const app = {
  token: localStorage.getItem("pacs_web_token") || "",
  user: null,
  studies: [],
  study: null,
  series: [],
  activeSeries: null,
  draft: null,
  slice: 0,
  plane: "axial",
  window: "default",
  rotate: 0,
  zoom: 1,
  panX: 0,
  panY: 0,
  imageUrl: "",
  searchTimer: null,
  statusTimer: null,
  saveTimer: null,
  savePromise: null,
  savingSeriesUid: "",
  draftVersion: 0,
  dirty: false,
  saving: false,
  pendingImage: null,
  drag: null,
  studySortField: "modified",
  studySortDir: "desc",
  studyFilter: "all",
  studyPartFilter: "all",
  exportDialog: { ctNumber: "", series: [] },
  aiEnabled: true,
  seriesSortField: "time",
  seriesSortDir: "asc",
  showOverlay: true,
  thumbUrls: new Map(),
  imageCache: new Map(),
  thumbObserver: null,
  thumbSeries: new WeakMap(),
};

const $ = (id) => document.getElementById(id);
const clamp = (value, min, max) => Math.max(min, Math.min(max, value));
const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
const BODY_PARTS = ["head_neck", "chest", "upper_abdomen", "abdomen_pelvis"];
const WINDOW_PRESETS = {
  bone: { wl: 500, ww: 1800 },
  soft: { wl: 50, ww: 360 },
  contrast: { wl: 90, ww: 140 },
};

function escapeHtml(value) {
  return String(value ?? "")
    .replaceAll("&", "&")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;")
    .replaceAll("'", "&#039;");
}

async function request(path, options = {}) {
  const headers = { ...(options.headers || {}) };
  if (app.token) headers.Authorization = `Bearer ${app.token}`;
  if (options.body) headers["Content-Type"] = "application/json";
  const res = await fetch(path, { ...options, headers });
  if (res.status === 401) {
    showLogin(true);
    throw new Error("unauthorized");
  }
  if (!res.ok) {
    let detail = res.statusText;
    try {
      const data = await res.json();
      detail = data.detail || detail;
    } catch (_) {
      detail = await res.text();
    }
    throw new Error(detail);
  }
  return res;
}

async function json(path, options = {}) {
  const res = await request(path, options);
  return res.json();
}

function showLogin(show) {
  $("loginOverlay").classList.toggle("hidden", !show);
}

function fmtDate(value) {
  const text = String(value || "");
  if (text.length !== 8) return text;
  return `${text.slice(0, 4)}-${text.slice(4, 6)}-${text.slice(6, 8)}`;
}

function fmtTime(value) {
  const digits = String(value || "").replace(/\D/g, "").slice(0, 6);
  if (digits.length < 6) return value || "";
  return `${digits.slice(0, 2)}:${digits.slice(2, 4)}:${digits.slice(4, 6)}`;
}

function timeRange(series) {
  const first = fmtTime(series.first_time || series.series_time || series.study_time);
  const last = fmtTime(series.last_time);
  if (first && last && first !== last) return `${first}-${last}`;
  return first || last || "未记录";
}

function timeKey(series) {
  return String(series.first_time || series.series_time || series.study_time || "").replace(/\D/g, "").padEnd(6, "0");
}

function studyTimeKey(study) {
  const date = String(study.study_date || "").replace(/\D/g, "").padEnd(8, "0");
  const time = String(study.study_time || "").replace(/\D/g, "").slice(0, 6).padEnd(6, "0");
  return `${date}${time}`;
}

function studyModifiedKey(study) {
  const raw = String(study.modified_at || study.annotation_updated_at || study.completion_updated_at || study.completed_at || "");
  return raw ? raw.replace(/\D/g, "").padEnd(14, "0") : studyTimeKey(study);
}

function sortArrow(direction) {
  return direction === "asc" ? "↑" : "↓";
}

function phaseLabel(value) {
  return { plain: "平扫", arterial: "动脉期", portal_venous: "门静脉期", delayed: "延迟期", unknown: "无法判别" }[value] || "";
}

function chestWindowLabel(value) {
  return { lung: "肺窗", mediastinal: "纵隔窗", unknown: "无法判别" }[value] || "";
}

function partLabel(value) {
  return {
    head_neck: "头颈部",
    chest: "胸部",
    upper_abdomen: "上腹部",
    abdomen_pelvis: "腹盆部",
  }[value] || value;
}

function asList(value) {
  return Array.isArray(value) ? value : [];
}

function uniq(list) {
  return Array.from(new Set(list.filter(Boolean)));
}

function parseFirstNumber(value) {
  const match = String(value || "").match(/-?\d+(\.\d+)?/);
  return match ? Number(match[0]) : null;
}

function ageText(birthDate, studyDate) {
  const birth = String(birthDate || "");
  const study = String(studyDate || "");
  if (birth.length !== 8 || study.length !== 8) return "";
  let age = Number(study.slice(0, 4)) - Number(birth.slice(0, 4));
  if (study.slice(4) < birth.slice(4)) age -= 1;
  return age > 0 ? `${age}Y` : "";
}

async function login(event) {
  event.preventDefault();
  $("loginError").textContent = "";
  try {
    const data = await json("/api/auth/login", {
      method: "POST",
      body: JSON.stringify({ username: $("username").value, password: $("password").value }),
    });
    app.token = data.token;
    app.user = { username: data.username, role: data.role };
    localStorage.setItem("pacs_web_token", app.token);
    applyPermissions();
    showLogin(false);
    await boot();
  } catch (_) {
    $("loginError").textContent = "登录失败";
  }
}

async function logout() {
  if (!(await confirmSaveIfDirty())) return;
  app.token = "";
  app.user = null;
  localStorage.removeItem("pacs_web_token");
  applyPermissions();
  showViewerPage(false);
  showLogin(true);
}

async function loadCurrentUser() {
  if (!app.token) return;
  app.user = await json("/api/auth/me");
  applyPermissions();
}

function isAdmin() {
  return app.user?.role === "管理员";
}

function applyPermissions() {
  $("settingsBtn").classList.toggle("hidden", !isAdmin());
  if (!isAdmin()) $("exportModal").classList.add("hidden");
}

async function refreshStatus() {
  try {
    const data = await fetch("/api/status").then((res) => res.json());
    const pill = $("dbStatus");
    pill.textContent = data.database?.ok ? `数据库 ${data.database.rows ?? ""}` : "数据库异常";
    pill.title = data.database?.message || "";
    pill.classList.toggle("offline", !data.database?.ok);
    pill.classList.toggle("online", Boolean(data.database?.ok));
    app.aiEnabled = Boolean(data.ai?.enabled && data.ai?.configured);
    $("aiClassify").disabled = !app.aiEnabled;
    $("aiClassify").title = app.aiEnabled ? "" : "AI 功能未启用或未配置";
  } catch (_) {
    $("dbStatus").textContent = "数据库异常";
    $("dbStatus").classList.add("offline");
    $("dbStatus").classList.remove("online");
  }
}

function sortSeries(list) {
  return [...list].sort((a, b) => {
    const skipA = a.annotation?.skipped ? 1 : 0;
    const skipB = b.annotation?.skipped ? 1 : 0;
    if (skipA !== skipB) return skipA - skipB;
    const timeResult = timeKey(a).localeCompare(timeKey(b)) || String(a.series_number || "").localeCompare(String(b.series_number || ""), undefined, { numeric: true });
    const countResult = Number(a.count || 0) - Number(b.count || 0) || timeResult;
    const result = app.seriesSortField === "count" ? countResult : timeResult;
    return app.seriesSortDir === "desc" ? -result : result;
  });
}

