using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Text;
using System.Web;

namespace CommonTool
{
	public class ValidateCode
	{
		public ValidateCode()
		{
			Code = CreateValidateCode(4);
		}

		public string Code { get; }

		/// <summary>
		/// 验证码的最大长度
		/// </summary>
		public int MaxLength => 10;

		/// <summary>
		/// 验证码的最小长度
		/// </summary>
		public int MinLength => 4;

		/// <summary>
		/// 生成验证码
		/// </summary>
		/// <param name="length">指定验证码的长度</param>
		/// <returns></returns>
		public string CreateValidateCode(int length)
		{
			int[] randMembers = new int[length];
			int[] validateNums = new int[length];
			string validateNumberStr = "";
			//生成起始序列值
			int seekSeek = unchecked((int)DateTime.Now.Ticks);
			Random seekRand = new Random(seekSeek);
			int beginSeek = seekRand.Next(0, Int32.MaxValue - length * 10000);
			int[] seeks = new int[length];
			for (int i = 0; i < length; i++)
			{
				beginSeek += 10000;
				seeks[i] = beginSeek;
			}
			//生成随机数字
			for (int i = 0; i < length; i++)
			{
				Random rand = new Random(seeks[i]);
				int pownum = 1 * (int)Math.Pow(10, length);
				randMembers[i] = rand.Next(pownum, Int32.MaxValue);
			}
			//抽取随机数字
			for (int i = 0; i < length; i++)
			{
				string numStr = randMembers[i].ToString();
				int numLength = numStr.Length;
				Random rand = new Random();
				int numPosition = rand.Next(0, numLength - 1);
				validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
			}
			//生成验证码
			for (int i = 0; i < length; i++)
			{
				validateNumberStr += validateNums[i].ToString();
			}
			return validateNumberStr;
		}

		/// <summary>
		/// 创建验证码的图片
		/// </summary>
		/// <param name="validateCode">验证码</param>
		public byte[] CreateValidateGraphic(string validateCode)
		{
			Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
			Graphics g = Graphics.FromImage(image);
			try
			{
				//生成随机生成器
				Random random = new Random();
				//清空图片背景色
				g.Clear(Color.White);
				//画图片的干扰线
				for (int i = 0; i < 25; i++)
				{
					int x1 = random.Next(image.Width);
					int x2 = random.Next(image.Width);
					int y1 = random.Next(image.Height);
					int y2 = random.Next(image.Height);
					g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
				}
				Font font = new Font("Arial", 16, (FontStyle.Bold | FontStyle.Italic));
				LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
				 Color.Blue, Color.DarkRed, 1.2f, true);
				g.DrawString(validateCode, font, brush, 3, 2);
				//画图片的前景干扰点
				for (int i = 0; i < 100; i++)
				{
					int x = random.Next(image.Width);
					int y = random.Next(image.Height);
					image.SetPixel(x, y, Color.FromArgb(random.Next()));
				}
				//画图片的边框线
				g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
				//保存图片数据
				MemoryStream stream = new MemoryStream();
				image.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				return stream.ToArray();
			}
			finally
			{
				g.Dispose();
				image.Dispose();
			}
		}

		/// <summary>
		/// 创建验证码的图片
		/// </summary>
		/// <param name="validateCode">验证码</param>
		/// <param name="context">要输出到的page对象</param>
		public void CreateValidateGraphic(string validateCode, HttpContext context)
		{
			Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
			Graphics g = Graphics.FromImage(image);
			try
			{
				//生成随机生成器
				Random random = new Random();
				//清空图片背景色
				g.Clear(Color.White);
				//画图片的干扰线
				for (int i = 0; i < 25; i++)
				{
					int x1 = random.Next(image.Width);
					int x2 = random.Next(image.Width);
					int y1 = random.Next(image.Height);
					int y2 = random.Next(image.Height);
					g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
				}
				Font font = new Font("Arial", 16, (FontStyle.Bold | FontStyle.Italic));
				LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
				 Color.Blue, Color.DarkRed, 1.2f, true);
				g.DrawString(validateCode, font, brush, 3, 2);
				//画图片的前景干扰点
				for (int i = 0; i < 100; i++)
				{
					int x = random.Next(image.Width);
					int y = random.Next(image.Height);
					image.SetPixel(x, y, Color.FromArgb(random.Next()));
				}
				//画图片的边框线
				g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
				//保存图片数据
				MemoryStream stream = new MemoryStream();
				image.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				context.Response.Clear();
				context.Response.ContentType = "image/jpeg";
				context.Response.BinaryWrite(stream.ToArray());
			}
			finally
			{
				g.Dispose();
				image.Dispose();
			}
		}

