import { NextResponse } from "next/server";
import { checkDatabaseHealth } from "@/lib/db";
import { ErrorCode, ok, withErrorHandling } from "@/lib/api/response";

/**
 * GET /api/health —— 健康检查
 *
 * 用于部署后的可用性探测与监控。返回：
 * - status: "ok" | "degraded"
 * - database: 连通性与往返延迟
 * - timestamp: 服务端时间
 *
 * 数据库不可用时返回 503，便于负载均衡/监控直接判定为不健康。
 */
export const dynamic = "force-dynamic";

export const GET = withErrorHandling(async () => {
	const database = await checkDatabaseHealth();

	const payload = {
		status: database.ok ? ("ok" as const) : ("degraded" as const),
		database: {
			ok: database.ok,
			latencyMs: database.latencyMs,
			...(database.error ? { error: database.error } : {}),
		},
		timestamp: new Date().toISOString(),
	};

	if (!database.ok) {
		return NextResponse.json(
			{
				error: {
					code: ErrorCode.SERVICE_UNAVAILABLE,
					message: "数据库不可用",
				},
				...payload,
			},
			{ status: 503 },
		);
	}

	return ok(payload);
});