Rkns.Model = {}

Rkns.Model._BaseElement = function(_project, _props) {

    if (typeof _props !== "undefined") {

        this._project = _project;

        this.id = _props.id || Rkns.utils.getUID(this.type);

        this.title = _props.title || "(untitled " + this.type + ")";

        this.description = _props.description || "";

        this.uri = _props.uri || "";

//        this._backRefs = [];

    }

}

Rkns.Model._BaseElement.prototype.addReference = function(_propName, _list, _id) {

    this[ _propName + "_id" ] = _id;

    var _element = _list.getElement(_id);

    this[ _propName ] = _element;

/*    if (typeof _element !== "undefined" && typeof _element._backRefs !== "undefined") {

        _element._backRefs.push({

            type: this.type,

            id: this.id,

            pointing_property: _propName,

            element: this

        });

    } */

}

/* Element Class Generator */

Rkns.Model._elementClass = function(_type) {

    return Rkns.Utils.inherit(Rkns.Model._BaseElement, function() {

        this.type = _type;

    });

}

/* User Model */

Rkns.Model.User = Rkns.Model._elementClass("user");

Rkns.Model.User.prototype._init = function(_project, _props) {

    this.color = _props.color || "#666666";

}

/* Node Model */

Rkns.Model.Node = Rkns.Model._elementClass("node");

Rkns.Model.Node.prototype._init = function(_project, _props) {

    this.addReference("created_by", this._project.users, _props.created_by);

    this.position = _props.position;

}

/* Edge Model */

Rkns.Model.Edge = Rkns.Model._elementClass("edge");

Rkns.Model.Edge.prototype._init = function(_project, _props) {

    this.addReference("from", this._project.nodes, _props.from);

    this.addReference("to", this._project.nodes, _props.to);

}

/* List Helper Functions */

Rkns.Model.List = function() {

    Array.call(this);

    this.idIndex = [];

}

Rkns.Model.List.prototype = new Array();

Rkns.Model.List.prototype.hasId = function(_id) {

    return Rkns._(this.idIndex).include(_id);

}

Rkns.Model.List.prototype.getIds = function(_id) {

    return this.idIndex;

}

/* On recent browsers, forEach and map are defined and do what we want.

 * Otherwise, we'll use the Underscore.js functions

 */

if (typeof Array.prototype.forEach === "undefined") {

    Rkns.Model.List.prototype.forEach = function(_callback) {

        var _this = this;

        Rkns._(this).forEach(function(_value, _key) {

            _callback(_value, _key, _this);

        });

    }

}

if (typeof Array.prototype.map === "undefined") {

    Rkns.Model.List.prototype.map = function(_callback) {

        var _this = this;

        return Rkns._(this).map(function(_value, _key) {

            return _callback(_value, _key, _this);

        });

    }

}

/* We override Array's filter function because it doesn't return an Rkns.Model.List

 */

Rkns.Model.List.prototype.filter = function(_callback) {

    var _this = this,

        _res = new Rkns.Model.List();

    _res.addElements(Rkns._(this).filter(function(_value, _key) {

        return _callback(_value, _key, _this);

    }));

    return _res;

}

Rkns.Model.List.prototype.slice = function(_start, _end) {

    var _res = new Rkns.Model.List();

    _res.addElements(Array.prototype.slice.call(this, _start, _end));

    return _res;

}

Rkns.Model.List.prototype.splice = function(_start, _end) {

    var _res = new Rkns.Model.List();

    _res.addElements(Array.prototype.splice.call(this, _start, _end));

    this.idIndex.splice(_start, _end);

    return _res;

}

/* Array has a sort function, but it's not as interesting as Underscore.js's sortBy

 * and won't return a new Rkns.Model.List

 */

Rkns.Model.List.prototype.sortBy = function(_callback) {

    var _this = this,

        _res = new Rkns.Model.List();

    _res.addElements(Rkns._(this).sortBy(function(_value, _key) {

        return _callback(_value, _key, _this);

    }));

    return _res;

}

Rkns.Model.List.prototype.push = function(_el) {

    if (typeof _el === "undefined" || typeof _el.id === "undefined") {

        return;

    }

    var _index = (Rkns._(this.idIndex).indexOf(_el.id));

    if (_index === -1) {

        this.idIndex.push(_el.id);

        Array.prototype.push.call(this, _el);

    } else {

        this[_index] = _el;

    }

}

Rkns.Model.List.prototype.addElements = function(_array) {

    var _this = this;

    Rkns._(_array).forEach(function(_el) {

        _this.push(_el);

    });

}

Rkns.Model.List.prototype.removeId = function(_id) {

    var _index = (Rkns._(this.idIndex).indexOf(_id));

    if (_index !== -1) {

        this.splice(_index,1);

    }

}

Rkns.Model.List.prototype.removeIds = function(_list) {

    var _this = this;

    Rkns._(_list).forEach(function(_id) {

        _this.removeId(_id);

    });

}

Rkns.Model.List.prototype.getElement = function(_id) {

    var _index = Rkns._(this.idIndex).indexOf(_id);

    if (_index === -1) {

        return undefined;

    } else {

        return this[_index];

    }

}