var deform  = {
    callbacks: [],

    addCallback: function (oid, callback) {
        deform.callbacks.push([oid, callback]);
    },

    clearCallbacks: function () {
        deform.callbacks = [];
    },

    load: function() {
        $(function() {
            deform.processCallbacks();
            deform.focusFirstInput();
		});
    },
            

    processCallbacks: function () {
        $(deform.callbacks).each(function(num, item) {
            var oid = item[0];
            var callback = item[1];
            callback(oid);
            }
            );
        deform.clearCallbacks();
    },

    addSequenceItem: function (protonode, before, now_len) {
        // - Clone the prototype node and add it before the "before" node.
        //   Also ensure any callbacks are run for the widget.

        // In order to avoid breaking accessibility:
        //
        // - Find each tag within the prototype node with an id
        //   that has the string ``deformField(\d+)`` within it, and modify 
        //   its id to have a random component.
        // - For each label referencing an change id, change the label's
        //   htmlFor attribute to the new id.

        var fieldmatch = /deformField(\d+)/;
        var namematch = /(.+)?-[#]{3}/;
        var code = protonode.attr('prototype');
        var html = decodeURIComponent(code);
        var $htmlnode = $(html);
        var $idnodes = $htmlnode.find('[id]');
        var $namednodes = $htmlnode.find('[name]');
        var genid = deform.randomString(6);
        var idmap = {};

        // replace ids containing ``deformField`` and associated label for= 
        // items which point at them

        $idnodes.each(function(idx, node) {
            var $node = $(node);
            var oldid = $node.attr('id');
            var newid = oldid.replace(fieldmatch, "deformField$1-" + genid);
            $node.attr('id', newid);
            idmap[oldid] = newid;
            var labelselector = 'label[htmlFor=' + oldid + ']';
            var $fornodes = $htmlnode.find(labelselector);
            $fornodes.attr('htmlFor', newid);
        });

        // replace names a containing ```deformField`` like we do for ids

        $namednodes.each(function(idx, node) {
            var $node = $(node);
            var oldname = $node.attr('name');
            var newname = oldname.replace(fieldmatch, "deformField$1-" + genid);
            $node.attr('name', newname);
        });

        var anchorid = genid + '-anchor';
        var anchortext = '<a name="' + anchorid +'" id="' + anchorid + '"/>' 
        
        if($.browser.msie && parseInt($.browser.version, 10) == 7) {
			var before = $(".deformInsertBefore");
        	var beforeIE = $(before).parent();

        	if (now_len >= 2) {
				var before = $(before).closest('ul');
				$(before).append(anchortext);
				$(before).append($htmlnode);
			}
			else {
				var before = $(before).parent();
				$(anchortext).insertAfter(before);
				$htmlnode.insertAfter(before);
			}
			
			
			$(deform.callbacks).each(function(num, item) {
				var oid = item[0];
				var callback = item[1];
				var newid = idmap[oid];
				if (newid) { 
					callback(newid)
					};
				});
	
			deform.clearCallbacks();
			var old_len = parseInt(beforeIE.attr('now_len')||'1');
			beforeIE.attr('now_len', old_len + 1);
		}
		else {
			$(anchortext).insertBefore(before);
			$htmlnode.insertBefore(before);

			$(deform.callbacks).each(function(num, item) {
				var oid = item[0];
				var callback = item[1];
				var newid = idmap[oid];
				if (newid) { 
					callback(newid)
					};
				});
	
			deform.clearCallbacks();
			var old_len = parseInt(before.attr('now_len')||'0');
			before.attr('now_len', old_len + 1);
		}

        //deform.maybeScrollIntoView('#' + anchorid);
    },
    
    appendSequenceItem: function(node, count) {
        var $oid_node = $(node).parent();
        var $proto_node = $oid_node.children('.deformProto').first();
        var $before_node = $oid_node.children('ul').first().children('.deformInsertBefore');
		
       if($.browser.msie && parseInt($.browser.version, 10) == 7) {
       		var beforeIE = $(".deformInsertBefore").parent();
			var min_len = parseInt(beforeIE.attr('min_len')||'0');
			var max_len = parseInt(beforeIE.attr('max_len')||'9999');
			var now_len = parseInt(beforeIE.attr('now_len')||'1');
			
