var _gaq = _gaq || [];  // asynchronous stack used by google analytics

openerp.web_analytics = function(instance) {

    /*
    *  The Google Analytics Module inserts the Google Analytics JS Snippet
    *  at the top of the page, and sends to google an url each time the
    *  openerp url is changed.
    *  The pushes of the urls is made by triggering the 'state_pushed' event in the
    *  web_client.do_push_state() method which is responsible of changing the openerp current url
    */

    // Google Analytics Code snippet
    (function() {
        var ga   = document.createElement('script');
        ga.type  = 'text/javascript';
        ga.async = true;
        ga.src   = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
        var s = document.getElementsByTagName('script')[0];
        s.parentNode.insertBefore(ga,s);
    })();

    instance.web_analytics.Tracker = instance.web.Class.extend({
        /*
        *  This method initializes the tracker
        */
        init: function() {
            var self = this;

            /* Comment this lines when going on production, only used for testing on localhost */
            _gaq.push(['_setAccount', 'UA-35793871-1']);
            _gaq.push(['_setDomainName', 'none']);
            /**/

            /* Uncomment this lines when going on production
            _gaq.push(['_setAccount', 'UA-7333765-1']);
            _gaq.push(['_setDomainName', '.openerp.com']);  // Allow multi-domain
            */

            this.initialize_custom().then(function() {
                instance.client.on('state_pushed', self, self.on_state_pushed);
                self.include_tracker();
            });
        },
        /*
        * This method contains the initialization of all user-related custom variables
        * stored in GA. Also other modules can override it to add new custom variables
        */
        initialize_custom: function() {
            // Track User Access Level, Custom Variable 4 in GA with visitor level scope
            // Values: 'Admin User', 'Normal User', 'Portal User', 'Anonymous User'
            if (instance.session.uid === 1) {
                _gaq.push(['_setCustomVar', 4, 'User Access Level', 'Admin User', 1]);
            // Make the difference between portal users and anonymous users
            } else if (instance.session.username.indexOf('@') !== -1) {
                if (instance.session.username.indexOf('anonymous') === -1) {
                    _gaq.push(['_setCustomVar', 4, 'User Access Level', 'Portal User', 1]);
                } else {
                    _gaq.push(['_setCustomVar', 4, 'User Access Level', 'Anonymous User', 1]);
                }
            } else if (instance.session.username.indexOf('anonymous') !== -1) {
                _gaq.push(['_setCustomVar', 4, 'User Access Level', 'Anonymous User', 1]);
            } else {
                _gaq.push(['_setCustomVar', 4, 'User Access Level', 'Normal User', 1]);
            }
            // Fetch OpenERP's version of the instance
            return instance.session.rpc("/web/webclient/version_info", {})
                .done(function(res) {
                    _gaq.push(['_setCustomVar', 5, 'Version', res.server_version, 3]);
                });
        },
        /*
        *  This method contains the initialization of the object and view type
        *  custom variables stored in GA. Setting here the CV will work if web_analytics
        *  module is auto-install and not anonymous user, because the first view
        *  of a fresh DB is the modules kanban view (also in trial), otherwise the
        *  responsibility of the first initialization relies on
        *  instance.web.ActionManager#ir_actions_client method
        */
        on_state_pushed: function(state) {
            // Track only pages corresponding to a 'normal' view of OpenERP, views
            // related to client actions are tracked by the action manager
            if (state.model && state.view_type) {
                // Track object usage
                _gaq.push(['_setCustomVar', 2, 'Object', state.model, 3]);
                // Tack view usage
                _gaq.push(['_setCustomVar', 3, 'View Type', state.view_type, 3]);
                // Track the page
                var url = instance.web_analytics.generateUrl({'model': state.model, 'view_type': state.view_type});
                _gaq.push(['_trackPageview', url]);
            }
        },
        /*
        * This method includes the tracker into view and managers. It can be overriden
        * by other modules in order to extend tracking functionalities
        */
        include_tracker: function() {
            // Track the events related with the creation and the  modification of records,
            // the view type is always form
            instance.web.FormView = instance.web.FormView.extend({
                init: function(parent, dataset, view_id, options) {
                    this._super.apply(this, arguments);
                    var self = this;
                    this.on('record_created', self, function(r) {
                        var url = instance.web_analytics.generateUrl({'model': this.model, 'view_type': 'form'});
                        _gaq.push(['_trackEvent', this.model, 'on_button_create_save', url]);
                    });
                    this.on('record_saved', self, function(r) {
                        var url = instance.web_analytics.generateUrl({'model': this.model, 'view_type': 'form'});
                        _gaq.push(['_trackEvent', this.model, 'on_button_edit_save', url]);
                    });
                }
            });

            // Track client actions, also if not in a fresh DB or anonymous user,
            // it initializes the CV related to objects and view types
            instance.web.ActionManager.include({
                ir_actions_client: function (action, options) {
                    // Try to set the correct model, else it will be 'ir.actions.client'
                    if (action.res_model) {
                        _gaq.push(['_setCustomVar', 2, 'Object', action.res_model, 3]);
                    } else {
                        _gaq.push(['_setCustomVar', 2, 'Object', action.type, 3]);
                    }
                    // Try to set a view type as accurate as possible
                    if (action.name) {
                        _gaq.push(['_setCustomVar', 3, 'View Type', action.name, 3]);
                    } else {
                        _gaq.push(['_setCustomVar', 3, 'View Type', action.tag, 3]);
                    }
                    var url = instance.web_analytics.generateUrl({'action': action.tag});
                    _gaq.push(['_trackPageview', url]);
                    return this._super.apply(this, arguments);
                },
            });

            // Track button events
            instance.web.View.include({
                do_execute_action: function(action_data, dataset, record_id, on_closed) {
                    var category = this.model || dataset.model || '';
                    var action;
                    if (action_data.name && _.isNaN(action_data.name-0)) {
                        action = action_data.name;
                    } else {
                        action = action_data.string || action_data.special || '';
                    }
                    var label = instance.web_analytics.generateUrl({'model': category, 'view_type': this.view_type});
                    _gaq.push(['_trackEvent', category, action, label]);
                    return this._super.apply(this, arguments);
                },
            });

            // Track error events
            instance.web.CrashManager.include({
                show_error: function(error) {
                    var hash = window.location.hash;
                    var params = $.deparam(hash.substr(hash.indexOf('#')+1));
                    var options = {};
                    if (params.model && params.view_type) {
                        options = {'model': params.model, 'view_type': params.view_type};
                    } else {
                        options = {'action': params.action};
                    }
                    var label = instance.web_analytics.generateUrl(options);
                    if (error.code) {
                        _gaq.push(['_trackEvent', error.message, error.data.fault_code, label, ,true]);
                    } else {
                        _gaq.push(['_trackEvent', error.type, error.data.debug, label, ,true]);
                    }
                    this._super.apply(this, arguments);
                },
            });
        },
    });

    // Set correctly the tracker in the current instance
    if (instance.client instanceof instance.web.WebClient) {        // not for embedded clients
        instance.webclient.tracker = new instance.web_analytics.Tracker();
    } else if (!instance.client) {
        // client does not already exists, we are in monodb mode
        instance.web.WebClient.include({
            init: function() {
                var d = this._super.apply(this, arguments);
                this.tracker = new instance.web_analytics.Tracker();
                return d;
            },
        });
    }

    // ----------------------------------------------------------------
    // utility functions
    // ----------------------------------------------------------------

    instance.web_analytics.generateUrl = function(options) {
        var url = '';
        _.each(options, function(value, key) {
            url += '/' + key + '=' + value;
        });
        return url;
    };

};