"""
ISLES 病灶檢視（Gradio）
- 上傳 DWI / ADC / MSK (NIfTI)／切片疊圖／結構化報告
- Hugging Face Spaces：app_file 設為本檔；根目錄放 requirements.txt（須含 pydantic==2.10.6）
- 本機：python app.py
"""

from __future__ import annotations

import html as html_module
import json
import os
import tempfile
from datetime import datetime
from pathlib import Path

import gradio as gr
import nibabel as nib
import numpy as np
from PIL import Image
from scipy import ndimage

_ROOT = Path(__file__).resolve().parent
_APP_VERSION = "1.1"
_HAS_GRADIO_TIMER = hasattr(gr, "Timer")
_TIMER_INTERVAL_SEC = 0.25
_FALLBACK_INTERVAL_MS = int(_TIMER_INTERVAL_SEC * 1000)


# ---------------------------------------------------------------------------
# 資料路徑 / 載入
# ---------------------------------------------------------------------------
def default_isles_paths() -> tuple[Path, Path, Path]:
    dwi = _ROOT / "dwi.nii.gz"
    adc = _ROOT / "adc.nii.gz"
    msk = _ROOT / "msk.nii.gz"
    return dwi, adc, msk


def default_paths_exist() -> bool:
    return all(p.exists() for p in default_isles_paths())


def _resolve_file_path(f) -> str | None:
    if f is None:
        return None
    if isinstance(f, (str, Path)):
        return str(f)
    name = getattr(f, "name", None)
    if name:
        return str(name)
    return str(f)


def _load_vol(path: str | Path | None) -> tuple[np.ndarray, np.ndarray]:
    if not path:
        raise ValueError("缺少檔案路徑")
    path = str(path)
    img = nib.load(path)
    data = img.get_fdata()
    if data.ndim == 4:
        data = data[..., 0]
    return data.astype(np.float32), np.array(img.header.get_zooms()[:3], dtype=np.float32)


# ---------------------------------------------------------------------------
# 影像處理
# ---------------------------------------------------------------------------
def _norm_u8(v: np.ndarray) -> np.ndarray:
    lo = np.percentile(v, 1)
    hi = np.percentile(v, 99)
    if hi <= lo:
        hi = lo + 1e-6
    x = np.clip((v - lo) / (hi - lo), 0, 1)
    return (x * 255).astype(np.uint8)


def _overlay(base: np.ndarray, mask: np.ndarray, alpha: float = 0.5) -> np.ndarray:
    base_u8 = _norm_u8(base)
    rgb = np.stack([base_u8, base_u8, base_u8], axis=-1).astype(np.float32)
    lesion = mask > 0
    rgb[lesion, 0] = (1 - alpha) * rgb[lesion, 0] + alpha * 255
    rgb[lesion, 1] = (1 - alpha) * rgb[lesion, 1]
    rgb[lesion, 2] = (1 - alpha) * rgb[lesion, 2]
    return rgb.astype(np.uint8)


def _slice_img(vol: np.ndarray, z: int) -> np.ndarray:
    return np.flipud(vol[:, :, z].T)


# ---------------------------------------------------------------------------
# 量化統計
# ---------------------------------------------------------------------------
def _intensity_summary(vol: np.ndarray, mask: np.ndarray) -> dict:
    vals = vol[mask > 0]
    vals = vals[np.isfinite(vals)]
    if vals.size == 0:
        return {}
    return {
        "mean": round(float(np.mean(vals)), 4),
        "std": round(float(np.std(vals)), 4),
        "min": round(float(np.min(vals)), 4),
        "max": round(float(np.max(vals)), 4),
        "p5": round(float(np.percentile(vals, 5)), 4),
        "p25": round(float(np.percentile(vals, 25)), 4),
        "p50": round(float(np.percentile(vals, 50)), 4),
        "p75": round(float(np.percentile(vals, 75)), 4),
        "p95": round(float(np.percentile(vals, 95)), 4),
    }


