/**
 * 智能文献检索 Controller
 * 
 * SSE 流式 + PubMed 链接提取
 */

import { FastifyRequest, FastifyReply } from 'fastify';
import { researchService } from '../services/researchService.js';
import { logger } from '../../../common/logging/index.js';

interface SearchBody {
  projectId: string;
  query: string;
}

/**
 * POST /api/v1/asl/research/stream
 * SSE 实时流式检索
 */
export async function streamSearch(
  request: FastifyRequest<{ Body: SearchBody }>,
  reply: FastifyReply
) {
  const { projectId, query } = request.body;
  const userId = request.user?.userId;

  if (!userId) {
    return reply.code(401).send({ success: false, error: '用户未认证' });
  }

  if (!query?.trim()) {
    return reply.code(400).send({ success: false, error: '请输入检索问题' });
  }

  logger.info('[ResearchController] Starting SSE stream', { userId, queryLength: query.length });

  // 设置 SSE 响应头
  reply.raw.writeHead(200, {
    'Content-Type': 'text/event-stream',
    'Cache-Control': 'no-cache',
    'Access-Control-Allow-Origin': '*',
    'X-Accel-Buffering': 'no',
  });

  try {
    const task = await researchService.createTaskRecord(projectId, userId, query);

    reply.raw.write(`data: ${JSON.stringify({ type: 'task_created', taskId: task.id })}\n\n`);

    await researchService.executeStreamSearch(
      task.id,
      query,
      // 思考过程（统一追加）
      (reasoning: string) => {
        reply.raw.write(`data: ${JSON.stringify({ type: 'reasoning', content: reasoning })}\n\n`);
      },
      // 结果内容（统一追加）
      (content: string) => {
        reply.raw.write(`data: ${JSON.stringify({ type: 'content', content })}\n\n`);
      },
      // 完成（返回链接列表）
      (result: { links: string[] }) => {
        reply.raw.write(`data: ${JSON.stringify({ type: 'completed', links: result.links })}\n\n`);
        reply.raw.end();
      },
      // 错误
      (error: string) => {
        reply.raw.write(`data: ${JSON.stringify({ type: 'error', error })}\n\n`);
        reply.raw.end();
      }
    );
  } catch (error: any) {
    logger.error('[ResearchController] Stream search failed', { error: error.message });
    reply.raw.write(`data: ${JSON.stringify({ type: 'error', error: error.message })}\n\n`);
    reply.raw.end();
  }
}

/**
 * POST /api/v1/asl/research/tasks
 * 创建检索任务（异步模式）
 */
export async function createTask(
  request: FastifyRequest<{ Body: SearchBody }>,
  reply: FastifyReply
) {
  try {
    const { projectId, query } = request.body;
    const userId = request.user?.userId;

    if (!userId) {
      return reply.code(401).send({ success: false, error: '用户未认证' });
    }

    if (!projectId) {
      return reply.code(400).send({ success: false, error: '缺少 projectId' });
    }

    if (!query?.trim()) {
      return reply.code(400).send({ success: false, error: '请输入检索问题' });
    }

    const task = await researchService.createTask({ projectId, userId, query: query.trim() });
    return reply.send({ success: true, data: task });
  } catch (error: any) {
    logger.error('[ResearchController] Create task failed', { error: error.message });
    return reply.code(500).send({ success: false, error: error.message });
  }
}

/**
 * GET /api/v1/asl/research/tasks/:taskId/status
 * 获取任务状态
 */
export async function getTaskStatus(
  request: FastifyRequest<{ Params: { taskId: string } }>,
  reply: FastifyReply
) {
  try {
    const { taskId } = request.params;

    if (!taskId) {
      return reply.code(400).send({ success: false, error: '缺少 taskId' });
    }

    const status = await researchService.getTaskStatus(taskId);

    if (!status) {
      return reply.code(404).send({ success: false, error: '任务不存在' });
    }

    return reply.send({ success: true, data: status });
  } catch (error: any) {
    logger.error('[ResearchController] Get task status failed', { error: error.message });
    return reply.code(500).send({ success: false, error: error.message });
  }
}