function sortStudies(list) {
  return [...list].sort((a, b) => {
    const timeResult =
      studyTimeKey(a).localeCompare(studyTimeKey(b)) ||
      String(a.ct_number || "").localeCompare(String(b.ct_number || ""), undefined, { numeric: true });
    const modifiedResult = studyModifiedKey(a).localeCompare(studyModifiedKey(b)) || timeResult;
    const result = app.studySortField === "study_time" ? timeResult : modifiedResult;
    return app.studySortDir === "desc" ? -result : result;
  });
}

function studyStatus(study) {
  return study?.completed ? "complete" : "incomplete";
}

function studyStatusLabel(status) {
  return status === "complete" ? "已完成" : "待处理";
}

function visibleStudies() {
  return sortStudies(app.studies).filter((study) => {
    const status = studyStatus(study);
    if (app.studyFilter === "complete" && status !== "complete") return false;
    if (app.studyFilter === "incomplete" && status === "complete") return false;
    if (app.studyPartFilter !== "all" && !asList(study.body_parts).includes(app.studyPartFilter)) return false;
    return true;
  });
}

function updateSortButtons() {
  document.querySelectorAll("[data-study-sort]").forEach((button) => {
    const active = button.dataset.studySort === app.studySortField;
    button.classList.toggle("active", active);
    const arrow = button.querySelector(".sort-arrow");
    if (arrow) arrow.textContent = sortArrow(active ? app.studySortDir : "desc");
  });
  document.querySelectorAll("[data-series-sort]").forEach((button) => {
    const active = button.dataset.seriesSort === app.seriesSortField;
    button.classList.toggle("active", active);
    const arrow = button.querySelector(".sort-arrow");
    if (arrow) arrow.textContent = sortArrow(active ? app.seriesSortDir : "asc");
  });
  document.querySelectorAll("[data-study-filter]").forEach((button) => {
    button.classList.toggle("active", button.dataset.studyFilter === app.studyFilter);
  });
  document.querySelectorAll("[data-study-part-filter]").forEach((button) => {
    button.classList.toggle("active", button.dataset.studyPartFilter === app.studyPartFilter);
  });
}

function setSeries(list) {
  app.series = sortSeries(list || []);
  $("seriesCount").textContent = String(app.series.length);
  renderSeries();
  updateSortButtons();
}

function isSeriesAnnotated(series) {
  const annotation = series.annotation || {};
  return Boolean(annotation.skipped || asList(annotation.body_parts).length || annotation.notes || annotation.ai_model);
}

function isSeriesUndetermined(series) {
  const annotation = series.annotation || {};
  if (annotation.skipped) return false;
  const parts = asList(annotation.body_parts);
  return (
    (parts.includes("upper_abdomen") && annotation.upper_abdomen_phase === "unknown") ||
    (parts.includes("chest") && annotation.chest_window === "unknown")
  );
}

function refreshStudyAnnotationSummary() {
  if (!app.study || !app.series.length) return;
  const annotated = app.series.filter(isSeriesAnnotated).length;
  const undetermined = app.series.filter(isSeriesUndetermined).length;
  const total = app.series.length;
  const bodyParts = BODY_PARTS.filter((part) =>
    app.series.some((series) => asList(series.annotation?.body_parts).includes(part)),
  );
  const summary = {
    annotated_series: annotated,
    unannotated_series: Math.max(0, total - annotated),
    undetermined_series: undetermined,
    series_count: total,
    body_parts: bodyParts,
  };
  Object.assign(app.study, summary);
  const study = app.studies.find((item) => item.ct_number === app.study.ct_number);
  if (study) Object.assign(study, summary);
}

function exportDownloadUrl(ctNumber, seriesUids) {
  const params = new URLSearchParams();
  for (const uid of seriesUids) params.append("series_uids", uid);
  params.set("access_token", app.token);
  return `/api/studies/${encodeURIComponent(ctNumber)}/export?${params.toString()}`;
}

function triggerDownload(url) {
  const link = document.createElement("a");
  link.href = url;
  link.rel = "noopener";
  document.body.appendChild(link);
  link.click();
  link.remove();
}

function defaultExportChecked(series) {
  if (series.annotation?.skipped) return false;
  if (app.studyPartFilter !== "all") return asList(series.annotation?.body_parts).includes(app.studyPartFilter);
  return true;
}

function exportLabelText(series) {
  const tags = seriesTags(series)
    .filter((tag) => BODY_PARTS.some((part) => tag.label.startsWith(partLabel(part))) || tag.label === "无法判别" || tag.label === "略过/不采用")
    .map((tag) => tag.label);
  return tags.join(" / ") || "未标注";
}

function updateExportModalCount() {
  const selected = document.querySelectorAll("#exportSeriesList input[type=checkbox]:checked").length;
  $("exportModalCount").textContent = `${selected} 个序列`;
  $("downloadSelectedSeries").disabled = selected === 0;
}

function renderExportSeriesList(seriesList) {
  const list = $("exportSeriesList");
  list.innerHTML = "";
  for (const series of seriesList) {
    const checked = defaultExportChecked(series);
    const item = document.createElement("label");
    item.className = "export-series-item";
    item.classList.toggle("skipped", Boolean(series.annotation?.skipped));
    item.innerHTML = `
      <input type="checkbox" value="${escapeHtml(series.series_uid)}" ${checked ? "checked" : ""} />
      <div>
        <strong>${escapeHtml(series.description || "未命名序列")}</strong>
        <span>序列 ${escapeHtml(series.series_number || "-")} · ${Number(series.count || 0)} 张 · ${escapeHtml(timeRange(series))}</span>
        <em>${escapeHtml(exportLabelText(series))}</em>
      </div>
    `;
    item.querySelector("input").addEventListener("change", updateExportModalCount);
    list.appendChild(item);
  }
  updateExportModalCount();
}

async function loadSeriesForExport(ctNumber) {
  if (app.study?.ct_number === ctNumber && app.series.length) return app.series;
  const data = await json(`/api/studies/${encodeURIComponent(ctNumber)}/series`);
  const study = app.studies.find((item) => item.ct_number === ctNumber);
  if (study) Object.assign(study, data.study);
  return sortSeries(data.series || []);
}

async function exportStudy(ctNumber, event) {
  event.stopPropagation();
  if (!isAdmin()) return;
  if (!(await confirmSaveIfDirty())) return;
  $("exportStudyLabel").textContent = ctNumber;
  $("exportHint").textContent =
    app.studyPartFilter === "all"
      ? "默认不选择略过/不采用序列"
      : `默认仅选择 ${partLabel(app.studyPartFilter)}，且不选择略过/不采用序列`;
  $("exportSeriesList").innerHTML = `<p class="export-empty">正在读取序列...</p>`;
  $("exportModal").classList.remove("hidden");
  try {
    const seriesList = await loadSeriesForExport(ctNumber);
    app.exportDialog = { ctNumber, series: seriesList };
    renderExportSeriesList(seriesList);
  } catch (err) {
    $("exportSeriesList").innerHTML = `<p class="export-empty error-line">${escapeHtml(err.message)}</p>`;
    updateExportModalCount();
  }
}

function selectDefaultExportSeries() {
  document.querySelectorAll("#exportSeriesList input[type=checkbox]").forEach((input) => {
    const series = app.exportDialog.series.find((item) => item.series_uid === input.value);
    input.checked = series ? defaultExportChecked(series) : false;
  });
  updateExportModalCount();
}

function clearExportSeries() {
  document.querySelectorAll("#exportSeriesList input[type=checkbox]").forEach((input) => {
    input.checked = false;
  });
  updateExportModalCount();
}

function downloadSelectedSeries() {
  const selected = Array.from(document.querySelectorAll("#exportSeriesList input[type=checkbox]:checked")).map((input) => input.value);
  if (!app.exportDialog.ctNumber || selected.length === 0) return;
  triggerDownload(exportDownloadUrl(app.exportDialog.ctNumber, selected));
}

