class VuplexPolyfill {
    constructor() {
        this._listeners = {};
        window.addEventListener('message', this._handleWindowMessage.bind(this));
    }

    addEventListener(eventName, listener) {
        if (!this._listeners[eventName]) {
            this._listeners[eventName] = [];
        }
        if (this._listeners[eventName].indexOf(listener) === -1) {
            this._listeners[eventName].push(listener);
        }
    }

    removeEventListener(eventName, listener) {
        if (!this._listeners[eventName]) {
            return;
        }
        const index = this._listeners[eventName].indexOf(listener);
        if (index !== -1) {
            this._listeners[eventName].splice(index, 1);
        }
    }

    postMessage(message) {
        // Don't pass a string to JSON.stringify() because it adds extra quotes.
        const messageString = typeof message === 'string' ? message : JSON.stringify(message);
        parent.postMessage({
            type: 'vuplex.postMessage',
            message: messageString
        }, '*')
    }

    _emit(eventName, ...args) {
        if (!this._listeners[eventName]) {
            return;
        }
        for (const listener of this._listeners[eventName]) {
            try {
                listener(...args);
            } catch (error) {
                console.error(`An error occurred while invoking the '${eventName}' event handler.`, error);
            }
        }
    }

    _handleWindowMessage(event) {
        if (event.data && event.data.type === 'vuplex.postMessage') {
            this._emit('message', { data: event.data.message });
        }
    };
}

if (!window.vuplex) {
    window.vuplex = new VuplexPolyfill();
}

if (window.vuplex) {
    vrAddMessageListener();
} else {
    window.addEventListener('vuplexready', vrAddMessageListener);
}

function vrAddMessageListener() {
    window.vuplex.addEventListener('message', function(event) {
        let json = event.data;
        if(typeof json === 'string') json = JSON.parse(json);
        // > JSON received: { "type": "greeting", "message": "Hello from C#!" }
        console.log('JSON received: ');
        console.log(json);

        let messageObject = {
            name: 'VR',
            //sender: json.sender,
            type: json.type,
            data: json.data || {},
        };
        document.querySelector('#game-frame').contentWindow.postMessage(messageObject, "*");
    });
}


let vrEvent = null;
function VREvents() {
    this.receiveMessage = function() {
        window.addEventListener('message', EventHandler, false);

        function EventHandler(eventData) {
            if(eventData && eventData.data && eventData.data.name && eventData.data.name === 'VR') {
                let messageObject = {
                    //sender: eventData.data.sender,
                    type: eventData.data.type,
                    data: eventData.data.data,
                };
                //window.parent.postMessage(messageObject, '*');
                window.vuplex.postMessage(messageObject, '*');
            } else if(eventData && eventData.data && eventData.data.sender && eventData.data.sender === 'VR') {
                // let messageObject = {
                //     name: 'VR',
                //     sender: eventData.data.sender,
                //     type: eventData.data.type,
                //     data: eventData.data.data || {},
                // };
                // document.querySelector('#game-frame').contentWindow.postMessage(messageObject, "*");
            }
        }
    };
}

vrEvent = new VREvents();
vrEvent.receiveMessage();