const app = {
  token: localStorage.getItem("pacs_web_token") || "",
  studies: [],
  study: null,
  series: [],
  activeSeries: null,
  slice: 0,
  plane: "axial",
  window: "default",
  rotate: 0,
  zoom: 1,
  panX: 0,
  panY: 0,
  imageUrl: "",
  searchTimer: null,
  statusTimer: null,
  pendingImage: null,
  drag: null,
};

const $ = (id) => document.getElementById(id);
const clamp = (value, min, max) => Math.max(min, Math.min(max, value));

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

function partLabel(value) {
  return {
    head_neck: "头颈部",
    chest: "胸部",
    upper_abdomen: "上腹部",
    lower_abdomen: "下腹部",
    pelvis: "盆腔",
  }[value] || value;
}

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;
    localStorage.setItem("pacs_web_token", app.token);
    showLogin(false);
    await boot();
  } catch (_) {
    $("loginError").textContent = "登录失败";
  }
}

function logout() {
  app.token = "";
  localStorage.removeItem("pacs_web_token");
  showLogin(true);
}

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));
  } catch (_) {
    $("dbStatus").textContent = "数据库异常";
    $("dbStatus").classList.add("offline");
    $("dbStatus").classList.remove("online");
  }
}

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

function renderStudies() {
  const list = $("studyList");
  list.innerHTML = "";
  for (const study of app.studies) {
    const button = document.createElement("button");
    button.className = "study-card";
    button.classList.toggle("active", app.study?.ct_number === study.ct_number);
    const name = study.source_patient_name || study.patient_name_dicom || "无姓名";
    button.innerHTML = `
      <strong>${escapeHtml(study.ct_number)}</strong>
      <span>${escapeHtml(name)} · ${escapeHtml(study.patient_id || "无ID")}</span>
      <span>${escapeHtml(fmtDate(study.study_date))} ${escapeHtml(fmtTime(study.study_time))} · ${Number(study.dicom_file_count || 0)} 张</span>
      <span>${Number(study.annotated_series || 0)} 个序列已标注</span>
    `;
    button.onclick = () => selectStudy(study.ct_number);
    list.appendChild(button);
  }
}

async function selectStudy(ctNumber) {
  app.study = app.studies.find((item) => item.ct_number === ctNumber) || { ct_number: ctNumber };
  app.series = [];
  app.activeSeries = null;
  $("activeStudyLabel").textContent = ctNumber;
  $("seriesCount").textContent = "读取中";
  $("seriesGrid").innerHTML = "";
  resetViewer();
  renderStudies();
  try {
    const data = await json(`/api/studies/${encodeURIComponent(ctNumber)}/series`);
    app.study = data.study;
    app.series = data.series || [];
    $("seriesCount").textContent = String(app.series.length);
    renderSeries();
    if (app.series.length) selectSeries(app.series[0].series_uid);
  } catch (err) {
    $("seriesGrid").innerHTML = `<p class="error-line">${escapeHtml(err.message)}</p>`;
  }
}

function renderSeries() {
  const grid = $("seriesGrid");
  grid.innerHTML = "";
  for (const series of app.series) {
    const skipped = Boolean(series.annotation?.skipped);
    const parts = series.annotation?.body_parts || [];
    const tags = skipped
      ? ["略过"]
      : [series.body_part_dicom, ...parts.map(partLabel), phaseLabel(series.annotation?.upper_abdomen_phase)].filter(Boolean);
    const card = document.createElement("button");
    card.className = "series-card";
    card.classList.toggle("active", app.activeSeries?.series_uid === series.series_uid);
    card.classList.toggle("skipped", skipped);
    card.innerHTML = `
      <div class="thumb">
        <img alt="" />
        <b>${Number(series.count || 0)} 张</b>
        ${skipped ? "<i>略过</i>" : ""}
      </div>
      <div class="series-copy">
        <strong>${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>${escapeHtml(tag)}</em>`).join("") : "<em>未标注</em>"}</div>
      </div>
    `;
    card.onclick = () => selectSeries(series.series_uid);
    grid.appendChild(card);
    loadThumb(series, card.querySelector("img"));
  }
}

