import { prisma } from "../database/client";
import type { Config } from "../config";
import { AppError } from "../security/errors";
import { loadXtreamForToken } from "../iptv/service";
import {
  decodeEpgText,
  epgToIso,
  type XtreamClient,
  type XtreamEpgListing,
  type XtreamLiveStream,
  type XmltvNowNext,
} from "../iptv/xtream";

const AGGREGATE_LABELS = new Set([
  "alles",
  "all",
  "alle",
  "alle zenders",
  "all channels",
  "all channel",
  "all categories",
  "all cats",
  "everything",
]);

function normCatLabel(s: string): string {
  return s.toLowerCase().replace(/\s+/g, " ").trim();
}

/** Maak Xtream-categorienamen leesbaarder voor TV-gebruikers. */
export function friendlyCategoryName(raw: string): string {
  let s = raw.trim().replace(/^[\s★☆●▪•\-–—]+/, "");
  const m = s.match(/^([A-Z]{2,3})\s*[|·:]\s*(.+)$/i);
  if (m) {
    const rest = m[2].trim();
    // "NL | ALL" is een landpakket — niet reduceren tot "ALL" (dat verdween daarna als verzamelbak)
    if (AGGREGATE_LABELS.has(normCatLabel(rest))) {
      return m[1].toUpperCase();
    }
    s = rest;
  }
  return s.trim() || raw.trim() || "Overig";
}

export async function resolveViewerIptvToken(viewerId: string): Promise<string | null> {
  const viewer = await prisma.viewerUser.findUnique({
    where: { id: viewerId },
    select: { iptvAccess: true, iptvAddonTokenId: true, enabled: true, appAccess: true },
  });
  if (!viewer?.enabled || !viewer.appAccess || !viewer.iptvAccess) return null;

  // Gekoppelde lijn altijd proberen — lastError mag TV niet stilleggen
  if (viewer.iptvAddonTokenId) {
    const linked = await prisma.addonToken.findFirst({
      where: {
        id: viewer.iptvAddonTokenId,
        revoked: false,
        iptvLine: { enableLive: true },
      },
      select: { id: true },
    });
    if (linked) return linked.id;
  }

  const fallbackOk = await prisma.iptvLine.findFirst({
    where: {
      enableLive: true,
      lastError: null,
      addonToken: { revoked: false },
    },
    select: { addonTokenId: true },
    orderBy: { updatedAt: "desc" },
  });
  if (fallbackOk) return fallbackOk.addonTokenId;

  const fallbackAny = await prisma.iptvLine.findFirst({
    where: {
      enableLive: true,
      addonToken: { revoked: false },
    },
    select: { addonTokenId: true },
    orderBy: { updatedAt: "desc" },
  });
  return fallbackAny?.addonTokenId ?? null;
}

export async function getViewerIptvStatus(viewerId: string, config: Config) {
  const tokenId = await resolveViewerIptvToken(viewerId);
  if (!tokenId) return { enabled: false as const };

  const xt = await loadXtreamForToken(tokenId, config);
  if (!xt?.line.enableLive) return { enabled: false as const };

  const cats = await xt.client.getLiveCategories().catch(() => []);
  return {
    enabled: true as const,
    categoryCount: cats.length,
  };
}

export async function getViewerIptvCategories(viewerId: string, config: Config) {
  const tokenId = await resolveViewerIptvToken(viewerId);
  if (!tokenId) throw new AppError("FORBIDDEN", "Geen TV-toegang", 403);

  const xt = await loadXtreamForToken(tokenId, config);
  if (!xt?.line.enableLive) throw new AppError("FORBIDDEN", "Live TV niet beschikbaar", 403);

