import {
  Body,
  Controller,
  Get,
  HttpCode,
  HttpStatus,
  MessageEvent,
  NotFoundException,
  Param,
  ParseIntPipe,
  Post,
  Query,
  Res,
  Sse,
  StreamableFile,
} from '@nestjs/common';
import type { Response } from 'express';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { RequirePermissions } from '../auth/permissions.decorator';
import { Permission } from '../auth/permissions.enum';
import { LabelPrintAgentService } from './label-print-agent.service';

@Controller('api/label-print-agent')
export class LabelPrintAgentController {
  constructor(private readonly service: LabelPrintAgentService) {}

  @Post('preview')
  @HttpCode(HttpStatus.OK)
  @RequirePermissions(Permission.VIEW_SCANNER)
  async preview(
    @Body() body: { templateId: number; fieldValues?: Record<string, string> },
    @Res({ passthrough: true }) res: Response,
  ): Promise<StreamableFile> {
    const buf = await this.service.renderPreview(
      body.templateId,
      body.fieldValues ?? {},
    );
    const { Readable } = await import('stream');
    res.setHeader('Content-Type', 'image/png');
    return new StreamableFile(Readable.from(buf));
  }

  // Manuell einen Job anlegen (Frontend → Backend)
  @Post('jobs')
  @HttpCode(HttpStatus.CREATED)
  @RequirePermissions(Permission.VIEW_SCANNER)
  async createJob(
    @Body() body: { templateId: number; fieldValues?: Record<string, string> },
  ) {
    const job = await this.service.createJob(
      body.templateId,
      body.fieldValues ?? {},
    );
    return { jobId: String(job.Id) };
  }

  // Agent: SSE-Stream für neue Druckaufträge
  @Sse('events')
  sseEvents(
    @Res({ passthrough: true }) res: Response,
  ): Observable<MessageEvent> {
    res.setHeader('X-Accel-Buffering', 'no');
    return this.service.newJob$.pipe(
      map(() => ({ data: { type: 'label-job-available' } }) as MessageEvent),
    );
  }

  // Agent: nächsten Job abholen (Polling)
  @Get('jobs/next')
  async getNextJob(@Query('agentId') agentId: string, @Res() res: Response) {
    const job = await this.service.claimNextJob(agentId ?? 'unknown');
    if (!job) {
      res.status(HttpStatus.NO_CONTENT).send();
      return;
    }
    res.status(HttpStatus.OK).json({
      jobId: String(job.Id),
      labelImageBase64: job.LabelImageData
        ? job.LabelImageData.toString('base64')
        : null,
      labelImageContentType: 'image/png',
      labelWidthMm: job.LabelWidthMm,
      labelHeightMm: job.LabelHeightMm,
    });
  }

  // Agent: Bild separat abrufen
  @Get('jobs/:id/image')
  async getImage(
    @Param('id', ParseIntPipe) id: number,
    @Res({ passthrough: true }) res: Response,
  ): Promise<StreamableFile> {
    const buf = await this.service.getJobImage(id);
    if (!buf) throw new NotFoundException('Bild nicht gefunden');
    const { Readable } = await import('stream');
    res.setHeader('Content-Type', 'image/png');
    return new StreamableFile(Readable.from(buf));
  }

  // Agent: Druck erfolgreich
  @Post('jobs/:id/printed')
  @HttpCode(HttpStatus.OK)
  async markPrinted(
    @Param('id', ParseIntPipe) id: number,
    @Body() body: { agentId?: string; printerName?: string },
  ) {
    await this.service.markPrinted(
      id,
      body.agentId ?? 'unknown',
      body.printerName ?? '',
    );
    return { ok: true };
  }

  // Agent: Druckfehler
  @Post('jobs/:id/error')
  @HttpCode(HttpStatus.OK)
  async markError(
    @Param('id', ParseIntPipe) id: number,
    @Body()
    body: { agentId?: string; printerName?: string; errorMessage?: string },
  ) {
    await this.service.markError(
      id,
      body.agentId ?? 'unknown',
      body.printerName ?? '',
      body.errorMessage ?? '',
    );
    return { ok: true };
  }
}