/*
 * HTTP tunnel over WebRTC - P2P class
 * Author: Konstantinos Drakontidis
 * Email: gedra100sh@gmail.com
 */
import { v4 } from "uuid";
import { WebSocket } from "ws";
import config from "../config/config"

export class P2P {
    private server_instance: WebSocket | null;
    private clients: Map<string, { instance: WebSocket, timeout: NodeJS.Timeout | null }>;

    public constructor() {
        this.server_instance = null;
        this.clients = new Map();
    }

    // Sets the server websocket instance
    setServer(server_instance: WebSocket): void {
        this.server_instance = server_instance;
    }

    // Gets the server websocket instance
    getServer(): WebSocket | null {
        return this.server_instance;
    }

    // Adds a client websocket instance to the map
    addClient(client: WebSocket): string {
        const id = v4();
        this.clients.set(id, { instance: client, timeout: null });

        return id;
    }

    // Returns client peer instance
    getPeer(id: string, client: WebSocket): WebSocket | null {
        if (client == this.server_instance) {
            const client_instance = this.clients.get(id)?.instance;

            return (client_instance != undefined) ? client_instance : null;
        } else {
            return this.server_instance;
        }
    }

    // Removes client entry from map
    removeClient(id: string) {
        return this.clients.delete(id);
    }

    // Returns client id
    getId(client: WebSocket): string | null {
        var key = null;

        this.clients.forEach((v, k) => {
            if (v.instance == client) {
                key = k;
                return;
            }
        });

        return key;
    }

    // Clears the P2P instance
    clear() {
        this.clients.forEach((v) => {
            v.instance.close(3001, "Server shutdown.");
        })
        this.server_instance = null;
        this.clients.clear();
    }

    // Sets client timeout after register
    setClientTimeout(id: string, p2p: P2P, ws_client: WebSocket, callback: (id: string, p2p: P2P, ws_client: WebSocket) => void) {
        const instance = this.clients.get(id);
        if (instance) {
            this.clients.set(id, { ...instance, timeout: setTimeout(() => { callback(id, p2p, ws_client) }, config.timeout) });
        }
    }

    // Clears client timeout
    clearClientTimeout(id: string) {
        const timeout = this.clients.get(id)?.timeout;
        if (timeout && (timeout != null)) {
            clearTimeout(timeout);
        }
    }

    // Returns the total entries in the map
    getMapSize(): number {
        return this.clients.size;
    }
};