import * as Comlink from 'comlink';
import { APP_CONFIG } from '../config/constants';

// On redéfinit le type localement pour éviter d'importer tout le SDK WASM ici
type AnkFlag = 'Handshake' | 'NewTx' | 'Cipher' | 'Commit' | 'Faucet' | 'Ping';

export class NetworkBackend {
    private sockets: Map<string, WebSocket> = new Map();
    private relayAddresses: Map<string, string> = new Map(); // wsUrl -> spAddress
    private messageQueue: string[] = [];

    // Callback pour notifier le Main Thread
    private msgCallback: ((flag: string, content: string, url: string) => void) | null = null;
    private statusCallback: ((url: string, status: 'OPEN' | 'CLOSED', spAddress?: string) => void) | null = null;

    // Timers pour la gestion des reconnexions
    private reconnectTimers: Map<string, any> = new Map();
    private heartbeatInterval: any = null;

    constructor() {
        this.startHeartbeat();
    }

    public setCallbacks(
        msgCb: (flag: string, content: string, url: string) => void,
        statusCb: (url: string, status: 'OPEN' | 'CLOSED', spAddress?: string) => void
    ) {
        this.msgCallback = msgCb;
        this.statusCallback = statusCb;
    }

    public async connect(url: string) {
        if (this.sockets.has(url) && this.sockets.get(url)?.readyState === WebSocket.OPEN) return;

        console.log(`[NetworkWorker] 🔌 Connexion à ${url}...`);
        const ws = new WebSocket(url);

        ws.onopen = () => {
            console.log(`[NetworkWorker] ✅ Connecté à ${url}`);
            this.sockets.set(url, ws);

            // Reset timer reconnexion si existant
            if (this.reconnectTimers.has(url)) {
                clearTimeout(this.reconnectTimers.get(url));
                this.reconnectTimers.delete(url);
            }

            // Vider la file d'attente (si message en attente pour ce socket ou broadcast)
            this.flushQueue();

            if (this.statusCallback) this.statusCallback(url, 'OPEN');
        };

        ws.onmessage = (event) => {
            try {
                const msg = JSON.parse(event.data);
                // Si c'est un Handshake, on met à jour la map locale
                if (msg.flag === 'Handshake' && msg.content) {
                    const handshake = JSON.parse(msg.content);
                    if (handshake.sp_address) {
                        this.relayAddresses.set(url, handshake.sp_address);
                        if (this.statusCallback) this.statusCallback(url, 'OPEN', handshake.sp_address);
                    }
                }

                // On remonte TOUT au Main Thread (qui passera au Core)
                if (this.msgCallback) this.msgCallback(msg.flag, msg.content, url);
            } catch (e) {
                console.error('[NetworkWorker] Erreur parsing message:', e);
            }
        };

        ws.onerror = (e) => {
            // console.error(`[NetworkWorker] Erreur sur ${url}`, e);
        };

        ws.onclose = () => {
            console.warn(`[NetworkWorker] ❌ Déconnecté de ${url}.`);
            this.sockets.delete(url);
            this.relayAddresses.set(url, ''); // Reset spAddress

            if (this.statusCallback) this.statusCallback(url, 'CLOSED');
            this.scheduleReconnect(url);
        };
    }

    public sendMessage(flag: AnkFlag, content: string) {
        const msgStr = JSON.stringify({ flag, content });

        // Stratégie simple : On envoie à TOUS les relais connectés (Broadcast)
        // Ou on pourrait cibler un relais spécifique si besoin.
        let sent = false;
        for (const [url, ws] of this.sockets) {
            if (ws.readyState === WebSocket.OPEN) {
                ws.send(msgStr);
                sent = true;
            }
        }

        if (!sent) {
            // console.warn(`[NetworkWorker] Pas de connexion. Message ${flag} mis en file.`);
            this.messageQueue.push(msgStr);
        }
    }

    public getAvailableRelay(): string | null {
        // Retourne l'adresse SP d'un relais connecté
        for (const sp of this.relayAddresses.values()) {
            if (sp && sp !== '') return sp;
        }
        return null;
    }

    public getAllRelays() {
        return Object.fromEntries(this.relayAddresses);
    }

    // --- INTERNES ---

    private flushQueue() {
        while (this.messageQueue.length > 0) {
            const msg = this.messageQueue.shift();
            if (!msg) break;
            for (const ws of this.sockets.values()) {
                if (ws.readyState === WebSocket.OPEN) ws.send(msg);
            }
        }
    }

    private scheduleReconnect(url: string) {
        if (this.reconnectTimers.has(url)) return;

        console.log(`[NetworkWorker] ⏳ Reconnexion à ${url} dans 3s...`);
        const timer = setTimeout(() => {
            this.reconnectTimers.delete(url);
            this.connect(url);
        }, 3000); // Délai fixe ou APP_CONFIG.TIMEOUTS.RETRY_DELAY

        this.reconnectTimers.set(url, timer);
    }

    private startHeartbeat() {
        this.heartbeatInterval = setInterval(() => {
            // Envoi d'un ping léger ou gestion du keep-alive
            // this.sendMessage('Ping', '');
        }, 30000);
    }
}

Comlink.expose(new NetworkBackend());