import { BadRequestException, Body, Controller, Get, Param, Post, Query, Res, UploadedFile, UseInterceptors } from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import { ApiTags } from '@nestjs/swagger';
import { TenantId } from '../common/tenant-id.decorator';
import { CreateFileObjectDto, CreatePresignedUploadDto, FilesService } from './files.service';

type UploadedMultipartFile = {
  originalname: string;
  mimetype: string;
  size: number;
  buffer: Buffer;
};

type DownloadResponse = {
  setHeader(name: string, value: number | string): void;
  send(content: Buffer): void;
};

@ApiTags('files')
@Controller('admin/files')
export class FilesController {
  constructor(private readonly files: FilesService) {}

  @Get()
  list(@TenantId() tenantId?: string) {
    return this.files.list(tenantId);
  }

  @Get(':id/download')
  async download(@Param('id') id: string, @Query('disposition') disposition: string | undefined, @Res() response: DownloadResponse) {
    const { fileObject, content } = await this.files.getDownload(id);
    const mode = disposition === 'inline' ? 'inline' : 'attachment';
    const encodedName = encodeURIComponent(fileObject.fileName);
    response.setHeader('Content-Type', fileObject.contentType || 'application/octet-stream');
    response.setHeader('Content-Length', content.length);
    response.setHeader('Content-Disposition', `${mode}; filename*=UTF-8''${encodedName}`);
    response.send(content);
  }

  @Post()
  create(@Body() body: CreateFileObjectDto) {
    return this.files.create(body);
  }

  @Post('presigned-upload')
  createPresignedUpload(@Body() body: CreatePresignedUploadDto) {
    return this.files.createPresignedUpload(body);
  }

  @Post('upload')
  @UseInterceptors(FileInterceptor('file', {
    limits: {
      fileSize: 20 * 1024 * 1024,
      files: 1,
      fields: 4,
      parts: 5,
      fieldNameSize: 100,
      fieldSize: 1024,
      headerPairs: 100,
    },
  }))
  upload(@UploadedFile() file: UploadedMultipartFile, @Body('purpose') purpose: string, @Body('prefix') prefix?: string, @TenantId() tenantId?: string) {
    if (!file) {
      throw new BadRequestException('Upload file is required');
    }
    return this.files.upload({ tenantId, purpose: purpose || 'general', prefix }, file);
  }
}