(function() {
    var FORM_ID_ATTR = "data-form-id";
    var FORM_CLASS = "form-builder";
    var SAVE_BUTTON_CLASS = "form-builder-save";
    var CAPTCHA_PARAM_KEY = "g-recaptcha-response";

    var formCache = {};
    function Form(id, $element) {
        this.id = id;
        this.$element = $element;
        formCache[this.id] = this;
        this.actionUrl = "";

        this.captchaEnabled = false;
        this.confirmMessage = null;

        this.modified = false;
        this.recentlySubmitted = false;
        this.onceSubmitted = false;

        this.saveResponseDataCallbacks = [];
    }

    Form.prototype.getSaveButtons = function() {
        return $("." + SAVE_BUTTON_CLASS + "[" + FORM_ID_ATTR + '="' + this.id + '"]');
    };

    Form.prototype.save = function() {
        var form = this;
        if(form.recentlySubmitted || (form.confirmMessage && !confirm(form.confirmMessage))) {
            return $.Deferred().reject().promise();
        }
        form.onceSubmitted = true;
        form.recentlySubmitted = true;
        setTimeout(function() {
            form.recentlySubmitted = false;
        }, 2000);

        var loadIcons = form.getSaveButtons().find("i");
        loadIcons.show();

        function getFormData(additionalParams) {
            var dataArray = form.$element.serializeArray();
            var data = {};
            dataArray.forEach(function(item) {
                data[item.name] = item.value;
            });
            //Special case to ensure checkboxes are booleans
            form.$element.find("input[type=checkbox]").each(function() {
                data[this.name] = $(this).is(":checked") ? 1 : 0;
            });
            //Add in additional params
            if(additionalParams) {
                for(var key in additionalParams) {
                    if(additionalParams.hasOwnProperty(key)) {
                        data[key] = additionalParams[key];
                    }
                }
            }
            return data;
        }

        function sendFormData(additionalParams) {
            return $.post(form.actionUrl, getFormData(additionalParams))
            .then(function(response) {
                form.modified = false;
                return response;
            })
            .always(function(response) {
                loadIcons.hide();
                return response;
            });
        }

        if(form.captchaEnabled) {
            return ReCAPTCHA.challenge().then(function(response) {
                var params = {};
                params[CAPTCHA_PARAM_KEY] = response;
                return sendFormData(params);
            });
        }
        else {
            return sendFormData();
        }
    }

    Form.prototype.onDefaultSaveResponseData = function(callback) {
        this.saveResponseDataCallbacks.push(callback);
    }

    $(document).ready(function() {
        tryFocusFirstFormInput();
        $("form." + FORM_CLASS).each(function() {
            var $form = $(this);
            var form = new Form($form.attr("id"), $form);

            form.actionUrl = $form.attr("action");

            form.confirmMessage = $form.attr("data-confirm-message");
            form.captchaEnabled = !!$form.attr("data-captcha-enabled");

            $form.on("change", "input, select", function() {
                form.modified = true;
            });

            form.getSaveButtons().find("i").hide();

            form.getSaveButtons().click(function(e) {
                var redirectTo = $(this).attr("data-redirect-to");
                var redirectMessage = $(this).attr("data-redirect-message");
                if(!redirectTo) {
                    redirectTo = $form.attr("data-redirect-to");
                    redirectMessage = $form.attr("data-redirect-message");
                }
                var allowUnnecessarySubmit = !!$(this).attr("data-allow-unnecessary-submit");
                saveFormAndHandleResult(redirectTo, redirectMessage, allowUnnecessarySubmit);
                e.preventDefault();
            });

            $form.submit(function(e) {
                var redirectTo = $(this).attr("data-redirect-to");
                var redirectMessage = $(this).attr("data-redirect-message");
                var allowUnnecessarySubmit = !!$(this).attr("data-allow-unnecessary-submit");
                saveFormAndHandleResult(redirectTo, redirectMessage, allowUnnecessarySubmit);
                e.preventDefault();
            });

            $(window).on("beforeunload", function(e) {
                if(form.modified) {
                    var message = "There is unsaved information on the page. Are you sure you want to leave? Unsaved changes will be lost.";
                    e.returnValue = message;
                    return message;
                }
            });

            function saveFormAndHandleResult(redirectTo, redirectMessage, allowUnnecessarySubmit) {
                if(!form.modified && !allowUnnecessarySubmit && form.onceSubmitted) {
                    doRedirect(redirectTo, redirectMessage);
                    return;
                }
                var responseMan;
                form.save().always(function(response) {
                    var responseData = undefined;
                    if(response) {
                        responseMan = new ResponseMan(response);
                        responseData = responseMan.handle();
                    }
                    for (var i = 0; i < form.saveResponseDataCallbacks.length; i++) {
                        form.saveResponseDataCallbacks[i](responseData);
                    }
                }).then(function() {
                    if(responseMan) {
                        var hasErrors = responseMan.errors.length > 0;
                        if(!hasErrors) {
                            doRedirect(redirectTo, redirectMessage);
                        }
                    }
                });
            }

            function doRedirect(redirectTo, redirectMessage) {
                if(redirectTo) {
                    if(redirectMessage) {
                        kindlyRedirect(redirectMessage, redirectTo);
                    }
                    else {
                        window.location.href = redirectTo;
                    }
                }
            }
        });
    });

    function tryFocusFirstFormInput() {
        try {
            var $firstInput = $('form *:input[type!="hidden"][type!="submit"]').first();
            $firstInput.focus();
            var longerThanLength = $firstInput.val().length * 2;
            $firstInput[0].setSelectionRange(longerThanLength, longerThanLength);
        } catch(e) {
            // suppress error
        }
    }

    window.FormBuilder = {};
    FormBuilder.getFormById = function(id) {
        return formCache[id];
    }
})();