/**
 * Subviews (usually small side panels) for XBlockContainerPage.
 */
define(["jquery", "underscore", "gettext", "js/views/baseview", "js/views/utils/view_utils",
    "js/views/utils/xblock_utils"],
    function ($, _, gettext, BaseView, ViewUtils, XBlockViewUtils) {
        var VisibilityState = XBlockViewUtils.VisibilityState,
            disabledCss = "is-disabled";

        /**
         * A view that refreshes the view when certain values in the XBlockInfo have changed
         * after a server sync operation.
         */
        var ContainerStateListenerView = BaseView.extend({

            // takes XBlockInfo as a model
            initialize: function() {
                this.model.on('sync', this.onSync, this);
            },

            onSync: function(model) {
                if (this.shouldRefresh(model)) {
                   this.render();
                }
            },

            shouldRefresh: function(model) {
                return false;
            },

            render: function() {}
        });

        var MessageView = ContainerStateListenerView.extend({
            initialize: function () {
                ContainerStateListenerView.prototype.initialize.call(this);
                this.template = this.loadTemplate('container-message');
            },

            shouldRefresh: function(model) {
                return ViewUtils.hasChangedAttributes(model, ['currently_visible_to_students']);
            },

            render: function() {
                this.$el.html(this.template({
                    currentlyVisibleToStudents: this.model.get('currently_visible_to_students')
                }));
                return this;
            }
        });

        /**
         * A controller for updating the "View Live" button.
         */
        var ViewLiveButtonController = ContainerStateListenerView.extend({
            shouldRefresh: function(model) {
                return ViewUtils.hasChangedAttributes(model, ['published']);
            },

            render: function() {
                var viewLiveAction = this.$el.find('.button-view');
                if (this.model.get('published')) {
                    viewLiveAction.removeClass(disabledCss).attr('aria-disabled', false);
                }
                else {
                    viewLiveAction.addClass(disabledCss).attr('aria-disabled', true);
                }
            }
        });

        /**
         * Publisher is a view that supports the following:
         * 1) Publishing of a draft version of an xblock.
         * 2) Discarding of edits in a draft version.
         * 3) Display of who last edited the xblock, and when.
         * 4) Display of publish status (published, published with changes, changes with no published version).
         */
        var Publisher = BaseView.extend({
            events: {
                'click .action-publish': 'publish',
                'click .action-discard': 'discardChanges',
                'click .action-staff-lock': 'toggleStaffLock'
            },

            // takes XBlockInfo as a model

            initialize: function () {
                BaseView.prototype.initialize.call(this);
                this.template = this.loadTemplate('publish-xblock');
                this.model.on('sync', this.onSync, this);
                this.renderPage = this.options.renderPage;
            },

            onSync: function(model) {
                if (ViewUtils.hasChangedAttributes(model, [
                    'has_changes', 'published', 'edited_on', 'edited_by', 'visibility_state',
                    'has_explicit_staff_lock', 'has_content_group_components'
                ])) {
                   this.render();
                }
            },

            render: function () {
                this.$el.html(this.template({
                    visibilityState: this.model.get('visibility_state'),
                    visibilityClass: XBlockViewUtils.getXBlockVisibilityClass(this.model.get('visibility_state')),
                    hasChanges: this.model.get('has_changes'),
                    editedOn: this.model.get('edited_on'),
                    editedBy: this.model.get('edited_by'),
                    published: this.model.get('published'),
                    publishedOn: this.model.get('published_on'),
                    publishedBy: this.model.get('published_by'),
                    released: this.model.get('released_to_students'),
                    releaseDate: this.model.get('release_date'),
                    releaseDateFrom: this.model.get('release_date_from'),
                    hasExplicitStaffLock: this.model.get('has_explicit_staff_lock'),
                    staffLockFrom: this.model.get('staff_lock_from'),
                    hasContentGroupComponents: this.model.get('has_content_group_components')
                }));

                return this;
            },

            publish: function (e) {
                var xblockInfo = this.model;
                if (e && e.preventDefault) {
                    e.preventDefault();
                }
                ViewUtils.runOperationShowingMessage(gettext('Publishing'),
                    function () {
                        return xblockInfo.save({publish: 'make_public'}, {patch: true});
                    }).always(function() {
                        xblockInfo.set("publish", null);
                    }).done(function () {
                        xblockInfo.fetch();
                    });
            },

