import { EventEmitter } from "events";
import Packet from "./packet";
import PacketHandshake, { Device, HandshakeState } from "./packets/packet.handshake";
import { PacketMessage } from "./packets/packet.message";
import { PacketOnlineState } from "./packets/packet.onlinestate";
import { PacketOnlineSubscribe } from "./packets/packet.onlinesubscribe";
import { PacketRead } from "./packets/packet.read";
import { PacketResult } from "./packets/packet.result";
import { PacketSearch } from "./packets/packet.search";
import { PacketUserInfo } from "./packets/packet.userinfo";
import Stream from "./stream";
import { PacketDelivery } from "./packets/packet.delivery";
import { PacketRequestUpdate } from "./packets/packet.requestupdate";
import { RECONNECTING_INTERVAL } from "@/app/constants";
import { PacketTyping } from "./packets/packet.typeing";
import { PacketAvatar } from "./packets/packet.avatar";
import { PacketKernelUpdate } from "./packets/packet.kernelupdate";
import { PacketAppUpdate } from "./packets/packet.appupdate";
import { PacketRequestTransport } from "./packets/packet.requesttransport";
import { PacketPushNotification } from "./packets/packet.push.notification";
import { PacketCreateGroup } from "./packets/packet.create.group";
import { PacketGroupInfo } from "./packets/packet.group.info";
import { PacketGroupInviteInfo } from "./packets/packet.group.invite.info";
import { PacketGroupJoin } from "./packets/packet.group.join";
import { PacketGroupLeave } from "./packets/packet.group.leave";
import { PacketGroupBan } from "./packets/packet.group.ban";
import { PacketDeviceNew } from "./packets/packet.device.new";
import { PacketDeviceList } from "./packets/packet.device.list";
import { PacketDeviceResolve } from "./packets/packet.device.resolve";

export default class Protocol extends EventEmitter {
    private serverAddress: string;
    private socket: WebSocket | null = null;
    private reconnectInterval: number = RECONNECTING_INTERVAL * 1000;
    private isManuallyClosed: boolean = false;
    private _supportedPackets: Map<number, Packet> = new Map();
    private _packetWaiters: Map<number, ((packet: any) => void)[]> = new Map();
    private _packetQueue: Packet[] = []; // Очередь для пакетов
    private handshakeExchangeComplete : boolean = false;
    private heartbeatIntervalTimer : NodeJS.Timeout | null = null;

    constructor(serverAddress: string) {
        super();
        this.serverAddress = serverAddress;
        this.loadAllSupportedPackets();
        this.connect();

        let _this = this;
        this.waitPacket(0x00, (packet : PacketHandshake) => {
            if(packet.getHandshakeState() == HandshakeState.COMPLETED) {
                console.info('[protocol] %chandshake exchange complete', 'color: #12c456;');
                _this.emit('handshake_complete');
                _this.handshakeExchangeComplete = true;
                _this._flushPacketQueue();
                this.startHeartbeat(packet.getHeartbeatInterval());
            } 
            if(packet.getHandshakeState() == HandshakeState.NEED_DEVICE_VERIFICATION) {
                console.info('[protocol] %chandshake exchange need device verification', 'color: orange;');
                _this.emit('handshake_need_device_verification');
                _this._packetQueue = [];
                this.startHeartbeat(packet.getHeartbeatInterval());
            }
        });

    }

    public startHeartbeat(intervalS : number) {
        const heartbeat = () => {
            if(this.socket && this.socket.readyState === WebSocket.OPEN){
                this.socket?.send('heartbeat');
            }
        }
        if(this.heartbeatIntervalTimer){
            clearInterval(this.heartbeatIntervalTimer);
        }
        console.info(`[protocol] %cstarting heartbeat with interval: %c${intervalS} seconds`, 'color: #12c456;', 'color: orange;');
        heartbeat();
        this.heartbeatIntervalTimer = setInterval(() => {
            heartbeat();
        }, ((intervalS * 1000) / 2));
    }

    public startHandshakeExchange(publicKey: string, privateKey: string,
        device: Device
    ) {
        console.info(
            `[protocol] %cstarting handshake exchange with server, public key: %c${publicKey}%c, private key hash: %c${privateKey}`,
            'color: #deadcd;',
            'color: #12c456;',
            'color: #deadcd;',
            'color: #12c456;'
        );
        let handshake = new PacketHandshake();
        handshake.setPublicKey(publicKey);
        handshake.setPrivateKey(privateKey);
        handshake.setDevice(device);
        this.sendPacket(handshake);
        this.emit('handshake_start');
    }

    private loadAllSupportedPackets() {
        this._supportedPackets.set(0x00, new PacketHandshake());
        this._supportedPackets.set(0x01, new PacketUserInfo());
        this._supportedPackets.set(0x02, new PacketResult());
        this._supportedPackets.set(0x03, new PacketSearch());
        this._supportedPackets.set(0x04, new PacketOnlineSubscribe());
        this._supportedPackets.set(0x05, new PacketOnlineState());
        this._supportedPackets.set(0x06, new PacketMessage());
        this._supportedPackets.set(0x07, new PacketRead());
        this._supportedPackets.set(0x08, new PacketDelivery());
        this._supportedPackets.set(0x09, new PacketDeviceNew());
        this._supportedPackets.set(0x0A, new PacketRequestUpdate());
        this._supportedPackets.set(0x0B, new PacketTyping());
        this._supportedPackets.set(0x0C, new PacketAvatar());
        this._supportedPackets.set(0x0D, new PacketKernelUpdate());
        this._supportedPackets.set(0x0E, new PacketAppUpdate());
        this._supportedPackets.set(0x0F, new PacketRequestTransport());
        this._supportedPackets.set(0x10, new PacketPushNotification());
        this._supportedPackets.set(0x11, new PacketCreateGroup());
        this._supportedPackets.set(0x12, new PacketGroupInfo());
        this._supportedPackets.set(0x13, new PacketGroupInviteInfo());
        this._supportedPackets.set(0x14, new PacketGroupJoin());
        this._supportedPackets.set(0x15, new PacketGroupLeave());
        this._supportedPackets.set(0x16, new PacketGroupBan());
        this._supportedPackets.set(0x17, new PacketDeviceList());
        this._supportedPackets.set(0x18, new PacketDeviceResolve());
    }

