// Copyright 2009 Asa Wilson
// Available under both the GPL and MIT licenses, see license files for more details.

if (typeof jQuery == 'undefined') throw ("jQuery could not be found.");

(function ($) {

    $.extend({
        DirtyForm: {
            debug: false, // print out debug info? works best with firebug.
            changedClass: 'changed',
            addClassOn: new Function,
            hasFirebug: "console" in window && "firebug" in window.console,
            logger: function (msg) {
                if (this.debug) {
                    msg = "DirtyForm: " + msg;
                    this.hasFirebug ? console.log(msg) : alert(msg);
                }
            },
            input_value: function (input) {
                if (input.is(':radio,:checkbox')) {
                    return typeof (input.attr("checked")) == "undefined" ? false : input.attr("checked");
                } else {
                    return input.val();
                }
            },
            input_reset: function (input) {
                if (input.is(':radio,:checkbox')) {
                    input.attr('checked', input.data('initial'));
                } else {
                    input.val(input.data('initial'));
                }
                input.trigger('blur.dirty_form')
            },
            input_checker: function (event) {
                var npt = $(event.target), form = npt.parents('.dirtyform'), initial = npt.data("initial"), current = $.DirtyForm.input_value(npt), inputs = event.data.inputs, settings = event.data.settings

                if (initial != current) {
                    $.DirtyForm.logger("Form " + form.attr('class') + " is dirty. Changed from \"" + initial + "\" to \"" + current + "\"");
                    $.DirtyForm.logger("Class: " + settings.changedClass);
                    form
                            .data("dirty", true)                                      //TODO: check if we can use an expando property here
                            .trigger("dirty", { target: npt, from: initial, to: current, preventDefault: function () { return false }, stopPropagation: function () { return false }, bubbles: true, cancelable: true });
                    npt
                            .add(settings.addClassOn.apply(npt))
                            .addClass(settings.changedClass);                          // TODO: maybe we need to check if the class exists already?

                } else {
                    npt
                            .add(settings.addClassOn.apply(npt))
                            .removeClass(settings.changedClass)
                }

                if (!inputs.filter('.' + settings.changedClass).size()) {
                    form
                            .data("dirty", false)
                            .trigger("clean", { target: npt, preventDefault: function () { return false }, stopPropagation: function () { return false }, bubbles: true, cancelable: true });
                }
            }
        }

    });

    $.fn.clean_form = function () {
        return this.each(function () {
            var dirtyform = $(this)
            if (dirtyform.is('form')) {
                dirtyform.reset().find('.changed:input').each(function () {
                    $(this).trigger('blur.dirty_form');
                });
            } else {
                $(':input:not(:hidden,:submit,:password,:button)', dirtyform).each(function () {
                    $.DirtyForm.input_reset($(this));
                });
            }
        })
    }

    // will flag a form as dirty if something is changed on the form.
    $.fn.dirty_form = function () {
        var defaults = {
            changedClass: $.DirtyForm.changedClass,
            addClassOn: $.DirtyForm.addClassOn,
            dynamic: $.isFunction($.livequery)
        }

        var settings = $.extend(defaults, arguments.length != 0 ? arguments[0] : {});

        return this.each(function () {
            var form = $(this);

            var inputs = $(':input:not(:hidden,:submit,:password,:button)', form)

            if (form.hasClass('dirtyform')) {
                // unbind all DirtyForms specific events, then proceed to re-add them
                form.unbind("dirty").unbind("clean");
                inputs.unbind("blur.dirty_form");
            } else {
                // mark it as a dirtyform
                $(this).addClass('dirtyform')
            }

            $.DirtyForm.logger('Storing initial data for form ' + form.get(0));

            if (settings.dynamic) {
                inputs.livequery(function () { // use livequery to perform these functions on the new elements added to the form
                    $(this)
            .bind("blur.dirty_form", { inputs: inputs, settings: settings }, $.DirtyForm.input_checker)
            .data('initial', $.DirtyForm.input_value($(this)))
                });
            } else {
                inputs.each(function () {
                    $(this)
            .bind("blur.dirty_form", { inputs: inputs, settings: settings }, $.DirtyForm.input_checker)
            .data("initial", $.DirtyForm.input_value($(this)));
                });
            }
        });
    };


