var opera = navigator.userAgent.indexOf('Opera') > -1;
var ie = navigator.userAgent.indexOf('MSIE') > 1 && !opera;
var mozilla = navigator.userAgent.indexOf('Mozilla/5.') == 0 && !opera;

function Xavier(elem_id, target_id, shim_id) {
	this.elem = document.getElementById(elem_id);
	
	this.target = document.getElementById(target_id);
	this.target.style.zIndex = 40001;
	
	/* setup iframe shim for IE6 bug fix */
	this.shim = document.getElementById(shim_id);
	this.shim.style.top = this.target.style.top;
	this.shim.style.left = this.target.style.left;
	this.shim.style.zIndex = this.target.style.zIndex - 1;
		
	this.source = null;
	
	var self = this;
			
	this.separator = '; ';
	this.input_limit = 10000;
	this.display_limit = 10;
	this.selected_class = 'selected';
	this.ajax_matching = false;
	
	this.separator_regex = new RegExp("\\s+", "ig");
	
	this.prev_val = null;
	this.prev_arr = null;
	
	this.item_arr = null;
	this.curr_index = 0;
	
	this.match_arr = null;
	
	this.list_items = null;
	this.selected_index = 0;
	this.list_length = 0;
	
	/* ignore browser's autocomplete for this input */
	this.elem.setAttribute("autocomplete","off");
		
	this.elem.onkeydown = function(e) {
		if (self.list_length > 0) {
			switch (getKeyCode(e)) {
				case 40: /* down */
					self.moveSelection(-1);
					return false;
					break;
				case 38: /* up */
					self.moveSelection(1);
					return false;
					break;
				case 9:  /* tab */
				case 13: /* enter */
					self.insertSelection();
					return false;
					break;
				case 27: /* esc */
					self.reset();
					break;
			}
		}
	}
	
	this.elem.onkeyup = function(e) {
		if (this.shouldHandleEvent(e)) {
			self.handleMatching(this.value);
			this.prev_val = this.value;
		}
	}
	
	this.elem.onblur = function(e) {
		self.reset();
	}
	
	this.elem.shouldHandleEvent = function(e) {
		switch (getKeyCode(e)) { case 9: case 13: case 27: case 38: case 40: return false; break; }
		if (this.prev_val == this.value) { return false; }
		return true;
	}		
	
	this.handleMatching = function(value) {
		this.item_arr = this.getItemArray(value);
		if (this.item_arr.length <= this.input_limit) {
			this.curr_index = this.item_arr.length - 1;
			this.getMatches(this.item_arr[this.curr_index]);
		}
	}
		
	this.getItemArray = function(value) {
		var result_arr = new Array();
		if (this.input_limit > 1) { 
			var arr = value.split(this.separator_regex);
			var curr = null;
			for (var i = 0; i < arr.length; i++) {
				curr = trim(arr[i], ' ');
				if (curr.length > 0) { result_arr.push(curr); }
			}
		} else { 
			result_arr.push(value);
		}
		return result_arr;
	}
	
	this.moveSelection = function(direction) {			
		if (this.list_items && this.list_items.length > 0) {
			var new_index = 0;
			if (direction == -1) { new_index = (this.selected_index < this.list_length - 1) ? this.selected_index + 1 : 0; }
			else if (direction == 1) { new_index = (this.selected_index > 0) ? this.selected_index - 1 : this.list_length - 1; }
			this.setSelection(new_index);
		}
	}
	
	this.setSelection = function(index) {
		if (this.list_items.length > 0) {
			this.list_items.item(this.selected_index).className = '';
			
			this.selected_index = index;
			this.list_items.item(this.selected_index).className = this.selected_class;			
		}
	}
	
	this.insertSelection = function() {
	    if (this.match_arr) {
		    this.insertMatch(this.match_arr[this.selected_index]);
		}
	}
	
	this.getMatches = function(substr) {
		if (this.ajax_matching) { 
			this.getAjaxMatches(substr);
		} else { 
			this.getJavascriptMatches(substr); 
		}
	}
	  	
	this.getAjaxMatches = function(substr) {
		this.source.goGoGadgetAjax(this, substr, this.display_limit);
	}

