'use client';

import { useEffect, useRef, useState, useCallback } from 'react';
import * as signalR from '@microsoft/signalr';
import { DonationAlertData, DonationRemoteState } from '@/types/donation';

type AlertQueueItem = DonationAlertData & { status: 'queued'|'playing'|'done' };

export function useDonationAlert(
	widgetToken: string,
	hubUrl: string,
	getDurationSec?: (alert: DonationAlertData) => number
) {
	const connectionRef = useRef<signalR.HubConnection|null>(null);
	const [connected, setConnected] = useState(false);
	const [queue, setQueue] = useState<AlertQueueItem[]>([]);
	const [current, setCurrent] = useState<AlertQueueItem|null>(null);
	const [remoteState, setRemoteState] = useState<DonationRemoteState>({
		isPaused: false,
		isAccepting: true,
		isAudioOnly: false,
		isVideoOnly: false
	});
	const [skipSignal, setSkipSignal] = useState(0);

	// SignalR 연결
	useEffect(() => {
		const conn = new signalR.HubConnectionBuilder()
			.withUrl(hubUrl)
			.withAutomaticReconnect()
			.build();

		conn.on('ReceiveAlert', (data: DonationAlertData) => {
			setQueue(prev => {
				// 같은 alertID가 이미 큐에 있으면 무시 (중복 broadcast 방어)
				if (prev.some(q => q.alertID === data.alertID)) {
					return prev;
				}
				return [...prev, { ...data, status: 'queued' }];
			});
		});

		conn.on('ReceiveSkip', () => {
			setSkipSignal(prev => prev + 1);
		});

		conn.on('ReceivePause', (isPaused: boolean) => {
			setRemoteState(prev => ({ ...prev, isPaused }));
		});

		conn.on('ReceiveState', (state: DonationRemoteState) => {
			setRemoteState(state);
		});

		// 리모콘에서 큐 순서 변경 — 두 알림 위치 swap
		conn.on('ReceiveQueueReorder', (data: { swap?: number[] }) => {
			if (!data?.swap || data.swap.length !== 2) {
				return;
			}
			const [a, b] = data.swap;
			setQueue(prev => {
				const idxA = prev.findIndex(q => q.alertID === a);
				const idxB = prev.findIndex(q => q.alertID === b);
				if (idxA < 0 || idxB < 0) {
					return prev;
				}
				const next = [...prev];
				[next[idxA], next[idxB]] = [next[idxB], next[idxA]];
				return next;
			});
		});

		conn.start().then(() => {
			conn.invoke('JoinChannel', widgetToken);
			setConnected(true);
		}).catch(err => {
			console.error('[DonationHub] Connect failed:', err);
		});

		conn.onreconnected(() => {
			conn.invoke('JoinChannel', widgetToken);
			setConnected(true);
		});

		conn.onclose(() => setConnected(false));

		connectionRef.current = conn;

		return () => {
			conn.stop();
		};
	}, [widgetToken, hubUrl]);

	// 큐 처리 — 일시정지가 아닐 때 다음 알림 꺼내기
	useEffect(() => {
		if (current || remoteState.isPaused || queue.length === 0) {
			return;
		}

		const next = queue[0];
		setQueue(prev => prev.slice(1));
		setCurrent({ ...next, status: 'playing' });

		// 알림 재생 시작 보고 — duration 동봉 시 리모콘 타이머 ring 표시 가능
		const durationSec = getDurationSec?.(next);
		connectionRef.current?.invoke('AlertDelivered', next.alertID, durationSec ?? null).catch(() => {});
	}, [queue, current, remoteState.isPaused, getDurationSec]);

	// 스킵 시그널 처리
	useEffect(() => {
		if (skipSignal > 0 && current) {
			setCurrent(null);
		}
	}, [skipSignal]);

	// 알림 완료 콜백 — backend에 보고 + state 클리어
	const onAlertComplete = useCallback(() => {
		setCurrent(prev => {
			if (prev) {
				connectionRef.current?.invoke('AlertCompleted', prev.alertID).catch(() => {});
			}
			return null;
		});
	}, []);

	return {
		connected,
		current,
		queue,
		remoteState,
		skipSignal,
		onAlertComplete
	};
}