function initialCtNumber() {
  return new URLSearchParams(location.search).get("ct_number") || "";
}

function siblingSystemUrl(port, params = {}) {
  const url = new URL(window.location.href);
  url.port = String(port);
  url.pathname = "/";
  url.search = "";
  Object.entries(params).forEach(([key, value]) => {
    if (value) url.searchParams.set(key, value);
  });
  return url.toString();
}

function openSiblingSystem(kind) {
  const ctNumber = app.study?.ct_number || initialCtNumber();
  const port = kind === "registration" ? 8109 : 8108;
  window.open(siblingSystemUrl(port, { ct_number: ctNumber }), "_blank");
}

async function loadStudies(preferredCtNumber = "") {
  const q = encodeURIComponent($("studySearch").value.trim());
  app.studies = sortStudies(await json(`/api/studies?q=${q}&limit=500`));
  renderStudies();
  if (!app.study && app.studies.length) {
    const preferred = app.studies.find((study) => study.ct_number === preferredCtNumber);
    await selectStudy((preferred || app.studies[0]).ct_number);
  }
}

function renderStudies() {
  const list = $("studyList");
  app.studies = sortStudies(app.studies);
  updateSortButtons();
  const studies = visibleStudies();
  $("studyCount").textContent = studies.length === app.studies.length ? String(studies.length) : `${studies.length}/${app.studies.length}`;
  list.innerHTML = "";
  for (const study of studies) {
    const card = document.createElement("div");
    const status = studyStatus(study);
    const nextStatusLabel = status === "complete" ? "待处理" : "已完成";
    card.className = "study-card";
    card.tabIndex = 0;
    card.setAttribute("role", "button");
    card.classList.toggle("active", app.study?.ct_number === study.ct_number);
    card.classList.toggle("complete", status === "complete");
    const name = study.source_patient_name || study.patient_name_dicom || "无姓名";
    const bodyPartLabels = asList(study.body_parts)
      .filter((part) => BODY_PARTS.includes(part))
      .map((part) => partLabel(part));
    const partTags = bodyPartLabels
      .map((label) => `<em title="${escapeHtml(label)}">${escapeHtml(label)}</em>`)
      .join("");
    const studyDateTime = `${fmtDate(study.study_date)} ${fmtTime(study.study_time)}`.trim() || "未记录时间";
    const annotationSummary = `${Number(study.annotated_series || 0)} 个序列已标注，${Number(study.undetermined_series || 0)} 个序列待判别`;
    const cardTitle = [
      `检查号：${study.ct_number}`,
      `患者：${name} · ${study.patient_id || "无ID"}`,
      `时间：${studyDateTime}`,
      `DICOM：${Number(study.dicom_file_count || 0)} 张`,
      annotationSummary,
      `部位：${bodyPartLabels.join("、") || "无"}`,
    ].join("\n");
    const exportControls = isAdmin()
      ? `
        <span class="study-export-btn" role="button" tabindex="0" title="选择序列导出" aria-label="选择序列导出">
          <svg viewBox="0 0 24 24" aria-hidden="true">
            <path d="M12 3v11m0 0 4-4m-4 4-4-4M5 20h14" />
          </svg>
        </span>
      `
      : "";
    card.title = cardTitle;
    card.setAttribute("aria-label", cardTitle);
    card.innerHTML = `
      <div class="study-card-status-stack">
        <i class="study-status-badge status-${status}" title="点击切换为${nextStatusLabel}">${studyStatusLabel(status)}</i>
        <div class="study-part-tags">${partTags}</div>
      </div>
      <strong title="${escapeHtml(study.ct_number)}">${escapeHtml(study.ct_number)}</strong>
      <span class="study-patient" title="${escapeHtml(`${name} · ${study.patient_id || "无ID"}`)}">${escapeHtml(name)} · ${escapeHtml(study.patient_id || "无ID")}</span>
      <div class="study-meta">
        <span title="${escapeHtml(studyDateTime)}">${escapeHtml(studyDateTime)}</span>
        <div class="study-summary-line">
          <span title="${escapeHtml(annotationSummary)}">${escapeHtml(annotationSummary)}</span>
          ${exportControls}
        </div>
      </div>
    `;
    card.onclick = () => selectStudy(study.ct_number);
    card.onkeydown = (event) => {
      if (event.key === "Enter" || event.key === " ") {
        event.preventDefault();
        selectStudy(study.ct_number);
      }
    };
    card.querySelector(".study-status-badge").onclick = (event) => toggleStudyCompletion(study.ct_number, event);
    card.querySelector(".study-export-btn")?.addEventListener("click", (event) => exportStudy(study.ct_number, event));
    card.querySelector(".study-export-btn")?.addEventListener("keydown", (event) => {
      if (event.key === "Enter" || event.key === " ") {
        event.preventDefault();
        exportStudy(study.ct_number, event);
      }
    });
    list.appendChild(card);
  }
}

function applyStudyCompletion(data) {
  const completed = Boolean(data.completed);
  const modifiedAt = data.completion_updated_at || data.modified_at || data.completed_at || "";
  const study = app.studies.find((item) => item.ct_number === data.ct_number);
  if (study) {
    study.completed = completed;
    study.completed_by = data.completed_by || "";
    study.completed_at = data.completed_at || "";
    study.completion_updated_at = data.completion_updated_at || study.completion_updated_at || "";
    if (modifiedAt) study.modified_at = modifiedAt;
  }
  if (app.study?.ct_number === data.ct_number) {
    app.study.completed = completed;
    app.study.completed_by = data.completed_by || "";
    app.study.completed_at = data.completed_at || "";
    app.study.completion_updated_at = data.completion_updated_at || app.study.completion_updated_at || "";
    if (modifiedAt) app.study.modified_at = modifiedAt;
  }
}

async function toggleStudyCompletion(ctNumber, event) {
  event.stopPropagation();
  const study = app.studies.find((item) => item.ct_number === ctNumber);
  if (!study) return;
  const previous = Boolean(study.completed);
  applyStudyCompletion({ ct_number: ctNumber, completed: !previous });
  renderStudies();
  try {
    const data = await json(`/api/studies/${encodeURIComponent(ctNumber)}/completion`, {
      method: "PUT",
      body: JSON.stringify({ completed: !previous }),
    });
    applyStudyCompletion(data);
    renderStudies();
  } catch (err) {
    applyStudyCompletion({ ct_number: ctNumber, completed: previous });
    renderStudies();
    $("saveState").textContent = `状态更新失败：${err.message}`;
  }
}

async function selectStudy(ctNumber) {
  if (app.study?.ct_number && app.study.ct_number !== ctNumber && !(await confirmSaveIfDirty())) return;
  app.study = app.studies.find((item) => item.ct_number === ctNumber) || { ct_number: ctNumber };
  app.series = [];
  app.activeSeries = null;
  app.draft = null;
  $("activeStudyLabel").textContent = ctNumber;
  $("seriesCount").textContent = "读取中";
  renderSeriesLoading();
  resetViewer();
  renderStudies();
  try {
    const data = await json(`/api/studies/${encodeURIComponent(ctNumber)}/series`);
    app.study = data.study;
    applyStudyCompletion(data.study);
    setSeries(data.series || []);
    refreshStudyAnnotationSummary();
    renderStudies();
  } catch (err) {
    $("seriesGrid").innerHTML = `<p class="error-line">${escapeHtml(err.message)}</p>`;
  }
}

function sourceTag(value, annotation) {
  if (asList(annotation.manual_body_parts).includes(value)) return "manual";
  if (asList(annotation.ai_body_parts).includes(value)) return "ai";
  return "";
}