def _connected_lesion_stats(msk_bin: np.ndarray) -> dict:
    if int(msk_bin.sum()) == 0:
        return {
            "n_components_6_connected": 0,
            "largest_component_voxels": 0,
            "largest_component_volume_ml": 0.0,
        }
    struct = ndimage.generate_binary_structure(3, 1)
    labeled, nfeat = ndimage.label(msk_bin.astype(bool), structure=struct)
    if nfeat == 0:
        return {
            "n_components_6_connected": 0,
            "largest_component_voxels": 0,
            "largest_component_volume_ml": 0.0,
        }
    counts = np.bincount(labeled.ravel())
    comp_sizes = counts[1:] if len(counts) > 1 else np.array([], dtype=int)
    largest = int(comp_sizes.max()) if comp_sizes.size else 0
    return {
        "n_components_6_connected": int(nfeat),
        "largest_component_voxels": largest,
        "largest_component_volume_ml": 0.0,
    }


def _hemisphere_split_along_axis0(msk_bin: np.ndarray) -> dict:
    nx = msk_bin.shape[0]
    mid = nx // 2
    low = int(msk_bin[:mid, :, :].sum())
    high = int(msk_bin[mid:, :, :].sum())
    total = low + high
    if total == 0:
        dom = "none"
    elif low >= high * 1.2:
        dom = "low_index_half"
    elif high >= low * 1.2:
        dom = "high_index_half"
    else:
        dom = "bilateral"
    return {
        "note_zh": "依資料陣列第 0 維中線切分，非直接等同解剖學左/右；臨床解讀請對照影像方向與 affine。",
        "low_index_half_voxels": low,
        "high_index_half_voxels": high,
        "low_index_fraction": round(low / total, 4) if total else 0.0,
        "high_index_fraction": round(high / total, 4) if total else 0.0,
        "dominant": dom,
    }


_DOM_LABEL_ZH = {
    "none": "無病灶",
    "low_index_half": "低索引半側為主",
    "high_index_half": "高索引半側為主",
    "bilateral": "雙側相近",
}


# ---------------------------------------------------------------------------
# HTML 呈現
# ---------------------------------------------------------------------------
def _metric_card(label: str, value: str, sub: str = "") -> str:
    sub_html = f'<div class="metric-sub">{sub}</div>' if sub else ""
    return (
        f'<div class="metric-card">'
        f'<div class="metric-label">{html_module.escape(label)}</div>'
        f'<div class="metric-value">{value}</div>{sub_html}</div>'
    )


def _intensity_table(title: str, d: dict) -> str:
    if not d:
        return (
            f'<div class="intensity-panel"><h4 class="intensity-title">'
            f'{html_module.escape(title)}</h4><p class="intensity-empty">無病灶體素</p></div>'
        )
    rows = "".join(
        f"<tr><td>{html_module.escape(k)}</td><td>{v}</td></tr>"
        for k, v in [
            ("mean", d.get("mean")),
            ("std", d.get("std")),
            ("min", d.get("min")),
            ("max", d.get("max")),
            ("p5 / p50 / p95", f"{d.get('p5')} / {d.get('p50')} / {d.get('p95')}"),
        ]
    )
    return (
        f'<div class="intensity-panel">'
        f'<h4 class="intensity-title">{html_module.escape(title)}</h4>'
        f'<table class="intensity-table"><tbody>{rows}</tbody></table></div>'
    )


def _format_metrics_html(report: dict) -> str:
    lv = report.get("lesion_volume_ml", 0)
    sr = report.get("lesion_slice_range", {})
    cc = report.get("connected_lesions", {})
    hem = report.get("hemisphere_along_axis0", {})
    dwi_s = report.get("dwi_in_lesion", {})
    adc_s = report.get("adc_in_lesion", {})
    dom_key = hem.get("dominant", "none")
    dom_zh = _DOM_LABEL_ZH.get(dom_key, html_module.escape(str(dom_key)))

    if sr.get("z_min") is not None:
        slice_range_sub = f"共 {sr.get('n_slices_with_lesion', 0)} 張切片含病灶"
        slice_card = _metric_card(
            "病灶 Z 範圍（索引）",
            f"{sr['z_min']} – {sr['z_max']}",
            slice_range_sub,
        )
    else:
        slice_card = _metric_card("病灶 Z 範圍（索引）", "—", "無病灶")

