_label,
                    "value": item["value"],
                    "_matched_tok": tok_label,
                })

        # Use ALL cross-modal pairs if provided, else fall back to top-5.
        # Map subword token labels to whole caption words.
        from .medical_charts import _tok_to_word
        cross_source = all_cross_modal_pairs or clip_summary.get("cross_modal_interactions", [])

        def _seg_display(seg_raw: str) -> str:
            # Normalize cross-pair segment labels the same way we normalized
            # region labels above — otherwise arrows can't match regions.
            s = str(seg_raw)
            if looks_like_patch_grid and s.startswith("patch_"):
                try:
                    _, rr, cc = s.split("_", 2)
                    return str(int(rr) * grid_guess + int(cc) + 1)
                except (ValueError, IndexError):
                    return s
            return s

        for item in cross_source:
            cross_interactions.append({
                "seg": _seg_display(item["pair"][0]),
                "tok": _tok_to_word(item["pair"][1], caption) if caption else item["pair"][1].replace("tok:", "").lstrip("#"),
                "value": item["value"],
            })

    # Determine if we have real segment bounding boxes
    has_real_bboxes = (
        segment_bboxes is not None
        and len(segment_bboxes) == n_segs
        and any(b is not None for b in segment_bboxes)
    )
    has_label_map = bool(label_map_b64)

    # Build region overlays: real bboxes if available, else horizontal strips
    # When a pixel-accurate label map is available, skip the rectangular div
    # overlays entirely — the segmap image already shows real segment contours.
    # We still render small labels at segment centers for identification.
    region_overlays_html = ""
    max_abs_r = max((abs(r["value"]) for r in regions), default=1.0) or 1.0

    if has_label_map and has_real_bboxes and n_segs > 0:
        # Label-map mode: no rectangular divs, just center labels.
        # When segments look like a patch grid (perfect-square count and numeric
        # or patch-style labels), show reading-order numbers 1..N so the overlay
        # reads left-to-right top-to-bottom without the raw "patch_r_c" noise.
        grid = int(round(n_segs ** 0.5))
        is_patch_grid = (grid * grid == n_segs) and all(
            str(r["label"]).isdigit() or str(r["label"]).startswith("patch_")
            for r in regions
        )
        for r in regions:
            r_idx = r["index"]
            bbox = segment_bboxes[r_idx] if r_idx < len(segment_bboxes) else None
            if bbox is None:
                continue
            r_label = escape(str(r_idx + 1) if is_patch_grid else r["label"])
            r_value = r["value"]
            region_overlays_html += (
                f"<span class='bm-seg-label' data-idx='{r_idx}' "
                f"style='left:{bbox['cx_pct']:.1f}%;top:{bbox['cy_pct']:.1f}%;'>"
                f"{r_label}</span>"
            )
    elif has_real_bboxes and n_segs > 0:
        # No label map — use rectangular bounding box divs as fallback
        for r in regions:
            r_idx = r["index"]
            bbox = segment_bboxes[r_idx] if r_idx < len(segment_bboxes) else None
            if bbox is None:
                continue
            r_label = escape(r["label"])
            r_value = r["value"]
            if is_influence:
                norm = min(1.0, abs(r_value) / max_abs_r) if max_abs_r else 0.0
                bg = f"rgba(52,102,177,{0.25*norm:.2f})"
                border_color = "rgba(52,102,177,0.8)"
                val_str = f"{r_value:.2f}"
                title_str = f"{r_label}: {r_value:.3f}"
            else:
                bg = _value_to_rgba(r_value, max_abs_r, 0.25)
                border_color = "rgba(1,109,1,0.8)" if r_value >= 0 else "rgba(200,40,40,0.8)"
                val_str = f"{r_value:+.2f}"
                title_str = f"{r_label}: {r_value:+.3f}"
            region_overlays_html += (
                f"<div class='bm-region-box' data-idx='{r_idx}' "
                f"title='{title_str}' "
                f"style='left:{bbox['x0_pct']:.2f}%;top:{bbox['y0_pct']:.2f}%;"
                f"width:{bbox['w_pct']:.2f}%;height:{bbox['h_pct']:.2f}%;"
                f"background:{bg};border:2px solid {border_color};'>"
                f"<span class='bm-box-label'>{r_label} ({val_str})</span>"
                f"</div>"
            )
    elif n_segs > 0:
        # Fallback: horizontal strips
        strip_h = 100.0 / n_segs
        for r in regions:
            r_idx = r["index"]
            r_label = escape(r["label"])
            r_value = r["value"]
            top_pct = r_idx * strip_h
            if is_influence:
                norm = min(1.0, abs(r_value) / max_abs_r) if max_abs_r else 0.0
                bg = f"rgba(52,102,177,{0.3*norm:.2f})"
                border_color = "rgba(52,102,177,0.6)"
                val_str = f"{r_value:.2f}"
                title_str = f"{r_label}: {r_value:.3f}"
            else:
                bg = _value_to_rgba(r_value, max_abs_r, 0.3)
                border_color = "rgba(1,109,1,0.6)" if r_value >= 0 else "rgba(200,40,40,0.6)"
                val_str = f"{r_value:+.2f}"
                title_str = f"{r_label}: {r_value:+.3f}"
            region_overlays_html += (
                f"<div class='bm-region-box' data-idx='{r_idx}' "
                f"title='{title_str}' "
                f"style='top:{top_pct:.1f}%;height:{strip_h:.1f}%;left:0;width:100%;"
                f"background:{bg};border-bottom:2px solid {border_color};'>"
                f"<span class='bm-box-label'>{r_label} ({val_str})</span>"
                f"</div>"
            )

