import { Controller, Get, HttpException, HttpStatus } from "@nestjs/common";
import { sql } from "drizzle-orm";
import { getDb } from "../../config/database.js";

const SERVICE_NAME = "iam";

/**
 * 健康检查端点。
 *
 * - GET /healthz：liveness，仅返回进程存活，不检查依赖。
 * - GET /readyz：readiness，检查 DB 连接，失败返回 503。
 *
 * 不需要鉴权，必须在路由白名单中放行。本控制器内容在 iam / core-edu /
 * content / msg / classes 五个 NestJS 服务中一致，仅 SERVICE_NAME 不同。
 */
@Controller()
export class HealthController {
  @Get("healthz")
  liveness(): { status: string; service: string; timestamp: string } {
    return {
      status: "ok",
      service: SERVICE_NAME,
      timestamp: new Date().toISOString(),
    };
  }

  @Get("readyz")
  async readiness(): Promise<{
    status: string;
    service: string;
    timestamp: string;
  }> {
    try {
      const db = getDb();
      await db.execute(sql`SELECT 1`);
      return {
        status: "ok",
        service: SERVICE_NAME,
        timestamp: new Date().toISOString(),
      };
    } catch (error) {
      throw new HttpException(
        {
          status: "error",
          service: SERVICE_NAME,
          timestamp: new Date().toISOString(),
          error:
            error instanceof Error ? error.message : "database unreachable",
        },
        HttpStatus.SERVICE_UNAVAILABLE,
      );
    }
  }
}