    cards = [
        _metric_card(
            "病灶體積",
            f'{lv} <span class="unit">mL</span>',
            f"{report.get('lesion_voxels', 0)} voxels",
        ),
        slice_card,
        _metric_card(
            "連通病灶數（3D 六鄰域）",
            str(cc.get("n_components_6_connected", 0)),
            "獨立連通域個數",
        ),
        _metric_card(
            "最大病灶切面（Z）",
            str(report.get("largest_lesion_slice_z", 0)),
            f"該層面積 {report.get('largest_lesion_slice_area_voxels', 0)} voxels",
        ),
        _metric_card(
            "最大連通塊",
            f'{cc.get("largest_component_volume_ml", 0)} <span class="unit">mL</span>',
            f"{cc.get('largest_component_voxels', 0)} voxels",
        ),
        _metric_card(
            "半側分布（第 0 維）",
            dom_zh,
            f"低 {hem.get('low_index_half_voxels', 0)} / 高 {hem.get('high_index_half_voxels', 0)} voxels",
        ),
    ]

    note = html_module.escape(hem.get("note_zh", ""))
    return (
        '<div class="metrics-wrap">'
        '<h3 class="metrics-heading">量化摘要</h3>'
        f'<div class="metric-grid">{"".join(cards)}</div>'
        '<div class="intensity-row">'
        f'{_intensity_table("DWI（病灶內）", dwi_s)}'
        f'{_intensity_table("ADC（病灶內）", adc_s)}'
        "</div>"
        f'<p class="metrics-footnote">{note}</p>'
        "</div>"
    )


# ---------------------------------------------------------------------------
# 主流程
# ---------------------------------------------------------------------------
def prepare_case(dwi_file, adc_file, msk_file):
    p_dwi = _resolve_file_path(dwi_file)
    p_adc = _resolve_file_path(adc_file)
    p_msk = _resolve_file_path(msk_file)
    dwi, zooms = _load_vol(p_dwi)
    adc, _ = _load_vol(p_adc)
    msk, _ = _load_vol(p_msk)

    if dwi.shape != adc.shape or dwi.shape != msk.shape:
        raise gr.Error(f"shape 不一致: dwi={dwi.shape}, adc={adc.shape}, msk={msk.shape}")

    msk_bin = (msk > 0).astype(np.uint8)
    n_slices = int(dwi.shape[2])
    lesion_vox = int(msk_bin.sum())
    voxel_ml = float(np.prod(zooms) / 1000.0)
    lesion_ml = lesion_vox * voxel_ml
    lesion_slices = int((msk_bin.sum(axis=(0, 1)) > 0).sum())

    z_per_slice = msk_bin.sum(axis=(0, 1)).astype(np.int64)
    z_with = np.flatnonzero(z_per_slice > 0)
    if z_with.size > 0:
        z_min = int(z_with[0])
        z_max = int(z_with[-1])
    else:
        z_min = None
        z_max = None

    cc_stats = _connected_lesion_stats(msk_bin)
    cc_stats["largest_component_volume_ml"] = round(
        float(cc_stats["largest_component_voxels"]) * voxel_ml, 4
    )

    report = {
        "timestamp": datetime.now().isoformat(timespec="seconds"),
        "shape": [int(dwi.shape[0]), int(dwi.shape[1]), int(dwi.shape[2])],
        "voxel_spacing_mm": [float(zooms[0]), float(zooms[1]), float(zooms[2])],
        "lesion_voxels": lesion_vox,
        "lesion_volume_ml": round(float(lesion_ml), 4),
        "lesion_slices": lesion_slices,
        "lesion_slice_range": {
            "z_min": z_min,
            "z_max": z_max,
            "n_slices_with_lesion": int(z_with.size),
        },
        "connected_lesions": {
            "connectivity": "6-neighborhood_3D",
            "n_components_6_connected": cc_stats["n_components_6_connected"],
            "largest_component_voxels": cc_stats["largest_component_voxels"],
            "largest_component_volume_ml": cc_stats["largest_component_volume_ml"],
        },
        "hemisphere_along_axis0": _hemisphere_split_along_axis0(msk_bin),
        "dwi_in_lesion": _intensity_summary(dwi, msk_bin),
        "adc_in_lesion": _intensity_summary(adc, msk_bin),
        "dwi_mean_in_lesion": float(dwi[msk_bin > 0].mean()) if lesion_vox > 0 else 0.0,
        "adc_mean_in_lesion": float(adc[msk_bin > 0].mean()) if lesion_vox > 0 else 0.0,
    }