            discardChanges: function (e) {
                var xblockInfo = this.model, renderPage = this.renderPage;
                if (e && e.preventDefault) {
                    e.preventDefault();
                }
                ViewUtils.confirmThenRunOperation(gettext("Discard Changes"),
                    gettext("Are you sure you want to revert to the last published version of the unit? You cannot undo this action."),
                    gettext("Discard Changes"),
                    function () {
                        ViewUtils.runOperationShowingMessage(gettext('Discarding Changes'),
                            function () {
                                return xblockInfo.save({publish: 'discard_changes'}, {patch: true});
                            }).always(function() {
                                xblockInfo.set("publish", null);
                            }).done(function () {
                                renderPage();
                            });
                    }
                );
            },

            toggleStaffLock: function (e) {
                var xblockInfo = this.model, self=this, enableStaffLock, hasInheritedStaffLock,
                    saveAndPublishStaffLock, revertCheckBox;
                if (e && e.preventDefault) {
                    e.preventDefault();
                }
                enableStaffLock = !xblockInfo.get('has_explicit_staff_lock');
                hasInheritedStaffLock = xblockInfo.get('ancestor_has_staff_lock');

                revertCheckBox = function() {
                    self.checkStaffLock(!enableStaffLock);
                };

                saveAndPublishStaffLock = function() {
                    // Setting staff lock to null when disabled will delete the field from this xblock,
                    // allowing it to use the inherited value instead of using false explicitly.
                    return xblockInfo.save({
                        publish: 'republish',
                        metadata: {visible_to_staff_only: enableStaffLock ? true : null}},
                        {patch: true}
                    ).always(function() {
                        xblockInfo.set("publish", null);
                    }).done(function () {
                        xblockInfo.fetch();
                    }).fail(function() {
                        revertCheckBox();
                    });
                };

                this.checkStaffLock(enableStaffLock);
                if (enableStaffLock && !hasInheritedStaffLock) {
                    ViewUtils.runOperationShowingMessage(gettext('Hiding from Students'),
                        _.bind(saveAndPublishStaffLock, self));
                } else if (enableStaffLock && hasInheritedStaffLock) {
                    ViewUtils.runOperationShowingMessage(gettext('Explicitly Hiding from Students'),
                        _.bind(saveAndPublishStaffLock, self));
                } else if (!enableStaffLock && hasInheritedStaffLock) {
                    ViewUtils.runOperationShowingMessage(gettext('Inheriting Student Visibility'),
                        _.bind(saveAndPublishStaffLock, self));
                } else {
                    ViewUtils.confirmThenRunOperation(gettext("Make Visible to Students"),
                        gettext("If the unit was previously published and released to students, any changes you made to the unit when it was hidden will now be visible to students. Do you want to proceed?"),
                        gettext("Make Visible to Students"),
                        function() {
                            ViewUtils.runOperationShowingMessage(gettext('Making Visible to Students'),
                                _.bind(saveAndPublishStaffLock, self));
                        },
                        function() {
                            // On cancel, revert the check in the check box
                            revertCheckBox();
                        }
                    );
                }
            },

            checkStaffLock: function(check) {
                this.$('.action-staff-lock i').removeClass('fa-check-square-o fa-square-o');
                this.$('.action-staff-lock i').addClass(check ? 'fa-check-square-o' : 'fa-square-o');
            }
        });

        /**
         * PublishHistory displays when and by whom the xblock was last published, if it ever was.
         */
        var PublishHistory = BaseView.extend({
            // takes XBlockInfo as a model

            initialize: function () {
                BaseView.prototype.initialize.call(this);
                this.template = this.loadTemplate('publish-history');
                this.model.on('sync', this.onSync, this);
            },

            onSync: function(model) {
                if (ViewUtils.hasChangedAttributes(model, ['published', 'published_on', 'published_by'])) {
                   this.render();
                }
            },

            render: function () {
                this.$el.html(this.template({
                    published: this.model.get('published'),
                    published_on: this.model.get('published_on'),
                    published_by: this.model.get('published_by')
                }));

                return this;
            }
        });

        return {
            'MessageView': MessageView,
            'ViewLiveButtonController': ViewLiveButtonController,
            'Publisher': Publisher,
            'PublishHistory': PublishHistory
        };
    }); // end define();
