define(["dojo/_base/kernel", "dojo/_base/declare", "dojo/on", "dojo/has", "put-selector/put", "./List", "./util/misc", "dojo/_base/sniff"],
function(kernel, declare, listen, has, put, List, miscUtil){
	var contentBoxSizing = has("ie") < 8 && !has("quirks");
	var invalidClassChars = /[^\._a-zA-Z0-9-]/g;
	function appendIfNode(parent, subNode){
		if(subNode && subNode.nodeType){
			parent.appendChild(subNode);
		}
	}
	
	var Grid = declare(List, {
		columns: null,
		// cellNavigation: Boolean
		//		This indicates that focus is at the cell level. This may be set to false to cause
		//		focus to be at the row level, which is useful if you want only want row-level
		//		navigation.
		cellNavigation: true,
		tabableHeader: true,
		showHeader: true,
		column: function(target){
			// summary:
			//		Get the column object by node, or event, or a columnId
			if(typeof target != "object"){
				return this.columns[target];
			}else{
				return this.cell(target).column;
			}
		},
		listType: "grid",
		cell: function(target, columnId){
			// summary:
			//		Get the cell object by node, or event, id, plus a columnId
			
			if(target.column && target.element){ return target; }
			
			if(target.target && target.target.nodeType){
				// event
				target = target.target;
			}
			var element;
			if(target.nodeType){
				var object;
				do{
					if(this._rowIdToObject[target.id]){
						break;
					}
					var colId = target.columnId;
					if(colId){
						columnId = colId;
						element = target;
						break;
					}
					target = target.parentNode;
				}while(target && target != this.domNode);
			}
			if(!element && typeof columnId != "undefined"){
				var row = this.row(target),
					rowElement = row && row.element;
				if(rowElement){
					var elements = rowElement.getElementsByTagName("td");
					for(var i = 0; i < elements.length; i++){
						if(elements[i].columnId == columnId){
							element = elements[i];
							break;
						}
					}
				}
			}
			if(target != null){
				return {
					row: row || this.row(target),
					column: columnId && this.column(columnId),
					element: element
				};
			}
		},
		
		createRowCells: function(tag, each, subRows, object){
			// summary:
			//		Generates the grid for each row (used by renderHeader and and renderRow)
			var row = put("table.dgrid-row-table[role=presentation]"),
				cellNavigation = this.cellNavigation,
				// IE < 9 needs an explicit tbody; other browsers do not
				tbody = (has("ie") < 9 || has("quirks")) ? put(row, "tbody") : row,
				tr,
				si, sl, i, l, // iterators
				subRow, column, id, extraClasses, className,
				cell, innerCell, colSpan, rowSpan; // used inside loops
			
			// Allow specification of custom/specific subRows, falling back to
			// those defined on the instance.
			subRows = subRows || this.subRows;
			
			for(si = 0, sl = subRows.length; si < sl; si++){
				subRow = subRows[si];
				// for single-subrow cases in modern browsers, TR can be skipped
				// http://jsperf.com/table-without-trs
				tr = put(tbody, "tr");
				if(subRow.className){
					put(tr, "." + subRow.className);
				}

				for(i = 0, l = subRow.length; i < l; i++){
					// iterate through the columns
					column = subRow[i];
					id = column.id;

					extraClasses = column.field ? ".field-" + column.field : "";
					className = typeof column.className === "function" ?
						column.className(object) : column.className;
					if(className){
						extraClasses += "." + className;
					}

					cell = put(tag + (
							".dgrid-cell.dgrid-cell-padding" +
							(id ? ".dgrid-column-" + id : "") +
							extraClasses.replace(/ +/g, ".")
						).replace(invalidClassChars,"-") +
						"[role=" + (tag === "th" ? "columnheader" : "gridcell") + "]");
					cell.columnId = id;
					if(contentBoxSizing){
						// The browser (IE7-) does not support box-sizing: border-box, so we emulate it with a padding div
						innerCell = put(cell, "!dgrid-cell-padding div.dgrid-cell-padding");// remove the dgrid-cell-padding, and create a child with that class
						cell.contents = innerCell;
					}else{
						innerCell = cell;
					}
					colSpan = column.colSpan;
					if(colSpan){
						cell.colSpan = colSpan;
					}
					rowSpan = column.rowSpan;
					if(rowSpan){
						cell.rowSpan = rowSpan;
					}
					each(innerCell, column);
					// add the td to the tr at the end for better performance
					tr.appendChild(cell);
				}
			}
			return row;
		},
		
