/************************************************************************
 * This file is part of EspoCRM.
 *
 * EspoCRM - Open Source CRM application.
 * Copyright (C) 2014-2022 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
 * Website: https://www.espocrm.com
 *
 * EspoCRM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * EspoCRM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU General Public License version 3.
 *
 * In accordance with Section 7(b) of the GNU General Public License version 3,
 * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
 ************************************************************************/

define('collection', [], function () {

    /**
     * On sync with backend.
     *
     * @event module:collection.Class#sync
     * @param {module:collection.Class} collection A collection.
     * @param {Object} response Response from backend.
     * @param {Object} o Options.
     */

    /**
     * Any number of models have been added, removed or changed.
     *
     * @event module:collection.Class#update
     * @param {module:collection.Class} collection A collection.
     * @param {Object} o Options.
     */

    /**
     * Add a model or models.
     *
     * @function add
     * @memberof module:collection.Class#
     * @param {module:model.Class|module:model.Class[]} models A model or models.
     * @param {Object} [options] Options.
     *
     * @fires module:collection.Class#update Unless `{silent: true}`.
     */

    /**
     * Remove a model or models.
     *
     * @function remove
     * @memberof module:collection.Class#
     * @param {module:model.Class|module:model.Class[]|string|string[]} models A model, models, ID or IDs.
     * @param {Object} [options] Options.
     *
     * @fires module:collection.Class#update Unless `{silent: true}`.
     */

    /**
     * Append a model.
     *
     * @function push
     * @memberof module:collection.Class#
     * @param {module:model.Class} model A model.
     * @param {Object} [options] Options.
     */

    /**
     * Remove and return the last model from the collection.
     *
     * @function pop
     * @memberof module:collection.Class#
     * @param {Object} [options] Options.
     */

    /**
     * @class
     * @name Class
     * @memberOf module:collection
     * @extends Backbone.Collection.prototype
     * @mixes Backbone.Events
     */
    return Backbone.Collection.extend(/** @lends module:collection.Class# */ {

        /**
         * An entity type.
         *
         * @name entityType
         * @type {string}
         * @memberof module:collection.Class#
         */

        /**
         * A number of records.
         *
         * @name length
         * @type {number}
         * @memberof module:collection.Class#
         */

        /**
         * Models.
         *
         * @name length
         * @type {module:model.Class[]}
         * @memberof module:collection.Class#
         */

        /**
         * A name.
         *
         * @type {string|null}
         */
        name: null,

        /**
         * A total number of records.
         *
         * @type {number}
         */
        total: 0,

        /**
         * A current offset (for pagination).
         *
         * @type {number}
         */
        offset: 0,

        /**
         * A max size (for pagination).
         *
         * @type {number}
         */
        maxSize: 20,

        /**
         * An order.
         *
         * @type {boolean|'asc'|'desc'|null}
         */
        order: null,

        /**
         * An order-by field.
         *
         * @type {string|null}
         */
        orderBy: null,

        /**
         * A where clause.
         *
         * @type {Array.<Object>|null}
         */
        where: null,

        whereAdditional: null,

        /**
         * @type {number}
         */
        lengthCorrection: 0,

        /**
         * @type {number}
         */
        maxMaxSize: 0,

        /**
         * @private
         */
        _user: null,

        /**
         * Initialize.
         *
         * @protected
         * @param {module:model.Class[]} models Models.
         * @param {Object} options Options.
         */
        initialize: function (models, options) {
            options = options || {};

            this.name = options.name || this.name;
            this.urlRoot = this.urlRoot || this.name;
            this.url = this.url || this.urlRoot;

            this.orderBy = this.sortBy = options.orderBy || options.sortBy || this.orderBy || this.sortBy;
            this.order = options.order || this.order;

            this.defaultOrder = this.order;
            this.defaultOrderBy = this.orderBy;

            this.data = {};
        },

        /**
         * @private
         */
        _onModelEvent: function(event, model, collection, options) {
            if (event === 'sync' && collection !== this) {
                return;
            }

            Backbone.Collection.prototype._onModelEvent.apply(this, arguments);
        },

        /**
         * Reset.
         *
         * @param {module:model.Class[]} [models]
         * @param {Object} [options]
         */
        reset: function (models, options) {
            this.lengthCorrection = 0;

