import { Controller, Get, HttpStatus, Res } from '@nestjs/common';
import { HealthResponse, healthResponse } from '@dorfteich/shared';
import type { Response } from 'express';

import { Public } from '../auth/auth.guard';
import { MaintenanceExempt } from '../backup/maintenance.guard';
import { AppConfig } from '../config/app-config.service';
import { SetupExempt } from '../setup/setup.guard';
import { ReadinessService } from './readiness.service';

@Public()
@SetupExempt() // deploys and monitors must see health during first-run setup
@MaintenanceExempt() // …and during an in-app restore (issue #103)
@Controller()
export class HealthController {
  constructor(
    private readonly config: AppConfig,
    private readonly readiness: ReadinessService,
  ) {}

  /** Liveness: the process is up. Used by Docker healthchecks. */
  @Get('healthz')
  healthz(): HealthResponse {
    return healthResponse('api', this.config.env.APP_VERSION);
  }

  /**
   * Readiness: the api can do real work. Used by uptime monitoring.
   * The report body is sent as-is with 200/503 (not through the exception
   * filter) so monitors always see which check failed. `degraded` stays
   * HTTP 200 — 503 is reserved for hard failures (issue #85); monitors
   * catch degradation via a keyword check on the body (deploy/monitoring.md).
   */
  @Get('readyz')
  async readyz(@Res() res: Response): Promise<void> {
    const report = await this.readiness.report();
    res
      .status(report.status === 'unready' ? HttpStatus.SERVICE_UNAVAILABLE : HttpStatus.OK)
      .json(report);
  }
}