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`;
}

async function loadThumb(series, img) {
  try {
    const index = Math.floor((Number(series.count) || 1) / 2);
    const blob = await request(imageUrlFor(series, index, "soft", "axial")).then((res) => res.blob());
    img.src = URL.createObjectURL(blob);
  } catch (_) {
    img.removeAttribute("src");
  }
}

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();
}

function selectSeries(seriesUid) {
  const series = app.series.find((item) => item.series_uid === seriesUid);
  if (!series) return;
  app.activeSeries = series;
  app.slice = Math.floor(maxSlice() / 2);
  resetViewState();
  $("sliceSlider").max = String(maxSlice());
  $("sliceSlider").value = String(app.slice);
  hydrateAnnotation();
  renderSeries();
  updateImage();
}

function resetViewer() {
  if (app.imageUrl) URL.revokeObjectURL(app.imageUrl);
  app.imageUrl = "";
  app.pendingImage = null;
  app.activeSeries = null;
  $("dicomImage").removeAttribute("src");
  $("imageEmpty").classList.remove("hidden");
  $("sliceText").textContent = "0 / 0";
  $("saveState").textContent = "未保存";
  resetViewState();
}

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

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}`;
  $("imageEmpty").classList.add("hidden");
  const ticket = Symbol("image");
  app.pendingImage = ticket;
  try {
    const blob = await request(imageUrlFor()).then((res) => res.blob());
    if (app.pendingImage !== ticket) return;
    if (app.imageUrl) URL.revokeObjectURL(app.imageUrl);
    app.imageUrl = URL.createObjectURL(blob);
    $("dicomImage").src = app.imageUrl;
    applyTransform();
  } catch (err) {
    $("saveState").textContent = `图像读取失败：${err.message}`;
  }
}

function isSkippedChecked() {
  return Boolean(document.querySelector('.part-grid input[value="skip"]')?.checked);
}

function selectedParts() {
  return Array.from(document.querySelectorAll('.part-grid input:checked:not([value="skip"])')).map((input) => input.value);
}

function syncPartState() {
  const skipped = isSkippedChecked();
  document.querySelectorAll('.part-grid input:not([value="skip"])').forEach((input) => {
    input.disabled = skipped;
    if (skipped) input.checked = false;
  });
  if (skipped) {
    document.querySelectorAll("input[name=phase]").forEach((input) => {
      input.checked = false;
    });
  }
  const show = !skipped && selectedParts().includes("upper_abdomen");
  $("phaseBox").classList.toggle("visible", show);
}

function hydrateAnnotation() {
  const annotation = app.activeSeries?.annotation || {};
  const parts = new Set(annotation.body_parts || []);
  document.querySelectorAll(".part-grid input").forEach((input) => {
    if (input.value === "skip") {
      input.checked = Boolean(annotation.skipped);
      return;
    }
    input.checked = !annotation.skipped && parts.has(input.value);
    input.disabled = Boolean(annotation.skipped);
  });
  document.querySelectorAll("input[name=phase]").forEach((input) => {
    input.checked = !annotation.skipped && input.value === (annotation.upper_abdomen_phase || "");
  });
  $("annotationNotes").value = annotation.notes || "";
  syncPartState();
}

async function reloadCurrentStudySeries(keepUid) {
  const data = await json(`/api/studies/${encodeURIComponent(app.study.ct_number)}/series`);
  app.study = data.study;
  app.series = data.series || [];
  app.activeSeries = app.series.find((item) => item.series_uid === keepUid) || app.series[0] || null;
  $("seriesCount").textContent = String(app.series.length);
  renderSeries();
  hydrateAnnotation();
}