function mergeTagSource(...sources) {
  if (sources.includes("manual")) return "manual";
  if (sources.includes("ai")) return "ai";
  return "";
}

function seriesTags(series) {
  const annotation = series.annotation || {};
  const tags = [];
  if (annotation.skipped) {
    tags.push({ label: "略过/不采用", source: annotation.ai_skipped ? "ai" : "manual" });
  }
  const phase = phaseLabel(annotation.upper_abdomen_phase);
  const phaseSource = annotation.manual_upper_abdomen_phase ? "manual" : annotation.ai_upper_abdomen_phase ? "ai" : "";
  const chestWindow = chestWindowLabel(annotation.chest_window);
  const chestWindowSource = annotation.manual_chest_window ? "manual" : annotation.ai_chest_window ? "ai" : "";
  for (const part of asList(annotation.body_parts)) {
    const partSource = sourceTag(part, annotation);
    if (part === "upper_abdomen" && phase && annotation.upper_abdomen_phase !== "unknown") {
      tags.push({ label: `${partLabel(part)}-${phase}`, source: mergeTagSource(partSource, phaseSource) });
      continue;
    }
    if (part === "chest" && chestWindow && annotation.chest_window !== "unknown") {
      tags.push({ label: `${partLabel(part)}-${chestWindow}`, source: mergeTagSource(partSource, chestWindowSource) });
      continue;
    }
    tags.push({ label: partLabel(part), source: partSource });
  }
  if (phase && annotation.upper_abdomen_phase === "unknown") {
    tags.push({
      label: phase,
      source: phaseSource,
      warn: annotation.upper_abdomen_phase === "unknown",
    });
  }
  if (chestWindow && annotation.chest_window === "unknown") {
    tags.push({
      label: chestWindow,
      source: chestWindowSource,
      warn: annotation.chest_window === "unknown",
    });
  }
  if (series.body_part_dicom) tags.unshift({ label: series.body_part_dicom, source: "" });
  return tags;
}

function renderSeries() {
  const grid = $("seriesGrid");
  if (app.thumbObserver) app.thumbObserver.disconnect();
  grid.innerHTML = "";
  for (const series of app.series) {
    const skipped = Boolean(series.annotation?.skipped);
    const tags = seriesTags(series);
    const card = document.createElement("button");
    card.className = "series-card";
    card.classList.toggle("active", app.activeSeries?.series_uid === series.series_uid);
    card.classList.toggle("skipped", skipped);
    card.innerHTML = `
      <div class="thumb">
        <img alt="" />
        <span class="thumb-state">加载中</span>
        <b>${Number(series.count || 0)} 张</b>
        ${skipped ? "<i>略过/不采用</i>" : ""}
      </div>
      <div class="series-copy">
        <strong>${escapeHtml(series.description || "未命名序列")}</strong>
        <span class="shot-time">拍摄 ${escapeHtml(timeRange(series))}</span>
        <small>序列 ${escapeHtml(series.series_number || "-")} · ${escapeHtml(series.rows || "-")}×${escapeHtml(series.columns || "-")} · ${escapeHtml(series.modality || "")}</small>
        <div class="tag-line">${tags.length ? tags.map((tag) => `<em class="${[tag.source ? `tag-${tag.source}` : "", tag.warn ? "tag-warn" : ""].filter(Boolean).join(" ")}">${escapeHtml(tag.label)}</em>`).join("") : "<em>未标注</em>"}</div>
      </div>
    `;
    card.onclick = () => selectSeries(series.series_uid);
    grid.appendChild(card);
    queueThumb(series, card.querySelector("img"));
  }
}

function renderSeriesLoading() {
  $("seriesGrid").innerHTML = Array.from({ length: 4 })
    .map(
      () => `
        <div class="series-card loading-card">
          <div class="thumb"><span class="thumb-state">序列读取中</span></div>
          <div class="series-copy">
            <strong>读取中</strong>
            <span class="shot-time">正在同步序列信息</span>
            <small>请稍候</small>
          </div>
        </div>
      `,
    )
    .join("");
}

function imageUrlFor(series = app.activeSeries, index = app.slice, windowName = app.window, plane = app.plane) {
  return `/api/image?ct_number=${encodeURIComponent(app.study.ct_number)}&series_uid=${encodeURIComponent(series.series_uid)}&index=${index}&plane=${plane}&window=${windowName}&rotate=0`;
}

function cacheImageUrl(key, url) {
  app.imageCache.set(key, url);
  while (app.imageCache.size > 90) {
    const oldestKey = app.imageCache.keys().next().value;
    const oldestUrl = app.imageCache.get(oldestKey);
    URL.revokeObjectURL(oldestUrl);
    app.imageCache.delete(oldestKey);
  }
}

function showImageMessage(message) {
  const empty = $("imageEmpty");
  empty.textContent = message;
  empty.classList.remove("hidden");
}

function hideImageMessage() {
  $("imageEmpty").classList.add("hidden");
}

async function loadThumb(series, img) {
  const thumb = img.closest(".thumb");
  const state = thumb?.querySelector(".thumb-state");
  try {
    const key = thumbKey(series);
    if (app.thumbUrls.has(key)) {
      img.src = app.thumbUrls.get(key);
      thumb?.classList.add("thumb-ready");
      return;
    }
    thumb?.classList.add("thumb-loading");
    if (state) state.textContent = "加载中";
    const index = Math.floor((Number(series.count) || 1) / 2);
    const blob = await request(imageUrlFor(series, index, "soft", "axial")).then((res) => res.blob());
    const url = URL.createObjectURL(blob);
    app.thumbUrls.set(key, url);
    img.src = url;
    thumb?.classList.remove("thumb-loading");
    thumb?.classList.add("thumb-ready");
  } catch (_) {
    img.removeAttribute("src");
    thumb?.classList.remove("thumb-loading");
    thumb?.classList.add("thumb-failed");
    if (state) state.textContent = "未加载";
  }
}

function thumbKey(series) {
  return `${series.ct_number || app.study?.ct_number || ""}:${series.series_uid}`;
}

function queueThumb(series, img) {
  const key = thumbKey(series);
  if (app.thumbUrls.has(key)) {
    img.src = app.thumbUrls.get(key);
    img.closest(".thumb")?.classList.add("thumb-ready");
    return;
  }
  if (!("IntersectionObserver" in window)) {
    loadThumb(series, img);
    return;
  }
  if (!app.thumbObserver) {
    app.thumbObserver = new IntersectionObserver(
      (entries) => {
        for (const entry of entries) {
          if (!entry.isIntersecting) continue;
          const target = entry.target;
          app.thumbObserver.unobserve(target);
          const queuedSeries = app.thumbSeries.get(target);
          if (queuedSeries) loadThumb(queuedSeries, target);
        }
      },
      { rootMargin: "320px 0px" },
    );
  }
  app.thumbSeries.set(img, series);
  app.thumbObserver.observe(img);
}

function maxSlice() {
  if (!app.activeSeries) return 0;
  if (app.plane === "sagittal") return Math.max(0, Number(app.activeSeries.columns || 1) - 1);
  if (app.plane === "coronal") return Math.max(0, Number(app.activeSeries.rows || 1) - 1);
  return Math.max(0, Number(app.activeSeries.count || 1) - 1);
}

function resetViewState() {
  app.rotate = 0;
  app.zoom = 1;
  app.panX = 0;
  app.panY = 0;
  applyTransform();
}

async function selectSeries(seriesUid) {
  if (app.activeSeries?.series_uid && app.activeSeries.series_uid !== seriesUid && !(await confirmSaveIfDirty())) return;
  const series = app.series.find((item) => item.series_uid === seriesUid);
  if (!series) return;
  app.activeSeries = series;
  app.slice = Math.floor(maxSlice() / 2);
  app.pendingImage = null;
  $("dicomImage").removeAttribute("src");
  showImageMessage("图像加载中");
  resetViewState();
  $("sliceSlider").max = String(maxSlice());
  $("sliceSlider").value = String(app.slice);
  hydrateAnnotation();
  renderSeries();
  updateImage();
}

