const state = {
  userId: null,
  files: [],
  sessions: [],
  currentSessionId: null,
  currentTaskId: null,
  pollTimer: null,
};

function ensureUserId() {
  const key = "vibe_data_ana_user_id";
  let userId = localStorage.getItem(key);
  if (!userId) {
    userId = `guest_${crypto.randomUUID()}`;
    localStorage.setItem(key, userId);
  }
  state.userId = userId;
  document.getElementById("user-id").textContent = userId;
}

async function api(path, options = {}) {
  const response = await fetch(path, options);
  const text = await response.text();
  let data = {};
  try {
    data = text ? JSON.parse(text) : {};
  } catch {
    data = { raw: text };
  }
  if (!response.ok) {
    throw new Error(data.detail || data.error || response.statusText);
  }
  return data;
}

function setText(id, value) {
  document.getElementById(id).textContent = value || "";
}

function renderFiles() {
  const fileList = document.getElementById("file-list");
  const picker = document.getElementById("session-file-picker");
  fileList.innerHTML = "";
  picker.innerHTML = "";

  if (!state.files.length) {
    fileList.innerHTML = '<div class="empty">还没有上传文件。</div>';
    picker.innerHTML = '<div class="empty">先上传文件后才能创建会话。</div>';
    return;
  }

  state.files.forEach((file) => {
    const item = document.createElement("div");
    item.className = "file-item";
    item.innerHTML = `<strong>${file.original_name}</strong><div class="hint">${file.id}</div>`;
    fileList.appendChild(item);

    const label = document.createElement("label");
    label.className = "checkbox-item";
    label.innerHTML = `
      <input type="checkbox" value="${file.id}" />
      <span>${file.original_name}</span>
    `;
    picker.appendChild(label);
  });
}

function statusBadge(status) {
  return `<span class="status ${status}">${status}</span>`;
}

function renderSessions() {
  const container = document.getElementById("session-list");
  container.innerHTML = "";
  if (!state.sessions.length) {
    container.innerHTML = '<div class="empty">暂无会话。</div>';
    return;
  }

  state.sessions.forEach((session) => {
    const card = document.createElement("button");
    card.type = "button";
    card.className = `session-card ${session.id === state.currentSessionId ? "active" : ""}`;
    card.innerHTML = `
      <div><strong>${session.title}</strong></div>
      <div class="hint">${session.id}</div>
      <div>${statusBadge(session.status)}</div>
    `;
    card.onclick = () => loadSessionDetail(session.id);
    container.appendChild(card);
  });
}

function renderTasks(tasks) {
  const container = document.getElementById("task-list");
  container.innerHTML = "";
  if (!tasks.length) {
    container.innerHTML = '<div class="empty">当前会话还没有专题任务。</div>';
    return;
  }

  tasks.forEach((task) => {
    const card = document.createElement("button");
    card.type = "button";
    card.className = `task-card ${task.id === state.currentTaskId ? "active" : ""}`;
    card.innerHTML = `
      <div><strong>${task.query}</strong></div>
      <div class="hint">${task.created_at}</div>
      <div>${statusBadge(task.status)}</div>
    `;
    card.onclick = () => loadTaskReport(task.id);
    container.appendChild(card);
  });
}

async function refreshFiles() {
  const data = await api(`/files?user_id=${encodeURIComponent(state.userId)}`);
  state.files = data.files || [];
  renderFiles();
}

async function refreshSessions(selectSessionId = null) {
  const data = await api(`/sessions?user_id=${encodeURIComponent(state.userId)}`);
  state.sessions = data.sessions || [];
  renderSessions();
  if (selectSessionId) {
    await loadSessionDetail(selectSessionId);
  } else if (state.currentSessionId) {
    const exists = state.sessions.some((session) => session.id === state.currentSessionId);
    if (exists) {
      await loadSessionDetail(state.currentSessionId, false);
    }
  }
}

async function loadSessionDetail(sessionId, renderReport = true) {
  const data = await api(`/sessions/${sessionId}?user_id=${encodeURIComponent(state.userId)}`);
  state.currentSessionId = sessionId;
  document.getElementById("detail-title").textContent = data.session.title;
  document.getElementById("detail-meta").textContent = `${data.session.id} · ${data.session.status}`;
  renderSessions();
  renderTasks(data.tasks || []);

  const latestDoneTask = (data.tasks || []).slice().reverse().find((task) => task.status === "succeeded");
  if (renderReport && latestDoneTask) {
    await loadTaskReport(latestDoneTask.id);
  } else if (!latestDoneTask) {
    setText("report-title", "暂无已完成专题");
    setText("report-content", "当前会话还没有可展示的报告。");
    document.getElementById("artifact-gallery").innerHTML = "";
  }
}

