var validation = {
    resetValidation: function () {
        // Reset all errors
        $('[data-validation-key]')
            .removeClass('invalid');
        $('[data-validation-message]')
            .removeClass('validationMessageVisible')
            .addClass('validationMessageHidden');
    },

    presentValidationErrors: function (errors) {
        // Clear all validation errors on display
        validation.resetValidation();

        if (errors) {
            // Get a list of properties that are invalid
            var invalidKeys = errors.
                getUniqueArrayFromProperty('key');

            $(invalidKeys).each(function () {
                // Set the invalid class for the property input
                $('[data-validation-key=' + this + ']')
                    .addClass('invalid');

                // Build up a list of failed validations for the property
                // We do this as a property can have multiple validation
                // errors.
                var keyClosure = this;
                var failedValidations =
                    errors
                        .where(function (x) { return (x.key == keyClosure) })
                        .select(function (x) { return x });

                // Build up an UL with the errors
                var listString = '<ul>';
                $(failedValidations).each(function () {
                    listString += '<li>' + this.value + '</li>';
                });
                listString += '</ul>'

                // Find where to display the messages and replace the html
                // with the UL, also set the visible class
                $('[data-validation-message=' + this + ']')
                    .html(listString)
                    .addClass('validationMessageVisible');
            });
        }
    },

    /*
    This call is based on the ValidatingJsonReturnValue return class.
    */
    callValidatingJsonReturnValueService: function (
        serviceURL,
        getOrPost,
        requestData,
        successFunction,            // function(data) where data is of type T ValidatingJsonReturnValue<T> 
        successNoDataFunction,      // function(messageString) where messageString is of type string
        validationFailedFunction,   // function(errors) where errors is of List<KeyValuePair<string, string>> (property, message)
        serverErrorFunction) {      // function(messageString) where messageString is of type string

        $.ajax({
            cache: false,
            url: serviceURL,
            type: getOrPost,
            dataType: "text",                                           // DateTime fixup
            data: { val: JSON.stringify(requestData) },
            dataFilter: function (data, type) {                         // Datetime fixup
                var d = data.replace(/"\\\/(Date\(.*?\))\\\/"/gi, 'new $1');
                return d;
            },
            success: function (result) {
                try {
                    result = eval('(' + result + ')');                  // DateTime Fixup
                }
                catch (e) {
                    if(serverErrorFunction)
                        serverErrorFunction('An error occured on the whilst evaluate the server response.');
                    return;
                }

                if (result && result.d && result.d.IsSuccessful) {
                    var data = result.d.Data;
                    if (data) {
                        // Success
                        if (successFunction)
                            successFunction(data);
                    }
                    else {
                        // Successful but no data
                        if (successNoDataFunction)
                            successNoDataFunction(result.d.Message);
                    }
                }
                else {
                    if (result && result.d) {
                        if (result.d.HasValidationErrors) {
                            // Failed Validation
                            if (validationFailedFunction)
                                validationFailedFunction(result.d.ValidationErrors);
                        }
                        else {
                            // Unsuccessful
                            if(serverErrorFunction)
                                serverErrorFunction(result.d.Message);
                        }
                    }
                    else {
                        if (serverErrorFunction)
                            serverErrorFunction('An error occured on the server whilst trying to process your request.');
                    }
                }
            },
            error: function () {
                if (serverErrorFunction)
                    serverErrorFunction('An error occured while contacting the server.');
            }
        });
    }
}