// CLIENT API KEY
var api = 'lite.visitor.info';

(function() {
    // CHECK FOR API KEY
    if (!api) {
        console.error('client.js has no API key');
        return;
    }

    // ENVIRONMENT ORIGIN
    var origin;
    // TODO: move to outer settings file
    if (location.host === '127.0.0.1:5000')
        origin = 'http://' + location.host;
    else
        origin = 'https://visitor.info';

    // CREATE VISITOR CONTAINER
    var container = document.createElement('div');
        container.style.position = 'absolute';
        container.style.top = '-10000px';
    document.body.appendChild(container);
    var frame_name = 'visitor_frame',
        url = origin + '/visitor/iframe?api=' + api;
    var iframe = document.createElement('iframe');
        iframe.name = frame_name;
        iframe.src = url;
    container.appendChild(iframe);
    var form = document.createElement('form');
        form.action = url;
        form.method = 'POST';
        form.target = frame_name;
    container.appendChild(form);

    // LISTEN FOR IFRAME SCRIPT MESSAGE
    var iframe_listener = function(event) {
        // CLIENT CALLBACK FUNCTION HANDLER
        if (typeof visitorCallback !== 'undefined' &&
            typeof visitorCallback === 'function') {
            console.log('RUN client defined callback function');
            visitorCallback(event.data);
        }
    };

    if (window.addEventListener)
        window.addEventListener('message', iframe_listener, false);
    else
        window.attachEvent('onmessage', iframe_listener);

    // INITIAL VISITOR DATA
    var visitor = {
        'display_window': {
            'width': window.innerWidth
                  || document.documentElement.clientWidth
                  || document.body.clientWidth,
            'height': window.innerHeight
                   || document.documentElement.clientHeight
                   || document.body.clientHeight
        },
        'http_referrer': document.referrer
    };

    // POST VISITOR DATA TO MAIN VISITOR SCRIPT
    window.onload = function() {
        window.frames[iframe.name].postMessage(visitor, '*');
    };
})();

// compatibility with older version
// TODO: review code
if(!Visitor)var Visitor=function(){return{init:function(f){}}};