		/// <summary>
		/// 得到验证码图片的长度
		/// </summary>
		/// <param name="validateNumLength">验证码的长度</param>
		/// <returns></returns>
		public static int GetImageWidth(int validateNumLength)
		{
			return (int)(validateNumLength * 16.0);
		}
		/// <summary>
		/// 得到验证码的高度
		/// </summary>
		/// <returns></returns>
		public static double GetImageHeight()
		{
			return 24;
		}
	}

	public class ValidateCodePic
	{
		private readonly List<string> _fuHao;
		private readonly List<Color> _color;
		private readonly List<Font> _font;
		private int _x;
		private int _y;
		private readonly int _width;
		private readonly int _height;
		private readonly Random _r = new Random();
		public bool IsExp { get; set; }
		public Bitmap FileBitmap { get; set; }
		public byte[] FileBytes { get; set; }
		public string Code { get; set; }
		public HttpContext Context { get; set; }

		public ValidateCodePic()
		{
			_width = 100;
			_height = 40;
			_fuHao = new List<string>() { "加", "减" };
			_color = new List<Color>() {Color.Red,Color.Black,Color.Blue,Color.Green,
					ColorTranslator.FromHtml("#FF00FF"),
					ColorTranslator.FromHtml("#CD0000"),
					ColorTranslator.FromHtml("#912CEE"),
					ColorTranslator.FromHtml("#00F5FF"),
					ColorTranslator.FromHtml("#00FF00")
			};
			_font = new List<Font>() {
				// ReSharper disable once PossibleLossOfFraction
				new Font("宋体",_width/8,FontStyle.Bold),
				// ReSharper disable once PossibleLossOfFraction
				new Font("楷体",_width/8,FontStyle.Italic),
				// ReSharper disable once PossibleLossOfFraction
				new Font("新宋体",_width/8,FontStyle.Regular)
			};
		}
		/// <summary>
		/// 构造函数重载
		/// </summary>
		/// <param name="isExp">默认 true 公式图片 、falae 字母图片</param>
		/// <param name="width"></param>
		/// <param name="height"></param>
		/// <param name="isByte">默认true返回数据流、false返回图片</param>
		public ValidateCodePic(int width, int height, bool isExp=true,bool isByte=true):this()
		{
			IsExp =isExp;
			_width = width;
			_height = height;

			if (isByte)
			{
				var tempTupleByte = IsExp ? DrawExpByte() : DrawStrByte();
				FileBytes = tempTupleByte.Item1;
				Code = tempTupleByte.Item2;
			}
			else
			{
				var tempTupleBitmap = IsExp ? DrawExpBitmap() : DrawStrBigmap();
				FileBitmap = tempTupleBitmap.Item1;
				Code = tempTupleBitmap.Item2;
			}			
		}

		public ValidateCodePic(HttpContext content,int width, int height, bool isExp = true) : this()
		{
			IsExp = isExp;
			_width = width;
			_height = height;
			Context = content;
			var tempTupleContext = IsExp ? DrawExp(Context) : DrawStr(Context);
			FileBitmap = tempTupleContext.Item1;
			Code = tempTupleContext.Item2;

		}

		//public ValidateCodePic(int width=100, int height=30)
		//{
		//	_width = width;
		//	_height = height;
		//	_fuHao = new List<string>() {"加","减"};
		//	_color = new List<Color>() {Color.Red,Color.Black,Color.Blue,Color.Green,
		//			ColorTranslator.FromHtml("#6A5ACD"),
		//			ColorTranslator.FromHtml("#008B8B"),
		//			ColorTranslator.FromHtml("#556B2F"),
		//			ColorTranslator.FromHtml("#4B0082"),
		//			ColorTranslator.FromHtml("#20B2AA"),
		//			ColorTranslator.FromHtml("#9ACD32"),
		//			ColorTranslator.FromHtml("#B22222"),
		//			ColorTranslator.FromHtml("#BA55D3"),
		//			ColorTranslator.FromHtml("#F0E68C"),
		//			ColorTranslator.FromHtml("#1E90FF")
		//	};
		//	_font = new List<Font>() {
		//		// ReSharper disable once PossibleLossOfFraction
		//		new Font("宋体",width/5,FontStyle.Bold),
		//		// ReSharper disable once PossibleLossOfFraction
		//		new Font("楷体",width/6,FontStyle.Italic),
		//		// ReSharper disable once PossibleLossOfFraction
		//		new Font("新宋体",width/5,FontStyle.Regular)
		//	};