  // Categorieën + (korte) zenderlijst parallel — categorieën nooit laten falen op trage streams
  const [catsRaw, streamsRaw] = await Promise.all([
    xt.client.getLiveCategories().catch(() => []),
    Promise.race([
      xt.client.getLiveStreams().catch(() => []),
      new Promise<unknown[]>((resolve) => setTimeout(() => resolve([]), 6_000)),
    ]),
  ]);
  const cats = Array.isArray(catsRaw) ? catsRaw : [];
  const streams = Array.isArray(streamsRaw) ? streamsRaw : [];

  const counts = new Map<string, number>();
  for (const s of streams) {
    const key = normalizeIptvCategoryId(s.category_id);
    if (!key) continue;
    counts.set(key, (counts.get(key) ?? 0) + 1);
  }

  let categories = cats
    .map((c) => {
      const id = normalizeIptvCategoryId(c.category_id);
      const rawName = String(c.category_name ?? "");
      return {
        id,
        name: friendlyCategoryName(rawName),
        rawName,
        channelCount: counts.get(id) ?? 0,
      };
    })
    // Alleen pure provider-dump "Alles/All" weg — niet "NL | ALL" landpakketten
    .filter((c) => c.id.length > 0 && !isAggregateCategoryName(c.rawName))
    .sort((a, b) => a.name.localeCompare(b.name, "nl"));

  // Fallback: bouquets uit zenders afleiden als get_live_categories leeg/fout is
  if (categories.length === 0 && counts.size > 0) {
    categories = [...counts.entries()]
      .map(([id, channelCount]) => ({
        id,
        name: `Groep ${id}`,
        rawName: `Groep ${id}`,
        channelCount,
      }))
      .sort((a, b) => a.name.localeCompare(b.name, "nl"));
  }

  // Één eigen verzamelknop
  categories.unshift({
    id: "__all__",
    name: "Alle zenders",
    rawName: "Alle zenders",
    channelCount: streams.length,
  });

  return { categories };
}

/**
 * Alleen pure verzamelbakken (Alles / All), géén landpakketten zoals "NL | ALL".
 * Match op ruwe naam (zonder landcode te strippen).
 */
export function isAggregateCategoryName(raw: string): boolean {
  const n = normCatLabel(String(raw ?? "").replace(/^[\s★☆●▪•\-–—]+/, ""));
  return AGGREGATE_LABELS.has(n);
}

/** Xtream geeft category_id soms als number, "12" of "12.0". */
export function normalizeIptvCategoryId(raw: unknown): string {
  if (raw == null) return "";
  const s = String(raw).trim();
  if (!s) return "";
  if (/^\d+(\.0+)?$/.test(s)) return String(parseInt(s, 10));
  return s;
}

function sortChannels(streams: XtreamLiveStream[]): XtreamLiveStream[] {
  return [...streams].sort((a, b) => (a.num ?? a.stream_id) - (b.num ?? b.stream_id));
}

type EpgTitlePair = { now: string | null; next: string | null };

export async function getViewerIptvChannels(
  viewerId: string,
  config: Config,
  categoryId?: string,
  includeEpg = false
) {
  const tokenId = await resolveViewerIptvToken(viewerId);
  if (!tokenId) throw new AppError("FORBIDDEN", "Geen TV-toegang", 403);

  const xt = await loadXtreamForToken(tokenId, config);
  if (!xt?.line.enableLive) throw new AppError("FORBIDDEN", "Live TV niet beschikbaar", 403);

  let streams =
    !categoryId || categoryId === "__all__"
      ? await xt.client.getLiveStreams()
      : await xt.client.getLiveStreams(categoryId);
  if (!Array.isArray(streams)) streams = [];
  streams = sortChannels(streams);

  const epgTitles = includeEpg
    ? await resolveCategoryEpgTitles(tokenId, categoryId, streams, xt.client, {
        waitForXmltv: true,
      })
    : peekCategoryEpgTitles(tokenId, categoryId);

  return {
    channels: streams.map((s) => {
      const pair = epgTitles?.get(s.stream_id);
      return {
        streamId: s.stream_id,
        name: s.name.trim(),
        logoUrl: s.stream_icon || null,
        number: s.num ?? null,
        categoryId: s.category_id ? String(s.category_id) : null,
        nowTitle: pair?.now ?? null,
        nextTitle: pair?.next ?? null,
      };
    }),
  };
}

export async function getViewerIptvPlayUrl(
  viewerId: string,
  config: Config,
  streamId: number
) {
  const tokenId = await resolveViewerIptvToken(viewerId);
  if (!tokenId) throw new AppError("FORBIDDEN", "Geen TV-toegang", 403);

  const xt = await loadXtreamForToken(tokenId, config);
  if (!xt?.line.enableLive) throw new AppError("FORBIDDEN", "Live TV niet beschikbaar", 403);