	this.getJavascriptMatches = function(substr) {
		if (this.source.arr && this.source.arr.length > 0 && substr && substr.length > 0) {
			substr = substr.toLowerCase();
			var result_arr = new Array();
			for (var i = 0; i < this.source.arr.length; i++) {
				if (this.source.arr[i].toLowerCase().indexOf(substr) == 0 && result_arr.length < this.display_limit) { 
					result_arr.push(this.source.arr[i]); 
				}
			}
			this.match_arr = result_arr;
			this.displayMatches(this.match_arr, substr);
		} else {
			this.reset();
		}
	}
	
	this.onSourceUpdate = function(substr) {
		this.getJavascriptMatches(substr);
	}
	
	this.insertMatch = function(match) {
		this.item_arr[this.curr_index] = match;
		this.elem.value = join_items(this.item_arr, this.separator);
		this.moveCursor();
		this.reset();
		this.elem.focus();
	}
		
	this.moveCursor = function() {
		if (ie || opera) {
			var range = this.elem.createTextRange();
			range.move("character", this.elem.value.length);
			range.select();
		}
		this.elem.scrollTop = this.elem.clientHeight;
	}
	
	this.reset = function() {
		this.match_arr = null;
		this.list_items = null;
		this.selected_index = 0;
		this.target.innerHTML = '';
		this.target.style.display = 'none';
		this.shim.style.display = 'none';
	}
	
	this.displayMatches = function(arr, substr) {
		if (arr && arr.length > 0) {
			this.target.innerHTML = '';
			if (this.list_length != arr.length) { this.selected_index = 0; }
			this.list_length = arr.length;
			var substr_reg = new RegExp("(" + substr + ")", "i")
			var ul = document.createElement('ul');
			for (var i = 0; i < this.match_arr.length && i < this.display_limit; i++) {
				ul.appendChild(this.formatMatch(this.match_arr[i], substr_reg, i));
			}
			ul.style.padding = '0px';
			ul.style.margin = '0px';
			ul.style.height = 'auto';
			this.target.appendChild(ul);
			this.target.style.display = 'block';
			this.iframeShim();
			this.list_items = this.target.getElementsByTagName("li");
			this.setSelection(this.selected_index);
		} else {
			this.reset();
		}
	}
	
	this.formatMatch = function(match, substr_reg, index) {
		var li = document.createElement('li');
		li.innerHTML = match.replace(substr_reg, '<span class="substr">' + "$1" + '</span>');
		li.onmousedown = function(e) { self.insertMatch(match); }
		li.onmouseover = function(e) { self.setSelection(index); }
		li.style.margin = '0px';
		return li;
	}
	
	this.iframeShim = function() {
		this.shim.style.width = this.target.offsetWidth;
		this.shim.style.height = this.target.offsetHeight;
		this.shim.style.display = 'block';
	}
}

function XavierSource(for_user, key1, key2) {
	this.for_user = for_user;
	this.key1 = key1;
	this.key2 = key2;
	this.ajaxPage = 'Xavier.aspx';
	
	var self = this;
	
	this.arr = new Array();
   	this.observers = new Array();
   		
	this.add = function(obj) {
		this.observers.push(obj);
		obj.source = this;
	}
	
	this.update = function(value, substr, obj) {
		if (value && value.length > 0) { this.arr = value.split(','); }
		else { this.arr = new Array(); }
		if (obj) { obj.onSourceUpdate(substr); }
		else {
			for (var i = 0; i < this.observers.length; i++) {
				this.observers[i].onSourceUpdate(substr);
			}
		}
	}
	
	this.goGoGadgetAjax = function(obj, substr, limit) {
		var data = 'fu=' + this.for_user + '&key1=' + this.key1 + '&key2=' + this.key2;
		if (substr) data += '&substr=' + substr;
		if (limit) data += '&limit=' + limit;
		submitCallback(data, 'Xavier.aspx', function(success, response_text) { self.update(response_text, substr, obj); });
	}
}

function getKeyCode(e) {
	if (!e) var e = window.event;
	if (e.keyCode) return e.keyCode;
	else if (e.which) return e.which;
	return false;
}

function trim(s, c) {
	if (s) {
		var len = s.length;
		if (len > 0) {
			while (s.substring(0, 1) == c) { s = s.substring(1, len); }
			while (s.substring(len - 1, len) == c) { s = s.substring(0, len - 1); }
		}
	}
	return s;
}

function join_items(arr, separator) {
	var result = '';
	var curr = null;
	var separator_wo_spaces = trim(separator, ' ');
	for (var i = 0; i < arr.length; i++) {
		curr = trim(arr[i], separator_wo_spaces);
		if (curr && curr.length > 0) {
			result += curr + separator;
		}
	}
	return result;
}