function snapr_add_tag()
{
	var image = document.getElementById('snapr_preview_img');
	image.parentNode.onclick = function(e)
	{
		canvas_click(this);
	}
	image.parentNode.setAttribute('canvas:oncomplete', 'snapr_process_canvas_add(this);');
	image.parentNode.setAttribute('canvas:oncancel', 'obj.onclick = null;');
}

function snapr_process_canvas_add(obj, tag_data)
{
	obj.onclick = null;
	var abs_x = $dynano(obj).Left() + obj.canvas.left;
	var abs_y = $dynano(obj).Top()  + obj.canvas.top;
	var height = obj.canvas.height + 2;
	
	var entry_div = document.createElement('div');
	entry_div.className = 'snapr_tag_entry';
	entry_div.style.position = 'absolute';
	entry_div.style.top = String(abs_y + height) + 'px';
	entry_div.style.left = String(abs_x)+ 'px';
	
	entry_div.appendChild(document.createTextNode('Enter a tag:'));
	entry_div.appendChild(document.createElement('br'));
	
	var ta = document.createElement('textarea');
	ta.rows = '7';
	ta.cols = '30';
	if ( typeof(tag_data) == 'string' )
		ta.value = tag_data;
	entry_div.appendChild(ta);
	
	entry_div.appendChild(document.createElement('br'));
	
	var a_add = document.createElement('a');
	a_add.href = '#';
	a_add.onclick = function()
	{
		var el = this.previousSibling;
		while ( el.tagName != 'TEXTAREA' )
			el = el.previousSibling;
		
		snapr_finalize_canvas_add(this.parentNode, this.parentNode.parentNode.canvas, el.value);
		return false;
	}
	a_add.appendChild(document.createTextNode('Add tag'));
	entry_div.appendChild(a_add);
	
	entry_div.appendChild(document.createTextNode(' | '));
	
	var a_cancel = document.createElement('a');
	a_cancel.href = '#';
	a_cancel.onclick = function()
	{
		snapr_finalize_canvas_cancel(this.parentNode);
		return false;
	}
	a_cancel.appendChild(document.createTextNode('Cancel'));
	entry_div.appendChild(a_cancel);
	
	obj.appendChild(entry_div);
	ta.focus();
}

function snapr_finalize_canvas_add(obj, canvas_data, tag)
{
	// add the new box
	var id = obj.parentNode.getAttribute('snapr:imgid');
	if ( !id )
		return false;
	
	// destroy form, etc.
	var parent = obj.parentNode;
	parent.removeChild(parent.canvas_box_obj);
	parent.removeChild(obj);
	
	var canvas_json = toJSONString(canvas_data);
	ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=add_tag&tag=' + ajaxEscape(tag) + '&canvas_params=' + ajaxEscape(canvas_json), snapr_process_ajax_tag_packet);
}

function snapr_finalize_canvas_cancel(obj)
{
	var parent = obj.parentNode;
	parent.removeChild(parent.canvas_box_obj);
	parent.removeChild(obj);
}

function snapr_finalize_canvas_edit_cancel(obj)
{
	var old_value = obj.getElementsByTagName('textarea')[0];
	old_value = old_value.OriginalValue;
	var canvas = obj.parentNode;
	var canvas_data = canvas.canvas;
	var note_id = canvas.tag_id;
	var auth_delete = canvas.auth_delete;
	var parent = canvas.parentNode;
	canvas.removeChild(obj);
	parent.removeChild(canvas);
	// redraw the note
	snapr_draw_note(parent, old_value, canvas_data, note_id, false, auth_delete);
}

function snapr_finalize_canvas_edit_delete(obj)
{
	var old_value = obj.getElementsByTagName('textarea')[0];
	old_value = old_value.OriginalValue;
	var canvas = obj.parentNode;
	var canvas_data = canvas.canvas;
	var note_id = canvas.tag_id;
	var auth_delete = canvas.auth_delete;
	var parent = canvas.parentNode;
	canvas.removeChild(obj);
	parent.removeChild(canvas);
	// redraw the note
	var note = snapr_draw_note(parent, old_value, canvas_data, note_id, false, auth_delete);
	// now nuke it
	snapr_nuke_tag(note);
}