  const streams = await xt.client.getLiveStreams();
  const ch = streams.find((s) => s.stream_id === streamId);
  if (!ch) throw new AppError("NOT_FOUND", "Zender niet gevonden", 404);

  const resolved = await xt.client.resolveLivePlayUrls(streamId);

  const classicTs = resolved.classic.find((u) => /\.ts$/i.test(u));
  const classicHls = resolved.classic.find((u) => /\.m3u8$/i.test(u) || u.includes("m3u8"));
  const playlistHls = resolved.hls ?? resolved.llhls;
  const playlistTs = resolved.ts;

  const candidates = [classicTs, playlistTs, classicHls, playlistHls, ...resolved.classic].filter(
    (u): u is string => Boolean(u)
  );
  const unique = [...new Set(candidates)];
  const primary = unique[0];
  if (!primary) throw new AppError("UNAVAILABLE", "Geen afspeel-URL voor deze zender", 503);
  const fallback = unique[1];

  const formatFor = (url: string): "hls" | "ts" =>
    url.includes(".m3u8") || url.includes("m3u8") ? "hls" : "ts";

  return {
    streamId,
    name: ch.name,
    logoUrl: ch.stream_icon || null,
    streamUrl: primary,
    format: formatFor(primary),
    fallbackStreamUrl: fallback ?? null,
    fallbackFormat: fallback ? formatFor(fallback) : null,
  };
}

export async function getViewerIptvEpg(viewerId: string, config: Config, streamId: number) {
  const tokenId = await resolveViewerIptvToken(viewerId);
  if (!tokenId) throw new AppError("FORBIDDEN", "Geen TV-toegang", 403);

  const xt = await loadXtreamForToken(tokenId, config);
  if (!xt?.line.enableLive) throw new AppError("FORBIDDEN", "Live TV niet beschikbaar", 403);

  const streams = await xt.client.getLiveStreams();
  const ch = streams.find((s) => s.stream_id === streamId);
  if (!ch) throw new AppError("NOT_FOUND", "Zender niet gevonden", 404);

  const cached = getCachedStreamEpg(tokenId, streamId);
  if (cached && (cached.now || cached.next)) {
    return {
      streamId,
      channelName: ch.name,
      logoUrl: ch.stream_icon || null,
      now: cached.now,
      next: cached.next,
    };
  }

  // Probeer eerst XMLTV (bulk, al warm) via epg_channel_id
  const epgId = ch.epg_channel_id?.trim();
  if (epgId) {
    try {
      const xmlMap = await xt.client.getXmltvNowNextByChannelId();
      const hit = xmlMap.get(epgId) ?? xmlMap.get(epgId.toLowerCase());
      if (hit && (hit.now || hit.next)) {
        setCachedStreamEpg(tokenId, streamId, hit.now, hit.next);
        return {
          streamId,
          channelName: ch.name,
          logoUrl: ch.stream_icon || null,
          now: hit.now,
          next: hit.next,
        };
      }
    } catch {
      // fall through naar short_epg
    }
  }

  const epg = await xt.client.getShortEpg(streamId, 12);
  const { now: nowProgram, next: nextProgram } = parseNowNextPrograms(epg);
  setCachedStreamEpg(tokenId, streamId, nowProgram, nextProgram);

  return {
    streamId,
    channelName: ch.name,
    logoUrl: ch.stream_icon || null,
    now: nowProgram,
    next: nextProgram,
  };
}

/** Fris tot 10 min; stale tot 30 min (SWR). */
const EPG_FRESH_MS = 10 * 60_000;
const EPG_STALE_MS = 30 * 60_000;
const EPG_DETAIL_TTL_MS = 20 * 60_000;

type CategoryEpgCacheEntry = {
  at: number;
  titles: Map<number, EpgTitlePair>;
  /** true als XMLTV + short_epg-pass voor missing klaar is / voldoende dekking */
  complete: boolean;
};
const epgCategoryCache = new Map<string, CategoryEpgCacheEntry>();
const epgCategoryRefreshing = new Set<string>();
const xmltvLineRefreshing = new Set<string>();

type StreamEpgCacheEntry = {
  at: number;
  now: { title: string; start: string; end: string | null } | null;
  next: { title: string; start: string; end: string | null } | null;
};
const epgStreamCache = new Map<string, StreamEpgCacheEntry>();