    # Prefer overlay.png over segmap.png — the segmap has patch labels
    # ("patch_0_0" etc.) burned into the image pixels during precompute,
    # which visually dominate the clean 1..16 labels we render in HTML.
    # overlay.png has no baked text, so only our HTML spans show through.
    display_img_url = img_url
    if overlay_b64:
        ov_url = overlay_b64
        if ov_url and not ov_url.startswith("data:"):
            ov_url = f"data:image/png;base64,{ov_url}"
        display_img_url = ov_url
    elif segmap_b64:
        seg_url = segmap_b64
        if seg_url and not seg_url.startswith("data:"):
            seg_url = f"data:image/png;base64,{seg_url}"
        display_img_url = seg_url

    # Label map data URL for canvas click detection
    label_map_url = ""
    if has_label_map:
        label_map_url = f"data:image/png;base64,{label_map_b64}"

    # Build token chips
    max_abs_t = max((abs(t["value"]) for t in tokens), default=1.0) or 1.0
    tokens_html = ""
    for t in tokens:
        color = _value_to_color(t["value"], max_abs_t, single_color=is_influence)
        t_idx = t["index"]
        t_label = escape(t["label"])
        t_value = t["value"]
        t_title = (f"{t_label}: {t_value:.4f}" if is_influence
                   else f"{t_label}: {t_value:+.4f}")
        tokens_html += (
            f"<span class='bm-token' data-idx='{t_idx}' "
            f"title='{t_title}' "
            f"style='background:{color};'>"
            f"{t_label}"
            f"</span>"
        )

    # Build cross-modal link data for JS
    seg_idx_map = {r["label"]: r["index"] for r in regions}

    clip_tok_to_word_indices: Dict[str, List[int]] = {}
    for t in tokens:
        matched = t.get("_matched_tok")
        if matched:
            clip_tok_to_word_indices.setdefault(matched, []).append(t["index"])
            clip_tok_to_word_indices.setdefault(matched.lower(), []).append(t["index"])

    links = []
    seen_links: set = set()
    for ci in cross_interactions:
        si = seg_idx_map.get(ci["seg"])
        if si is None:
            continue
        tok_key = ci["tok"]
        word_indices = (clip_tok_to_word_indices.get(tok_key) or
                        clip_tok_to_word_indices.get(tok_key.lower()) or [])
        for ti in word_indices:
            link_key = (si, ti)
            if link_key not in seen_links:
                seen_links.add(link_key)
                tok_display = tokens[ti]["label"] if ti < len(tokens) else tok_key
                links.append({"seg": si, "tok": ti, "value": ci["value"],
                              "seg_label": ci["seg"], "tok_label": tok_display})