            Backbone.Collection.prototype.reset.call(this, models, options);
        },

        /**
         * @param {string} orderBy An order field.
         * @param {bool|null|'desc'|'asc'} [order] True for desc.
         * @returns {Promise}
         */
        sort: function (orderBy, order) {
            this.orderBy = orderBy;

            if (order === true) {
                order = 'desc';
            }
            else if (order === false) {
                order = 'asc';
            }

            this.order = order || 'asc';

            if (typeof this.asc !== 'undefined') { // TODO remove in 5.7
                this.asc = this.order === 'asc';
                this.sortBy = orderBy;
            }

            return this.fetch();
        },

        /**
         * Next page.
         */
        nextPage: function () {
            var offset = this.offset + this.maxSize;

            this.setOffset(offset);
        },

        /**
         * Previous page.
         */
        previousPage: function () {
            var offset = this.offset - this.maxSize;

            this.setOffset(offset);
        },

        /**
         * First page.
         */
        firstPage: function () {
            this.setOffset(0);
        },

        /**
         * Last page.
         */
        lastPage: function () {
            let offset = this.total - this.total % this.maxSize;

            if (offset === this.total) {
                offset = this.total - this.maxSize;
            }

            this.setOffset(offset);
        },

        /**
         * Set an offset.
         *
         * @param {number} offset Offset.
         */
        setOffset: function (offset) {
            if (offset < 0) {
                throw new RangeError('offset can not be less than 0');
            }

            if (offset > this.total && this.total !== -1 && offset > 0) {
                throw new RangeError('offset can not be larger than total count');
            }

            this.offset = offset;
            this.fetch();
        },

        /**
         * Parse a response from the backend.
         *
         * @param {Object} response A response.
         * @param {Object} options Options.
         * @returns {module:collection.Class[]}
         */
        parse: function (response, options) {
            this.total = response.total;

            if ('additionalData' in response) {
                this.dataAdditional = response.additionalData;
            }
            else {
                this.dataAdditional = null;
            }

            return response.list;
        },

        /**
         * Fetches from the backend.
         *
         * @param {Object} [options] Options.
         * @returns {Promise}
         *
         * @fires module:collection.Class#sync Unless `{silent: true}`.
         */
        fetch: function (options) {
            options = options || {};

            options.data = _.extend(options.data || {}, this.data);

            this.offset = options.offset || this.offset;
            this.orderBy = options.orderBy || options.sortBy || this.orderBy;
            this.order = options.order || this.order;

            this.where = options.where || this.where;

            let length = this.length + this.lengthCorrection;

            if (!('maxSize' in options)) {
                options.data.maxSize = options.more ? this.maxSize : (
                    (length > this.maxSize) ? length : this.maxSize
                );

                if (this.maxMaxSize && options.data.maxSize > this.maxMaxSize) {
                    options.data.maxSize = this.maxMaxSize;
                }
            }
            else {
                options.data.maxSize = options.maxSize;
            }

            options.data.offset = options.more ? length : this.offset;
            options.data.orderBy = this.orderBy;
            options.data.order = this.order;
            options.data.where = this.getWhere();

            if (typeof this.asc !== 'undefined') { // TODO remove in 5.7
                options.data.asc = this.asc;
                options.data.sortBy = this.sortBy;

                delete options.data.orderBy;
                delete options.data.order;
            }

            this.lastXhr = Backbone.Collection.prototype.fetch.call(this, options);

            return this.lastXhr;
        },

        /**
         * Abort the last fetch.
         */
        abortLastFetch: function () {
            if (this.lastXhr && this.lastXhr.readyState < 4) {
                this.lastXhr.abort();
            }
        },

        /**
         * Get a where clause.
         *
         * @returns {Object[]}
         */
        getWhere: function () {
            var where = (this.where || []).concat(this.whereAdditional || []);

            if (this.whereFunction) {
                where = where.concat(this.whereFunction() || []);
            }

            return where;
        },

        /**
         * @protected
         */
        getUser: function () {
            return this._user;
        },

        /**
         * @returns {string}
         */
        getEntityType: function () {
            return this.name;
        },

        /**
         * Reset the order to default.
         */
        resetOrderToDefault: function () {
            this.orderBy = this.defaultOrderBy;
            this.order = this.defaultOrder;
        },

        /**
         * Set an order.
         *
         * @param {string|null} orderBy
         * @param {boolean|'asc'|'desc'|null} [order]
         * @param {boolean} [setDefault]
         */
        setOrder: function (orderBy, order, setDefault) {
            this.orderBy = orderBy;
            this.order = order;

            if (setDefault) {
                this.defaultOrderBy = orderBy;
                this.defaultOrder = order;
            }
        },
    });
});