/**
 * A class which represents a graphical list of DataCells.
 * This class allows list, queue and stack operations on it.
 */
/* ## class DataList implements IDataSet */

/**
 * DataList constructor
 */
function DataList(dataCellsCount, width, height) {
	var divName = "dataList" + getNewGUID();
	this.frameDiv = document.createElement('DIV');
	this.frameDiv.id = divName;
	
	this.frameDiv.style.width = width + "px";
	this.frameDiv.style.height = height + "px"; 
	this.frameDiv.style.borderWidth = "1px"; 
	this.frameDiv.style.borderStyle = "Solid";
	this.frameDiv.style.borderColor = "#000000";
	this.frameDiv.style.backgroundColor = CELL_COLOR;
	this.frameDiv.style.overflow = "auto";
	
	this.frameDiv.list = this;
	
	this.enabled = true;
	this.cursor = 0;
	this.dataSetType = "DataList";
	
	var that = this;
	
	/**
	 * Adds the given DataCell to the end of the list
	 */
	this.addDataCell = function(dataCell) {
		that.frameDiv.appendChild(dataCell.itemDiv);
		dataCell.parent = that;
		dataCell.onenterpressed = function() {
			if (dataCell.itemDiv.nextSibling) dataCell.itemDiv.nextSibling.onmousedown();
			else {
				var newCell = new DataCell();
				that.addDataCell(newCell);
				newCell.itemDiv.onmousedown();
			}
		}
		dataCell.ondatachange = function() {
			if (dataCell.itemDiv.nextSibling) {
				return true;
			}
			else {
				var newCell = new DataCell();
				that.addDataCell(newCell);
				//newCell.itemDiv.onmousedown();
			}
		}
	}
	
	/**
	 * Pushes a given DataCell to the top of the list
	 */
	this.push = function(dataCell) {
		if (!dataCell || !(dataCell.getValue())) return;
		if (that.frameDiv.firstChild) {
			that.frameDiv.insertBefore(dataCell.itemDiv, that.frameDiv.firstChild);
			dataCell.parent = that;
			dataCell.onenterpressed = function() {
				dataCell.itemDiv.nextSibling.onmousedown();
			}
		}
		else {
			that.addDataCell(dataCell);
		}
	}
	
	/**
	 * Pushes a given DataCell to the top of the list,
	 * but keeps the size of the list by removing last DataCell
	 */
	this.pushKeepSize = function(dataCell) {
		if (!dataCell || !(dataCell.getValue())) return;
		that.push(dataCell);
		that.frameDiv.lastChild.dataCell.parent = null;
		that.frameDiv.removeChild(that.frameDiv.lastChild);
	}
	
	/**
	 * Pops the top DataCell from the top of the list
	 * Returns the poped cell
	 */
	this.pop = function() {
		var oldFirst = that.frameDiv.firstChild;
		if (!oldFirst) return null;
		if (oldFirst.dataCell.getValue() == undefined) return null;
		that.frameDiv.removeChild(oldFirst);
		oldFirst.dataCell.parent = null;
		return oldFirst.dataCell;
	}
	
	/**
	 * Pops the top DataCell from the top of the list,
	 * but keeps the size of the list by adding new DataCell to its end
	 * value - A value for the new DataCell, null for empty
	 * Returns the poped cell
	 */
	this.popKeepSize = function(value) {
		var poped = that.pop();
		if (!poped) return null;
		var dc = new DataCell();
		dc.setValue(value);
		that.addDataCell(dc);
		return poped;
	}
	
	/**
	 * Returns the DataCell at the specified index
	 */
	this.getCellAt = function(index) {
		var i = 0;
		var cell = that.frameDiv.firstChild;
		if (!cell) return null;
		while (i < index) {
			cell = cell.nextSibling;
			if (!cell) return null;
			i++;
		}
		return cell.dataCell;
	}
	
	/**
	 * Returns the current DataCell at cursor's position
	 */
	this.getCurrent = function() {
		return that.getCellAt(that.cursor);
	}
	
	/**
	 * Increments the cursor to the next cell
	 */
	this.goNext = function() {
		var nextCellDiv = that.getCurrent().itemDiv.nextSibling;
		var nextCell = null;
		if (nextCellDiv) nextCell = nextCellDiv.dataCell;
		
		if (nextCell && (that.getCurrent().getValue() != undefined)) {
			that.cursor++;
			return true;
		} else if (!nextCell && (that.getCurrent().getValue() != undefined)) {
			that.cursor++;
			that.addDataCell(new DataCell());
		}
		return false;
	}
	
	/**
	 * Decrements the cursor to the previous cell
	 */
	this.goBack = function() {
		if (that.cursor > 0) {
			that.cursor--;
			return true;
		}
		return false;
	}
	
	/**
	 * Clears a given cell in the list
	 */
	this.clearCell = function(dataCell) {
		//find cell index
		var i = 0;
		var cell = that.frameDiv.firstChild;
		while (cell && cell != dataCell.itemDiv) {
			cell = cell.nextSibling;
			i++;
		}

		//remove it
		that.frameDiv.removeChild(dataCell.itemDiv);
		//that.addDataCell(new DataCell());
		
		//if index < cursor, goBack
		if (that.cursor > i) that.cursor--;
		
		//set highlight
		var current = that.getCurrent();
		if (current) current.highlight(true);
	}
	
	/**
	 * Returns an array representation of this DataList
	 */
	this.toArray = function() {
		var result = [];
		var c = that.getCellAt(0);
		for (var i=0; c && (c.getValue() != undefined); i++) {
			result[i] = c.getValue();
			var b = c.itemDiv.nextSibling;
			if (b) c = b.dataCell;
			else c = null;
		}  
		return result;
	}
	
	/**
	 * Dehighlights the whole list
	 */
	this.dehighlight = function() {
		var x = that.frameDiv.firstChild;
		while (x) {
			x.dataCell.highlight(false);
			x = x.nextSibling;
		}
	}
	
	/**
	 * Clears the list and adds one new empty DataCell.
	 */
	this.clearList = function() {
		while (that.pop()) { }
		that.push(new DataCell());
		that.cursor = 0;
	}
	
	this.showValues = function() {
		var cell = that.frameDiv.firstChild;
		while (cell) {
			cell.dataCell.showValue();
			cell = cell.nextSibling;
		}
	}
		
	//Init list if a size was given
	if (dataCellsCount) {
		for (var i = 0; i < dataCellsCount; i++) {
			this.addDataCell(new DataCell());
		}
	}
}