/**
 * Session storage object - singleton instance model
 */
export default class SessionStorage {

    // Static instance
    private static _instance: any;

    /**
     *
     * @private
     */
    private _proxy: any;

    // Meta props
    private _metaProps = {};


    // Create proxy
    constructor() {
        this._proxy = new Proxy({}, {
            get: (target: any, key: string): any => {

                if (key == "hasOwnProperty") {

                    return (propertyName: any) => {
                        if (propertyName == "__rv") {
                            return !!(<any>this._metaProps)["__rv"];
                        }

                    }
                } else if (key == "__rv") {

                    return (<any>this._metaProps)["__rv"];
                }
                return sessionStorage.getItem(key);
            },
            set: (target: any, key: string, value: any): boolean => {

                if (key == "__rv") {
                    (<any>this._metaProps)["__rv"] = value;
                } else {
                    sessionStorage.setItem(key, value);
                    (<any>this)[key] = value;
                }
                return true;
            }, defineProperty: (target: any, key: any, desc: any) => {
                if (key == "__rv") {
                    if (!(<any>this._metaProps)["__rv"])
                        (<any>this._metaProps)["__rv"] = desc.value;
                } else {
                    Object.defineProperty(this, key, desc);
                }
                return target;
            }

        });
    }


    get proxy() {
        return this._proxy;
    }

    /**
     * Get a singleton version of this request
     */
    public static get instance() {
        if (!this._instance) {
            this._instance = new SessionStorage();
        }

        return this._instance.proxy;
    }

}