import * as cron from "node-cron";
import { createClient } from "@supabase/supabase-js";

const TMDB_API_BASE_URL = "https://api.themoviedb.org/3";
const REEL_POSTER_COUNT = 20;

// Mirror of PINNED_REEL_POSTERS in src/app/api/tmdb/reel-posters/route.ts.
// Keep in sync if either side changes.
const PINNED_REEL_POSTERS: ReelPoster[] = [
  {
    tmdb_id: 615,
    title: "The Passion of the Christ",
    poster_path: "/rBM5o2HpmCfDejuIPybI09tkY3V.jpg",
  },
];

interface ReelPoster {
  tmdb_id: number;
  poster_path: string;
  title: string;
}

interface TMDBMovie {
  id: number;
  title: string;
  poster_path: string | null;
  adult: boolean;
}

interface TMDBPopularResponse {
  results: TMDBMovie[];
}

const SUPABASE_URL = process.env.SUPABASE_URL;
const SUPABASE_SERVICE_ROLE_KEY = process.env.SUPABASE_SERVICE_ROLE_KEY;
const TMDB_API_KEY = process.env.TMDB_API_KEY;

function requireEnv(): { supabaseUrl: string; serviceKey: string; tmdbKey: string } {
  if (!SUPABASE_URL) throw new Error("SUPABASE_URL not set");
  if (!SUPABASE_SERVICE_ROLE_KEY) throw new Error("SUPABASE_SERVICE_ROLE_KEY not set");
  if (!TMDB_API_KEY) throw new Error("TMDB_API_KEY not set");
  return {
    supabaseUrl: SUPABASE_URL,
    serviceKey: SUPABASE_SERVICE_ROLE_KEY,
    tmdbKey: TMDB_API_KEY,
  };
}

async function fetchTMDBPopular(tmdbKey: string, page: number): Promise<TMDBMovie[]> {
  const params = new URLSearchParams({
    language: "en-US",
    page: String(page),
    include_adult: "false",
  });
  const res = await fetch(`${TMDB_API_BASE_URL}/movie/popular?${params.toString()}`, {
    headers: {
      Authorization: `Bearer ${tmdbKey}`,
      Accept: "application/json",
    },
  });
  if (!res.ok) {
    throw new Error(`TMDB popular request failed: ${res.status}`);
  }
  const data = (await res.json()) as TMDBPopularResponse;
  // Server-side adult filter (defense in depth alongside include_adult=false).
  return data.results.filter((m) => !m.adult && m.poster_path);
}

async function refreshReelPosters(): Promise<void> {
  const { supabaseUrl, serviceKey, tmdbKey } = requireEnv();

  const popular = await fetchTMDBPopular(tmdbKey, 1);

  const seen = new Set<number>();
  const posters: ReelPoster[] = [];
  for (const p of [
    ...PINNED_REEL_POSTERS,
    ...popular.map((m) => ({
      tmdb_id: m.id,
      poster_path: m.poster_path!,
      title: m.title,
    })),
  ]) {
    if (seen.has(p.tmdb_id)) continue;
    seen.add(p.tmdb_id);
    posters.push(p);
    if (posters.length >= REEL_POSTER_COUNT) break;
  }

  if (posters.length === 0) {
    throw new Error("No posters resolved; aborting refresh to avoid wiping table");
  }

  const supabase = createClient(supabaseUrl, serviceKey, {
    auth: { persistSession: false, autoRefreshToken: false },
  });

  // Replace full set: delete-all then insert. Bi-weekly cadence makes this safe.
  const { error: delErr } = await supabase.from("landing_reel_posters").delete().gte("id", 0);
  if (delErr) throw new Error(`Delete failed: ${delErr.message}`);

  const { error: insErr } = await supabase.from("landing_reel_posters").insert(
    posters.map((p) => ({
      tmdb_id: p.tmdb_id,
      poster_path: p.poster_path,
      title: p.title,
    })),
  );
  if (insErr) throw new Error(`Insert failed: ${insErr.message}`);

  console.log(`[${new Date().toISOString()}] Reel refresh: wrote ${posters.length} posters`);
}

console.log("MovieDice cron service started");

// Refresh landing reel posters — bi-weekly on the 1st and 15th at 3:00 AM UTC.
// (PROJECT_SCOPE.md task 5.2 specifies bi-weekly cadence.)
cron.schedule("0 3 1,15 * *", async () => {
  console.log(`[${new Date().toISOString()}] Reel refresh: starting`);
  try {
    await refreshReelPosters();
    console.log(`[${new Date().toISOString()}] Reel refresh: complete`);
  } catch (err) {
    console.error(`[${new Date().toISOString()}] Reel refresh: failed`, err);
  }
});

// Refresh trailer URLs — daily at 4:00 AM UTC
cron.schedule("0 4 * * *", async () => {
  console.log(`[${new Date().toISOString()}] Trailer refresh: starting`);
  // TODO: re-validate trailer URLs for movies missing trailers
  console.log(`[${new Date().toISOString()}] Trailer refresh: complete`);
});

// Refresh TMDB metadata — monthly on the 1st at 5:00 AM UTC
cron.schedule("0 5 1 * *", async () => {
  console.log(`[${new Date().toISOString()}] Metadata refresh: starting`);
  // TODO: refresh metadata for movies where metadata_refreshed_at > 30 days
  console.log(`[${new Date().toISOString()}] Metadata refresh: complete`);
});

// Run reel refresh once at startup if the table appears empty, so a fresh
// deploy doesn't have to wait up to two weeks for the first cron tick.
(async () => {
  try {
    const { supabaseUrl, serviceKey } = requireEnv();
    const supabase = createClient(supabaseUrl, serviceKey, {
      auth: { persistSession: false, autoRefreshToken: false },
    });
    const { count, error } = await supabase
      .from("landing_reel_posters")
      .select("id", { count: "exact", head: true });
    if (error) {
      console.error("Startup reel-table check failed:", error.message);
      return;
    }
    if ((count ?? 0) === 0) {
      console.log(
        `[${new Date().toISOString()}] Reel refresh: table empty at startup, running initial refresh`,
      );
      await refreshReelPosters();
    }
  } catch (err) {
    console.error("Startup reel-refresh check failed:", err);
  }
})();

// Keep the process alive
process.on("SIGTERM", () => {
  console.log("Received SIGTERM, shutting down cron service");
  process.exit(0);
});