    # Pass bounding box data to JS for arrow origin computation
    bboxes_json = json.dumps([
        segment_bboxes[i] if (has_real_bboxes and i < len(segment_bboxes)) else None
        for i in range(n_segs)
    ])
    links_json = json.dumps(links)
    # Build regions lookup keyed by actual segment index (not sequential)
    regions_by_idx = {}
    for r in regions:
        regions_by_idx[r["index"]] = {"label": r["label"], "value": r["value"]}
    regions_json = json.dumps(regions_by_idx)

    # JS for interactivity
    js_code = f"""
    (function() {{
      const VIEW_ID = '{view_id}';
      const root = document.getElementById(VIEW_ID);
      if (!root) return;

      // --- Staleness guard ---
      // Mark this root with the current view ID so stale closures can detect
      // they belong to a replaced component and bail out.
      root.setAttribute('data-bm-active', VIEW_ID);
      function isStale() {{
        // If root was removed from DOM or replaced by a new render, bail out
        if (!document.contains(root)) return true;
        return root.getAttribute('data-bm-active') !== VIEW_ID;
      }}

      const links = {links_json};
      const bboxes = {bboxes_json};
      const regions = {regions_json};
      const nSegs = {n_segs};
      const METHOD_IS_INFLUENCE = {str(is_influence).lower()};
      const INFLUENCE_ARROW_COLOR = 'rgba(52,102,177,0.75)';
      const regionEls = root.querySelectorAll('.bm-region-box');
      const tokenEls = root.querySelectorAll('.bm-token');
      const svg = root.querySelector('.bm-svg');
      const linkList = root.querySelector('.bm-link-list');
      const imgWrap = root.querySelector('.bm-img-wrap');
      const mainImg = root.querySelector('.bm-main-img');

      // --- Highlight canvas: draws real segment contours on click ---
      let hlCanvas = root.querySelector('.bm-highlight-canvas');
      let hlCtx = hlCanvas ? hlCanvas.getContext('2d') : null;
      function syncHighlightCanvas() {{
        if (!hlCanvas || !mainImg) return;
        hlCanvas.width = mainImg.naturalWidth || mainImg.width;
        hlCanvas.height = mainImg.naturalHeight || mainImg.height;
      }}
      if (mainImg) {{
        if (mainImg.complete) syncHighlightCanvas();
        else mainImg.addEventListener('load', syncHighlightCanvas);
      }}

      // --- Canvas-based label map for pixel-perfect click detection ---
      let labelCanvas = null;
      let labelCtx = null;
      let labelMapReady = false;
      const labelMapUrl = '{label_map_url}';
      if (labelMapUrl) {{
        labelCanvas = document.createElement('canvas');
        labelCtx = labelCanvas.getContext('2d', {{willReadFrequently: true}});
        const lmImg = new window.Image();
        lmImg.onload = function() {{
          if (isStale()) return;  // Don't populate canvas if replaced
          labelCanvas.width = lmImg.naturalWidth;
          labelCanvas.height = lmImg.naturalHeight;
          labelCtx.drawImage(lmImg, 0, 0);
          labelMapReady = true;
          buildSegMasks();
        }};
        lmImg.src = labelMapUrl;
      }}

      // ── Hover-dim state ─────────────────────────────────────────────
      // Per-segment boolean masks (Uint8Array, 1=inside seg, 0=outside),
      // indexed by the label-map's flat coords so we don't re-read
      // getImageData on every mousemove.
      let segMasks = new Array(nSegs).fill(null);
      let hoveredSeg = -1;
      let clickedSeg = -1;
      let hoverRafPending = false;
      const HOVER_SUPPORTED = window.matchMedia && window.matchMedia('(hover: hover)').matches;

      function buildSegMasks() {{
        if (!labelMapReady || !labelCanvas || !labelCtx) return;
        const w = labelCanvas.width, h = labelCanvas.height;
        const data = labelCtx.getImageData(0, 0, w, h).data;
        for (let i = 0; i < nSegs; i++) segMasks[i] = new Uint8Array(w * h);
        for (let p = 0, i = 0; p < data.length; p += 4, i++) {{
          const seg = data[p] - 1;
          if (seg >= 0 && seg < nSegs) segMasks[seg][i] = 1;
        }}
      }}

