window.PluginUI = (() => {
  async function request(path, options = {}) {
    const response = await fetch(path, options);
    const contentType = response.headers.get("content-type") || "";
    const payload = contentType.includes("application/json")
      ? await response.json()
      : await response.text();

    if (!response.ok) {
      const detail = typeof payload === "object" ? payload.detail || payload.message : payload;
      throw new Error(detail || `请求失败：${response.status}`);
    }

    return payload;
  }

  async function requestBlob(path, options = {}) {
    const response = await fetch(path, options);
    if (!response.ok) {
      let detail = "";
      try {
        const payload = await response.json();
        detail = payload.detail || payload.message || "";
      } catch {
        detail = await response.text();
      }
      throw new Error(detail || `请求失败：${response.status}`);
    }
    return response.blob();
  }

  function showMessage(id, text, type = "success") {
    const el = document.getElementById(id);
    if (!el) return;
    el.textContent = text;
    el.className = `plugin-message show ${type}`;
  }

  function clearMessage(id) {
    const el = document.getElementById(id);
    if (!el) return;
    el.textContent = "";
    el.className = "plugin-message";
  }

  function setText(id, value) {
    const el = document.getElementById(id);
    if (el) el.textContent = value == null ? "" : String(value);
  }

  function setJson(id, value) {
    setText(id, typeof value === "string" ? value : JSON.stringify(value, null, 2));
  }

  function downloadBlob(blob, filename) {
    const url = URL.createObjectURL(blob);
    const link = document.createElement("a");
    link.href = url;
    link.download = filename;
    document.body.appendChild(link);
    link.click();
    link.remove();
    URL.revokeObjectURL(url);
  }

  function fileSize(bytes) {
    if (!Number.isFinite(bytes)) return "-";
    if (bytes < 1024) return `${bytes} B`;
    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
    return `${(bytes / 1024 / 1024).toFixed(1)} MB`;
  }

  async function copyText(text) {
    await navigator.clipboard.writeText(text);
  }

  // ============================================================
  // Run Log 组件 — 从后端 run/log API 轮询真实事件
  // ============================================================

  /** 时间格式化辅助 */
  function _formatTs(ts) {
    try {
      const d = new Date(ts);
      const pad = (n) => String(n).padStart(2, "0");
      return `${pad(d.getHours())}:${pad(d.getMinutes())}:${pad(d.getSeconds())}`;
    } catch {
      return ts || "";
    }
  }

  /** 事件级别对应的 CSS class */
  function _levelClass(level) {
    if (level === "error") return "run-log-entry--error";
    if (level === "warning") return "run-log-entry--warn";
    return "";
  }

  /** 事件级别对应的中文标签 */
  function _levelLabel(level) {
    if (level === "error") return "错误";
    if (level === "warning") return "警告";
    if (level === "debug") return "调试";
    return "信息";
  }

  /**
   * 创建 run 日志容器，返回日志 DOM 元素。
   * 调用方应将其插入到期望的位置。
   *
   * @param {Object} [options]
   * @param {string} [options.title] - 面板标题，默认"运行日志"
   * @returns {HTMLElement} 日志容器 DOM
   */
  function createRunLog(options = {}) {
    const title = options.title || "运行日志";

    const panel = document.createElement("div");
    panel.className = "plugin-panel run-log-panel";

    const titleEl = document.createElement("h3");
    titleEl.className = "plugin-panel-title";
    titleEl.textContent = title;
    panel.appendChild(titleEl);

    // 运行状态指示器
    const statusBar = document.createElement("div");
    statusBar.className = "run-log-status";
    statusBar.innerHTML = `<span class="run-log-status-dot"></span><span class="run-log-status-text">等待运行...</span>`;
    panel.appendChild(statusBar);

    // 日志列表
    const logList = document.createElement("div");
    logList.className = "run-log-list";
    panel.appendChild(logList);

    // 存储内部状态（不在 DOM 中暴露）
    panel._runLogState = {
      seenSeq: new Set(),
      pollingTimer: null,
      apiBase: "",
      runId: "",
      statusBar,
      logList,
    };

    return panel;
  }

  /**
   * 渲染单条事件到日志列表。
   *
   * @param {HTMLElement} logPanel - createRunLog 返回的面板
   * @param {Object} event - 事件对象 {seq, ts, stage, level, message, detail, artifact_id}
   */
  function _renderEvent(logPanel, event) {
    const state = logPanel._runLogState;
    if (!state) return;

    // 去重
    if (state.seenSeq.has(event.seq)) return;
    state.seenSeq.add(event.seq);

    const entry = document.createElement("div");
    entry.className = `run-log-entry ${_levelClass(event.level)}`;

    // 事件头部：时间 + 阶段 + 级别
    const header = document.createElement("div");
    header.className = "run-log-entry-header";

    const ts = document.createElement("span");
    ts.className = "run-log-entry-ts";
    ts.textContent = _formatTs(event.ts);

    const stage = document.createElement("span");
    stage.className = "run-log-entry-stage";
    stage.textContent = event.stage || "";

    const level = document.createElement("span");
    level.className = `run-log-entry-level run-log-level--${event.level || "info"}`;
    level.textContent = _levelLabel(event.level);

    header.appendChild(ts);
    header.appendChild(stage);
    header.appendChild(level);
    entry.appendChild(header);

    // 消息
    const msg = document.createElement("div");
    msg.className = "run-log-entry-message";
    msg.textContent = event.message || "";
    entry.appendChild(msg);

    // 详情（折叠显示）
    if (event.detail) {
      const detail = document.createElement("details");
      detail.className = "run-log-entry-detail";
      const summary = document.createElement("summary");
      summary.textContent = "详情";
      detail.appendChild(summary);
      const pre = document.createElement("pre");
      pre.textContent = event.detail;
      detail.appendChild(pre);
      entry.appendChild(detail);
    }