    state = {"dwi": dwi, "adc": adc, "msk": msk_bin, "n_slices": n_slices, "report": report}

    if lesion_vox > 0:
        z0 = int(np.argmax(z_per_slice))
    else:
        z0 = 0
    report["default_slice_z"] = z0
    report["largest_lesion_slice_z"] = z0
    report["largest_lesion_slice_area_voxels"] = int(z_per_slice[z0]) if lesion_vox > 0 else 0

    first_dwi = Image.fromarray(_overlay(_slice_img(dwi, z0), _slice_img(msk_bin, z0)))
    first_adc = Image.fromarray(_overlay(_slice_img(adc, z0), _slice_img(msk_bin, z0)))
    report_pretty = json.dumps(report, ensure_ascii=False, indent=2)
    metrics_html = _format_metrics_html(report)

    tmp = Path(tempfile.gettempdir()) / f"report_isles_{datetime.now().strftime('%Y%m%d%H%M%S')}.json"
    tmp.write_text(report_pretty, encoding="utf-8")
    return (
        state,
        gr.update(minimum=0, maximum=n_slices - 1, value=z0, step=1, interactive=True),
        first_dwi,
        first_adc,
        metrics_html,
        report_pretty,
        str(tmp),
    )


def update_slice(z, state):
    if not state:
        raise gr.Error("請先按「執行分析並產生報告」")
    z = int(z)
    dwi = state["dwi"]
    adc = state["adc"]
    msk = state["msk"]
    dwi_img = Image.fromarray(_overlay(_slice_img(dwi, z), _slice_img(msk, z)))
    adc_img = Image.fromarray(_overlay(_slice_img(adc, z), _slice_img(msk, z)))
    return dwi_img, adc_img


def tick_advance_slice(z, state):
    if not state:
        return gr.update(), gr.update(), gr.update()
    n = int(state["n_slices"])
    if n <= 1:
        return gr.update(), gr.update(), gr.update()
    z_cur = int(z) if z is not None else 0
    z_next = (z_cur + 1) % n
    dwi = state["dwi"]
    adc = state["adc"]
    msk = state["msk"]
    dwi_pil = Image.fromarray(_overlay(_slice_img(dwi, z_next), _slice_img(msk, z_next)))
    adc_pil = Image.fromarray(_overlay(_slice_img(adc, z_next), _slice_img(msk, z_next)))
    return z_next, dwi_pil, adc_pil


def prepare_case_stop_timer(dwi_file, adc_file, msk_file):
    out = prepare_case(dwi_file, adc_file, msk_file)
    if _HAS_GRADIO_TIMER:
        return (*out, gr.Timer(_TIMER_INTERVAL_SEC, active=False))
    return out


def prepare_default_case():
    if not default_paths_exist():
        raise gr.Error("找不到檔案（dwi.nii.gz、adc.nii.gz、msk.nii.gz）。")
    dwi_def, adc_def, msk_def = default_isles_paths()
    return prepare_case(str(dwi_def), str(adc_def), str(msk_def))


def prepare_default_case_stop_timer():
    out = prepare_default_case()
    if _HAS_GRADIO_TIMER:
        return (*out, gr.Timer(_TIMER_INTERVAL_SEC, active=False))
    return out


def _js_clear_fallback_autoplay() -> str:
    return """
() => {
  if (window.__islesAutoplayId) {
    clearInterval(window.__islesAutoplayId);
    window.__islesAutoplayId = null;
  }
}
""".strip()


