/**
 * Session控制器
 * 
 * API端点：
 * - POST   /sessions/upload      上传Excel文件创建Session
 * - GET    /sessions/:id         获取Session信息
 * - GET    /sessions/:id/preview 获取预览数据（⭐ 已改为全量加载）
 * - GET    /sessions/:id/full    获取完整数据
 * - DELETE /sessions/:id         删除Session
 * - POST   /sessions/:id/heartbeat 更新心跳
 * 
 * @module SessionController
 */

import { FastifyRequest, FastifyReply } from 'fastify';
import { MultipartFile } from '@fastify/multipart';
import { logger } from '../../../../common/logging/index.js';
import { sessionService } from '../services/SessionService.js';
import { dataProcessService } from '../services/DataProcessService.js';
import { jobQueue } from '../../../../common/jobs/index.js';
import * as xlsx from 'xlsx';
import { activityService } from '../../../../common/services/activity.service.js';

/**
 * 获取用户ID（从JWT Token中获取）
 */
function getUserId(request: FastifyRequest): string {
  const userId = (request as any).user?.userId;
  if (!userId) {
    throw new Error('User not authenticated');
  }
  return userId;
}

// ==================== 请求参数类型定义 ====================

interface SessionIdParams {
  id: string;
}

interface GetUniqueValuesQuery {
  column: string;
}

// ==================== 控制器 ====================

export class SessionController {
  /**
   * 上传Excel文件创建Session
   * 
   * POST /api/v1/dc/tool-c/sessions/upload
   */
  async upload(request: FastifyRequest, reply: FastifyReply) {
    try {
      logger.info('[SessionController] 收到文件上传请求');

      // 1. 获取multipart数据
      const data = await request.file();
      
      if (!data) {
        return reply.code(400).send({
          success: false,
          error: '未找到上传的文件',
        });
      }

      const file = data as MultipartFile;
      const fileName = file.filename;

      logger.info(`[SessionController] 文件名: ${fileName}`);

      // 2. 读取文件到Buffer
      const fileBuffer = await file.toBuffer();

      // 3. 验证文件
      const validation = dataProcessService.validateFile(fileBuffer, fileName);
      if (!validation.valid) {
        return reply.code(400).send({
          success: false,
          error: validation.error,
        });
      }

      // 4. 获取用户ID
      const userId = getUserId(request);

      // 5. 创建Session（Postgres-Only架构 - 异步处理）
      const sessionResult = await sessionService.createSession(
        userId,
        fileName,
        fileBuffer
      );

      logger.info(`[SessionController] Session创建成功: ${sessionResult.id}, jobId: ${sessionResult.jobId}`);

      // 埋点：DC 上传数据文件
      try {
        const user = (request as any).user;
        if (user) {
          activityService.log(
            user.tenantId,
            user.tenantName || null,
            user.userId || user.id,
            user.name || null,
            'DC',
            '智能数据清洗',
            'USE',
            `upload:${fileName}, session:${sessionResult.id}`,
          );
        }
      } catch { /* 埋点失败不影响主业务 */ }

      // 6. 返回Session信息 + jobId（用于前端轮询）
      return reply.code(201).send({
        success: true,
        message: 'Session创建成功',
        data: {
          sessionId: sessionResult.id,
          jobId: sessionResult.jobId,  // ✅ 返回 jobId 供前端轮询
          fileName: sessionResult.fileName,
          fileSize: dataProcessService.formatFileSize(sessionResult.fileSize),
          totalRows: sessionResult.totalRows,
          totalCols: sessionResult.totalCols,
          columns: sessionResult.columns,
          expiresAt: sessionResult.expiresAt,
          createdAt: sessionResult.createdAt,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 文件上传失败: ${error.message}`);
      return reply.code(500).send({
        success: false,
        error: error.message || '文件上传失败，请重试',
      });
    }
  }

  /**
   * 获取Session信息（只含元数据）
   * 
   * GET /api/v1/dc/tool-c/sessions/:id
   */
  async getSession(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 获取Session: ${id}`);

      const session = await sessionService.getSession(id);

      return reply.code(200).send({
        success: true,
        data: {
          sessionId: session.id,
          fileName: session.fileName,
          fileSize: dataProcessService.formatFileSize(session.fileSize),
          totalRows: session.totalRows,
          totalCols: session.totalCols,
          columns: session.columns,
          encoding: session.encoding,
          expiresAt: session.expiresAt,
          createdAt: session.createdAt,
          updatedAt: session.updatedAt,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 获取Session失败: ${error.message}`);
      
      const statusCode = error.message.includes('不存在') || error.message.includes('过期') 
        ? 404 
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '获取Session失败',
      });
    }
  }

