/**
 * Serves the caller's own notifications to the client's `/notifications`
 * page, which marks them all read when it opens. New ones arrive over the
 * WebSocket instead, as `notification_created`.
 *
 * - `GET /api/notifications?page=&limit=` — signed in. Answers a page of them,
 *   newest first.
 * - `POST /api/notifications/read-all` — signed in. Marks them all read.
 * - `PATCH /api/notifications/:id/read` — signed in. Marks one of them read.
 *   The client doesn't use it.
 *
 * @module
 */

import { Router } from "@oak/oak";
import { type APIResponse, type PaginatedData } from "../../shared/api.ts";
import { APIException } from "../lib/api-exception.ts";
import type { Notification } from "../../shared/notification.ts";
import { parsePagination } from "../lib/pagination.ts";
import { type AuthContext, authMiddleware } from "../middleware/auth.ts";
import {
  getNotificationsForUser,
  markAllRead,
  markOneRead,
} from "../services/notification-service.ts";

/**
 * Mounted by `api/main.ts` behind the error, Open Graph and CORS middleware.
 * An `APIException` thrown by a handler becomes the JSON error response there.
 */
const router: Router = new Router({ prefix: "/api/notifications" });

router.get("/", authMiddleware, (ctx: AuthContext) => {
  if (!ctx.state.user) {
    throw new APIException(401, "Not authenticated");
  }
  const { page, limit } = parsePagination(ctx.request.url.searchParams);
  const { items, hasMore } = getNotificationsForUser(
    ctx.state.user.userId,
    page,
    limit,
  );
  const responseBody: APIResponse<PaginatedData<Notification>> = {
    success: true,
    data: { items, hasMore },
  };
  ctx.response.body = responseBody;
});

router.post("/read-all", authMiddleware, (ctx: AuthContext) => {
  if (!ctx.state.user) {
    throw new APIException(401, "Not authenticated");
  }
  markAllRead(ctx.state.user.userId);
  ctx.response.status = 204;
});

router.patch("/:id/read", authMiddleware, (ctx) => {
  const user = ctx.state.user;
  if (!user) {
    throw new APIException(401, "Not authenticated");
  }
  markOneRead(ctx.params.id, user.userId);
  ctx.response.status = 204;
});

export default router;