def _js_start_fallback_autoplay(interval_ms: int) -> str:
    return f"""
() => {{
  if (window.__islesAutoplayId) {{
    clearInterval(window.__islesAutoplayId);
    window.__islesAutoplayId = null;
  }}
  const pickSlider = () => {{
    const sliders = Array.from(document.querySelectorAll('input[type="range"]'));
    for (const s of sliders) {{
      const max = Number(s.max ?? '0');
      if (!Number.isNaN(max) && max > 0) return s;
    }}
    return sliders[0] || null;
  }};
  const stepOnce = () => {{
    const slider = pickSlider();
    if (!slider) return;
    const min = Number(slider.min ?? '0');
    const max = Number(slider.max ?? '0');
    if (Number.isNaN(max) || max <= min) return;
    const cur = Number(slider.value ?? String(min));
    const next = cur >= max ? min : (cur + 1);
    slider.value = String(next);
    slider.dispatchEvent(new Event('input', {{ bubbles: true }}));
    slider.dispatchEvent(new Event('change', {{ bubbles: true }}));
  }};
  window.__islesAutoplayId = setInterval(stepOnce, {interval_ms});
}}
""".strip()


_METRICS_PLACEHOLDER_HTML = """
<div class="metrics-placeholder">
  <span class="ph-dot"></span>
  <p>請上傳 NIfTI 後，點選 <strong>執行分析並產生報告</strong></p>
  <p class="ph-hint">紅色疊圖為病灶標註（mask）與 DWI／ADC 之 overlay</p>
</div>
"""

_APP_CSS = """
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;600;700&display=swap');

:root {
  --cl-bg: #ffffff;
  --cl-surface: #e5e7eb;
  --cl-elevated: #d9dde3;
  --cl-border: #cfd5dd;
  --cl-text: #1f2937;
  --cl-muted: #6b7280;
  --cl-accent: #f97316;
  --cl-accent-soft: rgba(249, 115, 22, 0.12);
  --cl-lesion: #f87171;
  --cl-radius: 10px;
  --cl-font: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", ui-sans-serif, system-ui, sans-serif;
}

.gradio-container {
  font-family: var(--cl-font) !important;
  max-width: 1440px !important;
  margin: 0 auto !important;
  background: var(--cl-bg) !important;
}

.gradio-container .contain {
  padding: 0 1.25rem 2rem !important;
}

.app-header {
  background: linear-gradient(180deg, #f3f4f6 0%, #eceff3 55%, var(--cl-surface) 100%);
  border: 1px solid var(--cl-border);
  border-radius: var(--cl-radius);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
  box-shadow: 0 4px 18px rgba(15,23,42,0.08);
}
.app-header-top {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
}
.app-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--cl-accent);
  letter-spacing: 0.02em;
}
.app-badge {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--cl-accent);
  background: var(--cl-accent-soft);
  border: 1px solid rgba(59,130,246,0.35);
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
}
.app-desc {
  margin: 0.65rem 0 0;
  font-size: 0.95rem;
  color: var(--cl-muted);
  line-height: 1.55;
  max-width: 66rem;
}
.app-disclaimer {
  margin-top: 0.5rem;
  font-size: 0.78rem;
  color: var(--cl-muted);
  opacity: 0.9;
}

.panel-card {
  background: var(--cl-surface) !important;
  border: 1px solid var(--cl-border) !important;
  border-radius: var(--cl-radius) !important;
  padding: 1rem 1.25rem !important;
  margin-bottom: 1rem !important;
}
.panel-card label, .panel-card .label-wrap span {
  font-weight: 500 !important;
  color: var(--cl-muted) !important;
  font-size: 0.82rem !important;
}
.upload-compact {
  min-height: 40px !important;
}
.upload-compact [data-testid="file-upload"] {
  min-height: 42px !important;
  padding: 6px 8px !important;
}
.upload-compact button {
  min-height: 30px !important;
  height: 30px !important;
  font-size: 0.78rem !important;
}