function epgCacheKey(tokenId: string, categoryId?: string): string {
  return `${tokenId}:${categoryId?.trim() || "__all__"}`;
}

function streamEpgKey(tokenId: string, streamId: number): string {
  return `${tokenId}:s:${streamId}`;
}

function getCachedStreamEpg(tokenId: string, streamId: number): StreamEpgCacheEntry | null {
  const hit = epgStreamCache.get(streamEpgKey(tokenId, streamId));
  if (!hit) return null;
  if (Date.now() - hit.at > EPG_DETAIL_TTL_MS) return null;
  return hit;
}

function setCachedStreamEpg(
  tokenId: string,
  streamId: number,
  now: StreamEpgCacheEntry["now"],
  next: StreamEpgCacheEntry["next"]
) {
  epgStreamCache.set(streamEpgKey(tokenId, streamId), { at: Date.now(), now, next });
}

function isNowPlayingFlag(v: XtreamEpgListing["now_playing"]): boolean {
  return v === 1 || v === true || v === "1";
}

export function parseNowNextPrograms(epg: XtreamEpgListing[]): {
  now: { title: string; start: string; end: string | null } | null;
  next: { title: string; start: string; end: string | null } | null;
} {
  const now = Date.now();
  type Prog = { title: string; start: string; end: string | null };
  let nowProgram: Prog | null = null;
  let nextProgram: Prog | null = null;
  let flaggedNow: Prog | null = null;

  for (const listing of epg) {
    const start = epgToIso(listing, "start");
    const end = epgToIso(listing, "end");
    const title = decodeEpgText(listing.title) || "Programma";

    if (isNowPlayingFlag(listing.now_playing) && start) {
      flaggedNow = { title, start, end: end ?? null };
    }

    if (!start) continue;
    const startMs = Date.parse(start);
    const endMs = end ? Date.parse(end) : startMs + 30 * 60_000;
    if (!Number.isFinite(startMs)) continue;

    if (startMs <= now && now < endMs) {
      nowProgram = { title, start, end: end ?? null };
    } else if (startMs > now && !nextProgram) {
      nextProgram = { title, start, end: end ?? null };
    }
  }

  // Tijd-match heeft voorrang; now_playing als fallback als tijd mist/scheef zit
  if (!nowProgram && flaggedNow) nowProgram = flaggedNow;

  return { now: nowProgram, next: nextProgram };
}

function peekCategoryEpgTitles(
  tokenId: string,
  categoryId: string | undefined
): Map<number, EpgTitlePair> | null {
  const key = epgCacheKey(tokenId, categoryId);
  const cached = epgCategoryCache.get(key);
  if (!cached) return null;
  if (Date.now() - cached.at > EPG_STALE_MS) return null;
  return cached.titles;
}

function coverageRatio(titles: Map<number, EpgTitlePair>, streamIds: number[]): number {
  if (streamIds.length === 0) return 1;
  let hit = 0;
  for (const id of streamIds) {
    const t = titles.get(id);
    if (t && (t.now || t.next)) hit++;
  }
  return hit / streamIds.length;
}

function mergeTitles(
  into: Map<number, EpgTitlePair>,
  from: Map<number, EpgTitlePair>
): Map<number, EpgTitlePair> {
  for (const [id, pair] of from) {
    const prev = into.get(id);
    if (!prev) {
      into.set(id, pair);
      continue;
    }
    into.set(id, {
      now: pair.now ?? prev.now,
      next: pair.next ?? prev.next,
    });
  }
  return into;
}

function titlesFromXmltv(
  streams: XtreamLiveStream[],
  xmlMap: Map<string, XmltvNowNext>,
  tokenId: string
): Map<number, EpgTitlePair> {
  const titles = new Map<number, EpgTitlePair>();
  for (const s of streams) {
    const epgId = s.epg_channel_id?.trim();
    if (!epgId) continue;
    const hit =
      xmlMap.get(epgId) ??
      xmlMap.get(epgId.toLowerCase()) ??
      xmlMap.get(epgId.toUpperCase());
    if (!hit) continue;
    titles.set(s.stream_id, {
      now: hit.now?.title ?? null,
      next: hit.next?.title ?? null,
    });
    if (hit.now || hit.next) {
      setCachedStreamEpg(tokenId, s.stream_id, hit.now, hit.next);
    }
  }
  return titles;
}

