/**
 * Ext.ux.data.PagingMemoryProxy.js
 * 
 * A proxy for local / in-browser data structures supports paging / sorting /
 * filtering / etc
 * 
 * @file Ext.ux.PagingMemoryProxy.js
 * @author Ing. Ido Sebastiaan Bas van Oostveen
 * 
 * @changelog:
 * @version 1.4
 * @date 21-Februari-2008 - added filter prototype method for array's
 * @version 1.3
 * @date 30-September-2007 - added customFilter config option
 * @version 1.2
 * @date 29-September-2007 - fixed several sorting bugs
 * @version 1.1
 * @date 30-August-2007
 * @version 1.0
 * @date 22-August-2007
 * 
 */

Ext.namespace("Ext.ux");
Ext.namespace("Ext.ux.data");

/* Fixes for IE/Opera old javascript versions */
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;
	};
}

if (!Array.prototype.filter) {
	Array.prototype.filter = function(fun /* , thisp */) {
		var len = this.length;
		if (typeof fun != "function")
			throw new TypeError();

		var res = new Array();
		var thisp = arguments[1];
		for (var i = 0;i < len; i++) {
			if (i in this) {
				var val = this[i]; // in case fun mutates this
				if (fun.call(thisp, val, i, this))
					res.push(val);
			}
		}
		return res;
	};
}

/* Paging Memory Proxy, allows to use paging grid with in memory dataset */
Ext.ux.data.PagingMemoryProxy = function(data, config) {
	Ext.ux.data.PagingMemoryProxy.superclass.constructor.call(this);
	this.data = data;
	Ext.apply(this, config);
};

Ext.extend(Ext.ux.data.PagingMemoryProxy, Ext.data.MemoryProxy, {
	customFilter : null,

	load : function(params, reader, callback, scope, arg) {
		params = params || {};
		var result;
		try {
			result = reader.readRecords(this.data);
		} catch (e) {
			this.fireEvent("loadexception", this, arg, null, e);
			callback.call(scope, null, arg, false);
			return;
		}

		// filtering
		if (this.customFilter != null) {
			result.records = result.records.filter(this.customFilter);
			result.totalRecords = result.records.length;
		} else 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 ? 0 : r1 < r2 ? -1 : 1;
		};
		var st = reader.recordType.getField(params.sort).sortType;
		result.records.sort(function(a, b) {
			var v = 0;
			if (typeof(a) == "object") {
				v = fn(st(a.data[params.sort]), st(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, arg, true);
}
});