'use client';

import { useCallback, useEffect, useState } from 'react';

export type PublicRoomState = {
  id: string;
  settings: {
    chzzkEnabled: boolean;
    liveUrl: string;
    channelId: string | null;
    cheesePerDice: number;
    multiplyByCheese: boolean;
    maxMultiplier: number;
  };
  diceQueue: number;
  channelName: string | null;
  chatChannelId: string | null;
  chatStatus: 'idle' | 'connecting' | 'connected' | 'error' | 'disconnected';
  chatError: string | null;
  lastDonations: Array<{
    id: string;
    at: number;
    payAmount: number;
    diceAdded: number;
    donatorNickname: string;
    donationText?: string;
    simulated?: boolean;
  }>;
  chatFeed: Array<{
    id: string;
    at: number;
    nickname: string;
    message: string;
    kind: 'chat' | 'donation';
    payAmount?: number;
  }>;
};

export function useRoom(roomId: string | null) {
  const [room, setRoom] = useState<PublicRoomState | null>(null);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (!roomId) return;

    const clientId =
      typeof crypto !== 'undefined' && 'randomUUID' in crypto
        ? crypto.randomUUID()
        : `c-${Date.now()}-${Math.random().toString(16).slice(2)}`;

    let es: EventSource | null = null;
    let cancelled = false;

    void fetch(`/api/rooms/${roomId}`)
      .then(async (r) => {
        const j = await r.json();
        if (cancelled) return;
        if (!r.ok) {
          setError(j.error || '방을 불러오지 못했습니다.');
          return;
        }
        if (j.room) setRoom(j.room as PublicRoomState);
        else setError(j.error || '방을 불러오지 못했습니다.');

        es = new EventSource(
          `/api/rooms/${roomId}/events?clientId=${encodeURIComponent(clientId)}`,
        );
        es.addEventListener('room', (ev) => {
          try {
            setRoom(JSON.parse((ev as MessageEvent).data) as PublicRoomState);
            setError(null);
          } catch {
            // ignore
          }
        });
        es.onerror = () => {
          // keep last state; browser will retry SSE
        };
      })
      .catch(() => {
        if (!cancelled) setError('방을 불러오지 못했습니다.');
      });

    const leave = () => {
      try {
        const payload = JSON.stringify({ clientId });
        if (typeof navigator !== 'undefined' && navigator.sendBeacon) {
          navigator.sendBeacon(
            `/api/rooms/${roomId}/leave`,
            new Blob([payload], { type: 'application/json' }),
          );
        } else {
          void fetch(`/api/rooms/${roomId}/leave`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: payload,
            keepalive: true,
          });
        }
      } catch {
        // ignore
      }
    };

    window.addEventListener('pagehide', leave);
    return () => {
      cancelled = true;
      window.removeEventListener('pagehide', leave);
      es?.close();
      leave();
    };
  }, [roomId]);

  const consumeDice = useCallback(
    async (count = 1) => {
      if (!roomId) return { ok: true as const };
      const res = await fetch(`/api/rooms/${roomId}/consume-dice`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ count }),
      });
      const json = await res.json();
      if (!res.ok) {
        return {
          ok: false as const,
          error: (json.error as string) || '주사위를 소모할 수 없습니다.',
        };
      }
      setRoom(json.room as PublicRoomState);
      return { ok: true as const };
    },
    [roomId],
  );

  const simulateDonation = useCallback(
    async (payAmount: number) => {
      if (!roomId) return;
      const res = await fetch(`/api/rooms/${roomId}/simulate-donation`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ payAmount }),
      });
      const json = await res.json();
      if (!res.ok) throw new Error(json.error || '시뮬레이션 실패');
      setRoom(json.room as PublicRoomState);
    },
    [roomId],
  );

  const addDice = useCallback(
    async (count = 1) => {
      if (!roomId) return { ok: false as const, error: '방이 없습니다.' };
      const res = await fetch(`/api/rooms/${roomId}/add-dice`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ count }),
      });
      const json = await res.json();
      if (!res.ok) {
        return {
          ok: false as const,
          error: (json.error as string) || '주사위를 추가할 수 없습니다.',
        };
      }
      setRoom(json.room as PublicRoomState);
      return { ok: true as const };
    },
    [roomId],
  );

  return { room, error, consumeDice, simulateDonation, addDice };
}