function resetViewer() {
  app.imageUrl = "";
  app.pendingImage = null;
  app.activeSeries = null;
  $("dicomImage").removeAttribute("src");
  hideImageMessage();
  $("sliceText").textContent = "0 / 0";
  $("saveState").textContent = "已保存";
  clearAnnotationControls();
  app.dirty = false;
  app.saving = false;
  resetViewState();
  updateOverlay();
}

function applyTransform() {
  $("dicomImage").style.transform = `translate(${app.panX}px, ${app.panY}px) scale(${app.zoom}) rotate(${app.rotate}deg)`;
  updateOverlay();
}

function windowInfo() {
  if (WINDOW_PRESETS[app.window]) return WINDOW_PRESETS[app.window];
  return {
    wl: parseFirstNumber(app.activeSeries?.window_center) ?? 50,
    ww: parseFirstNumber(app.activeSeries?.window_width) ?? 360,
  };
}

function updateOverlay() {
  const overlay = $("imageOverlay");
  overlay.classList.toggle("hidden", !app.showOverlay || !app.activeSeries);
  $("overlayToggle").textContent = app.showOverlay ? "隐藏信息" : "显示信息";
  if (!app.activeSeries) return;
  const s = app.activeSeries;
  const win = windowInfo();
  const age = ageText(s.patient_birth_date, s.study_date || app.study?.study_date);
  const sex = s.patient_sex || "";
  document.querySelector(".ov-left-top").innerHTML = [
    s.patient_name || app.study?.source_patient_name || "",
    [fmtDate(s.patient_birth_date), age, sex].filter(Boolean).join(" "),
    s.patient_id || app.study?.patient_id || "",
    fmtDate(s.study_date || app.study?.study_date),
  ].filter(Boolean).map(escapeHtml).join("<br />");
  document.querySelector(".ov-right-top").innerHTML = [
    s.institution_name || "",
    s.manufacturer || "",
  ].filter(Boolean).map(escapeHtml).join("<br />");
  document.querySelector(".ov-left-bottom").textContent = `Img:${app.slice + 1}/${maxSlice() + 1}`;
  document.querySelector(".ov-right-bottom").innerHTML = `WW:${Math.round(win.ww)}<br />WL:${Math.round(win.wl)}<br />Zoom:${app.zoom.toFixed(2)}`;
}

async function updateImage() {
  if (!app.study || !app.activeSeries) return;
  const max = maxSlice();
  app.slice = clamp(app.slice, 0, max);
  $("sliceSlider").max = String(max);
  $("sliceSlider").value = String(app.slice);
  $("sliceText").textContent = `${app.slice + 1} / ${max + 1}`;
  const url = imageUrlFor();
  if (app.imageCache.has(url)) {
    app.imageUrl = app.imageCache.get(url);
    $("dicomImage").src = app.imageUrl;
    hideImageMessage();
    updateOverlay();
    applyTransform();
    preloadNeighborImages();
    return;
  }
  showImageMessage("图像加载中");
  updateOverlay();
  const ticket = Symbol("image");
  app.pendingImage = ticket;
  try {
    const blob = await request(url).then((res) => res.blob());
    if (app.pendingImage !== ticket) return;
    app.imageUrl = URL.createObjectURL(blob);
    cacheImageUrl(url, app.imageUrl);
    $("dicomImage").src = app.imageUrl;
    hideImageMessage();
    applyTransform();
    preloadNeighborImages();
  } catch (err) {
    showImageMessage("图像读取失败");
    $("saveState").textContent = `图像读取失败：${err.message}`;
  }
}

function preloadNeighborImages() {
  if (!app.study || !app.activeSeries) return;
  const max = maxSlice();
  const indexes = [app.slice - 2, app.slice - 1, app.slice + 1, app.slice + 2].filter((index) => index >= 0 && index <= max);
  for (const index of indexes) {
    const url = imageUrlFor(app.activeSeries, index, app.window, app.plane);
    if (app.imageCache.has(url)) continue;
    request(url)
      .then((res) => res.blob())
      .then((blob) => cacheImageUrl(url, URL.createObjectURL(blob)))
      .catch(() => {});
  }
}

function cloneAnnotation(annotation = {}) {
  return {
    body_parts: asList(annotation.body_parts),
    manual_body_parts: asList(annotation.manual_body_parts),
    ai_body_parts: asList(annotation.ai_body_parts),
    upper_abdomen_phase: annotation.upper_abdomen_phase || "",
    manual_upper_abdomen_phase: annotation.manual_upper_abdomen_phase || "",
    ai_upper_abdomen_phase: annotation.ai_upper_abdomen_phase || "",
    chest_window: annotation.chest_window || "",
    manual_chest_window: annotation.manual_chest_window || "",
    ai_chest_window: annotation.ai_chest_window || "",
    plain_ct: Boolean(annotation.plain_ct),
    manual_plain_ct: annotation.manual_plain_ct ?? null,
    ai_plain_ct: annotation.ai_plain_ct ?? null,
    skipped: Boolean(annotation.skipped),
    ai_skipped: Boolean(annotation.ai_skipped),
    notes: annotation.notes || "",
    ai_model: annotation.ai_model || "",
  };
}

function effectiveParts(draft = app.draft) {
  if (!draft) return [];
  return uniq([...asList(draft.manual_body_parts), ...asList(draft.ai_body_parts)]);
}

function effectivePhase(draft = app.draft) {
  if (!effectiveParts(draft).includes("upper_abdomen")) return "";
  return draft.manual_upper_abdomen_phase || draft.ai_upper_abdomen_phase || "";
}

function effectiveChestWindow(draft = app.draft) {
  if (!effectiveParts(draft).includes("chest")) return "";
  return draft.manual_chest_window || draft.ai_chest_window || "unknown";
}

function setLabelSource(input, source) {
  const label = input.closest("label");
  label.classList.toggle("manual-selected", source === "manual");
  label.classList.toggle("ai-selected", source === "ai");
}

function clearAnnotationControls() {
  $("annotationNotes").value = "";
  document.querySelectorAll(".part-grid input, input[name=phase], input[name=chestWindow]").forEach((input) => {
    input.checked = false;
    input.disabled = true;
    setLabelSource(input, "");
  });
  $("phaseBox").classList.remove("visible");
  $("chestWindowBox").classList.remove("visible");
}

function applyAnnotationControls() {
  if (!app.draft) return;
  const parts = new Set(effectiveParts());
  document.querySelectorAll(".part-grid input").forEach((input) => {
    const value = input.value;
    if (value === "skip") {
      input.checked = app.draft.skipped;
      input.disabled = false;
      setLabelSource(input, app.draft.skipped ? (app.draft.ai_skipped ? "ai" : "manual") : "");
      return;
    }
    input.checked = parts.has(value);
    input.disabled = false;
    setLabelSource(input, app.draft.manual_body_parts.includes(value) ? "manual" : app.draft.ai_body_parts.includes(value) ? "ai" : "");
  });

  const phase = effectivePhase();
  document.querySelectorAll("input[name=phase]").forEach((input) => {
    input.checked = input.value === phase;
    input.disabled = false;
    setLabelSource(input, app.draft.manual_upper_abdomen_phase === input.value ? "manual" : app.draft.ai_upper_abdomen_phase === input.value ? "ai" : "");
  });
  $("phaseBox").classList.toggle("visible", parts.has("upper_abdomen"));

