betajs/betajs-data

Scoped.define("module:Stores.DumbStore", [
                                          "module:Stores.BaseStore",
                                          "base:Promise",
                                          "base:Objs",
                                          "base:Iterators.Iterator"
                                          ], function (BaseStore, Promise, Objs, Iterator, scoped) {
    return BaseStore.extend({scoped: scoped}, function (inherited) {            
        return {

            _read_last_id: function () {},
            _write_last_id: function (id) {},
            _remove_last_id: function () {},
            _read_first_id: function () {},
            _write_first_id: function (id) {},
            _remove_first_id: function () {},
            _read_item: function (id) {},
            _write_item: function (id, data) {},
            _remove_item: function (id) {},
            _read_next_id: function (id) {},
            _write_next_id: function (id, next_id) {},
            _remove_next_id: function (id) {},
            _read_prev_id: function (id) {},
            _write_prev_id: function (id, prev_id) {},
            _remove_prev_id: function (id) {},

            constructor: function (options) {
                options = options || {};
                options.create_ids = true;
                inherited.constructor.call(this, options);
            },

            _insert: function (data) {
                return Promise.tryCatch(function () {
                    var last_id = this._read_last_id();
                    var id = data[this._id_key];
                    if (last_id !== null) {
                        this._write_next_id(last_id, id);
                        this._write_prev_id(id, last_id);
                    } else
                        this._write_first_id(id);
                    this._write_last_id(id);
                    this._write_item(id, data);
                    return data;
                }, this);
            },

            _remove: function (id) {
                return Promise.tryCatch(function () {
                    var row = this._read_item(id);
                    if (row) {
                        this._remove_item(id);
                        var next_id = this._read_next_id(id);
                        var prev_id = this._read_prev_id(id);
                        if (next_id !== null) {
                            this._remove_next_id(id);
                            if (prev_id !== null) {
                                this._remove_prev_id(id);
                                this._write_next_id(prev_id, next_id);
                                this._write_prev_id(next_id, prev_id);
                            } else {
                                this._remove_prev_id(next_id);
                                this._write_first_id(next_id);
                            }
                        } else if (prev_id !== null) {
                            this._remove_next_id(prev_id);
                            this._write_last_id(prev_id);
                        } else {
                            this._remove_first_id();
                            this._remove_last_id();
                        }
                    }
                    return row;
                }, this);
            },

            _get: function (id) {
                return Promise.tryCatch(function () {
                    return this._read_item(id);
                }, this);
            },

            _update: function (id, data) {
                return Promise.tryCatch(function () {
                    var row = this._get(id);
                    if (row) {
                        delete data[this._id_key];
                        Objs.extend(row, data);
                        this._write_item(id, row);
                    }
                    return row;
                }, this);
            },

            _query: function (query, options) {
                return Promise.tryCatch(function () {
                    var iter = new Iterator();
                    var store = this;
                    var fid = this._read_first_id();
                    Objs.extend(iter, {
                        __id: fid === null ? 1 : fid,
                                __store: store,
                                __query: query,

                                hasNext: function () {
                                    var last_id = this.__store._read_last_id();
                                    if (last_id === null)
                                        return false;
                                    while (this.__id < last_id && !this.__store._read_item(this.__id))
                                        this.__id++;
                                    return this.__id <= last_id;
                                },

                                next: function () {
                                    if (this.hasNext()) {
                                        var item = this.__store.get(this.__id);
                                        if (this.__id == this.__store._read_last_id())
                                            this.__id++;
                                        else
                                            this.__id = this.__store._read_next_id(this.__id);
                                        return item;
                                    }
                                    return null;
                                }
                    });
                    return iter;
                }, this);
            }    

        };
    });
});