      function drawHoverDim(segIdx) {{
        // Dim the entire image except the pixels belonging to `segIdx`.
        if (isStale() || !hlCtx || !hlCanvas || !labelCanvas) return;
        syncHighlightCanvas();
        hlCtx.clearRect(0, 0, hlCanvas.width, hlCanvas.height);
        if (segIdx < 0 || !segMasks[segIdx]) return;

        const cw = hlCanvas.width, ch = hlCanvas.height;
        const lw = labelCanvas.width, lh = labelCanvas.height;
        const mask = segMasks[segIdx];

        const imgData = hlCtx.createImageData(cw, ch);
        const px = imgData.data;
        const dimAlpha = 140;  // ≈55% black
        // First: alpha=dim everywhere (rgb=0 by default)
        for (let i = 3; i < px.length; i += 4) px[i] = dimAlpha;
        // Second: punch through (alpha=0) wherever the hovered seg lives
        const sx = lw / cw, sy = lh / ch;
        for (let y = 0; y < ch; y++) {{
          const ly = Math.floor(y * sy) * lw;
          const rowBase = y * cw * 4 + 3;
          for (let x = 0; x < cw; x++) {{
            if (mask[ly + Math.floor(x * sx)]) px[rowBase + x * 4] = 0;
          }}
        }}
        hlCtx.putImageData(imgData, 0, 0);
      }}

      function getSegAtPixel(clientX, clientY) {{
        if (isStale() || !labelMapReady || !labelCanvas || !labelCtx || !mainImg) return -1;
        const rect = mainImg.getBoundingClientRect();
        const rx = (clientX - rect.left) / rect.width;
        const ry = (clientY - rect.top) / rect.height;
        if (rx < 0 || rx > 1 || ry < 0 || ry > 1) return -1;
        const px = Math.floor(rx * labelCanvas.width);
        const py = Math.floor(ry * labelCanvas.height);
        const data = labelCtx.getImageData(px, py, 1, 1).data;
        const segIdx = data[0] - 1;  // red channel: index+1, 0=bg
        return (segIdx >= 0 && segIdx < nSegs) ? segIdx : -1;
      }}

      function clearAll() {{
        regionEls.forEach(el => el.classList.remove('bm-active', 'bm-linked'));
        tokenEls.forEach(el => el.classList.remove('bm-active', 'bm-linked'));
        // Clear segment labels highlight
        root.querySelectorAll('.bm-seg-label').forEach(el => el.classList.remove('bm-seg-active'));
        if (svg) svg.innerHTML = '';
        if (hlCtx && hlCanvas) hlCtx.clearRect(0, 0, hlCanvas.width, hlCanvas.height);
        if (linkList) linkList.innerHTML = '<div class="bm-hint">Click a segment or word to see connections.</div>';
        clickedSeg = -1;
      }}

      function drawSegmentContour(segIdx) {{
        // Draw the real segment contour on the highlight canvas using the label map
        if (isStale() || !labelMapReady || !hlCtx || !hlCanvas || !labelCtx || !labelCanvas) return;
        syncHighlightCanvas();
        hlCtx.clearRect(0, 0, hlCanvas.width, hlCanvas.height);
        var w = labelCanvas.width, h = labelCanvas.height;
        var imgData = labelCtx.getImageData(0, 0, w, h);
        var px = imgData.data;
        var target = segIdx + 1;  // label map red channel = index + 1
        // Find edge pixels: pixels that belong to this segment where at
        // least one 4-connected neighbor does NOT belong to this segment
        hlCtx.fillStyle = 'rgba(0, 229, 255, 0.9)';  // cyan highlight
        var scaleX = hlCanvas.width / w;
        var scaleY = hlCanvas.height / h;
        for (var y = 0; y < h; y++) {{
          for (var x = 0; x < w; x++) {{
            var idx = (y * w + x) * 4;
            if (px[idx] !== target) continue;
            // Check 4-connected neighbors
            var isEdge = false;
            if (x === 0 || px[idx - 4] !== target) isEdge = true;
            else if (x === w - 1 || px[idx + 4] !== target) isEdge = true;
            else if (y === 0 || px[idx - w * 4] !== target) isEdge = true;
            else if (y === h - 1 || px[idx + w * 4] !== target) isEdge = true;
            if (isEdge) {{
              hlCtx.fillRect(Math.round(x * scaleX), Math.round(y * scaleY),
                             Math.max(2, Math.round(scaleX) + 1),
                             Math.max(2, Math.round(scaleY) + 1));
            }}
          }}
        }}
      }}

