var groupview = $.extend({}, $.fn.datagrid.defaults.view, {
	render: function(target, container, frozen){
		var table = [];
		var groups = this.groups;
		for(var i=0; i<groups.length; i++){
			table.push(this.renderGroup.call(this, target, i, groups[i], frozen));
		}
		$(container).html(table.join(''));
	},
	
	renderGroup: function(target, groupIndex, group, frozen){
		var state = $.data(target, 'datagrid');
		var opts = state.options;
		var fields = $(target).datagrid('getColumnFields', frozen);
		
		var table = [];
		table.push('<div class="datagrid-group" group-index=' + groupIndex + '>');
		table.push('<table cellspacing="0" cellpadding="0" border="0" style="height:100%"><tbody>');
		table.push('<tr>');
		if ((frozen && (opts.rownumbers || opts.frozenColumns.length)) ||
				(!frozen && !(opts.rownumbers || opts.frozenColumns.length))){
			table.push('<td style="border:0;text-align:center;width:25px"><span class="datagrid-row-expander datagrid-row-collapse" style="display:inline-block;width:16px;height:16px;cursor:pointer">&nbsp;</span></td>');
		}
		table.push('<td style="border:0;">');
		if (!frozen){
			table.push('<span class="datagrid-group-title">');
			table.push(opts.groupFormatter.call(target, group.value, group.rows));
			table.push('</span>');
		}
		table.push('</td>');
		table.push('</tr>');
		table.push('</tbody></table>');
		table.push('</div>');
		
		table.push('<table class="datagrid-btable" cellspacing="0" cellpadding="0" border="0"><tbody>');
		var index = group.startIndex;
		for(var j=0; j<group.rows.length; j++) {
			var css = opts.rowStyler ? opts.rowStyler.call(target, index, group.rows[j]) : '';
			var classValue = '';
			var styleValue = '';
			if (typeof css == 'string'){
				styleValue = css;
			} else if (css){
				classValue = css['class'] || '';
				styleValue = css['style'] || '';
			}
			
			var cls = 'class="datagrid-row ' + (index % 2 && opts.striped ? 'datagrid-row-alt ' : ' ') + classValue + '"';
			var style = styleValue ? 'style="' + styleValue + '"' : '';
			var rowId = state.rowIdPrefix + '-' + (frozen?1:2) + '-' + index;
			table.push('<tr id="' + rowId + '" datagrid-row-index="' + index + '" ' + cls + ' ' + style + '>');
			table.push(this.renderRow.call(this, target, fields, frozen, index, group.rows[j]));
			table.push('</tr>');
			index++;
		}
		table.push('</tbody></table>');
		return table.join('');
	},
	
	bindEvents: function(target){
		var state = $.data(target, 'datagrid');
		var dc = state.dc;
		var body = dc.body1.add(dc.body2);
		var clickHandler = ($.data(body[0],'events')||$._data(body[0],'events')).click[0].handler;
		body.unbind('click').bind('click', function(e){
			var tt = $(e.target);
			var expander = tt.closest('span.datagrid-row-expander');
			if (expander.length){
				var gindex = expander.closest('div.datagrid-group').attr('group-index');
				if (expander.hasClass('datagrid-row-collapse')){
					$(target).datagrid('collapseGroup', gindex);
				} else {
					$(target).datagrid('expandGroup', gindex);
				}
			} else {
				clickHandler(e);
			}
			e.stopPropagation();
		});
	},
	
	onBeforeRender: function(target, rows){
		var state = $.data(target, 'datagrid');
		var opts = state.options;
		
		initCss();
		
		var groups = [];
		for(var i=0; i<rows.length; i++){
			var row = rows[i];
			var group = getGroup(row[opts.groupField]);
			if (!group){
				group = {
					value: row[opts.groupField],
					rows: [row]
				};
				groups.push(group);
			} else {
				group.rows.push(row);
			}
		}
		
		var index = 0;
		var newRows = [];
		for(var i=0; i<groups.length; i++){
			var group = groups[i];
			group.startIndex = index;
			index += group.rows.length;
			newRows = newRows.concat(group.rows);
		}
		
		state.data.rows = newRows;
		this.groups = groups;
		
		var that = this;
		setTimeout(function(){
			that.bindEvents(target);
		},0);
		
		function getGroup(value){
			for(var i=0; i<groups.length; i++){
				var group = groups[i];
				if (group.value == value){
					return group;
				}
			}
			return null;
		}
		function initCss(){
			if (!$('#datagrid-group-style').length){
				$('head').append(
					'<style id="datagrid-group-style">' +
					'.datagrid-group{height:25px;overflow:hidden;font-weight:bold;border-bottom:1px solid #ccc;}' +
					'</style>'
				);
			}
		}
	}
});

