import fetch from "node-fetch";
import { JellyfinItemSummary, JellyfinStreamOption } from "./types";

const JELLYFIN_URL = (process.env.JELLYFIN_URL || "").replace(/\/+$/, "");
const JELLYFIN_API_KEY = process.env.JELLYFIN_API_KEY || "";
const JELLYFIN_USER_ID = process.env.JELLYFIN_USER_ID || "";

function assertConfigured(): void {
  if (!JELLYFIN_URL || !JELLYFIN_API_KEY || !JELLYFIN_USER_ID) {
    throw new Error(
      "Jellyfin isn't configured. Set JELLYFIN_URL, JELLYFIN_API_KEY, and JELLYFIN_USER_ID."
    );
  }
}

function authHeaders(): Record<string, string> {
  return {
    "X-Emby-Token": JELLYFIN_API_KEY,
    "Content-Type": "application/json",
  };
}

/** Ask Jellyfin to rescan the library after a new file lands on disk. */
export async function refreshLibrary(): Promise<void> {
  assertConfigured();
  const res = await fetch(`${JELLYFIN_URL}/Library/Refresh`, {
    method: "POST",
    headers: authHeaders(),
  });
  if (!res.ok) {
    throw new Error(`Jellyfin library refresh failed: ${res.status} ${res.statusText}`);
  }
}

/**
 * Find an item in the Jellyfin library by (approximate) title. Jellyfin needs
 * a moment after a refresh before a freshly-ripped file is indexed, so callers
 * should retry a few times if this comes back empty.
 */
export async function findItemByTitle(title: string): Promise<JellyfinItemSummary | null> {
  assertConfigured();
  const params = new URLSearchParams({
    searchTerm: title,
    IncludeItemTypes: "Movie",
    Recursive: "true",
    Fields: "Overview,ProductionYear,RunTimeTicks,MediaSources",
    Limit: "5",
  });
  const res = await fetch(
    `${JELLYFIN_URL}/Users/${JELLYFIN_USER_ID}/Items?${params.toString()}`,
    { headers: authHeaders() }
  );
  if (!res.ok) {
    throw new Error(`Jellyfin search failed: ${res.status} ${res.statusText}`);
  }
  const body = (await res.json()) as any;
  const item = body?.Items?.[0];
  if (!item) return null;

  return {
    itemId: item.Id,
    name: item.Name,
    overview: item.Overview ?? null,
    year: item.ProductionYear ?? null,
    runtimeMinutes: item.RunTimeTicks ? Math.round(item.RunTimeTicks / 600000000) : null,
    posterUrl: `${JELLYFIN_URL}/Items/${item.Id}/Images/Primary?api_key=${JELLYFIN_API_KEY}`,
    streamOptions: buildStreamOptions(item),
  };
}

/** Lists recently-added movies for the TrayFlix poster grid. */
export async function listLibrary(limit = 24): Promise<JellyfinItemSummary[]> {
  assertConfigured();
  const params = new URLSearchParams({
    IncludeItemTypes: "Movie",
    Recursive: "true",
    SortBy: "DateCreated",
    SortOrder: "Descending",
    Fields: "Overview,ProductionYear,RunTimeTicks,MediaSources",
    Limit: String(limit),
  });
  const res = await fetch(
    `${JELLYFIN_URL}/Users/${JELLYFIN_USER_ID}/Items?${params.toString()}`,
    { headers: authHeaders() }
  );
  if (!res.ok) {
    throw new Error(`Jellyfin library listing failed: ${res.status} ${res.statusText}`);
  }
  const body = (await res.json()) as any;
  const items: any[] = body?.Items || [];
  return items.map((item) => ({
    itemId: item.Id,
    name: item.Name,
    overview: item.Overview ?? null,
    year: item.ProductionYear ?? null,
    runtimeMinutes: item.RunTimeTicks ? Math.round(item.RunTimeTicks / 600000000) : null,
    posterUrl: `${JELLYFIN_URL}/Items/${item.Id}/Images/Primary?api_key=${JELLYFIN_API_KEY}`,
    streamOptions: buildStreamOptions(item),
  }));
}

export async function getItemById(itemId: string): Promise<JellyfinItemSummary | null> {
  assertConfigured();
  const params = new URLSearchParams({ Fields: "Overview,ProductionYear,RunTimeTicks,MediaSources" });
  const res = await fetch(
    `${JELLYFIN_URL}/Users/${JELLYFIN_USER_ID}/Items/${itemId}?${params.toString()}`,
    { headers: authHeaders() }
  );
  if (!res.ok) return null;
  const item = (await res.json()) as any;
  return {
    itemId: item.Id,
    name: item.Name,
    overview: item.Overview ?? null,
    year: item.ProductionYear ?? null,
    runtimeMinutes: item.RunTimeTicks ? Math.round(item.RunTimeTicks / 600000000) : null,
    posterUrl: `${JELLYFIN_URL}/Items/${item.Id}/Images/Primary?api_key=${JELLYFIN_API_KEY}`,
    streamOptions: buildStreamOptions(item),
  };
}

/** Turn Jellyfin's MediaSources into simple resolution choices the UI can render as ticket stubs. */
function buildStreamOptions(item: any): JellyfinStreamOption[] {
  const sources: any[] = item?.MediaSources ?? [];
  if (sources.length === 0) {
    // Fall back to a single "Original" option driven straight through Jellyfin's transcoding.
    return [
      {
        resolution: "Original",
        container: "mp4",
        bitrate: null,
        playUrl: buildPlayUrl(item.Id, "Original"),
      },
    ];
  }

  const options: JellyfinStreamOption[] = [];
  for (const source of sources) {
    const videoStream = (source.MediaStreams || []).find((s: any) => s.Type === "Video");
    const height: number | undefined = videoStream?.Height;
    const label = height ? `${height}p` : "Original";
    options.push({
      resolution: label,
      container: source.Container || "mp4",
      bitrate: source.Bitrate ?? null,
      playUrl: buildPlayUrl(item.Id, label),
    });
  }
  // De-dupe by resolution label and always offer an explicit "Original" (direct play) choice.
  const seen = new Set(options.map((o) => o.resolution));
  if (!seen.has("Original")) {
    options.unshift({
      resolution: "Original",
      container: "mp4",
      bitrate: null,
      playUrl: buildPlayUrl(item.Id, "Original"),
    });
  }
  return options;
}

function buildPlayUrl(itemId: string, resolution: string): string {
  // Routed back through our own /api/jellyfin/stream proxy so the API key
  // never has to reach the browser.
  return `/api/jellyfin/stream/${itemId}?resolution=${encodeURIComponent(resolution)}`;
}

/**
 * Build the real, signed Jellyfin stream URL for a given item + resolution.
 * Called server-side only, by the stream proxy route.
 */
export function buildUpstreamStreamUrl(itemId: string, resolution: string): string {
  assertConfigured();
  const params = new URLSearchParams({
    api_key: JELLYFIN_API_KEY,
    Static: resolution === "Original" ? "true" : "false",
  });
  if (resolution !== "Original") {
    const height = parseInt(resolution.replace("p", ""), 10);
    if (!Number.isNaN(height)) {
      params.set("maxHeight", String(height));
    }
  }
  return `${JELLYFIN_URL}/Videos/${itemId}/stream.mp4?${params.toString()}`;
}