!(function(window, document) {
	function gverify(options) { //创建一个图形验证码对象，接收options对象为参数
		this.options = { //默认options参数值
			id: "", //容器id
			canvasid: "verifycanvas", //canvas的id
			width: "120", //默认canvas宽度
			height: "30", //默认canvas高度
			type: "letter", //图形验证码默认类型blend:数字字母混合类型、number:纯数字、letter:纯字母
			code: ""
		}
		
		if(object.prototype.tostring.call(options) == "[object object]"){//判断传入参数类型
			for(var i in options) { //根据传入的参数，修改默认参数值
				this.options[i] = options[i];
			}
		}else{
			this.options.id = options;
		}
		
		this.options.numarr = "0,1,2,3,4,5,6,7,8,9".split(",");
		this.options.letterarr = getallletter();

		this._init();
		this.refresh();
	}

	gverify.prototype = {
		/**版本号**/
		version: '1.0.0',
		
		/**初始化方法**/
		_init: function() {
			var con = document.getelementbyid(this.options.id);
			var canvas = document.createelement("canvas");
			this.options.width = con.offsetwidth > 0 ? con.offsetwidth : "120";
			this.options.height = con.offsetheight > 0 ? con.offsetheight : "30";
			canvas.id = this.options.canvasid;
			canvas.width = this.options.width;
			canvas.height = this.options.height;
			canvas.style.cursor = "pointer";
			canvas.innerhtml = "您的浏览器版本不支持canvas";
			con.appendchild(canvas);
			var parent = this;
			canvas.onclick = function(){
				parent.refresh();
			}
		},
		
		/**生成验证码**/
		refresh: function() {
			this.options.code = "";
			var canvas = document.getelementbyid(this.options.canvasid);
			if(canvas.getcontext) {
				var ctx = canvas.getcontext('2d');
			}else{
				return;
			}
			
			ctx.textbaseline = "middle";

			ctx.fillstyle = randomcolor(180, 240);
			ctx.fillrect(0, 0, this.options.width, this.options.height);

			if(this.options.type == "blend") { //判断验证码类型
				var txtarr = this.options.numarr.concat(this.options.letterarr);
			} else if(this.options.type == "number") {
				var txtarr = this.options.numarr;
			} else {
				var txtarr = this.options.letterarr;
			}

			for(var i = 1; i <= 4; i++) {
				var txt = txtarr[randomnum(0, txtarr.length)];
				this.options.code += txt;
				ctx.font = randomnum(this.options.height/2, this.options.height) + 'px simhei'; //随机生成字体大小
				ctx.fillstyle = randomcolor(50, 160); //随机生成字体颜色		
				ctx.shadowoffsetx = randomnum(-3, 3);
				ctx.shadowoffsety = randomnum(-3, 3);
				ctx.shadowblur = randomnum(-3, 3);
				ctx.shadowcolor = "rgba(0, 0, 0, 0.3)";
				var x = this.options.width / 5 * i;
				var y = this.options.height / 2;
				var deg = randomnum(-30, 30);
				/**设置旋转角度和坐标原点**/
				ctx.translate(x, y);
				ctx.rotate(deg * math.pi / 180);
				ctx.filltext(txt, 0, 0);
				/**恢复旋转角度和坐标原点**/
				ctx.rotate(-deg * math.pi / 180);
				ctx.translate(-x, -y);
			}
			/**绘制干扰线**/
			for(var i = 0; i < 2; i++) {
				ctx.strokestyle = randomcolor(40, 180);
				ctx.beginpath();
				ctx.moveto(randomnum(0, this.options.width), randomnum(0, this.options.height));
				ctx.lineto(randomnum(0, this.options.width), randomnum(0, this.options.height));
				ctx.stroke();
			}
			/**绘制干扰点**/
			for(var i = 0; i < this.options.width/4; i++) {
				ctx.fillstyle = randomcolor(0, 255);
				ctx.beginpath();
				ctx.arc(randomnum(0, this.options.width), randomnum(0, this.options.height), 1, 0, 2 * math.pi);
				ctx.fill();
			}
		},
		
		/**验证验证码**/
		validate: function(code){
			var code = code.tolowercase();
			var v_code = this.options.code.tolowercase();
			console.log(v_code);
			if(code == v_code){
				return true;
			}else{
				this.refresh();
				return false;
			}
		}
	}
	/**生成字母数组**/
	function getallletter() {
		var letterstr = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
		return letterstr.split(",");
	}
	/**生成一个随机数**/
	function randomnum(min, max) {
		return math.floor(math.random() * (max - min) + min);
	}
	/**生成一个随机色**/
	function randomcolor(min, max) {
		var r = randomnum(min, max);
		var g = randomnum(min, max);
		var b = randomnum(min, max);
		return "rgb(" + r + "," + g + "," + b + ")";
	}
	window.gverify = gverify;
})(window, document);