$.extend($.fn.datagrid.methods, {
    expandGroup:function(jq, groupIndex){
        return jq.each(function(){
            var view = $.data(this, 'datagrid').dc.view;
            var group = view.find(groupIndex!=undefined ? 'div.datagrid-group[group-index="'+groupIndex+'"]' : 'div.datagrid-group');
            var expander = group.find('span.datagrid-row-expander');
            if (expander.hasClass('datagrid-row-expand')){
                expander.removeClass('datagrid-row-expand').addClass('datagrid-row-collapse');
                group.next('table').show();
            }
            $(this).datagrid('fixRowHeight');
        });
    },
    collapseGroup:function(jq, groupIndex){
        return jq.each(function(){
            var view = $.data(this, 'datagrid').dc.view;
            var group = view.find(groupIndex!=undefined ? 'div.datagrid-group[group-index="'+groupIndex+'"]' : 'div.datagrid-group');
            var expander = group.find('span.datagrid-row-expander');
            if (expander.hasClass('datagrid-row-collapse')){
                expander.removeClass('datagrid-row-collapse').addClass('datagrid-row-expand');
                group.next('table').hide();
            }
            $(this).datagrid('fixRowHeight');
        });
    }
});

$.extend(groupview, {
	refreshGroupTitle: function(target, groupIndex){
		var state = $.data(target, 'datagrid');
		var opts = state.options;
		var dc = state.dc;
		var group = this.groups[groupIndex];
		var span = dc.body2.children('div.datagrid-group[group-index=' + groupIndex + ']').find('span.datagrid-group-title');
		span.html(opts.groupFormatter.call(target, group.value, group.rows));
	},
	
	insertRow: function(target, index, row){
		var state = $.data(target, 'datagrid');
		var opts = state.options;
		var dc = state.dc;
		var group = null;
		var groupIndex;
		
		for(var i=0; i<this.groups.length; i++){
			if (this.groups[i].value == row[opts.groupField]){
				group = this.groups[i];
				groupIndex = i;
				break;
			}
		}
		if (group){
			if (index == undefined || index == null){
				index = state.data.rows.length;
			}
			if (index < group.startIndex){
				index = group.startIndex;
			} else if (index > group.startIndex + group.rows.length){
				index = group.startIndex + group.rows.length;
			}
			$.fn.datagrid.defaults.view.insertRow.call(this, target, index, row);
			
			if (index >= group.startIndex + group.rows.length){
				_moveTr(index, true);
				_moveTr(index, false);
			}
			group.rows.splice(index - group.startIndex, 0, row);
		} else {
			group = {
				value: row[opts.groupField],
				rows: [row],
				startIndex: state.data.rows.length
			}
			groupIndex = this.groups.length;
			dc.body1.append(this.renderGroup.call(this, target, groupIndex, group, true));
			dc.body2.append(this.renderGroup.call(this, target, groupIndex, group, false));
			this.groups.push(group);
			state.data.rows.push(row);
		}
		
		this.refreshGroupTitle(target, groupIndex);
		
		function _moveTr(index,frozen){
			var serno = frozen?1:2;
			var prevTr = opts.finder.getTr(target, index-1, 'body', serno);
			var tr = opts.finder.getTr(target, index, 'body', serno);
			tr.insertAfter(prevTr);
		}
	},
	
	updateRow: function(target, index, row){
		var opts = $.data(target, 'datagrid').options;
		$.fn.datagrid.defaults.view.updateRow.call(this, target, index, row);
		var tb = opts.finder.getTr(target, index, 'body', 2).closest('table.datagrid-btable');
		var groupIndex = parseInt(tb.prev().attr('group-index'));
		this.refreshGroupTitle(target, groupIndex);
	},
	
	deleteRow: function(target, index){
		var state = $.data(target, 'datagrid');
		var opts = state.options;
		var dc = state.dc;
		var body = dc.body1.add(dc.body2);
		
		var tb = opts.finder.getTr(target, index, 'body', 2).closest('table.datagrid-btable');
		var groupIndex = parseInt(tb.prev().attr('group-index'));
		
		$.fn.datagrid.defaults.view.deleteRow.call(this, target, index);
		
		var group = this.groups[groupIndex];
		if (group.rows.length > 1){
			group.rows.splice(index-group.startIndex, 1);
			this.refreshGroupTitle(target, groupIndex);
		} else {
			body.children('div.datagrid-group[group-index='+groupIndex+']').remove();
			for(var i=groupIndex+1; i<this.groups.length; i++){
				body.children('div.datagrid-group[group-index='+i+']').attr('group-index', i-1);
			}
			this.groups.splice(groupIndex, 1);
		}
		
		var index = 0;
		for(var i=0; i<this.groups.length; i++){
			var group = this.groups[i];
			group.startIndex = index;
			index += group.rows.length;
		}
	}
});

