/*! Icinga Web 2 | (c) 2019 Icinga GmbH | GPLv2+ */

;(function(Icinga, $) {

    'use strict';

    Icinga.Behaviors = Icinga.Behaviors || {};

    /**
     * Behavior for collapsible containers.
     *
     * @param  icinga  Icinga  The current Icinga Object
     */
    var Collapsible = function(icinga) {
        Icinga.EventListener.call(this, icinga);

        this.on('rendered', '.container', this.onRendered, this);
        this.on('click', '.collapsible + .collapsible-control', this.onControlClicked, this);

        this.icinga = icinga;
        this.state = new StateStorage();
        this.defaultVisibleRows = 2;
        this.defaultVisibleHeight = 36;
    };
    Collapsible.prototype = new Icinga.EventListener();

    /**
     * Initializes all collapsibles. Triggered on rendering of a container.
     *
     * @param event  Event  The `onRender` event triggered by the rendered container
     */
    Collapsible.prototype.onRendered = function(event) {
        var _this = event.data.self;

        $('.collapsible:not(.can-collapse)', event.currentTarget).each(function() {
            var $collapsible = $(this);
            var collapsiblePath = _this.icinga.utils.getCSSPath($collapsible);

            // Assumes that any newly rendered elements are expanded
            if (_this.canCollapse($collapsible)) {
                $collapsible.after($('#collapsible-control-ghost').clone().removeAttr('id'));
                $collapsible.addClass('can-collapse');

                if (! _this.state.isExpanded(collapsiblePath)) {
                    _this.collapse($collapsible);
                }
            }
        });
    };

    /**
     * Event handler for toggling collapsibles. Switches the collapsed state of the respective container.
     *
     * @param event  Event  The `onClick` event triggered by the clicked collapsible-control element
     */
    Collapsible.prototype.onControlClicked = function(event) {
        var _this = event.data.self;
        var $target = $(event.currentTarget);
        var $collapsible = $target.prev('.collapsible');

        if (! $collapsible.length) {
            _this.icinga.logger.error('[Collapsible] Collapsible control has no associated .collapsible: ', $target);
        } else {
            var collapsiblePath = _this.icinga.utils.getCSSPath($collapsible);
            if (_this.state.isExpanded(collapsiblePath)) {
                _this.state.collapse(collapsiblePath);
                _this.collapse($collapsible);
            } else {
                _this.state.expand(collapsiblePath);
                _this.expand($collapsible);
            }
        }
    };

    /**
     * Return an appropriate row element selector
     *
     * @param $collapsible jQuery  The given collapsible container element
     *
     * @returns {string}
     */
    Collapsible.prototype.getRowSelector = function($collapsible) {
        if ($collapsible.is('table')) {
            return '> tbody > tr';
        } else if ($collapsible.is('ul, ol')) {
            return '> li';
        }

        return '';
    };

    /**
     * Check whether the given collapsible needs to collapse
     *
     * @param $collapsible jQuery  The given collapsible container element
     *
     * @returns {boolean}
     */
    Collapsible.prototype.canCollapse = function($collapsible) {
        var rowSelector = this.getRowSelector($collapsible);
        if (!! rowSelector) {
            return $(rowSelector, $collapsible).length > ($collapsible.data('visibleRows') || this.defaultVisibleRows);
        } else {
            var actualHeight = $collapsible.innerHeight(),
                maxHeight = $collapsible.data('visibleHeight') || this.defaultVisibleHeight;

            if (actualHeight <= maxHeight) {
                return false;
            }

            // Although the height seems larger than what it should be, make sure it's not just a small fraction
            // i.e. more than 12 pixel and at least 10% difference
            return actualHeight - maxHeight > 12 && actualHeight / maxHeight >= 1.1;
        }
    };

    /**
     * Collapse the given collapsible
     *
     * @param   $collapsible    jQuery      The given collapsible container element
     */
    Collapsible.prototype.collapse = function($collapsible) {
        $collapsible.addClass('collapsed');

        var rowSelector = this.getRowSelector($collapsible);
        if (!! rowSelector) {
            var $rows = $(rowSelector, $collapsible).slice(0, $collapsible.data('visibleRows') || this.defaultVisibleRows);

            var totalHeight = $rows.offset().top - $collapsible.offset().top;
            $rows.outerHeight(function(_, height) {
                totalHeight += height;
            });

            $collapsible.css({display: 'block', height: totalHeight});
        } else {
            $collapsible.css({display: 'block', height: $collapsible.data('visibleHeight') || this.defaultVisibleHeight});
        }
    };

    /**
     * Expand the given collapsible
     *
     * @param   $collapsible    jQuery      The given collapsible container element
     */
    Collapsible.prototype.expand = function($collapsible) {
        $collapsible.removeClass('collapsed');
        $collapsible.css({display: '', height: ''});
    };

    Icinga.Behaviors.Collapsible = Collapsible;

    // State-Storage abstraction, not for use externally until we've had time to think this properly through

    var StateStorage = function() {};

    StateStorage.prototype.isExpanded = function(selector) {
        return this.load().has(selector);
    };

    StateStorage.prototype.expand = function(selector) {
        var set = this.load();
        set.add(selector);
        this.save(set);
    };

    StateStorage.prototype.collapse = function(selector) {
        var set = this.load();
        set.delete(selector);
        this.save(set);
    };

    StateStorage.prototype.load = function () {
        var set = new Set();

        var expanded = localStorage.getItem('behavior.collapsible.expanded');
        if (!! expanded) {
            // .forEach() is used because IE11 doesn't support constructor arguments
            JSON.parse(expanded).forEach(function(value) {
                set.add(value);
            }, this);
        }

        return set;
    };

    StateStorage.prototype.save = function(set) {
        if (set.size > 0) {
            var expanded = [];
            // .forEach() is used because IE11 doesn't support .values()
            set.forEach(function(value) {
                expanded.push(value);
            });

            localStorage.setItem('behavior.collapsible.expanded', JSON.stringify(expanded));
        } else {
            localStorage.removeItem('behavior.collapsible.expanded');
        }
    };

})(Icinga, jQuery);