import { Inject } from '@angular/core';
import { Observable } from 'rxjs';
import { share } from 'rxjs/operators';

import * as io from 'socket.io-client';

import { SocketIoConfig } from './config/socket-io.config';

export class WrappedSocket {
    subscribersCounter: Record<string, number> = {};
    eventObservables$: Record<string, Observable<any>> = {};
    ioSocket: any;
    emptyConfig: SocketIoConfig = {
        url: '',
        options: {}
    };

    constructor(private config: SocketIoConfig) {
        if (config === undefined) {
            config = this.emptyConfig;
        }
        const url: string = config.url;
        const options: any = config.options;
        const ioFunc = (io as any).default ? (io as any).default : io;
        this.ioSocket = ioFunc(url, options);
    }

    of(namespace: string) {
        this.ioSocket.of(namespace);
    }

    on(eventName: string, callback: Function) {
        this.ioSocket.on(eventName, callback);
    }

    once(eventName: string, callback: Function) {
        this.ioSocket.once(eventName, callback);
    }

    connect() {
        return this.ioSocket.connect();
    }

    disconnect(close?: any) {
        return this.ioSocket.disconnect.apply(this.ioSocket, arguments);
    }

    emit(eventName: string, ...args: any[]) {
        return this.ioSocket.emit.apply(this.ioSocket, arguments);
    }

    removeListener(eventName: string, callback?: Function) {
        return this.ioSocket.removeListener.apply(this.ioSocket, arguments);
    }

    removeAllListeners(eventName?: string) {
        return this.ioSocket.removeAllListeners.apply(this.ioSocket, arguments);
    }

    fromEvent<T>(eventName: string): Observable<T> {
        if (!this.subscribersCounter[eventName]) {
            this.subscribersCounter[eventName] = 0;
        }
        this.subscribersCounter[eventName]++;

        if (!this.eventObservables$[eventName]) {
            this.eventObservables$[eventName] = new Observable((observer: any) => {
                const listener = (data: T) => {
                    observer.next(data);
                };
                 this.ioSocket.on(eventName, listener);
                 return () => {
                     this.subscribersCounter[eventName]--;
                     if (this.subscribersCounter[eventName] === 0) {
                        this.ioSocket.removeListener(eventName, listener);
                        delete this.eventObservables$[eventName];
                     }
                };
            }).pipe(
                share()
            );
        }
        return this.eventObservables$[eventName];
    }

    fromOneTimeEvent<T>(eventName: string): Promise<T> {
        return new Promise<T>(resolve => this.once(eventName, resolve));
    }

}