import { NextResponse } from "next/server";
import { randomUUID } from "node:crypto";
import { createLogger } from "@/lib/logger";

const log = createLogger("api");

type RouteHandler<Ctx> = (req: Request, ctx: Ctx) => Promise<Response> | Response;

/**
 * Wraps an App Router route handler with consistent request/response logging:
 * a reqId (also echoed as `x-request-id`), method/path, status, and duration on
 * every call, plus a logged stack trace and JSON 500 for anything the handler
 * doesn't catch itself. Every export in app/api/** goes through this so log
 * shape and error handling stay uniform across routes instead of being
 * reimplemented per file.
 */
export function withRouteLogging<Ctx = unknown>(routeName: string, handler: RouteHandler<Ctx>): RouteHandler<Ctx> {
  return async (req, ctx) => {
    const reqId = randomUUID();
    const start = performance.now();
    const { pathname, search } = new URL(req.url);
    const reqLog = log.child({ reqId, route: routeName, method: req.method });

    reqLog.debug("request start", { path: pathname + search });

    try {
      const res = await handler(req, ctx);
      const durationMs = Math.round(performance.now() - start);
      const level = res.status >= 500 ? "error" : res.status >= 400 ? "warn" : "info";
      reqLog[level]("request end", { status: res.status, durationMs });
      res.headers.set("x-request-id", reqId);
      return res;
    } catch (err) {
      const durationMs = Math.round(performance.now() - start);
      reqLog.error("request failed", {
        durationMs,
        error: err instanceof Error ? err.message : String(err),
        stack: err instanceof Error ? err.stack : undefined,
      });
      return NextResponse.json({ error: "internal error", reqId }, { status: 500 });
    }
  };
}