SKYPE.util.ConditionalContent = function()
{
    var E = YAHOO.util.Event;
    var D = YAHOO.util.Dom;
    
    var alts;
    
    E.onDOMReady(function()
    {
        // Get all alternative content blocks
        alts = D.getElementsByClassName("alternative", "DIV", document.body, function()
        {
            // Hide if it's not default block
            D.setStyle(this, "display", (D.hasClass(this, "cond-default") ? "block" : "none"));
        });
    });
    
    var filters = {
        "30days": function()
        {
            var age = SKYPE.util.ClientDetection.getSkypeUserAge();
            if (age >= 1 && age <= 30)
            {
                return D.getElementsByClassName("cond-30days", "DIV");
            }
            return [];
        }
        ,"existing": function()
        {
            var installed = SKYPE.util.ClientDetection.isInstalled();
            if (installed)
            {
                return D.getElementsByClassName("cond-existing", "DIV");
            }
            return [];
        }
    };
    
    _getFiltered = function()
    {
        var result = [];
        var tmp;
        for (filter in filters)
        {
            tmp = filters[filter]();
            SKYPE.log("Running conditionals filter "+filter+" found "+tmp.length+" items");
            result = result.concat(tmp);
            if (result.length) break;
        }
        return result;
    };
    
    return {
        run: function()
        {
            SKYPE.util.ConditionalContent.switchPages();
            SKYPE.util.ConditionalContent.switchAlternatives();
        }
        
        ,switchPages: function()
        {
            // 
            // if landing on root
            //  - send to useskype if known user
            // 
            // if landing on useskype
            //  - send to completedownload if known download abandoner
            //  - send to newtoskype if seems totally new
            //  - send to welcomeback if returning user age > 30 days
            //  - leave on useskype if known and age < 30 days
            // 
            
            var installed = SKYPE.util.ClientDetection.isInstalled();
            var age = SKYPE.util.ClientDetection.getSkypeUserAge();
            var root = "";
            // Top root / or /intl/xx/ root
            var rootRE = /^(\/|\/intl\/[^\/]+\/)(useskype\/)?$/;
            
            // Check if we are on root page
            var result = location.pathname.match(rootRE);
            if (result)
            {
                root = result[1];
            }
            
            // known user on front page
            if (installed && location.pathname == root)
            {
                // returning user age > 30 days
                if (age > 30)
                {
                    location.href = root+"welcomeback/";
                }
                else
                {
                    location.href = root+"useskype/";
                }
            }
            else if (location.pathname == root+"useskype/")
            {
                // seems totally new
                if (!installed)
                {
                    location.href = root+"newtoskype/";
                }
                // returning user age > 30 days
                else if (installed && age > 30)
                {
                    location.href = root+"welcomeback/";
                }
                // known and age < 30 days
                else if (installed && age < 30)
                {
                    SKYPE.log("Leave on existing page");
                }
                // known download abandoner
                // TODO: add completedownload check with other SO data
            }
        }
        
        ,switchAlternatives: function()
        {
            SKYPE.log("Switching alternative content blocks");
            
            var enableAlts = _getFiltered();
            if (enableAlts.length)
            {
                D.setStyle(enableAlts, "display", "block");
                SKYPE.util.ConditionalContent.hideDefaults();
            }
            else
            {
                SKYPE.util.ConditionalContent.showDefaults();
            }
        }
        ,showDefaults: function()
        {
            D.getElementsByClassName("cond-default", "DIV", document.body, function()
            {
                D.setStyle(this, "display", "block");
            });
        }
        ,hideDefaults: function()
        {
            D.getElementsByClassName("cond-default", "DIV", document.body, function()
            {
                D.setStyle(this, "display", "none");
            });
        }
    };
}();

if (typeof SKYPE.util.ClientDetection != "undefined")
{
    SKYPE.util.ClientDetection.subscribe(
        SKYPE.util.ConditionalContent.run
        ,{}
        ,false
        ,function() {SKYPE.log('client detection failure'); }
    );
}