  const chestWindow = effectiveChestWindow();
  document.querySelectorAll("input[name=chestWindow]").forEach((input) => {
    input.checked = input.value === chestWindow;
    input.disabled = false;
    setLabelSource(input, app.draft.manual_chest_window === input.value ? "manual" : app.draft.ai_chest_window === input.value ? "ai" : "");
  });
  $("chestWindowBox").classList.toggle("visible", parts.has("chest"));
}

function hydrateAnnotation() {
  app.draft = cloneAnnotation(app.activeSeries?.annotation || {});
  app.draftVersion = 0;
  $("annotationNotes").value = app.draft.notes || "";
  applyAnnotationControls();
}

function updateLocalAnnotation(annotation, targetSeriesUid = app.activeSeries?.series_uid, options = {}) {
  if (!targetSeriesUid) return;
  const normalized = cloneAnnotation(annotation);
  normalized.body_parts = asList(annotation.body_parts);
  normalized.upper_abdomen_phase = annotation.upper_abdomen_phase || "";
  normalized.chest_window = annotation.chest_window || "";
  const index = app.series.findIndex((item) => item.series_uid === targetSeriesUid);
  if (index >= 0) app.series[index] = { ...app.series[index], annotation: normalized };
  app.series = sortSeries(app.series);
  const isActive = app.activeSeries?.series_uid === targetSeriesUid;
  const applyToActive = options.applyToActive !== false;
  if (isActive && applyToActive) {
    app.activeSeries = app.series.find((item) => item.series_uid === targetSeriesUid) || app.activeSeries;
    app.draft = cloneAnnotation(normalized);
    if (options.updateNotes !== false) $("annotationNotes").value = normalized.notes || "";
  }
  refreshStudyAnnotationSummary();
  const modifiedAt = normalized.updated_at || new Date().toISOString();
  if (app.study && modifiedAt) {
    app.study.modified_at = modifiedAt;
    app.study.annotation_updated_at = modifiedAt;
    const study = app.studies.find((item) => item.ct_number === app.study.ct_number);
    if (study) {
      study.modified_at = modifiedAt;
      study.annotation_updated_at = modifiedAt;
    }
  }
  renderSeries();
  renderStudies();
  if (isActive && applyToActive) applyAnnotationControls();
}

function annotationPayload(draft = app.draft, notes = $("annotationNotes").value) {
  const bodyParts = effectiveParts(draft);
  return {
    body_parts: bodyParts,
    manual_body_parts: asList(draft.manual_body_parts),
    ai_body_parts: asList(draft.ai_body_parts),
    upper_abdomen_phase: effectivePhase(draft),
    manual_upper_abdomen_phase: draft.manual_upper_abdomen_phase,
    ai_upper_abdomen_phase: draft.ai_upper_abdomen_phase,
    chest_window: effectiveChestWindow(draft),
    manual_chest_window: draft.manual_chest_window,
    ai_chest_window: draft.ai_chest_window,
    plain_ct: false,
    manual_plain_ct: null,
    ai_plain_ct: null,
    skipped: Boolean(draft.skipped),
    ai_skipped: Boolean(draft.ai_skipped),
    notes,
  };
}

async function saveAnnotationNow() {
  if (!app.study || !app.activeSeries || !app.draft) return;
  if (app.savePromise) return app.savePromise;
  const ctNumber = app.study.ct_number;
  const uid = app.activeSeries.series_uid;
  const draft = cloneAnnotation(app.draft);
  const payload = annotationPayload(draft, $("annotationNotes").value);
  const versionAtStart = app.draftVersion;
  app.saving = true;
  app.savingSeriesUid = uid;
  $("saveState").textContent = "保存中";
  $("saveAnnotation").disabled = true;
  let promise;
  promise = (async () => {
    try {
      const data = await json(`/api/series/${encodeURIComponent(ctNumber)}/${encodeURIComponent(uid)}/annotation`, {
        method: "PUT",
        body: JSON.stringify(payload),
      });
      const stillActive = app.study?.ct_number === ctNumber && app.activeSeries?.series_uid === uid;
      const unchanged = stillActive && app.draftVersion === versionAtStart;
      updateLocalAnnotation(data, uid, { applyToActive: unchanged });
      if (unchanged) {
        $("saveState").textContent = "已保存";
        app.dirty = false;
      } else if (stillActive) {
        $("saveState").textContent = "未保存";
        app.dirty = true;
      }
      return data;
    } catch (err) {
      if (app.study?.ct_number === ctNumber && app.activeSeries?.series_uid === uid) $("saveState").textContent = err.message;
      return null;
    } finally {
      if (app.savePromise === promise) {
        app.savePromise = null;
        app.saving = false;
        app.savingSeriesUid = "";
        $("saveAnnotation").disabled = false;
      }
    }
  })();
  app.savePromise = promise;
  return promise;
}

function markDirty() {
  clearTimeout(app.saveTimer);
  app.draftVersion += 1;
  app.dirty = true;
  $("saveState").textContent = "未保存";
}

async function confirmSaveIfDirty() {
  if (app.savePromise) {
    $("saveState").textContent = "保存中";
    await app.savePromise;
  }
  if (!app.dirty) return true;
  const shouldSave = window.confirm("当前标注尚未保存，是否先保存？");
  if (shouldSave) {
    await saveAnnotationNow();
    return !app.dirty;
  } else {
    app.dirty = false;
    $("saveState").textContent = "未保存";
  }
  return true;
}

function handlePartChange(event) {
  if (!app.draft) return;
  const input = event.target;
  const value = input.value;
  if (value === "skip") {
    app.draft.skipped = input.checked;
    if (!input.checked) app.draft.ai_skipped = false;
  } else if (BODY_PARTS.includes(value)) {
    if (input.checked) {
      app.draft.manual_body_parts = uniq([...app.draft.manual_body_parts, value]);
      if (value === "chest" && !app.draft.manual_chest_window && !app.draft.ai_chest_window) {
        app.draft.manual_chest_window = "unknown";
      }
    } else {
      app.draft.manual_body_parts = app.draft.manual_body_parts.filter((part) => part !== value);
      app.draft.ai_body_parts = app.draft.ai_body_parts.filter((part) => part !== value);
      if (value === "upper_abdomen") {
        app.draft.manual_upper_abdomen_phase = "";
        app.draft.ai_upper_abdomen_phase = "";
      }
      if (value === "chest") {
        app.draft.manual_chest_window = "";
        app.draft.ai_chest_window = "";
      }
    }
  }
  app.draft.body_parts = effectiveParts();
  app.draft.upper_abdomen_phase = effectivePhase();
  app.draft.chest_window = effectiveChestWindow();
  app.draft.plain_ct = false;
  app.draft.manual_plain_ct = null;
  app.draft.ai_plain_ct = null;
  applyAnnotationControls();
  markDirty();
}

function handlePhaseChange(event) {
  if (!app.draft) return;
  app.draft.manual_upper_abdomen_phase = event.target.value;
  if (app.draft.ai_upper_abdomen_phase !== event.target.value) app.draft.ai_upper_abdomen_phase = "";
  app.draft.upper_abdomen_phase = effectivePhase();
  applyAnnotationControls();
  markDirty();
}

function handleChestWindowChange(event) {
  if (!app.draft) return;
  app.draft.manual_chest_window = event.target.value;
  if (app.draft.ai_chest_window !== event.target.value) app.draft.ai_chest_window = "";
  app.draft.chest_window = effectiveChestWindow();
  applyAnnotationControls();
  markDirty();
}

