import { Injectable, Logger } from '@nestjs/common';
import { Device } from '@prisma/client';
import { plainToInstance } from 'class-transformer';
import { validate } from 'class-validator';
import { PrismaService } from '../prisma/prisma.service';
import { MqttJobMessageDto } from './dto/mqtt-messages.dto';
import { MqttClientService } from './mqtt-client.service';

@Injectable()
export class JobsIngestService {
  private readonly logger = new Logger(JobsIngestService.name);

  constructor(
    private readonly prisma: PrismaService,
    private readonly mqttClient: MqttClientService,
  ) {}

  async handle(device: Device, rawPayload: string) {
    let msg: MqttJobMessageDto;
    try {
      msg = plainToInstance(MqttJobMessageDto, JSON.parse(rawPayload) as object);
    } catch {
      this.ack(device, { ticket: null, status: 'error', reason: 'invalid JSON' });
      return;
    }

    const errors = await validate(msg, { whitelist: true });
    if (errors.length > 0) {
      this.ack(device, { ticket: msg.ticket ?? null, status: 'error', reason: 'validation failed' });
      this.logger.warn(`Invalid job message from ${device.mqttUsername}: ${errors}`);
      return;
    }

    const existing = await this.prisma.job.findUnique({
      where: { orgId_ticketNumber: { orgId: device.orgId, ticketNumber: msg.ticket } },
    });
    if (existing) {
      this.ack(device, { ticket: msg.ticket, jobId: existing.id, status: 'exists' });
      return;
    }

    const job = await this.prisma.job.create({
      data: {
        orgId: device.orgId,
        ticketNumber: msg.ticket,
        title: msg.title || `Ticket ${msg.ticket}`,
        description: msg.description,
        address: msg.address,
        source: 'DEVICE',
        createdByDeviceId: device.id,
      },
    });
    this.ack(device, { ticket: msg.ticket, jobId: job.id, status: 'created' });
    this.logger.log(`Device ${device.mqttUsername} created job ${job.ticketNumber}`);
  }

  private ack(device: Device, payload: object) {
    this.mqttClient.publish(`devices/${device.mqttUsername}/jobs/ack`, payload);
  }
}