<script lang="ts">
  import { library } from "$lib/stores/library";
  import { goto } from "$app/navigation";
  import { page } from "$app/stores";
  import Search from "$lib/components/Search.svelte";
  import SearchResults from "$lib/components/search/SearchResults.svelte";
  import SearchScopeChips from "$lib/components/search/SearchScopeChips.svelte";
  import {
    parseSearchScope,
    searchRouteUrl,
    seedFromSearchUrl,
    type SearchScope,
    type SearchSeed,
  } from "$lib/utils/searchScope";
  import { episodeFocusHref } from "$lib/components/library/seriesNavigation";
  import type { MediaItem } from "$lib/api/types";

  // `?q=` / `?scope=` seed the page so the header search bar can hand a query
  // over by navigating here — /search is the only surface that renders results,
  // so every other search affordance routes into it.
  // TRACES: UR-049 | DR-063
  let searchQuery = $state($page.url.searchParams.get("q") ?? "");
  let scope = $state<SearchScope>(parseSearchScope($page.url.searchParams.get("scope")));

  // The URL is *consumed*, not continuously reconciled: `applied` records the
  // seed already taken, so the user's typing and chip picks stand until a real
  // navigation brings a different one. It is a plain `let` on purpose — as
  // `$state` it would be a dependency of the effect that writes it and the
  // effect would re-run itself.
  //
  // Reading `$library.searchQuery` here instead (the previous shape) made every
  // search re-run this effect, which then re-asserted the URL's query over
  // whatever had been typed since — the input snapped back a keystroke later.
  // TRACES: UR-049 | DR-063, DR-064, DR-147
  let applied: SearchSeed | null = null;

  $effect(() => {
    const seed = seedFromSearchUrl($page.url.searchParams, applied);
    if (!seed) return;
    applied = seed;
    searchQuery = seed.query;
    scope = seed.scope;
    if (seed.query.trim()) {
      library.search(seed.query, seed.scope);
    } else {
      library.clearSearch();
    }
  });

  async function handleSearch(query: string) {
    if (query.trim()) {
      await library.search(query, scope);
    } else {
      library.clearSearch();
    }
  }

  // Chips write the scope to the URL so the header bar (which searches with
  // whatever scope the URL carries) and this page cannot disagree about it.
  // Applied optimistically as well, so the chip highlights on click rather than
  // a navigation later.
  // TRACES: UR-049 | DR-064, DR-147
  async function handleScopeChange(next: SearchScope) {
    scope = next;
    applied = { query: searchQuery, scope: next };
    await goto(searchRouteUrl(searchQuery, next), {
      replaceState: true,
      keepFocus: true,
      noScroll: true,
    });
    if (searchQuery.trim()) {
      await library.search(searchQuery, next);
    }
  }

  function handleItemClick(item: MediaItem) {
    switch (item.type) {
      case "Audio":
        // Navigate to album page if available, otherwise detail page
        if (item.albumId) {
          goto(`/library/${item.albumId}`);
        } else {
          goto(`/library/${item.id}`);
        }
        break;
      case "MusicAlbum":
      case "MusicArtist":
      case "Series":
      case "Movie":
        // Navigate to detail page to show metadata and cast
        goto(`/library/${item.id}`);
        break;
      case "Episode":
        // Tap opens, it does not play (ux-flows §5B.1/§5B.5) — a search hit
        // went straight to the player, so it was the one episode entry point
        // with no way to reach download, cast or the rest of the episode.
        // TRACES: UR-058 | DR-142
        goto(episodeFocusHref(item));
        break;
      default:
        goto(`/library/${item.id}`);
        break;
    }
  }
</script>

<div class="max-w-6xl mx-auto">
  <h1 class="text-2xl font-bold mb-6">Search</h1>

  <!-- Search input. On md+ the header bar owns the input (it is present on this
       route too), so rendering one here as well would put two search boxes on
       the same screen; below md the header has none and this is the only one. -->
  <div class="mb-6 space-y-3">
    <div class="md:hidden">
      <Search
        bind:value={searchQuery}
        placeholder="Search your library..."
        onSearch={handleSearch}
      />
    </div>
    <SearchScopeChips {scope} onChange={handleScopeChange} />
  </div>

  <!-- Search Results -->
  {#if searchQuery.trim()}
    <SearchResults
      results={$library.searchResults}
      loading={$library.loadingCount > 0}
      {scope}
      onItemClick={handleItemClick}
    />
  {:else}
    <div class="text-center text-gray-400 mt-12">
      <svg class="w-16 h-16 mx-auto mb-4 text-gray-600" fill="currentColor" viewBox="0 0 24 24">
        <path d="M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61 0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"/>
      </svg>
      <p>Search your entire library</p>
      <p class="text-sm text-gray-500 mt-2">Find music, movies, shows, and more</p>
    </div>
  {/if}
</div>