.primary-cta button {
  min-height: 44px !important;
  font-weight: 600 !important;
  border-radius: 8px !important;
}

.viewer-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}
.viewer-playback {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--cl-elevated);
  border: 1px solid var(--cl-border);
  border-radius: 999px;
  padding: 4px 8px;
}
.viewer-slider-wrap {
  min-width: 300px;
}
.viewer-slider-wrap [data-testid="block-label"] {
  display: none !important;
}
.viewer-slider-wrap input[type="range"] {
  accent-color: var(--cl-accent);
}
.legend-bar {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--cl-muted);
}
.legend-swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  background: var(--cl-lesion);
  box-shadow: 0 0 0 1px rgba(255,255,255,0.15);
}

#slice-viewer-row {
  flex-wrap: nowrap !important;
  gap: 14px !important;
  width: 100% !important;
  min-height: min(76vh, 880px) !important;
}
#slice-viewer-row > div:nth-child(1),
#slice-viewer-row > div:nth-child(2) {
  flex: 1 1 50% !important;
  min-width: 0 !important;
  background: var(--cl-elevated) !important;
  border: 1px solid var(--cl-border) !important;
  border-radius: var(--cl-radius) !important;
  overflow: hidden !important;
}
.playback-hint {
  font-size: 0.72rem !important;
  color: var(--cl-muted) !important;
  line-height: 1.45 !important;
  margin-top: 10px !important;
}
.playback-mini-btn button {
  min-height: 26px !important;
  height: 26px !important;
  padding: 0 8px !important;
  font-size: 0.75rem !important;
  font-weight: 600 !important;
  border-radius: 999px !important;
}
#slice-viewer-row .image-container,
#slice-viewer-row .image-frame,
#slice-viewer-row .wrap,
#slice-viewer-row [data-testid="image"] {
  width: 100% !important;
  min-height: min(70vh, 800px) !important;
  max-height: min(76vh, 880px) !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  background: #000000 !important;
}
#slice-viewer-row img {
  width: 100% !important;
  height: 100% !important;
  max-height: min(76vh, 880px) !important;
  object-fit: contain !important;
  background: #000000 !important;
}
#slice-viewer-row canvas,
#slice-viewer-row .empty,
#slice-viewer-row [data-testid="image"] > div,
#slice-viewer-row [data-testid="image"] > div > div {
  background: #000000 !important;
}
#slice-viewer-row *,
#slice-viewer-row img,
#slice-viewer-row canvas {
  transition: none !important;
  animation: none !important;
}

.metrics-wrap {
  background: var(--cl-surface);
  border: 1px solid var(--cl-border);
  border-radius: var(--cl-radius);
  padding: 1.25rem 1.35rem;
  margin: 1rem 0;
}
.metrics-heading {
  margin: 0 0 1rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--cl-text);
  letter-spacing: 0.04em;
}
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
}
.metric-card {
  background: var(--cl-elevated);
  border: 1px solid var(--cl-border);
  border-radius: 8px;
  padding: 12px 14px;
}
.metric-label {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--cl-muted);
  margin-bottom: 6px;
}
.metric-value {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--cl-text);
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}
.metric-value .unit {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--cl-muted);
  margin-left: 2px;
}
.metric-sub {
  font-size: 0.78rem;
  color: var(--cl-muted);
  margin-top: 6px;
}
.intensity-row {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
  margin-top: 1rem;
}
.intensity-panel {
  background: var(--cl-elevated);
  border: 1px solid var(--cl-border);
  border-radius: 8px;
  padding: 12px 14px;
}
.intensity-title {
  margin: 0 0 10px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--cl-text);
}
.intensity-empty { margin: 0; font-size: 0.85rem; color: var(--cl-muted); }
.intensity-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  color: var(--cl-text);
}
.intensity-table td {
  padding: 6px 8px;
  border-bottom: 1px solid var(--cl-border);
}
.intensity-table td:first-child {
  color: var(--cl-muted);
  width: 42%;
}
.metrics-footnote {
  margin: 1rem 0 0;
  font-size: 0.75rem;
  color: var(--cl-muted);
  line-height: 1.5;
}

