import { rm } from 'node:fs/promises';
import {
  BadRequestException,
  Controller,
  Delete,
  ForbiddenException,
  Get,
  HttpCode,
  HttpStatus,
  NotFoundException,
  Param,
  Post,
  Res,
  StreamableFile,
  UploadedFile,
  UseInterceptors,
} from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import { Session, type UserSession } from '@thallesp/nestjs-better-auth';
import type { Response } from 'express';
import { UploadFileUseCase } from '../../application/use-cases/upload-file/upload-file.use-case.js';
import { DownloadFileUseCase } from '../../application/use-cases/download-file/download-file.use-case.js';
import { DeleteFileUseCase } from '../../application/use-cases/delete-file/delete-file.use-case.js';
import { UploadFileCommand } from '../../application/use-cases/upload-file/upload-file.command.js';
import { DownloadFileQuery } from '../../application/use-cases/download-file/download-file.query.js';
import { DeleteFileCommand } from '../../application/use-cases/delete-file/delete-file.command.js';
import { FileNotFoundException } from '../../domain/exceptions/file-not-found.exception.js';
import { FileForbiddenException } from '../../domain/exceptions/file-forbidden.exception.js';
import { contentDisposition } from '../helpers/content-disposition.js';

@Controller('files')
export class FileController {
  constructor(
    private readonly uploadFileUseCase: UploadFileUseCase,
    private readonly downloadFileUseCase: DownloadFileUseCase,
    private readonly deleteFileUseCase: DeleteFileUseCase,
  ) {}

  /**
   * multipart/form-data с полем `file`. Лимиты и временный каталог задаёт
   * MulterModule в FileModule; превышение размера — 413 от Nest.
   */
  @Post()
  @UseInterceptors(FileInterceptor('file'))
  async upload(@UploadedFile() file: Express.Multer.File | undefined, @Session() session: UserSession) {
    if (!file) {
      throw new BadRequestException('Поле file обязательно');
    }

    try {
      return await this.uploadFileUseCase.execute(
        new UploadFileCommand(session.user.id, file.path, file.originalname, file.size),
      );
    } finally {
      await rm(file.path, { force: true });
    }
  }

  @Get(':id/download')
  async download(
    @Param('id') id: string,
    @Session() session: UserSession,
    @Res({ passthrough: true }) res: Response,
  ): Promise<StreamableFile> {
    const { file, inline, stream } = await this.handleErrors(() =>
      this.downloadFileUseCase.execute(new DownloadFileQuery(id, session.user.id)),
    );

    // Браузер не должен «угадывать» тип: иначе octet-stream с HTML внутри
    // может исполниться как страница на нашем домене
    res.setHeader('X-Content-Type-Options', 'nosniff');
    res.setHeader('Cache-Control', 'private, max-age=0, must-revalidate');

    return new StreamableFile(stream, {
      type: file.mimeType,
      length: file.size,
      disposition: contentDisposition(inline ? 'inline' : 'attachment', file.fileName),
    });
  }

  @Delete(':id')
  @HttpCode(HttpStatus.NO_CONTENT)
  async delete(@Param('id') id: string, @Session() session: UserSession) {
    await this.handleErrors(() => this.deleteFileUseCase.execute(new DeleteFileCommand(id, session.user.id)));
  }

  /** Транслирует доменные исключения в HTTP-ответ — это забота presentation-слоя */
  private async handleErrors<T>(fn: () => Promise<T>): Promise<T> {
    try {
      return await fn();
    } catch (error) {
      if (error instanceof FileNotFoundException) {
        throw new NotFoundException(error.message);
      }
      if (error instanceof FileForbiddenException) {
        throw new ForbiddenException(error.message);
      }
      throw error;
    }
  }
}