		left: function(cell, steps){
			if(!cell.element){ cell = this.cell(cell); }
			return this.cell(this._move(cell, -(steps || 1), "dgrid-cell"));
		},
		right: function(cell, steps){
			if(!cell.element){ cell = this.cell(cell); }
			return this.cell(this._move(cell, steps || 1, "dgrid-cell"));
		},
		
		renderRow: function(object, options){
			var self = this;
			var row = this.createRowCells("td", function(td, column){
				var data = object;
				// Support get function or field property (similar to DataGrid)
				if(column.get){
					data = column.get(object);
				}else if("field" in column && column.field != "_item"){
					data = data[column.field];
				}
				
				if(column.renderCell){
					// A column can provide a renderCell method to do its own DOM manipulation,
					// event handling, etc.
					appendIfNode(td, column.renderCell(object, data, td, options));
				}else{
					defaultRenderCell.call(column, object, data, td, options);
				}
			}, options && options.subRows, object);
			// row gets a wrapper div for a couple reasons:
			//	1. So that one can set a fixed height on rows (heights can't be set on <table>'s AFAICT)
			// 2. So that outline style can be set on a row when it is focused, and Safari's outline style is broken on <table>
			return put("div[role=row]>", row);
		},
		renderHeader: function(){
			// summary:
			//		Setup the headers for the grid
			var
				grid = this,
				columns = this.columns,
				headerNode = this.headerNode,
				i = headerNode.childNodes.length;
			
			headerNode.setAttribute("role", "row");
			
			// clear out existing header in case we're resetting
			while(i--){
				put(headerNode.childNodes[i], "!");
			}
			
			var row = this.createRowCells("th", function(th, column){
				var contentNode = column.headerNode = th;
				if(contentBoxSizing){
					// we're interested in the th, but we're passed the inner div
					th = th.parentNode;
				}
				var field = column.field;
				if(field){
					th.field = field;
				}
				// allow for custom header content manipulation
				if(column.renderHeaderCell){
					appendIfNode(contentNode, column.renderHeaderCell(contentNode));
				}else if("label" in column || column.field){
					contentNode.appendChild(document.createTextNode(
						"label" in column ? column.label : column.field));
				}
				if(column.sortable !== false && field && field != "_item"){
					th.sortable = true;
					th.className += " dgrid-sortable";
				}
			}, this.subRows && this.subRows.headerRows);
			this._rowIdToObject[row.id = this.id + "-header"] = this.columns;
			headerNode.appendChild(row);
			
			// If the columns are sortable, re-sort on clicks.
			// Use a separate listener property to be managed by renderHeader in case
			// of subsequent calls.
			if(this._sortListener){
				this._sortListener.remove();
			}
			this._sortListener = listen(row, "click,keydown", function(event){
				// respond to click, space keypress, or enter keypress
				if(event.type == "click" || event.keyCode == 32 /* space bar */ || (!has("opera") && event.keyCode == 13) /* enter */){
					var target = event.target,
						field, sort, newSort, eventObj;
					do{
						if(target.sortable){
							// If the click is on the same column as the active sort,
							// reverse sort direction
							newSort = [{
								attribute: (field = target.field || target.columnId),
								descending: (sort = grid._sort[0]) && sort.attribute == field &&
									!sort.descending
							}];
							
							// Emit an event with the new sort
							eventObj = {
								bubbles: true,
								cancelable: true,
								grid: grid,
								parentType: event.type,
								sort: newSort
							};
							
							if (listen.emit(event.target, "dgrid-sort", eventObj)){
								// Stash node subject to DOM manipulations,
								// to be referenced then removed by sort()
								grid._sortNode = target;
								grid.set("sort", newSort);
							}
							
							break;
						}
					}while((target = target.parentNode) && target != headerNode);
				}
			});
		},
		
		resize: function(){
			// extension of List.resize to allow accounting for
			// column sizes larger than actual grid area
			var
				headerTableNode = this.headerNode.firstChild,
				contentNode = this.contentNode,
				width;
			
			this.inherited(arguments);
			
			if(!has("ie") || (has("ie") > 7 && !has("quirks"))){
				// Force contentNode width to match up with header width.
				// (Old IEs don't have a problem due to how they layout.)
				
