import {
  Body,
  Controller,
  Delete,
  Get,
  Param,
  Post,
  Res,
  StreamableFile,
  UploadedFile,
  UseInterceptors,
} from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import {
  ApiBody,
  ApiConsumes,
  ApiCreatedResponse,
  ApiOkResponse,
  ApiOperation,
  ApiParam,
  ApiProduces,
  ApiTags,
} from '@nestjs/swagger';
import { User } from '@task-stream/api/identity/domain';
import {
  ApiOptionalPireonAuth,
  ApiPireonAuth,
  CurrentUser,
} from '@task-stream/api/identity/presenters';
import {
  ApiCommandErrors,
  ApiReadErrors,
} from '@task-stream/api/shared/presenters';
import { ValidationError } from '@task-stream/api/shared/domain';
import { IssuesService } from '@task-stream/api/tracker/application';
import type { Response } from 'express';
import { viewerOf } from '../common/viewer';
import { AttachFileDto } from './dto/requests.dto';
import { AttachmentResultDto, CommandResultDto } from './dto/responses.dto';
import { Refs } from './refs';

const ISSUE = ApiParam({
  name: 'issue',
  description: 'Ticket id or key',
  example: 'WEB-12',
});

/** What multer hands over for one uploaded field. */
interface UploadedPart {
  originalname: string;
  mimetype: string;
  buffer: Buffer;
}

/**
 * Types a browser may show in place. Anything else — HTML, SVG, scripts — is
 * always downloaded: a file someone uploaded must never run in this origin.
 */
const SHOWN_INLINE =
  /^(image\/(png|jpe?g|gif|webp|avif)|video\/(mp4|webm)|audio\/(mpeg|ogg|wav)|application\/pdf|text\/plain)$/;

/** REST adapter for a ticket's files: uploaded here, listed on the ticket. */
@ApiTags('Issues')
@ApiPireonAuth()
@Controller('issues/:issue/attachments')
export class AttachmentsController {
  constructor(
    private readonly issues: IssuesService,
    private readonly refs: Refs,
  ) {}

  @Post()
  @ISSUE
  @UseInterceptors(FileInterceptor('file'))
  @ApiConsumes('multipart/form-data')
  @ApiBody({ type: AttachFileDto })
  @ApiOperation({
    summary: 'Attach a file to a ticket (members)',
    description:
      'Multipart with the file as `file` and, optionally, `commentId` to place it under a comment. ' +
      'Up to ATTACHMENTS_MAX_MB megabytes (25 by default) and 50 files per ticket.',
  })
  @ApiCreatedResponse({ type: AttachmentResultDto })
  @ApiCommandErrors()
  async attach(
    @CurrentUser() me: User,
    @Param('issue') issue: string,
    @UploadedFile() file: UploadedPart | undefined,
    @Body() body: AttachFileDto,
  ) {
    if (!file) throw new ValidationError('Send the file as `file`');
    return this.issues.attach(
      me.id,
      await this.refs.issueId(me.id, issue),
      {
        fileName: Buffer.from(file.originalname, 'latin1').toString('utf8'),
        mimeType: file.mimetype,
        content: file.buffer,
      },
      body.commentId || null,
    );
  }

  @Get(':attachmentId')
  @ApiOptionalPireonAuth()
  @ISSUE
  @ApiOperation({ summary: "Download one of a ticket's files" })
  @ApiProduces('application/octet-stream')
  @ApiOkResponse({ description: 'The file' })
  @ApiReadErrors()
  async download(
    @CurrentUser() me: User | undefined,
    @Param('issue') issue: string,
    @Param('attachmentId') attachmentId: string,
    @Res({ passthrough: true }) res: Response,
  ): Promise<StreamableFile> {
    const viewer = viewerOf(me);
    const { attachment, content } = await this.issues.download(
      viewer,
      await this.refs.issueId(viewer, issue),
      attachmentId,
    );
    const inline = SHOWN_INLINE.test(attachment.mimeType);
    res.set({
      'Content-Type': inline ? attachment.mimeType : 'application/octet-stream',
      'Content-Length': String(attachment.size),
      'Content-Disposition': `${inline ? 'inline' : 'attachment'}; filename="${asciiName(attachment.fileName)}"; filename*=UTF-8''${encodeURIComponent(attachment.fileName)}`,
      'X-Content-Type-Options': 'nosniff',
      'Content-Security-Policy': "default-src 'none'; sandbox",
      'Cache-Control': 'private, max-age=3600',
    });
    return new StreamableFile(content);
  }

  @Delete(':attachmentId')
  @ISSUE
  @ApiOperation({
    summary: 'Remove a file (whoever uploaded it, or an owner/admin)',
  })
  @ApiOkResponse({ type: CommandResultDto })
  @ApiCommandErrors()
  async remove(
    @CurrentUser() me: User,
    @Param('issue') issue: string,
    @Param('attachmentId') attachmentId: string,
  ) {
    return this.issues.detach(
      me.id,
      await this.refs.issueId(me.id, issue),
      attachmentId,
    );
  }
}

/** The name with anything outside printable ASCII replaced, for old clients. */
function asciiName(name: string): string {
  return name.replace(/[^\x20-\x7e]|["\\]/g, '_');
}