var zkSignature = (function () {

	var empty = true;

	return {
		//public functions
		capture: function (){
				var parent = document.getElementById("canvas");
				parent.childNodes[0].nodeValue = "";

				var canvasArea = document.createElement("canvas");
				canvasArea.setAttribute("id", "newSignature");
				parent.appendChild(canvasArea);

				var canvas = document.getElementById("newSignature");
				var context = canvas.getContext("2d");

				if (!context) {
					throw new Error("Failed to get canvas' 2d context");
				}

				canvas.height=canvas.height*1.8;
				  
				context.fillStyle = "#fff";
				context.strokeStyle = "#444";
				context.lineWidth = 1;
				context.lineCap = "round";

				context.fillRect(0, 0, canvas.width, canvas.height);

				context.fillStyle = "#000000";
				context.strokeStyle = "#000000";
				
				
				//context.moveTo((canvas.width * 0.05 ), (canvas.height * 0.9));
				//context.lineTo((canvas.width * 0.95), (canvas.height * 0.9));
			 
				
				context.stroke();

				context.fillStyle = "#fff";
				context.strokeStyle = "#444";
				context.lineWidth = 3;
				var disableSave = true;
				var pixels = [];
				var cpixels = [];
				var xyLast = {};
				var xyAddLast = {};
				var calculate = false;
				//functions
				{
					function remove_event_listeners() {
						canvas.removeEventListener('mousemove', on_mousemove, false);
						canvas.removeEventListener('mouseup', on_mouseup, false);
						canvas.removeEventListener('touchmove', on_mousemove, false);
						canvas.removeEventListener('touchend', on_mouseup, false);

						document.body.removeEventListener('mouseup', on_mouseup, false);
						document.body.removeEventListener('touchend', on_mouseup, false);
					}

					function get_board_coords(e) {
						var x, y;

						if (e.changedTouches && e.changedTouches[0]) {
							var offsety = canvas.offsetTop || 0;
							var offsetx = canvas.offsetLeft || 0;

							x = e.changedTouches[0].pageX - offsetx;
							y = e.changedTouches[0].pageY - offsety;
							 
						} else if (e.layerX || 0 == e.layerX) {
							x = e.layerX;
							y = e.layerY;
						 
						} else if (e.offsetX || 0 == e.offsetX) {
							x = e.offsetX;
							y = e.offsetY;
						}
						 
						x=x*(canvas.width/screen.width);
						y=y*(canvas.width/screen.width);
						return {
							x : x,
							y : y
						};
					};

					function on_mousedown(e) {
						e.preventDefault();
						e.stopPropagation();

						canvas.addEventListener('mousemove', on_mousemove, false);
						canvas.addEventListener('mouseup', on_mouseup, false);
						canvas.addEventListener('touchmove', on_mousemove, false);
						canvas.addEventListener('touchend', on_mouseup, false);

						document.body.addEventListener('mouseup', on_mouseup, false);
						document.body.addEventListener('touchend', on_mouseup, false);

						empty = false;
						var xy = get_board_coords(e);
						
						context.beginPath();
						pixels.push('moveStart');
						
						context.moveTo(xy.x, xy.y);
						pixels.push(xy.x, xy.y);
						xyLast = xy;
					};

					function on_mousemove(e, finish) {
						e.preventDefault();
						e.stopPropagation();

						var xy = get_board_coords(e);
						var xyAdd = {
							x : (xyLast.x + (xy.x)) / 2,
							y : (xyLast.y + (xy.y)) / 2
						};

						if (calculate) {
							var xLast = (xyAddLast.x + xyLast.x + xyAdd.x) / 3;
							var yLast = (xyAddLast.y + xyLast.y + xyAdd.y) / 3;
							pixels.push(xLast, yLast);
						} else {
							calculate = true;
						}

						context.quadraticCurveTo(xyLast.x, xyLast.y, xyAdd.x, xyAdd.y);
						pixels.push(xyAdd.x, xyAdd.y);
						context.stroke();
						context.beginPath();
						context.moveTo(xyAdd.x, xyAdd.y);
						xyAddLast = xyAdd;
						xyLast = xy;

					};

					function on_mouseup(e) {
						remove_event_listeners();
						disableSave = false;
						context.stroke();
						pixels.push('e');
						calculate = false;
					};

				}

				canvas.addEventListener('mousedown', on_mousedown, false);
				canvas.addEventListener('touchstart', on_mousedown, false);

		}
		,
		save : function(){

				var canvas = document.getElementById("newSignature");
				// save canvas image as data url (png format by default)
				var dataURL = canvas.toDataURL("image/png");
				document.getElementById("saveSignature").src = dataURL;

		}
		,
		clear : function(){

				var parent = document.getElementById("canvas");
				var child = document.getElementById("newSignature");
				parent.removeChild(child);
				empty = true;
				this.capture();

		}
		,
		send : function(){

				if (empty == false){

				var canvas = document.getElementById("newSignature");
				var dataURL = canvas.toDataURL("image/png");
				document.getElementById("saveSignature").src = dataURL;
				var sendemail = document.getElementById('sendemail').value;
				var replyemail = document.getElementById('replyemail').value;

				var dataform = document.createElement("form");
				document.body.appendChild(dataform);
				dataform.setAttribute("action","upload_file.php");
				dataform.setAttribute("enctype","multipart/form-data");
				dataform.setAttribute("method","POST");
				dataform.setAttribute("target","_self");
				dataform.innerHTML = '<input type="text" name="image" value="' + dataURL + '"/>' + '<input type="email" name="email" value="' + sendemail + '"/>' + '<input type="email" name="replyemail" value="' + replyemail + '"/>'+'<input type="submit" value="Click me" />';
				dataform.submit();

				}
		}

	}

})()

var zkSignature;