    private _findWaiters(packetId: number): ((packet: Packet) => void)[] {
        if (!this._packetWaiters.has(packetId)) {
            return [];
        }
        return this._packetWaiters.get(packetId)!;
    }

    public connect() {
        this.socket = new WebSocket(this.serverAddress);
        /**
         * Сбрасываем флаг ручного закрытия соединения
         * при подключении
         */
        this.isManuallyClosed = false;

        this.socket.addEventListener('open', () => {
            //this.reconnectTryings = 0;
            this.emit('connect');
            this._flushPacketQueue(); // Отправляем все пакеты из очереди            
        });

        this.socket.addEventListener('message', async (event: MessageEvent) => {
            let stream = new Stream();
            const data = await event.data.arrayBuffer();
            const numbers = Array.from(new Uint8Array(data));
            stream.setStream(numbers);
            const packetId = stream.readInt16();
            this._supportedPackets.get(packetId);
            if (!this._supportedPackets.get(packetId)) {
                console.error(`Unsupported packet ID: ${packetId}`);
                return;
            }
            //чек безопасность
            const packet = this._supportedPackets.get(packetId)!.clone();
            packet._receive(stream);
            const waiters = this._findWaiters(packetId);
            if (waiters.length === 0) {
                console.error(`No waiters found for packet ID: ${packetId}`);
                return;
            }
            for (const waiter of waiters) {
                waiter(packet);
            }            
        });

        this.socket.addEventListener('close', (e: CloseEvent) => {
            console.log(`Connection reset by peer`, e.code);
            this.handshakeExchangeComplete = false;
            if (!this.isManuallyClosed) {
                console.log(`Attempting to reconnect...`);
                this.emit('reconnect');
                setTimeout(() => {
                    this.connect();
                    if(this.socket?.readyState == WebSocket.OPEN){
                        return;
                    }
                }, this.reconnectInterval);
            }            
        });
    }

    private _flushPacketQueue() { 
        if (this.socket && this.socket.readyState === WebSocket.OPEN) {
            for(let i = this._packetQueue.length - 1; i >= 0; i--){
                let packet : Packet = this._packetQueue[i];
                if(!this.handshakeExchangeComplete && packet.getPacketId() != 0x00){
                    /**
                     * Если рукопожатие еще не выполнено и текущий пакет для отправки из очереди -
                     *  не рукопожатие то пропускаем, отправим в следующее очищение очереди
                     */
                    continue; 
                }
                this.sendPacket(packet);
                this._packetQueue.splice(i, 1);
            }
        }
    }

    public async sendPacket(packet: Packet) {
        if(!this.socket){
            this.addPacketToQueue(packet);
            return;
        }
        if(this.socket.readyState !== WebSocket.OPEN){
            this.addPacketToQueue(packet);
            return; 
        }
        if(!this.handshakeExchangeComplete && packet.getPacketId() != 0x00){
            this.addPacketToQueue(packet);
            return;
        }
        const stream = await packet._send();
        const packetName = packet.constructor.name;

        const pIdHex = packet.getPacketId().toString(16).toLocaleUpperCase();
        const pIdHexPadded = pIdHex.length === 1 ? '0' + pIdHex : pIdHex;

        console.info(`[protocol] %csending packet: %c${packetName} (ID: 0x${pIdHexPadded})`, 'color: #deadcd;', 'color: orange;');

        /**
         * Если пакет больше максимально допустимого размера, то разбиваем его на чанки
         * и отправляем по частям
         */
        this.socket.send(Buffer.from(stream.getStream()));
    }

    public addPacketToQueue(packet : Packet) {
        this._packetQueue.push(packet);
    }

    public close() {
        this.isManuallyClosed = true;
        if (this.socket) {
            this.socket.close();
        }
    }

    public unwaitPacket<T>(packet: number, callback: (packet: T) => void) {
        if (!this._packetWaiters.has(packet)) {
            return;
        }
        const waiters = this._packetWaiters.get(packet)!;
        const index = waiters.indexOf(callback);
        if (index !== -1) {
            waiters.splice(index, 1);
        }
        if (waiters.length === 0) {
            this._packetWaiters.delete(packet);
        }
    }

    public waitPacket<T>(packet: number, callback: (packet: T) => void) : number {
        if (!this._packetWaiters.has(packet)) {
            this._packetWaiters.set(packet, []);
        }
        return this._packetWaiters.get(packet)!.push(callback);
    }

    /**
     * Wait for a single packet to be received.
     * @param packet packet number to wait
     * @param callback callback to execute once the packet is received
     */
    public waitPacketOnce<T>(packet: number, callback: (packet: T) => void) {
        let wrapper = (receivedPacket: T) => {
            callback(receivedPacket);
            this.unwaitPacket(packet, wrapper);
        };
        this.waitPacket(packet, wrapper);
    }
}