.metrics-placeholder {
  text-align: center;
  padding: 2.5rem 1.5rem;
  background: var(--cl-surface);
  border: 1px dashed var(--cl-border);
  border-radius: var(--cl-radius);
  color: var(--cl-muted);
}
.metrics-placeholder .ph-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--cl-accent);
  border-radius: 50%;
  margin-bottom: 0.75rem;
  box-shadow: 0 0 12px var(--cl-accent);
}
.metrics-placeholder p { margin: 0.35rem 0; font-size: 0.9rem; color: var(--cl-text); }
.metrics-placeholder .ph-hint { font-size: 0.8rem !important; color: var(--cl-muted) !important; }

.report-accordion {
  border: 1px solid var(--cl-border) !important;
  border-radius: var(--cl-radius) !important;
  overflow: hidden;
  margin-top: 0.5rem;
}

.app-footer {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--cl-border);
  font-size: 0.72rem;
  color: var(--cl-muted);
  line-height: 1.5;
}
"""

try:
    _APP_THEME = gr.themes.Soft(
        primary_hue=gr.themes.colors.blue,
        neutral_hue=gr.themes.colors.slate,
        font=("ui-sans-serif", "system-ui", "Segoe UI", "Microsoft JhengHei", "PingFang TC", "sans-serif"),
    )
except Exception:
    _APP_THEME = None


# ---------------------------------------------------------------------------
# 介面組裝 — css / theme 都放在 Blocks（不是 launch）
# ---------------------------------------------------------------------------
_blocks_kw: dict = {"title": "ISLES 病灶檢視與量化", "css": _APP_CSS}
if _APP_THEME is not None:
    _blocks_kw["theme"] = _APP_THEME

with gr.Blocks(**_blocks_kw) as app_ui:
    gr.HTML(
        f"""
        <header class="app-header">
          <div class="app-header-top">
            <span class="app-title">ISLES 病灶檢視與量化</span>
            <span class="app-badge">Report schema v1 · UI {_APP_VERSION}</span>
          </div>
          <p class="app-desc">
            本介面提供 ISLES 影像（DWI／ADC）與病灶標註（Mask）之視覺化檢閱，支援切片同步瀏覽、連續播放與量化摘要輸出，適用於研究與教學示範。
          </p>
          <p class="app-disclaimer">本介面僅供研究與演算法展示；非醫療器材，不取代醫師判讀。</p>
        </header>
        """
    )

    state = gr.State()

    with gr.Column(elem_classes=["panel-card"]):
        gr.Markdown("#### 資料載入")
        with gr.Row():
            dwi_file = gr.File(label="DWI", file_types=[".nii", ".gz"], elem_classes=["upload-compact"])
            adc_file = gr.File(label="ADC", file_types=[".nii", ".gz"], elem_classes=["upload-compact"])
            msk_file = gr.File(label="病灶標註 Mask", file_types=[".nii", ".gz"], elem_classes=["upload-compact"])
        run_btn = gr.Button("執行分析並產生報告", variant="primary", elem_classes=["primary-cta"])

