var AjaxProcessor = {
    //ErrorHandler: handler which will be called if any error occure while ajx request
    //parameters
    //error: object of XMLHttpRequest.error
    ErrorHandler: function(error, request) {

        var form = document.forms[0];

        if (error.Type == 'ConnectFailure') {
            var formId = AjaxProcessor.contexts_[request.args.id].formEl.id;
            Ext.get(formId).unmask();
            Ext.Msg.show({
                title: 'Server is not responding.',
                msg: 'Try again later.',
                buttons: Ext.Msg.OK,
                width: 200
            });
        }
        else {
            if (Ext.isIE) // IE
            {
                var input = document.createElement('<input name="' + request.args.action + '"/>');
            }
            else {
                var input = document.createElement('input');
                input.setAttribute('name', request.args.action);
            }

            input.setAttribute('type', 'hidden');
            form.appendChild(input);
            form.submit();
        }


    },
    TimeoutHandler: function() {
        var formId = AjaxProcessor.contexts_[this.args.id].formEl.id;
        Ext.get(formId).unmask();
        Ext.Msg.show({
            title: 'Timeout error',
            msg: 'Try again later.',
            buttons: Ext.Msg.OK,
            width: 200
        });
    },
    TimeoutPeriod: 60000,
    DefaultServerResponseHandler: null,

    //RegisterServerCallback: registers handler for parsed ajax response
    //parameters
    //commandName: string name of command
    //handler: function(cmd) - function which as parameter receive object of cmd
    //cmd.Action: String name of action
    //cmd.Params: object with params
    RegisterServerCallback: function(commandName, handler) {
        AjaxProcessor.handlers_[commandName] = { func: handler };
    },

    //Request: function which performs Ajax request to specified page with specified paramters
    //parameters
    //page: page object name
    //action: string action name, which will be executed on server side
    //action name format: action_[moduleName]_[actionName]_[paramName0]_[paramValue0]_[...]_[paramNameN]_[paramValueN]
    //parameters: additional parameters for action
    Request: function(page, action, parameters, context) {
        var customViewState = document.getElementById("__CUSTOMVIEWSTATE");
        var value;
        if (customViewState) {
            value = customViewState.getAttribute("value");
        }
        if (AjaxProcessor.TimeoutPeriod)
            AjaxPro.timeoutPeriod = AjaxProcessor.TimeoutPeriod;
        if (AjaxProcessor.TimeoutHandler) {
            if (AjaxPro.onTimeout)
                AjaxPro.onTimeout = AjaxProcessor.TimeoutHandler;
        }

        var id = AjaxProcessor.lastRequestId_;
        AjaxProcessor.lastRequestId_++;
        if (context) {
            AjaxProcessor.contexts_[id] = context;
        }
        page.ProcessAjaxRequest(id, action, parameters, value, AjaxProcessor.HandleAjaxResponse)
    },

    //Return context object by id (need to timeout handler, etc...)
    GetContext: function(id) {
        var ret = null;
        if (AjaxProcessor.contexts_) {
            try {
                ret = AjaxProcessor.contexts_[id];
            }
            catch (e) {
                ret = null;
            }
        }
        return ret;
    },

    HandleAjaxResponse: function(response) {
        if (response.error) {
            if (AjaxProcessor.ErrorHandler) {
                AjaxProcessor.ErrorHandler(response.error, response.request);
            }
        }
        else {
            AjaxProcessor.ProcessAjaxResponse(response.value);
        }
    },

    ProcessAjaxResponse: function(response) {
        var r = AjaxProcessor.ParseAjaxResponse(response);
        var id = r.id;
        var cmds = r.actions;
        var context = AjaxProcessor.contexts_[id];
        var newViewState = r.viewstate;
        var customViewState = document.getElementById("__CUSTOMVIEWSTATE");
        if (customViewState) {
            customViewState.setAttribute("value", newViewState);
        }
        AjaxProcessor.contexts_[id] = null;
        if (cmds) {
            for (var i = 0; i < cmds.Actions.length; i++) {
                var cmd = cmds.Actions[i];

                var handler = AjaxProcessor.handlers_[cmd.Action];
                var func = null;
                if (handler) {
                    func = handler.func;
                }
                else {
                    if (AjaxProcessor.DefaultServerResponseHandler) {
                        func = AjaxProcessor.DefaultServerResponseHandler;
                    }
                }
                if (func) {
                    func(cmd, context);
                }
                if ((cmd.Params["javascript"]) && (cmd.Params["javascript"] != '')) {
                    eval(cmd.Params["javascript"]);
                }
            }
        }
    },

    ParseAjaxResponse: function(response) {
        eval("var commands = " + response);
        return commands
    },

    handlers_: new Array(),
    contexts_: new Array(),
    lastRequestId_: 0
}