    // artifact 链接
    if (event.artifact_id) {
      const artifactLink = document.createElement("div");
      artifactLink.className = "run-log-entry-artifact";
      artifactLink.innerHTML = `<span class="run-log-artifact-icon">📎</span>产物: <code>${event.artifact_id}</code>`;
      entry.appendChild(artifactLink);
    }

    state.logList.appendChild(entry);
    // 自动滚动到底部
    state.logList.scrollTop = state.logList.scrollHeight;
  }

  /**
   * 开始轮询后端 run events API，自动追加事件到日志面板。
   *
   * @param {string} pluginName - 插件名（如 "audio"），用于拼真后端路径 /api/plugins/{pluginName}/runs/{runId}
   * @param {string} runId - 运行 ID
   * @param {HTMLElement} logPanel - createRunLog 返回的面板
   * @param {Object} [options]
   * @param {number} [options.interval] - 轮询间隔（毫秒），默认 1500
   * @param {Function} [options.onRunComplete] - run 完成回调，参数 (run)
   * @param {Function} [options.onError] - 轮询失败回调，参数 (error)
   */
  function pollRunEvents(pluginName, runId, logPanel, options = {}) {
    const state = logPanel._runLogState;
    if (!state) return;

    // 清理旧轮询
    if (state.pollingTimer) {
      clearInterval(state.pollingTimer);
      state.pollingTimer = null;
    }

    state.pluginName = pluginName;
    state.runId = runId;

    const interval = options.interval || 1500;

    // 更新状态指示器
    state.statusBar.querySelector(".run-log-status-text").textContent = "运行中...";
    state.statusBar.querySelector(".run-log-status-dot").className =
      "run-log-status-dot run-log-status-dot--running";

    // 真后端 run 日志路径由 app/api/plugin_runs.py 提供，前缀 /api/plugins/{pluginName}/runs/{runId}
    const runBase = `/api/plugins/${pluginName}/runs/${runId}`;

    const poll = async () => {
      try {
        // 获取 run 状态
        const runResp = await request(runBase);
        const runStatus = runResp.status;

        // 获取事件列表
        const eventsResp = await request(`${runBase}/events`);
        const events = eventsResp.events || [];

        for (const event of events) {
          _renderEvent(logPanel, event);
        }

        // 检查是否完成
        if (runStatus === "succeeded" || runStatus === "failed") {
          clearInterval(state.pollingTimer);
          state.pollingTimer = null;

          const dot = state.statusBar.querySelector(".run-log-status-dot");
          const text = state.statusBar.querySelector(".run-log-status-text");

          if (runStatus === "succeeded") {
            dot.className = "run-log-status-dot run-log-status-dot--done";
            text.textContent = "运行完成";
          } else {
            dot.className = "run-log-status-dot run-log-status-dot--error";
            text.textContent = runResp.error
              ? `运行失败: ${runResp.error}`
              : "运行失败";
          }

          if (options.onRunComplete) {
            options.onRunComplete(runResp);
          }
        }
      } catch (err) {
        // 轮询失败不清空已有日志，仅在状态栏显示错误
        state.statusBar.querySelector(".run-log-status-dot").className =
          "run-log-status-dot run-log-status-dot--error";
        state.statusBar.querySelector(".run-log-status-text").textContent =
          `轮询错误: ${err.message}`;

        if (options.onError) {
          options.onError(err);
        }
      }
    };

    // 立即执行一次
    poll();
    // 定时轮询
    state.pollingTimer = setInterval(poll, interval);
  }

  /**
   * 停止当前日志面板的轮询。
   *
   * @param {HTMLElement} logPanel - createRunLog 返回的面板
   */
  function stopPolling(logPanel) {
    const state = logPanel._runLogState;
    if (state && state.pollingTimer) {
      clearInterval(state.pollingTimer);
      state.pollingTimer = null;
    }
  }

  /**
   * 渲染 artifact 下载链接。
   *
   * @param {Object} artifact - artifact 元数据 {artifact_id, filename, media_type, size}
   * @param {HTMLElement} container - 容器元素
   * @param {string} pluginName - 插件名（如 "audio"）
   * @param {string} runId - 运行 ID
   * @returns {HTMLElement} artifact 项 DOM
   */
  function renderArtifactLink(artifact, container, pluginName, runId) {
    const item = document.createElement("div");
    item.className = "plugin-item";

    const info = document.createElement("div");
    info.innerHTML = `
      <strong>${escapeHtml(artifact.filename)}</strong>
      <div class="plugin-muted" style="font-size:12px">${fileSize(artifact.size)} · ${escapeHtml(artifact.media_type)}</div>
    `;
    item.appendChild(info);

    const btn = document.createElement("button");
    btn.className = "plugin-button secondary";
    btn.textContent = "下载";
    btn.addEventListener("click", async () => {
      try {
        const blob = await requestBlob(
          `/api/plugins/${pluginName}/runs/${runId}/artifacts/${artifact.artifact_id}/download`
        );
        downloadBlob(blob, artifact.filename);
      } catch (err) {
        alert(`下载失败: ${err.message}`);
      }
    });
    item.appendChild(btn);

    container.appendChild(item);
    return item;
  }

  /** HTML 转义辅助 */
  function escapeHtml(str) {
    if (!str) return "";
    const el = document.createElement("span");
    el.textContent = str;
    return el.innerHTML;
  }

  return {
    request,
    requestBlob,
    showMessage,
    clearMessage,
    setText,
    setJson,
    downloadBlob,
    fileSize,
    copyText,
    createRunLog,
    pollRunEvents,
    stopPolling,
    renderArtifactLink,
    escapeHtml,
  };
})();