      function getSegCenter(segIdx) {{
        // Use real bbox center if available
        const bb = bboxes[segIdx];
        if (bb) return {{ xPct: bb.cx_pct, yPct: bb.cy_pct }};
        // Fallback: center of horizontal strip
        const stripH = 100.0 / nSegs;
        return {{ xPct: 50, yPct: segIdx * stripH + stripH / 2 }};
      }}

      function drawLine(segIdx, tokIdx, value) {{
        if (!svg || !imgWrap) return;
        const rootRect = root.getBoundingClientRect();
        const imgRect = imgWrap.getBoundingClientRect();
        const tokEl = root.querySelector('.bm-token[data-idx="' + tokIdx + '"]');
        if (!tokEl) return;
        const tokRect = tokEl.getBoundingClientRect();

        // Arrow start: segment center in image coordinates
        const center = getSegCenter(segIdx);
        const x1 = imgRect.left + (center.xPct / 100) * imgRect.width - rootRect.left;
        const y1 = imgRect.top + (center.yPct / 100) * imgRect.height - rootRect.top;
        const x2 = tokRect.left + tokRect.width / 2 - rootRect.left;
        const y2 = tokRect.top - rootRect.top;

        const color = METHOD_IS_INFLUENCE
          ? INFLUENCE_ARROW_COLOR
          : (value >= 0 ? 'rgba(1,109,1,0.7)' : 'rgba(221,19,19,0.7)');
        const line = document.createElementNS('http://www.w3.org/2000/svg', 'line');
        line.setAttribute('x1', x1);
        line.setAttribute('y1', y1);
        line.setAttribute('x2', x2);
        line.setAttribute('y2', y2);
        line.setAttribute('stroke', color);
        line.setAttribute('stroke-width', '3');
        line.setAttribute('stroke-linecap', 'round');
        line.setAttribute('opacity', '0.7');
        svg.appendChild(line);
      }}

      function onClickRegion(segIdx) {{
        if (isStale()) return;
        clearAll();
        clickedSeg = segIdx;
        // Highlight the rectangular div (fallback mode) or segment label
        const segEl = root.querySelector('.bm-region-box[data-idx="' + segIdx + '"]');
        if (segEl) segEl.classList.add('bm-active');
        const segLabel = root.querySelector('.bm-seg-label[data-idx="' + segIdx + '"]');
        if (segLabel) segLabel.classList.add('bm-seg-active');
        // Draw pixel-accurate contour on highlight canvas
        drawSegmentContour(segIdx);

        const related = links.filter(l => l.seg === segIdx)
                              .sort((a, b) => Math.abs(b.value) - Math.abs(a.value));
        related.forEach(l => {{
          const tokEl = root.querySelector('.bm-token[data-idx="' + l.tok + '"]');
          if (tokEl) tokEl.classList.add('bm-linked');
          drawLine(l.seg, l.tok, l.value);
        }});

        if (linkList) {{
          var regInfo = regions[segIdx] || {{}};
          var regName = regInfo.label || ('seg_' + segIdx);
          var regVal = regInfo.value !== undefined
            ? (METHOD_IS_INFLUENCE ? regInfo.value.toFixed(3) : (regInfo.value >= 0 ? '+' : '') + regInfo.value.toFixed(3))
            : '';
          var header = '<div class="bm-link-header"><strong>' + regName + '</strong> <span style="color:#888">' + regVal + '</span></div>';
          if (related.length === 0) {{
            linkList.innerHTML = header + '<div class="bm-hint">No cross-modal links for this region.</div>';
          }} else {{
            linkList.innerHTML = header + related.map(l => {{
              var color = METHOD_IS_INFLUENCE
                ? '#34569F'
                : (l.value >= 0 ? '#016d01' : '#c82828');
              var formatted = METHOD_IS_INFLUENCE
                ? l.value.toFixed(3)
                : (l.value >= 0 ? '+' : '') + l.value.toFixed(3);
              return '<div class="bm-link-row">' +
                '<span>' + l.tok_label + '</span>' +
                '<strong style="color:' + color + '">' +
                formatted + '</strong></div>';
            }}).join('');
          }}
        }}
      }}

