/**
 * Searches dumps, users and playlists at once, for the client's `Search` page.
 * Only the dumps are paged. Private dumps and playlists are found only by
 * their owner.
 *
 * - `GET /api/search?q=&page=&limit=&category=&playlistCategory=` — optional
 *   sign-in. Answers a page of the matching dumps with their total, and up to
 *   20 matching users and playlists. A blank `q` finds nothing. `category`
 *   keeps the dumps in that dump category, `playlistCategory` the playlists in
 *   that playlist category; a slug that names none finds nothing.
 *
 * @module
 */

import { Router } from "@oak/oak";
import { parseOptionalAuth } from "../lib/auth.ts";
import { parsePagination } from "../lib/pagination.ts";
import { searchDumps } from "../services/dump-service.ts";
import { searchUsersGlobal } from "../services/user-service.ts";
import { searchPlaylists } from "../services/playlist-service.ts";
import { resolveCategoryFilter } from "../services/category-service.ts";
import type { APIResponse } from "../../shared/api.ts";
import type { SearchResults } from "../../shared/search.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/search" });

router.get("/", async (ctx) => {
  const params = ctx.request.url.searchParams;
  const q = (params.get("q") ?? "").trim();
  const { page, limit } = parsePagination(params);
  const requestingUserId = (await parseOptionalAuth(ctx)) ?? undefined;

  if (!q) {
    const responseBody: APIResponse<SearchResults> = {
      success: true,
      data: {
        dumps: { items: [], total: 0, hasMore: false },
        users: [],
        playlists: [],
      },
    };
    ctx.response.body = responseBody;
    return;
  }

  const dumpCategoryId = resolveCategoryFilter("dump", params);
  const playlistCategoryId = resolveCategoryFilter(
    "playlist",
    params,
    "playlistCategory",
  );
  const { items: dumpItems, total: dumpTotal } = dumpCategoryId === "missing"
    ? { items: [], total: 0 }
    : searchDumps(q, page, limit, requestingUserId, dumpCategoryId);
  const users = searchUsersGlobal(q, 20);
  const playlists = playlistCategoryId === "missing"
    ? []
    : searchPlaylists(q, 20, requestingUserId, playlistCategoryId);

  const responseBody: APIResponse<SearchResults> = {
    success: true,
    data: {
      dumps: {
        items: dumpItems,
        total: dumpTotal,
        hasMore: page * limit < dumpTotal,
      },
      users,
      playlists,
    },
  };
  ctx.response.body = responseBody;
});

export default router;