import { Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';
import { AuditService } from '../app/auditor/services/auditor.service';
import { JwtService } from '@nestjs/jwt';
import { TokenExpiredError } from 'jsonwebtoken';
import { Audit } from '../app/auditor/schemas/audit.schema';
import messages from '../shared/messages/messages';

@Injectable()
export class AuditMiddleware implements NestMiddleware {
  constructor(
    private readonly auditorService: AuditService,
    private readonly jwtService: JwtService,
  ) {}

  async use(req: Request, res: Response, next: NextFunction) {
    const { method, originalUrl, headers, body } = req;
    const originalSend = res.send;

    res.send = function (data, ...restArgs) {
      res.locals.data = data;
      return originalSend.apply(res, [data, ...restArgs]);
    };

    let tokenExpiredAt: Date | null = null;
    let userId: string | null = null;

    if (headers.authorization) {
      const token = headers.authorization.split(' ')[1];

      try {
        const decoded = this.jwtService.verify(token, { secret: 'puma1984' });
        userId = decoded.sub;
      } catch (e) {
        if (e instanceof TokenExpiredError) {
          tokenExpiredAt = e.expiredAt;
          return res.status(401).json({
            status: 401,
            message: messages.error.token.message,
            error: messages.error.token.summary,
          });
        } else {
          return res.status(401).json({
            status: 401,
            message: messages.error.token.message,
            error: messages.error.token.summary,
          });
        }
      }
    }

    res.on('finish', async () => {
      const response = res.locals.data || {};

      if (userId) {
        await this.auditorService.log({
          userId,
          method,
          url: originalUrl,
          headers,
          body,
          response:
            typeof response === 'string' ? JSON.parse(response) : response,
          tokenExpiredAt,
        } as unknown as Partial<Audit>);
      }
    });

    next();
  }
}