// Linked to offsite.

var EPStore = {
    // server is just a meta tag for the server this file is used on
    server: '6invegas.com',
    _initialized: null,

    init: function () {
        this.set_ep_site_links({adv: 'a', mid: 'm', imid: 'i'}, {adv: 'V101'});
        
        this._initialized = true; 
    },
    
    // elapsed time until expires, in minutes
    set_cookie: function (name, value, elapsed) {
        var expires = "";
        if (elapsed) { 
            var date = new Date();
            date.setTime(date.getTime()+(elapsed*60*1000));
            expires = "; expires="+date.toGMTString();
        }
        document.cookie = name + "=" + escape(value) + expires + "; path=/";
    },
    
    // An associative array containing parameter values keyed by name
    parameters: (function () {
        var loc = window.location.toString();
        var qI = loc.indexOf('?');
        var kvs = qI > 0 ? loc.substring(qI + 1).split('&') : [];
        var params = {};
        
        for (var i = 0; i < kvs.length; i++) {
            var pos = kvs[i].indexOf('=');
            if (pos > 0) {
                var key = kvs[i].substring(0,pos);
                var val = kvs[i].substring(pos+1);
                params[key] = val;
            }
        }

        return params;
     })(),

    /*
     name optional - if provided return the value of named cookie or null,
     otherwise return hash of all cookies
    */
    read_cookies: function (name) {
        var cookies = document.cookie.split(/; */);
        var cookie_hash = {};

        for(var i=0;i < cookies.length;i++) {
            var cookie = cookies[i];
            var c_pair = cookie.match(/^(\w+)=(.*)/);
            
            // IE doesn't always include the = when there is no value
            if (! c_pair) {
                c_pair = cookie.match(/^(\w+)/);
                if (! c_pair) { continue; }
            }
            // if we get here and c_pair doesn't have at least two elements
            // then we have failed to usefully parse this cookie
            if (c_pair.length < 2) { continue; }
            
            // If the cookies value is false here it is undefined, set it to
            // an empty string, which is generally more useful (urls etc)
            var val = c_pair[2] ? c_pair[2] : '';
            
            if (name) {
                if (c_pair[1] == name) { return val; }
            }
            else { cookie_hash[c_pair[1]] = val; }
        }
        
        if (name) { return null; }
        else { return cookie_hash; }
    },

    erase_cookie: function (name) {
        this.createCookie(name,"",-1);
    },

    extract_elements: function (keys, source) {
        var hash = {};
        source = source || {};
        keys = keys || [];
        
        for (var i = 0; i < keys.length; i++) {
            var key = keys[i];
            var value = source[key];
            
            if (value !== undefined) { 
                hash[key] = value; 
            }
        }
        
        return hash;
    },

    set_ep_site_links: function (param_map, defaults) {
        $("a.ep_site_link").each(function (j, link) {
            var url = link.href;
            var param_names = [];
            var ep_params = {};

            // load parameter names from keys of param_map
            for (name in param_map) {
                param_names[param_names.length] = name;
            }
            
            ep_params = EPStore.extract_elements(param_names, 
                                                 EPStore.parameters);

            url += url.match('\\?') ? '&' : '?';
            
            // If there wasn't cookie info in the parameters
            //    Load from cookies.
            
            var empty = true;

            for (k in ep_params) {
                empty = false;
                break;
            }

            if (empty) {
                console.info("looking to cookies");
                var cookie_names = [];
                var cookies = EPStore.read_cookies();

                // retrieve cookie names from param map
                for (param_name in param_map) {
                    var cookie_value = cookies[param_map[param_name]];

                    if (cookie_value !== undefined) {
                        ep_params[param_name] = cookie_value;
                    }
                }                
            }
            
            for (var i = 0; i < param_names.length; i++) {
                // each is either a string or null
                var key = param_names[i];
                var c = ep_params[key]; 
                var val = c !== undefined ? c : (defaults[key] || '');

                url +=  key + "=" + val + "&";
            }
            
            link.href = url;
        });
    }
};

$(function(){
    EPStore.init();
});