async function resolveCategoryEpgTitles(
  tokenId: string,
  categoryId: string | undefined,
  streams: XtreamLiveStream[],
  client: XtreamClient,
  opts: { waitForXmltv: boolean }
): Promise<Map<number, EpgTitlePair>> {
  const key = epgCacheKey(tokenId, categoryId);
  const streamIds = streams.map((s) => s.stream_id);
  const cached = epgCategoryCache.get(key);
  const age = cached ? Date.now() - cached.at : Number.POSITIVE_INFINITY;
  const cov = cached ? coverageRatio(cached.titles, streamIds) : 0;

  // Goede, recente cache met fatsoenlijke dekking → direct terug, optioneel refresh
  if (cached && age < EPG_STALE_MS && cov >= 0.55 && cached.complete) {
    if (age >= EPG_FRESH_MS) {
      void refreshCategoryEpgInBackground(tokenId, categoryId, streams, client);
    }
    return cached.titles;
  }

  // Incomplete of cold: XMLTV bulk laden (hoofdbron)
  let titles = new Map<number, EpgTitlePair>(cached?.titles ?? []);

  const applyXmltvMap = (xmlMap: Map<string, XmltvNowNext>) => {
    titles = mergeTitles(titles, titlesFromXmltv(streams, xmlMap, tokenId));
  };

  const xmlPromise = client.getXmltvNowNextByChannelId();
  if (opts.waitForXmltv) {
    // Max ~8s wachten zodat reverse-proxy niet timeout; rest via client-poll
    const raced = await Promise.race([
      xmlPromise.then((m) => ({ ready: true as const, m })),
      new Promise<{ ready: false }>((resolve) => setTimeout(() => resolve({ ready: false }), 8_000)),
    ]);
    if (raced.ready) {
      applyXmltvMap(raced.m);
    } else {
      void xmlPromise
        .then((m) => {
          const merged = mergeTitles(
            new Map(epgCategoryCache.get(key)?.titles ?? titles),
            titlesFromXmltv(streams, m, tokenId)
          );
          const ids = streams.map((s) => s.stream_id);
          epgCategoryCache.set(key, {
            at: Date.now(),
            titles: merged,
            complete: coverageRatio(merged, ids) >= 0.7,
          });
        })
        .catch((err) => console.warn("[iptv-epg] xmltv bg:", err));
    }
  } else {
    void xmlPromise
      .then((m) => {
        const merged = mergeTitles(
          new Map(epgCategoryCache.get(key)?.titles ?? titles),
          titlesFromXmltv(streams, m, tokenId)
        );
        const ids = streams.map((s) => s.stream_id);
        epgCategoryCache.set(key, {
          at: Date.now(),
          titles: merged,
          complete: coverageRatio(merged, ids) >= 0.7,
        });
      })
      .catch(() => undefined);
  }

  const afterXmltvCov = coverageRatio(titles, streamIds);
  epgCategoryCache.set(key, {
    at: Date.now(),
    titles,
    complete: afterXmltvCov >= 0.7,
  });

  // Ontbrekende zenders (geen epg_channel_id / niet in XMLTV) via short_epg bijwerken
  const missing = streams
    .filter((s) => {
      const t = titles.get(s.stream_id);
      return !t?.now && !t?.next;
    })
    .map((s) => s.stream_id);

  if (missing.length > 0) {
    void fillMissingShortEpg(tokenId, categoryId, missing, client);
  }

  return titles;
}

function refreshCategoryEpgInBackground(
  tokenId: string,
  categoryId: string | undefined,
  streams: XtreamLiveStream[],
  client: XtreamClient
) {
  const key = epgCacheKey(tokenId, categoryId);
  if (epgCategoryRefreshing.has(key)) return;
  epgCategoryRefreshing.add(key);
  void (async () => {
    try {
      await resolveCategoryEpgTitles(tokenId, categoryId, streams, client, {
        waitForXmltv: true,
      });
    } catch {
      // stale blijft
    } finally {
      epgCategoryRefreshing.delete(key);
    }
  })();
}