  /**
   * 获取预览数据（⭐ 已改为全量加载）
   * 
   * GET /api/v1/dc/tool-c/sessions/:id/preview
   */
  async getPreviewData(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 获取预览数据: ${id}`);

      const result = await sessionService.getPreviewData(id);

      return reply.code(200).send({
        success: true,
        data: {
          sessionId: result.id,
          fileName: result.fileName,
          totalRows: result.totalRows,
          totalCols: result.totalCols,
          columns: result.columns,
          previewRows: result.previewData.length,
          previewData: result.previewData,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 获取预览数据失败: ${error.message}`);
      
      const statusCode = error.message.includes('不存在') || error.message.includes('过期') 
        ? 404 
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '获取预览数据失败',
      });
    }
  }

  /**
   * 获取完整数据
   * 
   * GET /api/v1/dc/tool-c/sessions/:id/full
   */
  async getFullData(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 获取完整数据: ${id}`);

      const data = await sessionService.getFullData(id);

      return reply.code(200).send({
        success: true,
        data: {
          sessionId: id,
          totalRows: data.length,
          data,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 获取完整数据失败: ${error.message}`);
      
      const statusCode = error.message.includes('不存在') || error.message.includes('过期') 
        ? 404 
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '获取完整数据失败',
      });
    }
  }

  /**
   * 删除Session
   * 
   * DELETE /api/v1/dc/tool-c/sessions/:id
   */
  async deleteSession(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 删除Session: ${id}`);

      await sessionService.deleteSession(id);

      return reply.code(200).send({
        success: true,
        message: 'Session删除成功',
      });
    } catch (error: any) {
      logger.error(`[SessionController] 删除Session失败: ${error.message}`);
      return reply.code(500).send({
        success: false,
        error: error.message || '删除Session失败',
      });
    }
  }

  /**
   * 更新心跳（延长过期时间）
   * 
   * POST /api/v1/dc/tool-c/sessions/:id/heartbeat
   */
  async updateHeartbeat(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 更新心跳: ${id}`);

      const newExpiresAt = await sessionService.updateHeartbeat(id);

      return reply.code(200).send({
        success: true,
        message: '心跳更新成功',
        data: {
          sessionId: id,
          expiresAt: newExpiresAt,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 更新心跳失败: ${error.message}`);
      
      const statusCode = error.message.includes('不存在') 
        ? 404 
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '更新心跳失败',
      });
    }
  }

  /**
   * ✨ 导出Excel文件（新增）
   * 
   * GET /api/v1/dc/tool-c/sessions/:id/export
   */
  async exportData(
    request: FastifyRequest<{ Params: SessionIdParams }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;

      logger.info(`[SessionController] 导出Excel: ${id}`);

      // 1. 获取Session信息
      const session = await sessionService.getSession(id);

      // 2. 获取完整数据
      const data = await sessionService.getFullData(id);

      // 3. 生成Excel
      const workbook = xlsx.utils.book_new();
      const worksheet = xlsx.utils.json_to_sheet(data);
      
      // 设置列宽（自动调整）
      const colWidths = session.columns.map(col => {
        const maxLength = Math.max(
          col.length,
          ...data.slice(0, 100).map(row => String(row[col] || '').length)
        );
        return { wch: Math.min(maxLength + 2, 50) };
      });
      worksheet['!cols'] = colWidths;
      
      xlsx.utils.book_append_sheet(workbook, worksheet, 'Data');

      // 4. 生成Buffer
      const buffer = xlsx.write(workbook, { 
        type: 'buffer', 
        bookType: 'xlsx',
        compression: true,
      });

      // 5. 生成文件名（加上_cleaned后缀和时间戳）
      const timestamp = new Date().toISOString().replace(/[:.]/g, '-').slice(0, 19);
      const baseFileName = session.fileName.replace(/\.[^/.]+$/, ''); // 去除扩展名
      const exportFileName = `${baseFileName}_cleaned_${timestamp}.xlsx`;

      logger.info(`[SessionController] 导出成功: ${exportFileName}, 大小: ${(buffer.length / 1024).toFixed(2)}KB`);

      // 6. 返回文件
      reply.header('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
      reply.header('Content-Disposition', `attachment; filename="${encodeURIComponent(exportFileName)}"`);
      reply.header('Content-Length', buffer.length);
      
      return reply.send(buffer);
    } catch (error: any) {
      logger.error(`[SessionController] 导出Excel失败: ${error.message}`);
      
      const statusCode = error.message.includes('不存在') || error.message.includes('过期') 
        ? 404 
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '导出Excel失败',
      });
    }
  }

  /**
   * ✨ 获取列的唯一值（用于数值映射）
   * 
   * GET /api/v1/dc/tool-c/sessions/:id/unique-values?column=xxx
   */
  async getUniqueValues(
    request: FastifyRequest<{ Params: SessionIdParams; Querystring: GetUniqueValuesQuery }>,
    reply: FastifyReply
  ) {
    try {
      const { id } = request.params;
      const { column } = request.query;

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

      logger.info(`[SessionController] 获取唯一值: session=${id}, column=${column}`);

