/* Fix for Opera, which does not seem to include the map function on Array's */
if (!Array.prototype.map) {
    Array.prototype.map = function(fun){
        var len = this.length;
        if (typeof fun != 'function') {
            throw new TypeError();
        }
        var res = new Array(len);
        var thisp = arguments[1];
        for (var i = 0; i < len; i++) {
            if (i in this) {
                res[i] = fun.call(thisp, this[i], i, this);
            }
        }
        return res;
    };
}

Ext.ns('Ext.ux.data');

/**
 * @class Ext.ux.data.PagingMemoryProxy
 * @extends Ext.data.MemoryProxy
 * 
Paging Memory Proxy, allows to use paging grid with in memory dataset
 */
Ext.ux.data.PagingMemoryProxy = Ext.extend(Ext.data.MemoryProxy, {
    constructor : function(data){
        Ext.ux.data.PagingMemoryProxy.superclass.constructor.call(this);
        this.data = data;
    },
    doRequest : function(action, rs, params, reader, callback, scope, options){
        params = params ||
        {};
        var result;
        try {
            result = reader.readRecords(this.data);
        } 
        catch (e) {
            this.fireEvent('loadexception', this, options, null, e);
            callback.call(scope, null, options, false);
            return;
        }
        
        // filtering
        if (params.filter !== undefined) {
            result.records = result.records.filter(function(el){
                if (typeof(el) == 'object') {
                    var att = params.filterCol || 0;
                    return String(el.data[att]).match(params.filter) ? true : false;
                }
                else {
                    return String(el).match(params.filter) ? true : false;
                }
            });
            result.totalRecords = result.records.length;
        }
        
        // sorting
        if (params.sort !== undefined) {
            // use integer as params.sort to specify column, since arrays are not named
            // params.sort=0; would also match a array without columns
            var dir = String(params.dir).toUpperCase() == 'DESC' ? -1 : 1;
            var fn = function(r1, r2){
                return r1 < r2;
            };
            result.records.sort(function(a, b){
                var v = 0;
                if (typeof(a) == 'object') {
                    v = fn(a.data[params.sort], b.data[params.sort]) * dir;
                }
                else {
                    v = fn(a, b) * dir;
                }
                if (v == 0) {
                    v = (a.index < b.index ? -1 : 1);
                }
                return v;
            });
        }
        // paging (use undefined cause start can also be 0 (thus false))
        if (params.start !== undefined && params.limit !== undefined) {
            result.records = result.records.slice(params.start, params.start + params.limit);
        }
        callback.call(scope, result, options, true);
    }
});

//backwards compat.
Ext.data.PagingMemoryProxy = Ext.ux.data.PagingMemoryProxy;