/**
 * This file contains the capability overview search functionality.
 *
 * @module moodle-tool_capability-search
 */

/**
 * Constructs a new capability search manager.
 *
 * @namespace M.tool_capability.search
 * @class Search
 * @constructor
 * @extends Y.Base
 */
var SEARCH = function() {
    SEARCH.superclass.constructor.apply(this, arguments);
};
SEARCH.prototype = {
    /**
     * The search form.
     * @property form
     * @type Node
     * @protected
     */
    form : null,
    /**
     * The capability select node.
     * @property select
     * @type Node
     * @protected
     */
    select: null,
    /**
     * An associative array of search option. Populated from the select node above during initialisation.
     * @property selectoptions
     * @type Object
     * @protected
     */
    selectoptions : {},
    /**
     * The search input field.
     * @property input
     * @type Node
     * @protected
     */
    input: null,
    /**
     * The submit button for the form.
     * @property button
     * @type Node
     * @protected
     */
    button: null,
    /**
     * The last search node if there is one.
     * If there is a last search node then the last search term will be persisted between requests.
     * @property lastsearch
     * @type Node
     * @protected
     */
    lastsearch : null,
    /**
     * Constructs the search manager.
     * @method initializer
     */
    initializer : function() {
        this.form = Y.one('#capability-overview-form');
        this.select = this.form.one('select[data-search=capability]');
        this.select.setStyle('minWidth', this.select.get('offsetWidth'));
        this.select.get('options').each(function(option) {
            var capability = option.get('value');
            this.selectoptions[capability] = option;
        }, this);
        this.button = this.form.all('input[type=submit]');
        this.lastsearch = this.form.one('input[name=search]');

        var div = Y.Node.create('<div id="capabilitysearchui"></div>'),
            label = Y.Node.create('<label for="capabilitysearch">'+this.get('strsearch')+'</label>');
        this.input = Y.Node.create('<input type="text" id="capabilitysearch" />');

        div.append(label).append(this.input);

        this.select.insert(div, 'before');
        this.select.one('option').setStyle('display', 'none');

        this.input.on('keyup', this.typed, this);
        this.select.on('change', this.validate, this);

        if (this.lastsearch) {
            this.input.set('value', this.lastsearch.get('value'));
            this.typed();
            if (this.select.one('option[selected]')) {
                this.select.set('scrollTop', this.select.one('option[selected]').get('getX'));
            }
        }

        this.validate();
    },
    /**
     * Disables the submit button if there are no capabilities selected.
     * @method validate
     */
    validate : function() {
        this.button.set('disabled', (this.select.get('value') === ''));
    },
    /**
     * Called when ever the user types into the search field.
     * This method hides any capabilities that don't match the search term.
     * @method typed
     */
    typed : function() {
        var search = this.input.get('value'),
            matching = 0,
            last = null,
            capability;
        if (this.lastsearch) {
            this.lastsearch.set('value', search);
        }
        this.select.all('option').remove();
        for (capability in this.selectoptions) {
            if (capability.indexOf(search) >= 0) {
                matching++;
                last = this.selectoptions[capability];
                this.select.append(this.selectoptions[capability]);
            }
        }
        if (matching === 0) {
            this.input.addClass("error");
        } else {
            this.input.removeClass("error");
            if (matching === 1) {
                last.set('selected', true);
            }
        }
        this.validate();
    }
};
Y.extend(SEARCH, Y.Base, SEARCH.prototype, {
    NAME : 'tool_capability-search',
    ATTRS : {
        strsearch : {}
    }
});

/**
 * Core namespace.
 * @static
 * @class tool_capability
 */
M.tool_capability = M.tool_capability || {};

/**
 * Initialises capability search functionality.
 * @static
 * @method init_capability_search
 * @param {Object} options
 */
M.tool_capability.init_capability_search = function(options) {
    new SEARCH(options);
};