			if (now_len < max_len) {
				deform.addSequenceItem($proto_node, beforeIE, now_len);
				document.getElementById('deformInsertBefore').setAttribute('now_len', now_len + 1);
				deform.processSequenceButtons($oid_node, min_len, max_len, now_len + 1);
			};
		}
		else {
			var min_len = parseInt($before_node.attr('min_len')||'0');
			var max_len = parseInt($before_node.attr('max_len')||'9999');
			var now_len = parseInt($before_node.attr('now_len')||'0');
			
			if (now_len < max_len) {
				deform.addSequenceItem($proto_node, $before_node);
				deform.processSequenceButtons($oid_node, min_len, max_len, now_len + 1);
			};
		}
		
        return false;
    },

    removeSequenceItem: function(clicked) {
        var $item_node = $(clicked).parent();
        var $oid_node = $item_node.parent().parent();
        var $before_node = $oid_node.find('.deformInsertBefore').first();
                
        if($.browser.msie && parseInt($.browser.version, 10) == 7) {
        	var before = $(".deformInsertBefore");
			var min_len = parseInt($before_node.attr('min_len')||'0');
			var max_len = parseInt($before_node.attr('max_len')||'9999');
			var now_len = parseInt(before.attr('now_len')||'0');
				
			if (now_len > min_len) {
				document.getElementById('deformInsertBefore').setAttribute('now_len', now_len - 1);
				$item_node.remove();
				deform.processSequenceButtons($oid_node, min_len, max_len, now_len - 1);
			};

		}
		else {
			var min_len = parseInt($before_node.attr('min_len')||'0');
			var max_len = parseInt($before_node.attr('max_len')||'9999');
			var now_len = parseInt($before_node.attr('now_len')||'0');

			if (now_len > min_len) {
				$before_node.attr('now_len', now_len - 1);
				$item_node.remove();
				deform.processSequenceButtons($oid_node, min_len, max_len, now_len-1);
			};

		}
                
        return false;
    },

    processSequenceButtons: function(oid_node, min_len, max_len, now_len) {
        var $ul = oid_node.children('ul');
        var $lis = $ul.children('li');
        if($.browser.msie && parseInt($.browser.version, 10) == 7) {
        	document.getElementById('deformInsertBefore').setAttribute('now_len', now_len);
        	var before = $(".deformInsertBefore");

			$lis.find('.deformClosebutton').removeClass('deformClosebuttonActive');
			oid_node.children('.deformSeqAdd').show();
						
			$(".deformClosebutton").html("<div class='deformClosebuttonIE'><img src='/static/images/2012/removebtn.png' border='0' /></div>");
			
			var min_len = 1;			
			if (now_len >= max_len) {
				oid_node.children('.deformSeqAdd').hide();
			};
		}
		else {
			
			$lis.find('.deformClosebutton').removeClass('deformClosebuttonActive');
			oid_node.children('.deformSeqAdd').show();
			
			if (now_len > min_len) {
				$lis.find('.deformClosebutton').addClass('deformClosebuttonActive');
			};
			
			if (now_len >= max_len) {
				oid_node.children('.deformSeqAdd').hide();
			};
		}

    },

    maybeScrollIntoView: function(element_id) {
        var viewportWidth = $(window).width(),
            viewportHeight = $(window).height(),
            documentScrollTop = $(document).scrollTop(),
            documentScrollLeft = $(document).scrollLeft(),
            minTop = documentScrollTop,
            maxTop = documentScrollTop + viewportHeight,
            minLeft = documentScrollLeft,
            maxLeft = documentScrollLeft + viewportWidth,
            element = document.getElementById(element_id),
            elementOffset = $(element_id).offset();
        if (
            !(elementOffset.top > minTop && elementOffset.top < maxTop) &&
            !(elementOffset.left > minLeft && elementOffset.left < maxLeft)
            ) {
                element.scrollIntoView();
            };
    },

    focusFirstInput: function () {
        var input = $(':input').filter('[id ^= deformField]').first();
        if (input) {
            var raw = input.get(0);
            if (raw) {
                if (raw.type === 'text' || raw.type === 'file' || 
                    raw.type == 'password' || raw.type == 'text' || 
                    raw.type == 'textarea') { 
                    if (raw.className != "hasDatepicker") {
                        input.focus();
                    };
                };
            };
        };
    },

    randomString: function (length) {
        var chr='0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz';
        var chr = chr.split('');
    
        if (! length) {
            length = Math.floor(Math.random() * chr.length);
        };
    
        var str = '';
        for (var i = 0; i < length; i++) {
            str += chr[Math.floor(Math.random() * chr.length)];
        };
        return str;
    }

};