      // 1. 获取完整数据
      const data = await sessionService.getFullData(id);

      // 2. 提取唯一值（保留NA值，但清理字符串）
      const values = data.map((row) => row[column]);
      const cleanedValues = values.map((val) => {
        if (val === null || val === undefined || val === '') return null;
        // 如果是字符串，去除首尾空格
        return typeof val === 'string' ? val.trim() : val;
      });

      // 3. 去重（✨ 保留null值，但用特殊标记表示）
      const uniqueSet = Array.from(new Set(cleanedValues));
      const hasNA = uniqueSet.includes(null);
      const naCount = cleanedValues.filter(v => v === null).length;  // ✨ 统计NA数量
      
      // 过滤掉null和空白，然后排序
      const nonNAValues = uniqueSet
        .filter((v) => v !== null && v !== '' && v !== '(空白)')
        .sort(); // 排序，方便查看
      
      // ✨ 如果有NA，添加到数组末尾（用特殊字符串标记）
      const uniqueValues = hasNA 
        ? [...nonNAValues, '<空值/NA>']
        : nonNAValues;

      logger.info(`[SessionController] 唯一值数量: ${uniqueValues.length} (含NA: ${hasNA}, NA数量: ${naCount})`);

      // 4. 返回结果
      return reply.send({
        success: true,
        data: {
          column,
          uniqueValues,
          count: uniqueValues.length,
          naCount: hasNA ? naCount : 0,  // ✨ 返回NA数量
          totalCount: data.length,  // ✨ 总行数
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 获取唯一值失败: ${error.message}`);

      const statusCode = error.message.includes('不存在') || error.message.includes('过期')
        ? 404
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '获取唯一值失败',
      });
    }
  }

  /**
   * 获取Session状态（Postgres-Only架构）
   * 
   * 查询任务状态：
   * - 从 pg-boss 查询 job 状态
   * - 从 Session 表查询解析结果
   * - 合并返回给前端
   * 
   * GET /api/v1/dc/tool-c/sessions/:id/status
   * Query: jobId (可选，首次上传时提供)
   */
  async getSessionStatus(
    request: FastifyRequest<{ Params: SessionIdParams; Querystring: { jobId?: string } }>,
    reply: FastifyReply
  ) {
    try {
      const { id: sessionId } = request.params;
      const { jobId } = request.query;

      logger.info(`[SessionController] 获取Session状态: sessionId=${sessionId}, jobId=${jobId}`);

      // 1. 查询 Session 信息
      const session = await sessionService.getSession(sessionId);

      // 2. 判断解析状态
      //    - 如果 totalRows 不为 null，说明解析已完成
      //    - 否则查询 job 状态
      if (session.totalRows !== null && session.totalRows !== undefined) {
        // 解析已完成
        logger.info(`[SessionController] Session已解析完成: ${sessionId}`);
        return reply.code(200).send({
          success: true,
          data: {
            sessionId,
            status: 'ready',  // ✅ 解析完成
            progress: 100,
            session,
          },
        });
      }

      // 3. 解析中，查询 job 状态
      if (!jobId) {
        // 没有 jobId，可能是旧数据或直接查询
        logger.warn(`[SessionController] 没有jobId，Session可能处于pending状态`);
        return reply.code(200).send({
          success: true,
          data: {
            sessionId,
            status: 'processing',  // 处理中
            progress: 50,  // 估算进度
            session: {
              ...session,
              totalRows: null,
              totalCols: null,
              columns: null,
            },
          },
        });
      }

      // 4. 从 pg-boss 查询 job 状态
      const job = await jobQueue.getJob(jobId);

      if (!job) {
        logger.warn(`[SessionController] Job不存在: ${jobId}`);
        return reply.code(200).send({
          success: true,
          data: {
            sessionId,
            status: 'processing',
            progress: 50,
            session,
          },
        });
      }

      // 5. 映射 job 状态到前端状态
      let status = 'processing';
      let progress = 50;

      switch (job.status) {
        case 'completed':
          status = 'ready';
          progress = 100;
          break;
        case 'failed':
          status = 'error';
          progress = 0;
          break;
        case 'processing':
          status = 'processing';
          progress = 70;  // 处理中，估算70%
          break;
        default:
          status = 'processing';
          progress = 30;  // 队列中，估算30%
      }

      logger.info(`[SessionController] Job状态: ${job.status}, 前端状态: ${status}`);

      return reply.code(200).send({
        success: true,
        data: {
          sessionId,
          jobId,
          status,
          progress,
          session,
        },
      });
    } catch (error: any) {
      logger.error(`[SessionController] 获取Session状态失败: ${error.message}`);

      const statusCode = error.message.includes('不存在') || error.message.includes('过期')
        ? 404
        : 500;

      return reply.code(statusCode).send({
        success: false,
        error: error.message || '获取Session状态失败',
      });
    }
  }
}

// ==================== 导出单例实例 ====================

export const sessionController = new SessionController();