async function saveAnnotation() {
  if (!app.study || !app.activeSeries) return;
  const skipped = isSkippedChecked();
  const parts = skipped ? [] : selectedParts();
  let phase = skipped ? "" : document.querySelector("input[name=phase]:checked")?.value || "";
  if (parts.includes("upper_abdomen") && !phase) {
    $("saveState").textContent = "请选择上腹部期相";
    return;
  }
  if (!parts.includes("upper_abdomen")) phase = "";
  $("saveState").textContent = "保存中";
  const uid = app.activeSeries.series_uid;
  try {
    await json(`/api/series/${encodeURIComponent(app.study.ct_number)}/${encodeURIComponent(uid)}/annotation`, {
      method: "PUT",
      body: JSON.stringify({ body_parts: parts, upper_abdomen_phase: phase, skipped, notes: $("annotationNotes").value }),
    });
    $("saveState").textContent = "已保存";
    await reloadCurrentStudySeries(uid);
  } catch (err) {
    $("saveState").textContent = err.message;
  }
}

function applyAiSuggestion(data) {
  const parts = new Set(data.body_parts || []);
  document.querySelectorAll(".part-grid input").forEach((input) => {
    if (input.value === "skip") {
      input.checked = Boolean(data.skipped);
      return;
    }
    input.checked = !data.skipped && parts.has(input.value);
  });
  document.querySelectorAll("input[name=phase]").forEach((input) => {
    input.checked = !data.skipped && input.value === (data.upper_abdomen_phase || "");
  });
  if (data.notes) $("annotationNotes").value = data.notes;
  syncPartState();
}

async function runAI() {
  if (!app.study || !app.activeSeries) return;
  const button = $("aiClassify");
  button.disabled = true;
  $("saveState").textContent = "AI 识别中";
  try {
    const data = await json(`/api/series/${encodeURIComponent(app.study.ct_number)}/${encodeURIComponent(app.activeSeries.series_uid)}/ai`, {
      method: "POST",
      body: JSON.stringify({ sample_count: 3 }),
    });
    applyAiSuggestion(data);
    $("saveState").textContent = "AI 建议已填入，确认后保存";
  } catch (err) {
    $("saveState").textContent = err.message;
  } finally {
    button.disabled = false;
  }
}

async function openInfo() {
  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("");
}

async function openSettings() {
  const [settings, status] = await Promise.all([json("/api/settings"), fetch("/api/status").then((res) => res.json())]);
  $("settingsContent").innerHTML = `
    <section class="settings-section">
      <div class="settings-title"><h3>用户创建</h3><span>当前登录：admin</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>${settings.ai?.configured ? "已配置" : "未配置"}</span></div>
        <dl>
          <dt>供应商</dt><dd>${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>
        </dl>
      </div>
      <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);
  $("settingsModal").classList.remove("hidden");
}

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 openSettings();
  } catch (err) {
    button.textContent = err.message;
    setTimeout(() => {
      button.disabled = false;
      button.textContent = "创建";
    }, 1800);
  }
}

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

function wireImageGestures() {
  const wrap = document.querySelector(".image-wrap");
  document.querySelector(".slice-rail").addEventListener("pointerdown", (event) => event.stopPropagation());
  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) 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 wire() {
  $("loginForm").addEventListener("submit", login);
  $("logoutBtn").addEventListener("click", logout);
  $("settingsBtn").addEventListener("click", openSettings);
  $("infoBtn").addEventListener("click", openInfo);
  $("aiClassify").addEventListener("click", runAI);
  $("zoomIn").addEventListener("click", () => changeZoom(1.18));
  $("zoomOut").addEventListener("click", () => changeZoom(1 / 1.18));
  $("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", syncPartState));
  $("saveAnnotation").addEventListener("click", saveAnnotation);
  document.querySelectorAll("[data-close]").forEach((button) => {
    button.addEventListener("click", () => $(button.dataset.close).classList.add("hidden"));
  });
  wireImageGestures();
}

async function boot() {
  await refreshStatus();
  await loadStudies();
  if (!app.statusTimer) app.statusTimer = setInterval(refreshStatus, 15000);
}

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