import type { HealthResponse } from '@dorfteich/shared';

/** Result of a single dependency probe. */
export interface DatabaseProbe {
  ok: boolean;
  detail?: string;
}

/**
 * Liveness + dependency report for the collab service. Unlike the api, which
 * splits pure liveness (`/healthz`) from readiness (`/readyz`), the collab
 * skeleton only needs the one endpoint the compose healthcheck and pipeline
 * smoke test hit, so `/healthz` also carries the database probe (issue #33).
 */
export interface CollabHealthReport {
  status: 'ok' | 'unhealthy';
  service: HealthResponse['service'];
  version: string;
  time: string;
  checks: { name: 'database'; status: 'ok' | 'failed'; detail?: string }[];
}

/** Build the health payload and the HTTP status a monitor should see. */
export function buildHealthReport(
  version: string,
  database: DatabaseProbe,
): { httpStatus: 200 | 503; body: CollabHealthReport } {
  const body: CollabHealthReport = {
    status: database.ok ? 'ok' : 'unhealthy',
    service: 'collab',
    version,
    time: new Date().toISOString(),
    checks: [
      {
        name: 'database',
        status: database.ok ? 'ok' : 'failed',
        ...(database.detail ? { detail: database.detail } : {}),
      },
    ],
  };
  return { httpStatus: database.ok ? 200 : 503, body };
}

/**
 * Whether a plain HTTP request is a health probe. Matches both the container-
 * internal path (`/healthz`, used by the Docker healthcheck) and the path seen
 * through the host reverse proxy, which routes `/collab*` to this service
 * without stripping the prefix (deployment.md), i.e. `/collab/healthz`.
 */
export function isHealthRequest(method: string | undefined, url: string | undefined): boolean {
  if (method !== undefined && method !== 'GET' && method !== 'HEAD') {
    return false;
  }
  const pathname = pathnameOf(url);
  return pathname === '/healthz' || pathname === '/collab/healthz';
}

function pathnameOf(url: string | undefined): string {
  if (!url) {
    return '';
  }
  // The base only matters to parse a path-only request-target; it is discarded.
  return new URL(url, 'http://collab.internal').pathname.replace(/\/+$/, '') || '/';
}