'use client';

import { createContext, useContext, useEffect, useState, useRef } from 'react';
import * as signalR from '@microsoft/signalr';
import { fetchApi } from '@/lib/utils/client';

type FeedPostEvent = {
	postID: number;
	authorSID: string;
	authorName: string|null;
	authorThumb: string|null;
	subject: string;
	thumbnail: string|null;
	createdAt: string;
};

// Backend hub 매핑
//   chatConnection → /hubs/chat (ChatHub)      — 채팅, 향후 1:1 실시간 문의
//   appConnection  → /hubs/app  (AppHub)       — 알림, 쪽지, 피드 토스트
const SignalRContext = createContext<{
	chatConnection: signalR.HubConnection|null;
	chatConnected: boolean;
	appConnection: signalR.HubConnection|null;
	appConnected: boolean;
	stopConnections: () => Promise<void>;
	reconnectChat: (accessToken?: string|null) => Promise<void>;
	reconnectApp: (accessToken?: string|null) => Promise<void>;
	lastFeedPost: FeedPostEvent|null;
	clearLastFeedPost: () => void;
}>({
	chatConnection: null,
	chatConnected: false,
	appConnection: null,
	appConnected: false,
	stopConnections: async () => {},
	reconnectChat: async () => {},
	reconnectApp: async () => {},
	lastFeedPost: null,
	clearLastFeedPost: () => {}
});

type Props = {
	children: React.ReactNode;
	accessToken: string|null;
	signalRChatUrl: string;
	signalRAppUrl: string;
}

export function SignalRProvider({ children, accessToken, signalRChatUrl, signalRAppUrl }: Props) {
	const chatConnectionRef = useRef<signalR.HubConnection|null>(null);
	const appConnectionRef = useRef<signalR.HubConnection|null>(null);
	const [chatConnection, setChatConnection] = useState<signalR.HubConnection|null>(null);
	const [chatConnected, setChatConnected] = useState<boolean>(false);
	const [appConnection, setAppConnection] = useState<signalR.HubConnection|null>(null);
	const [appConnected, setAppConnected] = useState<boolean>(false);
	const [lastFeedPost, setLastFeedPost] = useState<FeedPostEvent|null>(null);

	// 초기 1회만 시작 — 토큰 갱신 시에는 reconnectChat / reconnectApp 으로 수동 재연결
	useEffect(() => {
		initChatConnection(accessToken);
		initAppConnection(accessToken);

		return () => {
			stopConnections();
		};
	}, []);

	useEffect(() => {
		if (chatConnected) {
			console.info('SignalR Chat Connected');
		}
	}, [chatConnected]);

	useEffect(() => {
		if (appConnected) {
			console.info('SignalR App Connected');
		}
	}, [appConnected]);

	const buildConn = (url: string, token: string|null|undefined) => {
		const options = token ? { accessTokenFactory: async () => token, withCredentials: true } : {};
		return new signalR.HubConnectionBuilder().withUrl(url, options).withAutomaticReconnect().build();
	};

	const initChatConnection = async (token?: string|null) => {
		if (!signalRChatUrl) {
			console.warn('SIGNALR_CHAT_URL not configured — chat hub disabled');
			return;
		}

		try {
			if (chatConnectionRef.current && chatConnectionRef.current.state !== signalR.HubConnectionState.Disconnected) {
				await chatConnectionRef.current.stop();
			}

			const conn = buildConn(signalRChatUrl, token);
			await conn.start();

			conn.on('Connected', (message) => {
				console.info('[chat]', message);
			});

			conn.on('Logout', (message) => {
				console.info('[chat]', message);
			});

			chatConnectionRef.current = conn;
			setChatConnection(conn);
			setChatConnected(true);
		} catch (error) {
			console.error('SignalR Chat Connect Failed:', error);
		}
	};

	const initAppConnection = async (token?: string|null) => {
		if (!signalRAppUrl) {
			console.warn('SIGNALR_APP_URL not configured — app hub disabled');
			return;
		}

		try {
			if (appConnectionRef.current && appConnectionRef.current.state !== signalR.HubConnectionState.Disconnected) {
				await appConnectionRef.current.stop();
			}

			const conn = buildConn(signalRAppUrl, token);
			await conn.start();

			conn.on('Connected', (message) => {
				console.info('[app]', message);
			});

			conn.on('Logout', (message) => {
				console.info('[app]', message);
			});

			// ── 피드 이벤트 ──
			conn.on('ReceiveFeedPost', (data: FeedPostEvent) => {
				setLastFeedPost(data);
			});

			// ── 강제 종료 ──
			conn.on('Kick', async () => {
				fetchApi('/api/auth/logout', {
					method: 'POST'
				}).then(() => {
					alert('관리자에 의해 강제 종료되었습니다.');

					localStorage.setItem('rememberMe', "false");
					localStorage.removeItem('member');
					location.replace('/');
				});
			});

			appConnectionRef.current = conn;
			setAppConnection(conn);
			setAppConnected(true);
		} catch (error) {
			console.error('SignalR App Connect Failed:', error);
		}
	};

	const stopConnections = async () => {
		if (chatConnectionRef.current && chatConnectionRef.current.state === signalR.HubConnectionState.Connected) {
			try {
				await chatConnectionRef.current.invoke('Logout');
				setChatConnected(false);
			} catch (error) {
				console.error('SignalR Chat Disconnect Failed:', error);
			}
		}

		if (appConnectionRef.current && appConnectionRef.current.state === signalR.HubConnectionState.Connected) {
			try {
				await appConnectionRef.current.invoke('Logout');
				setAppConnected(false);
			} catch (error) {
				console.error('SignalR App Disconnect Failed:', error);
			}
		}
	};

	const reconnectChat = async (token?: string|null) => {
		await initChatConnection(token);
	};

	const reconnectApp = async (token?: string|null) => {
		await initAppConnection(token);
	};

	return (
		<SignalRContext.Provider value={{
			chatConnection,
			chatConnected,
			appConnection,
			appConnected,
			stopConnections,
			reconnectChat,
			reconnectApp,
			lastFeedPost,
			clearLastFeedPost: () => setLastFeedPost(null)
		}}>
			{children}
		</SignalRContext.Provider>
	)
}

export function useSignalRContext() {
	return useContext(SignalRContext);
}