/**
Interface for self assessment view.

Args:
    element (DOM element): The DOM element representing the XBlock.
    server (OpenAssessment.Server): The interface to the XBlock server.
    baseView (OpenAssessment.BaseView): Container view.

Returns:
    OpenAssessment.SelfView
**/
OpenAssessment.SelfView = function(element, server, baseView) {
    this.element = element;
    this.server = server;
    this.baseView = baseView;
    this.rubric = null;
};

OpenAssessment.SelfView.prototype = {

    UNSAVED_WARNING_KEY: "self-assessment",

    /**
    Load the self assessment view.
    **/
    load: function(usageID) {
        var view = this;
        var stepID = '.step--self-assessment';
        this.server.render('self_assessment').done(
            function(html) {
                // Load the HTML and install event handlers
                $(stepID, view.element).replaceWith(html);
                view.server.renderLatex($(stepID, view.element));
                view.installHandlers();
                if (typeof usageID !== 'undefined' && $(stepID, view.element).hasClass("is--showing")) {
                    $("[id='oa_self_" + usageID + "']", view.element).focus();
                }
            }
        ).fail(function() {
            view.showLoadError('self-assessment');
        });
    },

    /**
    Install event handlers for the view.
    **/
    installHandlers: function() {
        var view = this;
        var sel = $('.step--self-assessment', view.element);

        // Install a click handler for collapse/expand
        this.baseView.setUpCollapseExpand(sel);

        // Initialize the rubric
        var rubricSelector = $(".self-assessment--001__assessment", this.element);
        if (rubricSelector.size() > 0) {
            var rubricElement = rubricSelector.get(0);
            this.rubric = new OpenAssessment.Rubric(rubricElement);
        }
        else {
            // If there was previously a rubric visible, clear the reference to it.
            this.rubric = null;
        }

        // Install a change handler for rubric options to enable/disable the submit button
        if (this.rubric !== null) {
            this.rubric.canSubmitCallback($.proxy(this.selfSubmitEnabled, this));

            this.rubric.changesExistCallback($.proxy(this.assessmentRubricChanges, this));
        }

        // Install a click handler for the submit button
        sel.find('.self-assessment--001__assessment__submit').click(
            function(eventObject) {
                // Override default form submission
                eventObject.preventDefault();

                // Handle the click
                view.selfAssess();
            }
        );
    },

    /**
     Enable/disable the self assess button.
     Check that whether the self assess button is enabled.

     Args:
     enabled (bool): If specified, set the state of the button.

     Returns:
     bool: Whether the button is enabled.

     Examples:
     >> view.selfSubmitEnabled(true);  // enable the button
     >> view.selfSubmitEnabled();  // check whether the button is enabled
     >> true
     **/
    selfSubmitEnabled: function(enabled) {
        var button = $('.self-assessment--001__assessment__submit', this.element);
        if (typeof enabled === 'undefined') {
            return !button.hasClass('is--disabled');
        } else {
            button.toggleClass('is--disabled', !enabled);
            return enabled;
        }
    },

    /**
     * Called when something is selected or typed in the assessment rubric.
     * Used to set the unsaved changes warning dialog.
     *
     * @param {boolean} changesExist true if unsaved changes exist
     */
    assessmentRubricChanges: function(changesExist) {
        if (changesExist) {
            this.baseView.unsavedWarningEnabled(
                true,
                this.UNSAVED_WARNING_KEY,
                gettext("If you leave this page without submitting your self assessment, you will lose any work you have done.") // jscs:ignore maximumLineLength
            );
        }
    },

    /**
    Send a self-assessment to the server and update the view.
    **/
    selfAssess: function() {
        // Send the assessment to the server
        var view = this;
        var baseView = this.baseView;
        var usageID = baseView.getUsageID();
        baseView.toggleActionError('self', null);
        view.selfSubmitEnabled(false);

        this.server.selfAssess(
            this.rubric.optionsSelected(),
            this.rubric.criterionFeedback(),
            this.rubric.overallFeedback()
        ).done(
            function() {
                baseView.unsavedWarningEnabled(false, view.UNSAVED_WARNING_KEY);
                baseView.loadAssessmentModules(usageID);
                view.load(usageID);
                baseView.scrollToTop(".step--self-assessment");
            }
        ).fail(function(errMsg) {
            baseView.toggleActionError('self', errMsg);
            view.selfSubmitEnabled(true);
        });
    }
};