      function onClickToken(tokIdx) {{
        if (isStale()) return;
        clearAll();
        const tokEl = root.querySelector('.bm-token[data-idx="' + tokIdx + '"]');
        if (tokEl) tokEl.classList.add('bm-active');

        const related = links.filter(l => l.tok === tokIdx)
                              .sort((a, b) => Math.abs(b.value) - Math.abs(a.value));
        related.forEach(l => {{
          const segEl = root.querySelector('.bm-region-box[data-idx="' + l.seg + '"]');
          if (segEl) segEl.classList.add('bm-linked');
          const segLabel = root.querySelector('.bm-seg-label[data-idx="' + l.seg + '"]');
          if (segLabel) segLabel.classList.add('bm-seg-active');
          drawLine(l.seg, l.tok, l.value);
        }});
        // Draw contours for all linked segments
        if (related.length > 0) drawSegmentContour(related[0].seg);

        if (linkList) {{
          var tokName = tokIdx < {len(tokens)} ? {json.dumps([t["label"] for t in tokens])}[tokIdx] : 'word ' + tokIdx;
          var header = '<div class="bm-link-header"><strong>"' + tokName + '"</strong></div>';
          if (related.length === 0) {{
            linkList.innerHTML = header + '<div class="bm-hint">No cross-modal links for this word.</div>';
          }} else {{
            linkList.innerHTML = header + related.map(l => {{
              var color = METHOD_IS_INFLUENCE
                ? '#34569F'
                : (l.value >= 0 ? '#016d01' : '#c82828');
              var formatted = METHOD_IS_INFLUENCE
                ? l.value.toFixed(3)
                : (l.value >= 0 ? '+' : '') + l.value.toFixed(3);
              return '<div class="bm-link-row">' +
                '<span>' + l.seg_label + '</span>' +
                '<strong style="color:' + color + '">' +
                formatted + '</strong></div>';
            }}).join('');
          }}
        }}
      }}

      // Click on the image: use label map canvas for pixel-perfect detection
      if (imgWrap) {{
        imgWrap.addEventListener('click', function(e) {{
          if (isStale()) return;
          const segIdx = getSegAtPixel(e.clientX, e.clientY);
          if (segIdx >= 0) {{
            onClickRegion(segIdx);
          }}
        }});

        // Hover-dim: highlight the segment under the cursor by dimming the rest.
        // Skipped on touch devices where there's no real hover.
        if (HOVER_SUPPORTED) {{
          imgWrap.addEventListener('mousemove', function(e) {{
            if (isStale() || hoverRafPending) return;
            hoverRafPending = true;
            requestAnimationFrame(function() {{
              hoverRafPending = false;
              const seg = getSegAtPixel(e.clientX, e.clientY);
              if (seg === hoveredSeg) return;
              hoveredSeg = seg;
              drawHoverDim(seg);
            }});
          }});
          imgWrap.addEventListener('mouseleave', function() {{
            if (isStale()) return;
            hoveredSeg = -1;
            // Restore the click-highlight if any, else clear the canvas.
            if (clickedSeg >= 0) drawSegmentContour(clickedSeg);
            else if (hlCtx && hlCanvas) hlCtx.clearRect(0, 0, hlCanvas.width, hlCanvas.height);
          }});
        }}
      }}

      // Also allow clicking the bbox overlay divs directly
      regionEls.forEach(el => {{
        el.addEventListener('click', function(e) {{
          if (isStale()) return;
          e.stopPropagation();
          // If label map is available, prefer pixel detection
          if (labelMapReady && labelCanvas && labelCtx) {{
            const segIdx = getSegAtPixel(e.clientX, e.clientY);
            if (segIdx >= 0) {{ onClickRegion(segIdx); return; }}
          }}
          onClickRegion(parseInt(el.dataset.idx));
        }});
      }});
      tokenEls.forEach(el => {{
        el.addEventListener('click', () => onClickToken(parseInt(el.dataset.idx)));
      }});

      const resetBtn = root.querySelector('.bm-reset');
      if (resetBtn) resetBtn.addEventListener('click', clearAll);
    }})();
    """

