import { WatcherProxy, WebsocketPayload } from "../interfaces";
import { Observable } from "rxjs";
import { shareReplay } from "rxjs/operators";

/**
 * @description Watcher Proxy decorator
 * This class can be use to cache a watcher proxy stream so it return an existing stream when it is asked the same request multiple time 
 */
export class CachedWatcherProxy implements WatcherProxy {
    private watchMap = new Map();

    watch(transactionId: string, address: string, network: string, nbConf: number): Observable<WebsocketPayload> {
        const key = `${transactionId}:${address}:${network}:${nbConf}`;
        if (!this.watchMap.has(key)) {
            this.watchMap.set(key, this.watcher.watch(transactionId, address, network, nbConf).pipe(shareReplay()));
        }
        return this.watchMap.get(key);
    }
    unwatch(transactionId: string, address: string, network: string, nbConf: number): Observable<void> {
        return this.watcher.unwatch(transactionId, address, network, nbConf);
    }
    constructor(private watcher: WatcherProxy) {

    }
}