import { onEvent, onError } from '../track';

export default function () {

    let oldOpen = XMLHttpRequest.prototype.open;
    let oldSend = XMLHttpRequest.prototype.send;

    XMLHttpRequest.prototype.open = open;
    XMLHttpRequest.prototype.send = send;
    
    function open(method, url, async, user, pass) {
        this._method = method;
        this._url = url;

        try {
            oldOpen.call(this, method, url, async, user, pass);
        } catch (ex) {
            onError({
                data: ex.name + ": " + ex.message,
                occurredAt: new Date(),
                source: 'Opening ' + method + ' request to ' + url,
                stack: 'Unavailable',
                category: 'Unavailable'
            });
            throw ex;
        }
    }

    function send(data) {
        let self = this;
        let start;
        let oldOnReadyStateChange;
        let url = this._url;
        let method = this._method;

        if (!this.noIntercept) {
            start = new Date().getMilliseconds();

            if (this.addEventListener) {
                this.addEventListener("readystatechange", onReadyStateChange, false);
            } else {
                oldOnReadyStateChange = this.onreadystatechange;
                this.onreadystatechange = onReadyStateChange;
            }
        }

        function onReadyStateChange() {
            if (self.readyState == 4) {
                let time = new Date().getMilliseconds() - start;

                onEvent({
                    type: 'xmlHttpRequest',
                    data: time + 'ms',
                    occurredAt: new Date(),
                    source: "[" + method + "] " + url,
                    page: window.location.href + window.location.hash,
                    HTML: "Not Available"
                });
            }

            if (oldOnReadyStateChange) {
                oldOnReadyStateChange();
            }
        }
        try {
            oldSend.call(this, data);

        } catch (ex) {

            onError({
                data: ex.name + ": " + ex.message,
                occurredAt: new Date(),
                source: 'Sending ' + method + ' request to ' + url,
                stack: 'Unavailable',
                category: 'Unavailable'
            });

            throw ex;
        }

        
    }
}