				contentNode.style.width = ""; // reset first
				
				if(contentNode && headerTableNode){
					if((width = headerTableNode.offsetWidth) != contentNode.offsetWidth){
						// update size of content node if necessary (to match size of rows)
						// (if headerTableNode can't be found, there isn't much we can do)
						contentNode.style.width = width + "px";
					}
				}
			}
		},
		
		destroy: function(){
			// Run _destroyColumns first to perform any column plugin tear-down logic.
			this._destroyColumns();
			if(this._sortListener){
				this._sortListener.remove();
			}
			
			this.inherited(arguments);
		},
		
		_setSort: function(property, descending){
			// summary:
			//		Extension of List.js sort to update sort arrow in UI
			
			// Normalize _sort first via inherited logic, then update the sort arrow
			this.inherited(arguments);
			this.updateSortArrow(this._sort);
		},
		
		updateSortArrow: function(sort, updateSort){
			// summary:
			//		Method responsible for updating the placement of the arrow in the
			//		appropriate header cell.  Typically this should not be called (call
			//		set("sort", ...) when actually updating sort programmatically), but
			//		this method may be used by code which is customizing sort (e.g.
			//		by reacting to the dgrid-sort event, canceling it, then
			//		performing logic and calling this manually).
			// sort: Array
			//		Standard sort parameter - array of object(s) containing attribute
			//		and optionally descending property
			// updateSort: Boolean?
			//		If true, will update this._sort based on the passed sort array
			//		(i.e. to keep it in sync when custom logic is otherwise preventing
			//		it from being updated); defaults to false
			
			// Clean up UI from any previous sort
			if(this._lastSortedArrow){
				// Remove the sort classes from the parent node
				put(this._lastSortedArrow, "<!dgrid-sort-up!dgrid-sort-down");
				// Destroy the lastSortedArrow node
				put(this._lastSortedArrow, "!");
				delete this._lastSortedArrow;
			}
			
			if(updateSort){ this._sort = sort; }
			if(!sort[0]){ return; } // nothing to do if no sort is specified
			
			var prop = sort[0].attribute,
				desc = sort[0].descending,
				target = this._sortNode, // stashed if invoked from header click
				columns, column, i;
			
			delete this._sortNode;
			
			if(!target){
				columns = this.columns;
				for(i in columns){
					column = columns[i];
					if(column.field == prop){
						target = column.headerNode;
						break;
					}
				}
			}
			// skip this logic if field being sorted isn't actually displayed
			if(target){
				target = target.contents || target;
				// place sort arrow under clicked node, and add up/down sort class
				this._lastSortedArrow = put(target.firstChild, "-div.dgrid-sort-arrow.ui-icon[role=presentation]");
				this._lastSortedArrow.innerHTML = "&nbsp;";
				put(target, desc ? ".dgrid-sort-down" : ".dgrid-sort-up");
				// call resize in case relocation of sort arrow caused any height changes
				this.resize();
			}
		},
		
		styleColumn: function(colId, css){
			// summary:
			//		Dynamically creates a stylesheet rule to alter a column's style.
			
			return this.addCssRule("#" + miscUtil.escapeCssIdentifier(this.domNode.id) +
				" .dgrid-column-" + colId, css);
		},
		
		/*=====
		_configColumn: function(column, columnId, rowColumns, prefix){
			// summary:
			//		Method called when normalizing base configuration of a single
			//		column.  Can be used as an extension point for behavior requiring
			//		access to columns when a new configuration is applied.
		},=====*/
		
		_configColumns: function(prefix, rowColumns){
			// configure the current column
			var subRow = [],
				isArray = rowColumns instanceof Array;
			
			function configColumn(column, columnId){
				if(typeof column == "string"){
					rowColumns[columnId] = column = {label:column};
				}
				if(!isArray && !column.field){
					column.field = columnId;
				}
				columnId = column.id = column.id || (isNaN(columnId) ? columnId : (prefix + columnId));
				if(isArray){ this.columns[columnId] = column; }
				