    script_id = f"{view_id}-script"
    loader_id = f"{view_id}-loader"

    if is_influence:
        legend_html = """
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(52,102,177,0.6);"></div>
          <span>Influence strength (always positive — higher = more important)</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgb(225,225,223);"></div>
          <span>Neutral / not scored</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(52,102,177,0.7); width:30px; height:3px; border-radius:2px;"></div>
          <span>Line thickness = cross-modal interaction strength</span>
        </div>
        """
    else:
        method_display = method_label or "Shapley"
        legend_html = f"""
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(1,109,1,0.6);"></div>
          <span>Positive {escape(method_display)} (contributes to matching)</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(221,19,19,0.6);"></div>
          <span>Negative {escape(method_display)} (detracts from matching)</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgb(225,225,223);"></div>
          <span>Neutral / not scored</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(1,109,1,0.7); width:30px; height:3px; border-radius:2px;"></div>
          <span>Green line = positive cross-modal interaction</span>
        </div>
        <div class="bm-legend-item">
          <div class="bm-legend-swatch" style="background:rgba(221,19,19,0.7); width:30px; height:3px; border-radius:2px;"></div>
          <span>Red line = negative cross-modal interaction</span>
        </div>
        """

    return f"""
    <style>
      .bm-root {{
        font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
        background: #f7f5f2;
        border: 1px solid #e3e3ec;
        border-radius: 16px;
        padding: 16px;
        position: relative;
      }}
      .bm-title {{
        font-size: 15px; font-weight: 700; color: #2d1f4a;
        margin-bottom: 10px;
      }}
      .bm-layout {{
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 14px;
      }}
      .bm-img-panel {{
        background: #fff; border: 1px solid #e3e3ec; border-radius: 14px;
        padding: 12px; box-shadow: 0 8px 16px rgba(32,25,40,0.06);
      }}
      .bm-img-wrap {{
        position: relative; border-radius: 12px; overflow: hidden;
        cursor: crosshair;
      }}
      .bm-img-wrap img.bm-main-img {{
        display: block; width: 100%; height: auto;
      }}
      /* Region bounding box overlay (real UnSAM bbox or fallback strip) */
      .bm-region-box {{
        position: absolute;
        cursor: pointer; transition: all 0.15s ease;
        display: flex; align-items: flex-start; justify-content: flex-start;
        box-sizing: border-box;
        border-radius: 4px;
      }}
      .bm-region-box:hover {{
        outline: 2px solid rgba(255,255,255,0.9);
        z-index: 10;
      }}
      .bm-region-box.bm-active {{
        outline: 3px solid #fff;
        z-index: 20;
        box-shadow: 0 0 0 2px #111, inset 0 0 0 2000px rgba(255,255,255,0.12);
      }}
      .bm-region-box.bm-linked {{
        outline: 2px dashed #c82828;
        z-index: 15;
      }}
      .bm-box-label {{
        font-size: 11px; font-weight: 700; color: #fff;
        background: rgba(0,0,0,0.7); padding: 2px 6px;
        border-radius: 0 0 6px 0; pointer-events: none;
        white-space: nowrap;
      }}
      .bm-right-panel {{
        display: flex; flex-direction: column; gap: 10px;
      }}
      .bm-tok-section {{
        background: #fff; border: 1px solid #e3e3ec; border-radius: 14px;
        padding: 12px; box-shadow: 0 8px 16px rgba(32,25,40,0.06);
      }}
      .bm-section-title {{
        font-size: 13px; font-weight: 600; color: #555; margin-bottom: 8px;
      }}
      .bm-tok-grid {{
        display: flex; flex-wrap: wrap; gap: 6px;
      }}
      .bm-token {{
        display: inline-flex; align-items: center; justify-content: center;
        padding: 5px 10px; border-radius: 10px; font-size: 13px; font-weight: 600;
        color: #2a2140; border: 1px solid rgba(60,44,80,0.12);
        cursor: pointer; transition: all 0.2s ease;
      }}
      .bm-token:hover {{ box-shadow: 0 4px 8px rgba(0,0,0,0.15); }}
