import { Body, Controller, HttpCode, HttpStatus, Post, Query, Request, Res, UseGuards } from '@nestjs/common';
import { Response } from 'express';
import * as fs from 'fs';
import * as path from 'path';
import { ExportService } from '../service/export.service';
import { JwtAuthGuard } from '../../auth/guards/jwt.guard';

@Controller()
export class ExportController {

  constructor(private readonly exportService: ExportService) {
  }

  @HttpCode(HttpStatus.OK)
  @UseGuards(JwtAuthGuard)
  @Post('download-report')
  async downloadExcel(
    @Body() body: any,
    @Request() req: Request & { user: any },
    @Query() queryParams: Record<string, string>,
    @Res() res: Response,
    @Query('level_type') levelType?: string,
    @Query('level_id') levelId?: number,
    @Query('appcode') appCode?: string,
  ) {
    try {
      const loggedInUser = req.user.userData;

      const {
        entity_type,
        quickFilter,
        savedFilterCode,
        attributeFilter,
        tabs,
        sortby,
        view
      } = body;

      const { ...otherQueryParams } = queryParams;

      const filePath = await this.exportService.generateExcelReport({
          entity_type,
          quickFilter,
          savedFilterCode,
          attributeFilter,
          tabs,
          sortby,
          page: null,
          size: null,
          loggedInUser,
          queryParams: otherQueryParams, // only remaining query params
          customLevelType: levelType,
          customLevelId: levelId,
          customAppCode: appCode,
          view
        },
      );

      if (!filePath || !fs.existsSync(filePath)) {
        return res.status(404).json({ message: 'File not found' });
      }

      res.setHeader(
        'Content-Disposition',
        `attachment; filename=${path.basename(filePath)}`,
      );
      res.setHeader(
        'Content-Type',
        'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      );

      const fileStream = fs.createReadStream(filePath);
      fileStream.pipe(res);

      // Optional: Delete file after sending response
      fileStream.on('end', () => {
        fs.unlinkSync(filePath);
      });
    } catch (error) {
      console.error('Error downloading Excel file:', error);
      res.status(500).json({ message: 'Internal server error' });
    }
  }
}