async function runAI() {
  if (!app.study || !app.activeSeries) return;
  if (!(await confirmSaveIfDirty())) return;
  const ctNumber = app.study.ct_number;
  const uid = app.activeSeries.series_uid;
  const versionAtStart = app.draftVersion;
  const button = $("aiClassify");
  button.disabled = true;
  $("saveState").textContent = "AI 识别中";
  try {
    const data = await json(`/api/series/${encodeURIComponent(ctNumber)}/${encodeURIComponent(uid)}/ai`, {
      method: "POST",
      body: JSON.stringify({ sample_count: 3 }),
    });
    const stillActive = app.study?.ct_number === ctNumber && app.activeSeries?.series_uid === uid;
    const unchanged = stillActive && app.draftVersion === versionAtStart;
    updateLocalAnnotation(data, uid, { applyToActive: unchanged });
    if (unchanged) {
      $("saveState").textContent = "AI 结果已保存";
      app.dirty = false;
    } else if (stillActive) {
      $("saveState").textContent = "未保存";
      app.dirty = true;
    }
  } catch (err) {
    if (app.study?.ct_number === ctNumber && app.activeSeries?.series_uid === uid) $("saveState").textContent = err.message;
  } finally {
    button.disabled = false;
  }
}

async function openInfo() {
  if (!(await confirmSaveIfDirty())) return;
  if (!app.study || !app.activeSeries) return;
  const data = await json(`/api/dicom-info?ct_number=${encodeURIComponent(app.study.ct_number)}&series_uid=${encodeURIComponent(app.activeSeries.series_uid)}&index=${app.slice}`);
  const content = $("infoContent");
  content.innerHTML = "";
  for (const [title, fields] of Object.entries(data.fields || {})) {
    const section = document.createElement("section");
    section.className = "info-card";
    section.innerHTML = `<h3>${escapeHtml(title)}</h3>${Object.entries(fields)
      .map(([key, value]) => `<p class="info-row"><span>${escapeHtml(key)}</span><b>${escapeHtml(value || "-")}</b></p>`)
      .join("")}`;
    content.appendChild(section);
  }
  $("infoModal").classList.remove("hidden");
}

function settingsTable(users) {
  return `
    <table class="settings-table">
      <thead><tr><th>账号</th><th>角色</th><th>状态</th></tr></thead>
      <tbody>
        ${(users || [])
          .map((user) => `<tr><td>${escapeHtml(user.username)}</td><td>${escapeHtml(user.role)}</td><td>${escapeHtml(user.status)}</td></tr>`)
          .join("")}
      </tbody>
    </table>
  `;
}

function roleCards(roles) {
  return (roles || [])
    .map(
      (role) => `
        <div class="role-card">
          <strong>${escapeHtml(role.name)}</strong>
          <span>${(role.permissions || []).map(escapeHtml).join(" / ")}</span>
        </div>
      `,
    )
    .join("");
}

function showViewerPage(push = true) {
  $("viewerPage").classList.remove("hidden");
  $("settingsPage").classList.add("hidden");
  if (push && location.pathname !== "/") history.pushState({}, "", "/");
}

async function showSettingsPage(push = true) {
  if (!(await confirmSaveIfDirty())) return;
  if (!isAdmin()) {
    if (location.pathname === "/settings") history.replaceState({}, "", "/");
    showViewerPage(false);
    return;
  }
  $("viewerPage").classList.add("hidden");
  $("settingsPage").classList.remove("hidden");
  if (push && location.pathname !== "/settings") history.pushState({}, "", "/settings");
  await renderSettingsPage();
}

async function handleRoute(push = false) {
  if (location.pathname === "/settings") {
    await showSettingsPage(push);
  } else {
    showViewerPage(push);
  }
}

async function openSettings() {
  await showSettingsPage(true);
}

async function renderSettingsPage() {
  const [settings, status] = await Promise.all([json("/api/settings"), fetch("/api/status").then((res) => res.json())]);
  const refresh = settings.summary_refresh || {};
  $("settingsContent").innerHTML = `
    <section class="settings-section">
      <div class="settings-title"><h3>用户创建</h3><span>当前登录：${escapeHtml(app.user?.username || "-")}</span></div>
      <form id="createUserForm" class="settings-form">
        <input name="username" placeholder="新账号" autocomplete="off" />
        <input name="password" type="password" placeholder="初始密码" autocomplete="new-password" />
        <select name="role">
          <option value="阅片员">阅片员</option>
          <option value="管理员">管理员</option>
          <option value="访客">访客</option>
        </select>
        <button type="submit">创建</button>
      </form>
      ${settingsTable(settings.users)}
    </section>
    <section class="settings-section">
      <div class="settings-title"><h3>权限控制</h3><span>按角色控制查看、标注、AI 与系统设置</span></div>
      <div class="role-grid">${roleCards(settings.roles)}</div>
    </section>
    <section class="settings-section split">
      <div>
        <div class="settings-title"><h3>AI 设置</h3><span>${settings.ai?.enabled ? "已启用" : "已关闭"}</span></div>
        <dl>
          <dt>供应商</dt><dd>${escapeHtml(settings.ai?.provider || "-")}</dd>
          <dt>名称</dt><dd>${escapeHtml(settings.ai?.name || "-")}</dd>
          <dt>模型</dt><dd>${escapeHtml(settings.ai?.model || "-")}</dd>
          <dt>状态</dt><dd>${settings.ai?.configured ? "API 已配置" : "API 未配置"}</dd>
        </dl>
        <button id="toggleAi" class="settings-action">${settings.ai?.enabled ? "关闭 AI" : "启用 AI"}</button>
      </div>
      <div>
        <div class="settings-title"><h3>检查摘要</h3><span>${refresh.running ? "刷新中" : "待命"}</span></div>
        <dl>
          <dt>计划刷新</dt><dd>每天 04:00（北京时间，全量）</dd>
          <dt>下次刷新</dt><dd>${escapeHtml(refresh.next_scheduled_at || "-")}</dd>
          <dt>最近开始</dt><dd>${escapeHtml(refresh.started_at || "-")}</dd>
          <dt>最近完成</dt><dd>${escapeHtml(refresh.finished_at || "-")}</dd>
          <dt>状态</dt><dd>${escapeHtml(refresh.message || "-")}</dd>
        </dl>
        <button id="refreshSummariesNow" class="settings-action"${refresh.running ? " disabled" : ""}>立刻更新检查列表</button>
      </div>
    </section>
    <section class="settings-section split">
      <div>
        <div class="settings-title"><h3>数据库</h3><span>${status.database?.ok ? "已连接" : "异常"}</span></div>
        <dl>
          <dt>主机</dt><dd>${escapeHtml(settings.database?.host || "-")}:${escapeHtml(settings.database?.port || "-")}</dd>
          <dt>库表</dt><dd>${escapeHtml(settings.database?.database || "-")}.${escapeHtml(settings.database?.table || "-")}</dd>
          <dt>DICOM</dt><dd>${escapeHtml(settings.dicom?.processed_root || "-")}</dd>
        </dl>
      </div>
    </section>
  `;
  $("createUserForm").addEventListener("submit", createUser);
  $("toggleAi").addEventListener("click", () => toggleAI(!settings.ai?.enabled));
  $("refreshSummariesNow").addEventListener("click", refreshSummariesNow);
}

async function createUser(event) {
  event.preventDefault();
  const button = event.currentTarget.querySelector("button");
  const form = new FormData(event.currentTarget);
  const payload = {
    username: String(form.get("username") || "").trim(),
    password: String(form.get("password") || ""),
    role: String(form.get("role") || "阅片员"),
  };
  if (!payload.username || !payload.password) return;
  button.disabled = true;
  button.textContent = "创建中";
  try {
    await json("/api/settings/users", { method: "POST", body: JSON.stringify(payload) });
    await renderSettingsPage();
  } catch (err) {
    button.textContent = err.message;
    setTimeout(() => {
      button.disabled = false;
      button.textContent = "创建";
    }, 1800);
  }
}