    with gr.Column(elem_classes=["panel-card"]):
        gr.Markdown("#### 切片檢視")
        gr.HTML(
            """
            <div class="viewer-toolbar">
              <div style="display:flex;align-items:center;gap:12px;flex-wrap:wrap;">
                <div class="legend-bar">
                  <span class="legend-swatch" title="病灶"></span>
                  <span>疊圖：病灶標註（紅）</span>
                </div>
                <div class="viewer-playback">
                  <span style="font-size:12px;color:#6b7280;">播放</span>
                </div>
              </div>
            </div>
            """
        )
        with gr.Row(equal_height=True):
            with gr.Column(scale=0, min_width=190):
                play_slice_btn = gr.Button("▶ 播放", interactive=True, elem_classes=["playback-mini-btn"])
            with gr.Column(scale=0, min_width=190):
                pause_slice_btn = gr.Button("⏸ 暫停", interactive=True, elem_classes=["playback-mini-btn"])
            with gr.Column(scale=3, elem_classes=["viewer-slider-wrap"]):
                slice_slider = gr.Slider(
                    label="軸向切片（Z 索引）",
                    minimum=0,
                    maximum=0,
                    value=0,
                    step=1,
                    interactive=False,
                )
        with gr.Row(equal_height=True, elem_id="slice-viewer-row"):
            dwi_img = gr.Image(label="DWI · 病灶疊圖", type="pil", height=820, show_label=True)
            adc_img = gr.Image(label="ADC · 病灶疊圖", type="pil", height=820, show_label=True)
        gr.HTML(
            f"""
            <p class="playback-hint">
              每 <strong>{_TIMER_INTERVAL_SEC}</strong> 秒切一張，Z 循環（末尾後回到 0）。
              重新執行分析會自動暫停。
            </p>
            """
            + (
                ""
                if _HAS_GRADIO_TIMER
                else '<p class="playback-hint" style="color:#f59e0b;margin-top:8px;">'
                "目前環境未啟用 <code>gr.Timer</code>，已改用前端自動步進 fallback。</p>"
            )
        )

    if _HAS_GRADIO_TIMER:
        slice_timer = gr.Timer(_TIMER_INTERVAL_SEC, active=False)
    else:
        slice_timer = None

    metrics_html = gr.HTML(value=_METRICS_PLACEHOLDER_HTML)

    with gr.Accordion("結構化報告（JSON）", open=False, elem_classes=["report-accordion"]):
        report_box = gr.Code(label="預覽", language="json")
        report_file = gr.File(label="下載 report.json")

    gr.HTML(
        """
        <footer class="app-footer">
          半側分布係依影像陣列第 0 維中線切分，與解剖學左／右之對應請依實際影像方向與 affine 確認。
        </footer>
        """
    )

    _run_outputs = [state, slice_slider, dwi_img, adc_img, metrics_html, report_box, report_file]
    if slice_timer is not None:
        _run_outputs.append(slice_timer)

    _run_fn = prepare_case_stop_timer if slice_timer is not None else prepare_case
    _load_fn = prepare_default_case_stop_timer if slice_timer is not None else prepare_default_case

    run_btn.click(
        fn=_run_fn,
        inputs=[dwi_file, adc_file, msk_file],
        outputs=_run_outputs,
        js=_js_clear_fallback_autoplay(),
    )
    slice_slider.change(
        fn=update_slice,
        inputs=[slice_slider, state],
        outputs=[dwi_img, adc_img],
        queue=False,
        show_progress="hidden",
    )

    if slice_timer is not None:
        slice_timer.tick(
            fn=tick_advance_slice,
            inputs=[slice_slider, state],
            outputs=[slice_slider, dwi_img, adc_img],
            queue=False,
            show_progress="hidden",
        )
        play_slice_btn.click(lambda: gr.Timer(_TIMER_INTERVAL_SEC, active=True), None, slice_timer)
        pause_slice_btn.click(lambda: gr.Timer(_TIMER_INTERVAL_SEC, active=False), None, slice_timer)
    else:
        play_slice_btn.click(fn=None, inputs=None, outputs=None, js=_js_start_fallback_autoplay(_FALLBACK_INTERVAL_MS))
        pause_slice_btn.click(fn=None, inputs=None, outputs=None, js=_js_clear_fallback_autoplay())

    app_ui.load(fn=_load_fn, outputs=_run_outputs)


# ---------------------------------------------------------------------------
# 啟動 — HF Spaces / Docker 需 0.0.0.0；requirements 須 pin pydantic==2.10.6
# ---------------------------------------------------------------------------
def main() -> None:
    # 避免 Gradio 對 127.0.0.1 做啟動探測失敗（HF / 容器常見）
    os.environ.setdefault("GRADIO_SERVER_NAME", "0.0.0.0")
    port = int(os.environ.get("PORT", "7860"))
    app_ui.launch(
        server_name="0.0.0.0",
        server_port=port,
        show_error=True,
        show_api=False,
        inbrowser=False,
    )


if __name__ == "__main__":
    main()