function snapr_draw_note(obj, tag, canvas_data, note_id, initial_hide, auth_delete)
{
	var newbox = canvas_create_box(obj, canvas_data.left, canvas_data.top, canvas_data.width, canvas_data.height);
	newbox.tag_id = note_id;
	newbox.canvas = canvas_data;
	newbox.auth_delete = auth_delete;
	obj.onmouseover = function()
	{
		var boxen = this.getElementsByTagName('div');
		for ( var i = 0; i < boxen.length; i++ )
			if ( boxen[i].className == 'canvasbox' )
				boxen[i].style.display = 'block';
	}
	obj.onmouseout = function()
	{
		var boxen = this.getElementsByTagName('div');
		for ( var i = 0; i < boxen.length; i++ )
			if ( boxen[i].className == 'canvasbox' )
				boxen[i].style.display = 'none';
	}
	newbox.onmouseover = function()
	{
		this.style.borderColor = '#FFFF00';
		this.firstChild.style.borderColor = '#000000';
		snapr_display_note(this.noteObj);
	}
	newbox.onmouseout = function()
	{
		this.style.borderColor = '#000000';
		this.firstChild.style.borderColor = '#FFFFFF';
		snapr_hide_note(this.noteObj);
	}
	if ( auth_delete )
	{
		/*
		var p = document.createElement('p');
		p.style.cssFloat = 'right';
		p.style.styleFloat = 'right';
		p.style.fontWeight = 'bold';
		p.style.margin = '5px';
		var a_del = document.createElement('a');
		a_del.style.color = '#FF0000';
		a_del.href = '#';
		a_del.onclick = function()
		{
			snapr_nuke_tag(this.parentNode.parentNode.parentNode);
			return false;
		}
		a_del.appendChild(document.createTextNode('[X]'));
		p.appendChild(a_del);
		newbox.firstChild.appendChild(p);
		*/
		newbox.style.cursor = 'pointer';
		newbox.onclick = function()
		{
			snapr_run_tag_editor(this);
		}
	}
	var abs_x = $dynano(newbox).Left();
	var abs_y = $dynano(newbox).Top() + $dynano(newbox).Height() + 2;
	var noteObj = document.createElement('div');
	newbox.noteObj = noteObj;
	noteObj.className = 'snapr_tag';
	noteObj.style.display = 'none';
	noteObj.style.position = 'absolute';
	noteObj.style.top = abs_y + 'px';
	noteObj.style.left = abs_x + 'px';
	noteObj.style.zIndex = '100';
	var re = new RegExp(unescape('%0A'), 'g');
	noteObj.innerHTML = tag.replace(re, "<br />\n");
	obj.appendChild(noteObj);
	if ( initial_hide )
		newbox.style.display = 'none';
	return newbox;
}

function snapr_display_note(note)
{
	//domObjChangeOpac(0, note);
	note.style.display = 'block';
	//domOpacity(note, 0, 100, 500);
}

function snapr_hide_note(note)
{
	//domOpacity(note, 100, 0, 500);
	//setTimeout(function()
	//  {
			note.style.display = 'none';
	//  }, 600);
}

function snapr_nuke_tag(obj)
{
	// add the new box
	var parent_obj = document.getElementById('snapr_preview_img').parentNode;
	var id = parent_obj.getAttribute('snapr:imgid');
	if ( !id )
		return false;
	ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=del_tag&tag_id=' + obj.tag_id, snapr_process_ajax_tag_packet);
}

function snapr_run_tag_editor(obj)
{
	obj.onclick = null;
	var abs_x = $dynano(obj).Left();
	var abs_y = $dynano(obj).Top();
	var height = $dynano(obj).Height() + 2;
	
	var value = obj.nextSibling.innerHTML;
	var regex = new RegExp('<br>', 'g');
	value = value.replace(regex, '');
	obj.parentNode.removeChild(obj.nextSibling);
	
	var entry_div = document.createElement('div');
	entry_div.className = 'snapr_tag_entry';
	entry_div.style.position = 'absolute';
	entry_div.style.top = String(height) + 'px';
	entry_div.style.left = '0px';
	entry_div.style.zIndex = '100';
	
	entry_div.appendChild(document.createTextNode('Enter a tag:'));
	entry_div.appendChild(document.createElement('br'));
	
	var ta = document.createElement('textarea');
	ta.rows = '7';
	ta.cols = '30';
	ta.value = value;
	ta.style.backgroundColor = '#FFFFFF';
	ta.style.borderWidth = '0';
	ta.style.color = '#000000';
	ta.OriginalValue = value;
	entry_div.appendChild(ta);
	
	entry_div.appendChild(document.createElement('br'));
	