    // this is meant for selecting links that will warn about proceeding if there are any dirty forms on the page
    $.fn.dirty_stopper = function () {
        var defaults = {
            dialog: {
                title: "Warning: Unsaved Changes!",
                height: 300,
                width: 500,
                modal: true,
                resizeable: false,
                autoResize: false,
                overlay: { backgroundColor: "black", opacity: 0.5 }
            },
            message: '<p>You have changed data on this page without saving.</p><p>If you want to save your changes click <strong>Cancel</strong> and then <strong>Save Changes</strong> on the right of the screen.</p><p>If you want to proceed <em>without saving</em>, click <strong>Proceed</strong> to move away from this page.</p>'
        }

        var settings = $.extend(true, defaults, arguments.length != 0 ? arguments[0] : {});

        $.DirtyForm.logger("Setting dirty stoppers")

        return this.each(function () {
            var stopper = $(this);

            if ($(this).parents('.ui-tabs-nav').length > 0) {
                // FIXME: not sure what the comment below is actually saying. "Unchaining ... made it NOT work"?? (dvd, 03-02-2009)
                // Unchaining these tabs calls made the tab links not work
                var tabs = $(this).parents('.ui-tabs-nav')
                tabs.find('a').unbind('click.dirty_form')
                tabs.unbind('tabsselect.dirty_form')
                tabs.bind('tabsselect.dirty_form', function (event, ui) {
                    if ($('.dirtyform').are_dirty()) {
                        event.preventDefault();
                        var div = $("<div id='dirty_stopper_dialog'/>").appendTo(document.body)
                        var href = $(this).attr('href')
                        div.dialog($.extend(settings.dialog, {
                            buttons: {
                                Proceed: function () {
                                    var selected_id = $(ui.tab).parent().siblings('.ui-tabs-selected').find('a').attr('href');
                                    // reset the form in the selected tab and make sure it cleans up after itself
                                    $('.dirtyform', selected_id).clean_form();

                                    // select the tab now that the old tab is clean
                                    tabs.tabs('select', $(ui.tab).attr('href'));

                                    // close the dialog with fire
                                    $(this).dialog('destroy').remove()
                                },
                                Cancel: function () { $(this).dialog('destroy').remove() }
                            }
                        })).dialog("moveToTop").append(settings.message);
                        // div.append(settings.message);
                        return false
                    }
                })
            } else {
                stopper.unbind('click.dirty_form')
                stopper.bind('click.dirty_form', function (event) {
                    if ($('.dirtyform').are_dirty()) {
                        event.preventDefault();
                        var div = $("<div id='dirty_stopper_dialog'/>").appendTo(document.body),
                href = $(this).attr('href');
                        div.dialog($.extend({ buttons: {
                            Proceed: function () { window.location = href },
                            Cancel: function () { $(this).dialog('destroy').remove(); return false }
                        }
                        }, settings.dialog)).dialog("moveToTop").append(settings.message);
                    }
                });
            }
        });
    }

    // not chainable
    // returns false if any of the forms on the page are dirty
    $.fn.are_dirty = function () {
        var dirty = false
        this.each(function () {
            if ($(this).data('dirty')) {
                dirty = true;
            }
        })
        return dirty
    }

    // This is just for testing purposes...
    $.fn.dirty_checker = function () {
        $.DirtyForm.logger("Setting dirty checkers!")

        return this.each(function () {
            checker = $(this);
            checker.click(function () {
                if ($("form").are_dirty()) {
                    alert("Dirty Form!!");
                } else {
                    alert("Clean Form ...phew!");
                }
            });
        });
    }

    // Shortcut to bind a handler to the "ondirty" event
    $.fn.extend({
        dirty: function (fn) {
            return this.bind('dirty', fn);
        },
        clean: function (fn) {
            return this.bind('clean', fn);
        }
    });
})(jQuery);