async function toggleAI(enabled) {
  await json("/api/settings/ai", { method: "POST", body: JSON.stringify({ enabled }) });
  await renderSettingsPage();
  await refreshStatus();
}

async function refreshSummariesNow() {
  const button = $("refreshSummariesNow");
  button.disabled = true;
  button.textContent = "已开始刷新";
  await json("/api/settings/refresh-summaries", { method: "POST", body: JSON.stringify({}) });
  let refresh = {};
  for (let i = 0; i < 300; i += 1) {
    await sleep(2000);
    const settings = await json("/api/settings");
    refresh = settings.summary_refresh || {};
    button.textContent = refresh.running ? refresh.message || "刷新中" : "刷新完成";
    if (!refresh.running) break;
  }
  await loadStudies(app.study?.ct_number || initialCtNumber());
  await renderSettingsPage();
}

function changeZoom(multiplier) {
  app.zoom = clamp(app.zoom * multiplier, 0.25, 6);
  applyTransform();
}

function wireImageGestures() {
  const wrap = document.querySelector(".image-wrap");
  const sliceRail = document.querySelector(".slice-rail");
  ["pointerdown", "pointermove", "pointerup", "pointercancel", "click"].forEach((name) => {
    sliceRail.addEventListener(name, (event) => event.stopPropagation());
  });
  sliceRail.addEventListener("wheel", (event) => event.stopPropagation(), { passive: true });
  wrap.addEventListener(
    "wheel",
    (event) => {
      if (!app.activeSeries) return;
      event.preventDefault();
      changeZoom(event.deltaY < 0 ? 1.12 : 1 / 1.12);
    },
    { passive: false },
  );
  wrap.addEventListener("pointerdown", (event) => {
    if (!app.activeSeries || event.target.closest(".slice-rail")) return;
    app.drag = { x: event.clientX, y: event.clientY, panX: app.panX, panY: app.panY };
    wrap.classList.add("dragging");
    wrap.setPointerCapture(event.pointerId);
  });
  wrap.addEventListener("pointermove", (event) => {
    if (!app.drag) return;
    app.panX = app.drag.panX + event.clientX - app.drag.x;
    app.panY = app.drag.panY + event.clientY - app.drag.y;
    applyTransform();
  });
  ["pointerup", "pointercancel", "pointerleave"].forEach((name) => {
    wrap.addEventListener(name, () => {
      app.drag = null;
      wrap.classList.remove("dragging");
    });
  });
}

function setStudySort(field) {
  if (app.studySortField === field) {
    app.studySortDir = app.studySortDir === "asc" ? "desc" : "asc";
  } else {
    app.studySortField = field;
    app.studySortDir = "desc";
  }
  renderStudies();
}

function setSeriesSort(field) {
  if (app.seriesSortField === field) {
    app.seriesSortDir = app.seriesSortDir === "asc" ? "desc" : "asc";
  } else {
    app.seriesSortField = field;
    app.seriesSortDir = field === "count" ? "desc" : "asc";
  }
  app.series = sortSeries(app.series);
  renderSeries();
  if (app.activeSeries) {
    app.activeSeries = app.series.find((item) => item.series_uid === app.activeSeries.series_uid) || app.activeSeries;
  }
  updateSortButtons();
}

function wire() {
  $("loginForm").addEventListener("submit", login);
  $("logoutBtn").addEventListener("click", logout);
  $("settingsBtn").addEventListener("click", openSettings);
  $("registrationLinkBtn").addEventListener("click", () => openSiblingSystem("registration"));
  $("relationLinkBtn").addEventListener("click", () => openSiblingSystem("relation"));
  $("backToViewer").addEventListener("click", () => showViewerPage(true));
  $("infoBtn").addEventListener("click", openInfo);
  $("aiClassify").addEventListener("click", runAI);
  $("selectExportableSeries").addEventListener("click", selectDefaultExportSeries);
  $("clearExportSeries").addEventListener("click", clearExportSeries);
  $("downloadSelectedSeries").addEventListener("click", downloadSelectedSeries);
  $("zoomIn").addEventListener("click", () => changeZoom(1.18));
  $("zoomOut").addEventListener("click", () => changeZoom(1 / 1.18));
  $("overlayToggle").addEventListener("click", () => {
    app.showOverlay = !app.showOverlay;
    updateOverlay();
  });
  document.querySelectorAll("[data-study-sort]").forEach((button) => {
    button.addEventListener("click", () => setStudySort(button.dataset.studySort));
  });
  document.querySelectorAll("[data-study-filter]").forEach((button) => {
    button.addEventListener("click", () => {
      app.studyFilter = button.dataset.studyFilter;
      renderStudies();
    });
  });
  document.querySelectorAll("[data-study-part-filter]").forEach((button) => {
    button.addEventListener("click", () => {
      app.studyPartFilter = button.dataset.studyPartFilter;
      renderStudies();
    });
  });
  document.querySelectorAll("[data-series-sort]").forEach((button) => {
    button.addEventListener("click", () => setSeriesSort(button.dataset.seriesSort));
  });
  $("studySearch").addEventListener("input", () => {
    clearTimeout(app.searchTimer);
    app.searchTimer = setTimeout(loadStudies, 250);
  });
  $("sliceSlider").addEventListener("input", (event) => {
    app.slice = Number(event.target.value);
    updateImage();
  });
  document.querySelectorAll("[data-plane]").forEach((button) => {
    button.addEventListener("click", () => {
      app.plane = button.dataset.plane;
      app.slice = Math.floor(maxSlice() / 2);
      document.querySelectorAll("[data-plane]").forEach((b) => b.classList.toggle("active", b === button));
      updateImage();
    });
  });
  document.querySelectorAll("[data-window]").forEach((button) => {
    button.addEventListener("click", () => {
      app.window = button.dataset.window;
      document.querySelectorAll("[data-window]").forEach((b) => b.classList.toggle("active", b === button));
      updateImage();
    });
  });
  $("rotateLeft").addEventListener("click", () => {
    app.rotate = (app.rotate - 90 + 360) % 360;
    applyTransform();
  });
  $("rotateRight").addEventListener("click", () => {
    app.rotate = (app.rotate + 90) % 360;
    applyTransform();
  });
  $("resetView").addEventListener("click", resetViewState);
  document.querySelectorAll(".part-grid input").forEach((input) => input.addEventListener("change", handlePartChange));
  document.querySelectorAll("input[name=phase]").forEach((input) => input.addEventListener("change", handlePhaseChange));
  document.querySelectorAll("input[name=chestWindow]").forEach((input) => input.addEventListener("change", handleChestWindowChange));
  $("annotationNotes").addEventListener("input", () => {
    if (!app.draft) return;
    app.draft.notes = $("annotationNotes").value;
    markDirty();
  });
  $("saveAnnotation").addEventListener("click", saveAnnotationNow);
  window.addEventListener("beforeunload", (event) => {
    if (!app.dirty) return;
    event.preventDefault();
    event.returnValue = "";
  });
  document.querySelectorAll("[data-close]").forEach((button) => {
    button.addEventListener("click", () => $(button.dataset.close).classList.add("hidden"));
  });
  window.addEventListener("popstate", () => handleRoute(false));
  wireImageGestures();
}

async function boot() {
  await loadCurrentUser();
  await refreshStatus();
  if (location.pathname === "/settings" && isAdmin()) {
    await showSettingsPage(false);
  } else {
    await loadStudies(initialCtNumber());
    await handleRoute(false);
  }
  if (!app.statusTimer) app.statusTimer = setInterval(refreshStatus, 15000);
}

wire();
applyPermissions();
refreshStatus();
if (app.token) {
  showLogin(false);
  boot().catch(() => showLogin(true));
} else {
  showLogin(true);
}