				// allow further base configuration in subclasses
				if(this._configColumn){
					this._configColumn(column, columnId, rowColumns, prefix);
				}
				
				// add grid reference to each column object for potential use by plugins
				column.grid = this;
				if(typeof column.init === "function"){ column.init(); }
				
				subRow.push(column); // make sure it can be iterated on
			}
			
			miscUtil.each(rowColumns, configColumn, this);
			return isArray ? rowColumns : subRow;
		},
		
		_destroyColumns: function(){
			// summary:
			//		Iterates existing subRows looking for any column definitions with
			//		destroy methods (defined by plugins) and calls them.  This is called
			//		immediately before configuring a new column structure.
			
			var subRows = this.subRows,
				// if we have column sets, then we don't need to do anything with the missing subRows, ColumnSet will handle it
				subRowsLength = subRows && subRows.length,
				i, j, column, len;
			
			// First remove rows (since they'll be refreshed after we're done),
			// so that anything aspected onto removeRow by plugins can run.
			// (cleanup will end up running again, but with nothing to iterate.)
			this.cleanup();
			
			for(i = 0; i < subRowsLength; i++){
				for(j = 0, len = subRows[i].length; j < len; j++){
					column = subRows[i][j];
					if(typeof column.destroy === "function"){ column.destroy(); }
				}
			}
		},
		
		configStructure: function(){
			// configure the columns and subRows
			var subRows = this.subRows,
				columns = this._columns = this.columns;
			
			// Reset this.columns unless it was already passed in as an object
			this.columns = !columns || columns instanceof Array ? {} : columns;
			
			if(subRows){
				// Process subrows, which will in turn populate the this.columns object
				for(var i = 0; i < subRows.length; i++){
					subRows[i] = this._configColumns(i + "-", subRows[i]);
				}
			}else{
				this.subRows = [this._configColumns("", columns)];
			}
		},
		
		_getColumns: function(){
			// _columns preserves what was passed to set("columns"), but if subRows
			// was set instead, columns contains the "object-ified" version, which
			// was always accessible in the past, so maintain that accessibility going
			// forward.
			return this._columns || this.columns;
		},
		_setColumns: function(columns){
			this._destroyColumns();
			// reset instance variables
			this.subRows = null;
			this.columns = columns;
			// re-run logic
			this._updateColumns();
		},
		
		_setSubRows: function(subrows){
			this._destroyColumns();
			this.subRows = subrows;
			this._updateColumns();
		},
		
		setColumns: function(columns){
			kernel.deprecated("setColumns(...)", 'use set("columns", ...) instead', "dgrid 0.4");
			this.set("columns", columns);
		},
		setSubRows: function(subrows){
			kernel.deprecated("setSubRows(...)", 'use set("subRows", ...) instead', "dgrid 0.4");
			this.set("subRows", subrows);
		},
		
		_updateColumns: function(){
			// summary:
			//		Called when columns, subRows, or columnSets are reset
			
			this.configStructure();
			this.renderHeader();
			
			this.refresh();
			// re-render last collection if present
			this._lastCollection && this.renderArray(this._lastCollection);
			
			// After re-rendering the header, re-apply the sort arrow if needed.
			if(this._started){
				if(this._sort && this._sort.length){
					this.updateSortArrow(this._sort);
				} else {
					// Only call resize directly if we didn't call updateSortArrow,
					// since that calls resize itself when it updates.
					this.resize();
				}
			}
		}
	});
	
	function defaultRenderCell(object, data, td, options){
		if(this.formatter){
			// Support formatter, with or without formatterScope
			var formatter = this.formatter,
				formatterScope = this.grid.formatterScope;
			td.innerHTML = typeof formatter === "string" && formatterScope ?
				formatterScope[formatter](data, object) : this.formatter(data, object);
		}else if(data != null){
			td.appendChild(document.createTextNode(data)); 
		}
	}
	
	// expose appendIfNode and default implementation of renderCell,
	// e.g. for use by column plugins
	Grid.appendIfNode = appendIfNode;
	Grid.defaultRenderCell = defaultRenderCell;
	
	return Grid;
});