async function loadTaskReport(taskId) {
  state.currentTaskId = taskId;
  renderSessions();
  const taskData = await api(`/tasks/${taskId}?user_id=${encodeURIComponent(state.userId)}`);
  setText("report-title", taskData.task.query);

  if (taskData.task.status !== "succeeded") {
    setText("report-content", `当前任务状态为 ${taskData.task.status}。\n错误信息：${taskData.task.error_message || "暂无"}`);
    document.getElementById("artifact-gallery").innerHTML = "";
    return;
  }

  const reportData = await api(`/tasks/${taskId}/report/content?user_id=${encodeURIComponent(state.userId)}`);
  setText("report-content", reportData.content || "");

  const artifactData = await api(`/tasks/${taskId}/artifacts?user_id=${encodeURIComponent(state.userId)}`);
  renderArtifacts(artifactData.artifacts || []);
}

function renderArtifacts(artifacts) {
  const gallery = document.getElementById("artifact-gallery");
  gallery.innerHTML = "";
  const images = artifacts.filter((item) => item.is_image);
  if (!images.length) {
    gallery.innerHTML = '<div class="empty">当前任务没有图片产物。</div>';
    return;
  }
  images.forEach((artifact) => {
    const card = document.createElement("div");
    card.className = "artifact-card";
    card.innerHTML = `
      <img src="${artifact.url}" alt="${artifact.name}" />
      <div><a href="${artifact.url}" target="_blank" rel="noreferrer">${artifact.name}</a></div>
    `;
    gallery.appendChild(card);
  });
}

async function handleUpload(event) {
  event.preventDefault();
  const input = document.getElementById("upload-input");
  if (!input.files.length) {
    setText("upload-status", "请选择至少一个文件。");
    return;
  }

  const formData = new FormData();
  formData.append("user_id", state.userId);
  Array.from(input.files).forEach((file) => formData.append("files", file));
  setText("upload-status", "上传中...");
  await api("/files/upload", { method: "POST", body: formData });
  setText("upload-status", "文件上传完成。");
  input.value = "";
  await refreshFiles();
}

async function handleCreateSession(event) {
  event.preventDefault();
  const checked = Array.from(document.querySelectorAll("#session-file-picker input:checked"));
  const fileIds = checked.map((item) => item.value);
  if (!fileIds.length) {
    setText("session-status", "请至少选择一个文件。");
    return;
  }

  const payload = {
    user_id: state.userId,
    title: document.getElementById("session-title").value.trim(),
    query: document.getElementById("session-query").value.trim(),
    file_ids: fileIds,
  };
  setText("session-status", "会话创建中...");
  const data = await api("/sessions", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(payload),
  });
  setText("session-status", "会话已创建，正在执行首个专题。");
  document.getElementById("session-form").reset();
  await refreshSessions(data.session.id);
}

async function handleFollowup() {
  if (!state.currentSessionId) {
    setText("detail-meta", "请先选择一个会话。");
    return;
  }
  const query = document.getElementById("followup-query").value.trim();
  if (!query) {
    return;
  }
  await api(`/sessions/${state.currentSessionId}/topics`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ user_id: state.userId, query }),
  });
  document.getElementById("followup-query").value = "";
  await refreshSessions(state.currentSessionId);
}

async function handleCloseSession() {
  if (!state.currentSessionId) {
    return;
  }
  await api(`/sessions/${state.currentSessionId}/close?user_id=${encodeURIComponent(state.userId)}`, {
    method: "POST",
  });
  await refreshSessions(state.currentSessionId);
}

function startPolling() {
  if (state.pollTimer) {
    clearInterval(state.pollTimer);
  }
  state.pollTimer = setInterval(() => {
    refreshSessions().catch((error) => console.error(error));
  }, 8000);
}

async function bootstrap() {
  ensureUserId();
  document.getElementById("upload-form").addEventListener("submit", (event) => {
    handleUpload(event).catch((error) => setText("upload-status", error.message));
  });
  document.getElementById("session-form").addEventListener("submit", (event) => {
    handleCreateSession(event).catch((error) => setText("session-status", error.message));
  });
  document.getElementById("submit-followup").onclick = () => {
    handleFollowup().catch((error) => setText("detail-meta", error.message));
  };
  document.getElementById("close-session").onclick = () => {
    handleCloseSession().catch((error) => setText("detail-meta", error.message));
  };
  document.getElementById("refresh-sessions").onclick = () => {
    refreshSessions().catch((error) => console.error(error));
  };

  await refreshFiles();
  await refreshSessions();
  startPolling();
}

bootstrap().catch((error) => {
  console.error(error);
  setText("detail-meta", error.message);
});