import { IncomingMessage, ServerResponse } from 'node:http';
import { createTask, getTask, getAllTasks, runTaskPipeline } from '../services/task-manager.service.ts';
import { generateExcelBuffer } from '../services/export.service.ts';
import { extractTextFromBuffer } from '../utils/file-parser.ts';
import { sendJson, readMultipartFile } from '../utils/http.ts';
import { ingestUploadedCreatorLibrary } from '../services/local-creator-db.service.ts';

/**
 * POST /api/tasks/upload-brief
 * 上传 Brief 文件，创建任务
 */
export async function handleUploadBrief(request: IncomingMessage, response: ServerResponse): Promise<void> {
  try {
    console.log('[Route] 收到上传请求, Content-Type:', request.headers['content-type']);
    const { fileName, buffer } = await readMultipartFile(request);
    console.log(`[Route] 解析文件: ${fileName}, 大小: ${buffer.length} bytes`);

    if (!buffer || buffer.length === 0) {
      sendJson(response, 400, { ok: false, message: '未收到文件内容' });
      return;
    }

    // 提取文件文本
    const briefText = extractTextFromBuffer(buffer, fileName);

    // 创建任务
    const task = createTask(fileName, briefText);
    const localCreatorCount = await ingestUploadedCreatorLibrary(buffer, fileName);
    console.log(`[Route] 任务已创建: ${task.id}, briefText长度: ${briefText.length}`);
    if (localCreatorCount > 0) {
      console.log(`[Route] 已从上传文件入库本地达人: ${localCreatorCount} 位`);
    }

    sendJson(response, 200, {
      taskId: task.id,
      fileName: task.fileName,
      localCreatorCount,
      message: `文件 ${fileName} 已上传，任务已创建`,
    });
  } catch (error) {
    console.error('[Upload] Error:', error);
    sendJson(response, 500, { ok: false, message: error instanceof Error ? error.message : '上传失败' });
  }
}

/**
 * POST /api/creator-library/upload
 * 上传本地达人资料库文件，入库到 PostgreSQL 清洗达人表
 */
export async function handleUploadCreatorLibrary(request: IncomingMessage, response: ServerResponse): Promise<void> {
  try {
    console.log('[Route] 收到达人资料库上传请求, Content-Type:', request.headers['content-type']);
    const { fileName, buffer } = await readMultipartFile(request);

    if (!buffer || buffer.length === 0) {
      sendJson(response, 400, { ok: false, message: '未收到文件内容' });
      return;
    }

    const localCreatorCount = await ingestUploadedCreatorLibrary(buffer, fileName);
    sendJson(response, 200, {
      ok: true,
      fileName,
      localCreatorCount,
      message: `达人资料库 ${fileName} 已入库 ${localCreatorCount} 位达人`,
    });
  } catch (error) {
    console.error('[CreatorLibraryUpload] Error:', error);
    sendJson(response, 500, { ok: false, message: error instanceof Error ? error.message : '达人资料库上传失败' });
  }
}

/**
 * POST /api/tasks/:taskId/start
 * 启动任务处理流水线（异步执行）
 */
export function handleStartTask(request: IncomingMessage, response: ServerResponse, taskId: string): void {
  const task = getTask(taskId);
  if (!task) {
    sendJson(response, 404, { ok: false, message: '任务不存在' });
    return;
  }

  if (task.status !== 'pending') {
    sendJson(response, 400, { ok: false, message: `任务状态为 ${task.status}，无法启动` });
    return;
  }

  console.log(`[Route] 启动任务: ${taskId}, 当前状态: ${task.status}`);

  // 异步执行流水线，不等待完成
  runTaskPipeline(taskId).catch((err) => {
    console.error(`[Task ${taskId}] Pipeline error:`, err);
  });

  sendJson(response, 200, { ok: true, message: '任务已启动，请轮询状态' });
}

/**
 * GET /api/tasks/:taskId
 * 获取任务状态与进度
 */
export function handleGetTask(response: ServerResponse, taskId: string): void {
  const task = getTask(taskId);
  if (!task) {
    sendJson(response, 404, { ok: false, message: '任务不存在' });
    return;
  }

  sendJson(response, 200, {
    taskId: task.id,
    status: task.status,
    fileName: task.fileName,
    steps: task.steps,
    requirements: task.requirements,
    searchCriteria: task.searchCriteria,
    totalPool: task.totalPool,
    candidateCount: task.candidates.length,
    strongCount: task.candidates.filter((c) => c.recommendStatus === '强推荐').length,
    backupCount: task.candidates.filter((c) => c.recommendStatus === '备选').length,
    error: task.error,
    createdAt: task.createdAt,
    updatedAt: task.updatedAt,
  });
}

/**
 * GET /api/tasks
 * 获取所有任务列表
 */
export function handleListTasks(response: ServerResponse): void {
  const tasks = getAllTasks().map((t) => ({
    taskId: t.id,
    status: t.status,
    fileName: t.fileName,
    candidateCount: t.candidates.length,
    createdAt: t.createdAt,
    updatedAt: t.updatedAt,
  }));

  sendJson(response, 200, { tasks });
}

/**
 * POST /api/tasks/:taskId/export
 * 导出推荐表 Excel 文件
 */
export function handleExportTask(response: ServerResponse, taskId: string): void {
  const task = getTask(taskId);
  if (!task) {
    sendJson(response, 404, { ok: false, message: '任务不存在' });
    return;
  }

  if (task.candidates.length === 0) {
    sendJson(response, 400, { ok: false, message: '暂无推荐候选人，无法导出' });
    return;
  }

  const excelBuffer = generateExcelBuffer(task.candidates, task.fileName);
  const exportFileName = `${task.fileName.replace(/\.[^.]+$/, '')}-推荐名单.xls`;

  response.writeHead(200, {
    'Access-Control-Allow-Origin': '*',
    'Content-Type': 'application/vnd.ms-excel; charset=utf-8',
    'Content-Disposition': `attachment; filename="${encodeURIComponent(exportFileName)}"`,
    'Content-Length': excelBuffer.byteLength,
  });
  response.end(excelBuffer);
}