import { Alpine } from "./alpine";
import { showToast } from "./toast";
import { setSelectedLibrary } from "./storage";

interface SeriesItem {
  name: string;
  book_count: number;
  total_in_series: number;
  cover_paths: string[];
  last_entry_at: string;
}

function renderSeriesCard(series: SeriesItem, libraryId: string): string {
  const href = `/bookshelf?series_filter=${encodeURIComponent(series.name)}&sort=series&library_id=${libraryId}`;
  const coverCount = series.cover_paths.length;
  const coverClass = `cover-count-${coverCount}`;

  let coversHtml = "";
  for (let i = 0; i < coverCount; i++) {
    coversHtml += `<img src="${series.cover_paths[i]}" class="cover-img cover-${i}" alt="${series.name}" loading="lazy" onerror="this.src='/static/placeholder-book.svg'">`;
  }

  if (coverCount === 0) {
    coversHtml = `<div class="cover-img cover-0 flex items-center justify-center" style="background: var(--bg-primary);"><span class="text-3xl">📚</span></div>`;
  }

  return `
    <a href="${href}" class="block">
      <div class="series-card rounded-lg overflow-hidden cursor-pointer hover:shadow-lg transition-shadow" style="background-color: var(--bg-secondary);">
        <div class="stacked-covers ${coverClass}">
          ${coversHtml}
        </div>
        <div class="series-card-info px-3 py-2">
          <h3 class="font-semibold text-sm line-clamp-2" style="color: var(--text-primary)">${series.name}</h3>
          <p class="text-xs mt-1" style="color: var(--text-secondary)">
            ${series.book_count} of ${series.total_in_series} books
          </p>
        </div>
      </div>
    </a>`;
}

function renderSeriesContent(
  seriesList: SeriesItem[],
  libraryId: string,
  totalPages: number,
  currentPage: number,
): string {
  if (seriesList.length === 0) {
    return `
      <main class="w-full px-4 py-8">
        <h1 class="text-3xl font-bold mb-6" style="color: var(--text-primary)">Series</h1>
        <div class="text-center py-16" style="color: var(--text-secondary)">
          <div class="text-6xl mb-4">📚</div>
          <h3 class="text-xl font-semibold mb-2" style="color: var(--text-primary)">No Series Found</h3>
          <p>Books with series metadata will appear here</p>
        </div>
      </main>`;
  }

  const cardsHtml = seriesList.map((s) => renderSeriesCard(s, libraryId)).join("");

  let paginationHtml = "";
  if (totalPages > 1) {
    const prevLink =
      currentPage > 1
        ? `<a href="/series?library_id=${libraryId}&page=${currentPage - 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">← Previous</a>`
        : "";
    const nextLink =
      currentPage < totalPages
        ? `<a href="/series?library_id=${libraryId}&page=${currentPage + 1}" class="px-4 py-2 rounded-lg border" style="border-color: var(--border); color: var(--text-primary);">Next →</a>`
        : "";
    paginationHtml = `
      <div class="flex justify-center items-center gap-4 mt-8">
        ${prevLink}
        <span class="text-sm" style="color: var(--text-secondary)">Page ${currentPage} of ${totalPages}</span>
        ${nextLink}
      </div>`;
  }

  return `
    <main class="w-full px-4 py-8">
      <h1 class="text-3xl font-bold mb-6" style="color: var(--text-primary)">Series</h1>
      <div class="grid grid-cols-2 md:grid-cols-4 lg:grid-cols-6 gap-6">
        ${cardsHtml}
      </div>
      ${paginationHtml}
    </main>`;
}

async function switchLibrary(libraryId: string): Promise<void> {
  const container = document.getElementById("series-container") as HTMLElement;
  const loading = document.getElementById("loading-spinner") as HTMLElement;

  if (!container || !loading) return;

  try {
    container.classList.add("opacity-0", "transition-opacity", "duration-150");
    await new Promise((resolve) => setTimeout(resolve, 150));

    loading.classList.remove("hidden");

    const response = await fetch(
      `/api/series?library_id=${libraryId}&limit=24&offset=0`,
      {
        headers: {
          Authorization: `Bearer ${localStorage.getItem("token")}`,
          "Content-Type": "application/json",
        },
      },
    );

    if (!response.ok) {
      throw new Error("Failed to load series");
    }

    const data = await response.json();
    const seriesList: SeriesItem[] = data.series || [];
    const total: number = data.total || 0;
    const totalPages = Math.max(1, Math.ceil(total / 24));

    container.innerHTML = renderSeriesContent(seriesList, libraryId, totalPages, 1);
    setSelectedLibrary(libraryId);
  } catch (error) {
    showToast("Failed to load series", "error");
    console.error("Switch library error:", error);
  } finally {
    loading.classList.add("hidden");

    container.classList.remove("duration-150");
    container.classList.add("duration-300");
    void container.offsetHeight;
    container.classList.remove("opacity-0");

    setTimeout(() => {
      container.classList.remove("transition-opacity", "duration-300");
    }, 300);
  }
}

Alpine.data("seriesPage", () => ({
  initSeriesPage() {
    const librarySelect = document.getElementById(
      "library-select",
    ) as HTMLSelectElement;
    if (librarySelect) {
      librarySelect.addEventListener("change", () => {
        if (librarySelect.value) {
          switchLibrary(librarySelect.value);
        }
      });
    }
  },
}));