      .bm-token.bm-active {{
        outline: 3px solid #111;
        box-shadow: 0 8px 16px rgba(1,109,1,0.25);
      }}
      .bm-token.bm-linked {{
        outline: 2px solid #016d01;
        box-shadow: 0 4px 10px rgba(1,109,1,0.2);
      }}
      .bm-link-list {{
        display: flex; flex-direction: column; gap: 4px;
        max-height: 200px; overflow-y: auto;
      }}
      .bm-link-row {{
        display: flex; justify-content: space-between; gap: 8px;
        font-size: 12px; color: #3a2f50;
        background: #f8f6ff; border-radius: 8px; padding: 5px 10px;
      }}
      .bm-hint {{ font-size: 12px; color: #888; font-style: italic; }}
      .bm-link-header {{
        font-size: 13px; color: #2d1f4a; padding: 4px 10px;
        background: #eee8ff; border-radius: 8px; margin-bottom: 4px;
      }}
      .bm-legend {{
        display: flex; flex-wrap: wrap; gap: 12px; padding: 8px 12px;
        background: #fff; border: 1px solid #e3e3ec; border-radius: 10px;
        margin-top: 10px; font-size: 11px; color: #444;
      }}
      .bm-legend-item {{
        display: flex; align-items: center; gap: 5px;
      }}
      .bm-legend-swatch {{
        width: 14px; height: 14px; border-radius: 3px; border: 1px solid #ccc;
      }}
      .bm-controls {{
        display: flex; justify-content: space-between; align-items: center;
      }}
      .bm-reset {{
        border: none; background: #eee; border-radius: 999px;
        padding: 4px 12px; font-size: 11px; font-weight: 600;
        color: #555; cursor: pointer;
      }}
      .bm-highlight-canvas {{
        position: absolute; top: 0; left: 0; width: 100%; height: 100%;
        pointer-events: none; z-index: 5;
      }}
      .bm-seg-label {{
        position: absolute; transform: translate(-50%, -50%);
        font-size: 14px; font-weight: 700; color: #fff;
        background: rgba(0,0,0,0.55); padding: 2px 7px;
        border-radius: 4px; pointer-events: none; z-index: 6;
        white-space: nowrap;
      }}
      .bm-seg-label.bm-seg-active {{
        background: rgba(0,229,255,0.85); color: #000;
        box-shadow: 0 0 6px rgba(0,229,255,0.6);
      }}
      .bm-svg {{
        position: absolute; top: 0; left: 0; width: 100%; height: 100%;
        pointer-events: none; z-index: 50;
      }}
      @media (max-width: 900px) {{
        .bm-layout {{ grid-template-columns: 1fr; }}
      }}
    </style>
    <div class="bm-root" id="{view_id}">
      <svg class="bm-svg" xmlns="http://www.w3.org/2000/svg"></svg>
      <div class="bm-title">{escape(title)}</div>
      <div class="bm-layout">
        <div class="bm-img-panel">
          <div class="bm-section-title">Image Regions (click a region to see linked words)</div>
          <div class="bm-img-wrap">
            <img class="bm-main-img" src="{display_img_url}" alt="segmented medical image" />
            <canvas class="bm-highlight-canvas"></canvas>
            {region_overlays_html}
          </div>
        </div>
        <div class="bm-right-panel">
          <div class="bm-tok-section">
            <div class="bm-controls">
              <div class="bm-section-title">Caption Words (click a word to see linked regions)</div>
              <button type="button" class="bm-reset">Reset</button>
            </div>
            <div class="bm-tok-grid">{tokens_html}</div>
          </div>
          <div class="bm-tok-section">
            <div class="bm-section-title">Cross-Modal Links</div>
            <div class="bm-link-list">
              <div class="bm-hint">Click a segment or word to see connections.</div>
            </div>
          </div>
        </div>
      </div>
      <div class="bm-legend">
        <strong>Legend ({escape(method_label)}):</strong>
        {legend_html}
      </div>
      <img class="bm-loader" id="{loader_id}" alt=""
        src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw=="
        onload="(function(){{var s=document.getElementById('{script_id}');
        if(!s||!s.textContent){{return;}}try{{(new Function(s.textContent))();}}catch(e){{
        console.warn('bm interaction init failed',e);}}}})()"/>
      <script type="text/plain" id="{script_id}">{js_code}</script>
    </div>
    """