	var a_add = document.createElement('a');
	a_add.href = '#';
	a_add.onclick = function()
	{
		snapr_finalize_canvas_edit(this.parentNode.parentNode, this.parentNode.getElementsByTagName('textarea')[0]['value'], this.parentNode);
		return false;
	}
	a_add.appendChild(document.createTextNode('Save tag'));
	entry_div.appendChild(a_add);
	
	entry_div.appendChild(document.createTextNode(' | '));
	
	var a_cancel = document.createElement('a');
	a_cancel.href = '#';
	a_cancel.onclick = function()
	{
		snapr_finalize_canvas_edit_cancel(this.parentNode);
		return false;
	}
	a_cancel.appendChild(document.createTextNode('Cancel'));
	entry_div.appendChild(a_cancel);
	
	entry_div.appendChild(document.createTextNode(' | '));
	
	var a_del = document.createElement('a');
	a_del.href = '#';
	a_del.onclick = function()
	{
		snapr_finalize_canvas_edit_delete(this.parentNode);
		return false;
	}
	a_del.style.color = '#FF0000';
	a_del.appendChild(document.createTextNode('Delete'));
	entry_div.appendChild(a_del);
	
	obj.appendChild(entry_div);
	ta.focus();
}

function snapr_finalize_canvas_edit(canvas, value, editor)
{
	var canvas_data = canvas.canvas;
	var note_id = canvas.tag_id;
	var parent = canvas.parentNode;
	canvas.removeChild(editor);
	parent.removeChild(canvas);
	// send the edit across the 'net
	var parent_obj = document.getElementById('snapr_preview_img').parentNode;
	var id = parent_obj.getAttribute('snapr:imgid');
	if ( !id )
		return false;
	
	var canvas_json = toJSONString(canvas_data);
	ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=edit_tag&tag=' + ajaxEscape(value) + '&canvas_params=' + ajaxEscape(canvas_json) + '&tag_id=' + note_id, snapr_process_ajax_tag_packet);
}

function snapr_process_ajax_tag_packet(ajax)
{
	if ( ajax.readyState == 4 && ajax.status == 200 )
	{
		var response = String(ajax.responseText + '');
		if ( response.substr(0, 1) != '[' && response.substr(0, 1) != '{' )
		{
			new messagebox(MB_OK|MB_ICONSTOP, 'JSON response invalid', 'Received unexpected response:<pre>' + response + '</pre>');
			return false;
		}
		response = parseJSON(response);
		if ( response.mode )
		{
			if ( response.mode == 'error' )
			{
				alert(response.error);
				return false;
			}
		}
		var parent_obj = document.getElementById('snapr_preview_img').parentNode;
		for ( var i = 0; i < response.length; i++ )
		{
			var packet = response[i];
			switch(packet.mode)
			{
				case 'add':
					snapr_draw_note(parent_obj, packet.tag, packet.canvas_data, packet.note_id, packet.initial_hide, packet.auth_delete);
					break;
				case 'remove':
					// Server requested to remove a tag
					var divs = parent_obj.getElementsByTagName('div');
					for ( var i = 0; i < divs.length; i++ )
					{
						var box = divs[i];
						if ( box.className == 'canvasbox' )
						{
							if ( box.tag_id == packet.note_id )
							{
								// You. We have orders to shoot. Stand in front of wall.
								var sibling = box.nextSibling;
								var parent = box.parentNode;
								// BLAM.
								parent.removeChild(sibling);
								parent.removeChild(box);
								break;
							}
						}
					}
					break;
			}
		}
	}
}

// Don't fire the tag init until JS init *and* image are finished.
// Thanks to pmccullough for pointing out this race condition.
var snapr_lock_onload_js = true;
var snapr_lock_onload_img = true;

var snapr_tags_onload_real = function()
{
	// make sure we aren't waiting...
	if ( snapr_lock_onload_img || snapr_lock_onload_js )
		return false;
	
	// add the new box
	var parent_obj = document.getElementById('snapr_preview_img').parentNode;
	var id = parent_obj.getAttribute('snapr:imgid');
	if ( !id )
		return false;
	ajaxPost(makeUrlNS('Gallery', id), 'ajax=true&act=get_tags', snapr_process_ajax_tag_packet);
}

var snapr_tags_onload = function()
{
	snapr_lock_onload_js = false;
	snapr_tags_onload_real();
}

addOnloadHook(snapr_tags_onload);