function fillMissingShortEpg(
  tokenId: string,
  categoryId: string | undefined,
  streamIds: number[],
  client: XtreamClient
) {
  const key = epgCacheKey(tokenId, categoryId);
  const jobKey = `${key}:missing`;
  if (epgCategoryRefreshing.has(jobKey)) return;
  epgCategoryRefreshing.add(jobKey);

  void (async () => {
    try {
      // Beperk burst: max 120 missing per ronde, concurrency 8
      const batch = streamIds.slice(0, 120);
      const filled = await fetchNowNextTitlesParallel(client, batch, 8, tokenId);
      const cached = epgCategoryCache.get(key);
      const merged = mergeTitles(new Map(cached?.titles ?? []), filled);
      const allIds = [...merged.keys()];
      // coverage t.o.v. deze fill-batch + bestaande
      epgCategoryCache.set(key, {
        at: Date.now(),
        titles: merged,
        complete: cached?.complete === true || coverageRatio(merged, allIds) >= 0.6,
      });
    } catch {
      // ignore
    } finally {
      epgCategoryRefreshing.delete(jobKey);
    }
  })();
}

async function fetchNowNextTitlesParallel(
  client: XtreamClient,
  streamIds: number[],
  concurrency: number,
  tokenId?: string
): Promise<Map<number, EpgTitlePair>> {
  const result = new Map<number, EpgTitlePair>();
  if (streamIds.length === 0) return result;

  const queue = [...streamIds];
  const workers = Array.from({ length: Math.min(concurrency, queue.length) }, async () => {
    while (queue.length > 0) {
      const streamId = queue.shift();
      if (streamId == null) return;
      try {
        const epg = await client.getShortEpg(streamId, 8);
        const { now, next } = parseNowNextPrograms(epg);
        result.set(streamId, {
          now: now?.title ?? null,
          next: next?.title ?? null,
        });
        if (tokenId) {
          setCachedStreamEpg(tokenId, streamId, now, next);
        }
      } catch {
        // zender zonder EPG overslaan
      }
    }
  });

  await Promise.all(workers);
  return result;
}

/**
 * Warm XMLTV + categorie-caches op zodat TV-lijsten meteen Nu/Straks hebben.
 */
export function startIptvEpgWarmup(config: Config) {
  const INTERVAL_MS = 15 * 60_000;

  const tick = async () => {
    try {
      const lines = await prisma.iptvLine.findMany({
        where: { enableLive: true, lastError: null, addonToken: { revoked: false } },
        select: { addonTokenId: true },
        take: 4,
        orderBy: { updatedAt: "desc" },
      });

      for (const line of lines) {
        if (xmltvLineRefreshing.has(line.addonTokenId)) continue;
        xmltvLineRefreshing.add(line.addonTokenId);
        try {
          const xt = await loadXtreamForToken(line.addonTokenId, config);
          if (!xt?.line.enableLive) continue;

          // Primair: hele XMLTV warmen (ttl=0 forceert refresh)
          try {
            await xt.client.getXmltvNowNextByChannelId(0);
          } catch (err) {
            console.warn("[iptv-epg-warmup] xmltv", err);
          }

          const cats = await xt.client.getLiveCategories().catch(() => []);
          const sorted = [...cats].sort((a, b) =>
            friendlyCategoryName(a.category_name).localeCompare(
              friendlyCategoryName(b.category_name),
              "nl"
            )
          );

          // Top categorieën + alle zenders via XMLTV-mapping
          for (const cat of sorted.slice(0, 20)) {
            const catId = String(cat.category_id);
            let streams = await xt.client.getLiveStreams(catId).catch(() => []);
            streams = sortChannels(streams);
            if (streams.length === 0) continue;
            await resolveCategoryEpgTitles(line.addonTokenId, catId, streams, xt.client, {
              waitForXmltv: true,
            });
          }

          const all = sortChannels(await xt.client.getLiveStreams().catch(() => []));
          if (all.length > 0) {
            await resolveCategoryEpgTitles(line.addonTokenId, "__all__", all, xt.client, {
              waitForXmltv: true,
            });
          }
        } finally {
          xmltvLineRefreshing.delete(line.addonTokenId);
        }
      }
    } catch (err) {
      console.warn("[iptv-epg-warmup]", err);
    }
  };

  setTimeout(() => void tick(), 12_000);
  setInterval(() => void tick(), INTERVAL_MS);
}