		//}

		public Tuple<byte[], string> DrawStrByte()
		{
			StringBuilder sb = new StringBuilder();
			Bitmap b = GetMap(_width, _height);
			//生成画布
			Graphics g = Graphics.FromImage(b);
			try
			{
				//清空图片背景色
				g.Clear(Color.White);
				//画背景图
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				//画字
				for (int i = 0; i < 4; i++)
				{
					string temp = RandomString();
					sb.Append(temp);
					DrawString(g, temp);
				}
				//画干扰线
				DrawGanRao(g, 40);
				//画干扰点
				DrawGanRaoDian(b, 1000);
				//画图片的边框线
				g.DrawRectangle(new Pen(Color.DarkGray), 0, 0, _width - 1, _height - 1);

				//保存图片数据
				MemoryStream stream = new MemoryStream();
				b.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				return new Tuple<byte[], string>(stream.ToArray(), sb.ToString());
			}
			finally
			{
				g.Dispose();
				b.Dispose();
			}
			
		}
		
		public Tuple<Bitmap, string> DrawStrBigmap()
		{
			StringBuilder sb = new StringBuilder();
			Bitmap b = GetMap(_width, _height);
			//生成画布
			Graphics g = Graphics.FromImage(b);
			try
			{
				//清空图片背景色
				g.Clear(Color.White);
				//画背景图
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				//画字
				for (int i = 0; i < 4; i++)
				{
					string temp = RandomString();
					sb.Append(temp);
					DrawString(g, temp);
				}
				//画干扰线
				DrawGanRao(g, 40);
				//画干扰点
				DrawGanRaoDian(b, 1000);
				
				//输出图片
				return new Tuple<Bitmap, string>(b, sb.ToString());
			}
			finally
			{
				g.Dispose();
				b.Dispose();
			}
			
		}

		public Tuple<Bitmap, string> DrawStr(HttpContext context)
		{
			StringBuilder sb = new StringBuilder();
			Bitmap b = GetMap(_width, _height);
			//生成画布
			Graphics g = Graphics.FromImage(b);
			try
			{
				//清空图片背景色
				g.Clear(Color.White);
				//画背景图
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				//画字
				for (int i = 0; i < 4; i++)
				{
					string temp = RandomString();
					sb.Append(temp);
					DrawString(g, temp);
				}
				//画干扰线
				DrawGanRao(g, 40);
				//画干扰点
				DrawGanRaoDian(b, 1000);
				//画图片的边框线
				g.DrawRectangle(new Pen(Color.DarkGray), 0, 0, _width - 1, _height - 1);

				//保存图片数据
				MemoryStream stream = new MemoryStream();
				b.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				context.Response.Clear();
				context.Response.ContentType = "image/jpeg";
				context.Response.BinaryWrite(stream.ToArray());

			}
			finally 
			{
				g.Dispose();
				b.Dispose();
			}
			return new Tuple<Bitmap, string>(b, sb.ToString());
		}

		private Bitmap GetMap(int width, int height)
		{
			Bitmap b = new Bitmap(width, height);
			return b;
		}
		private string RandomString()
		{
			string s = ((char)_r.Next(65, 90)).ToString();
			return s;
		}
		private void DrawString(Graphics g, string s)
		{
			Font font = _font[RandomToInt(_font.Count)];
			Color color = _color[RandomToInt(_color.Count)];
			_x += _width /6;
			_y = RandomToInt(_height/6);
			g.DrawString(s,
			font,
			new SolidBrush(color),
			new PointF(_x, _y)
			);
			g.RotateTransform(RandomToInt(6));
			
		}
		private void DrawGanRao(Graphics g, int j)
		{
			for (int i = 0; i < j; i++)
			{
				g.DrawLine(new Pen(_color[RandomToInt(_color.Count)]),
				RandomToInt(_width),
				RandomToInt(_height),
				RandomToInt(_width),
				RandomToInt(_height)
				);
			}

		}
		private void DrawGanRaoDian(Bitmap b, int j)
		{
			for (int i = 0; i < j; i++)
			{
				b.SetPixel(RandomToInt(_width),
				RandomToInt(_height),
				_color[RandomToInt(_color.Count)]);
			}

		}
		/// <summary>
		/// 随机字符
		/// </summary>
		/// <returns></returns>
		private int RandomToInt(int i)
		{
			return _r.Next(0, i);
		}

		public Tuple<byte[], string> DrawExpByte()
		{
			int frist = GetString();
			int scoend = GetString();
			string fuhao = _fuHao[RandomToInt(_fuHao.Count)];
			Bitmap b = GetMap(_width, _height);
			Graphics g = Graphics.FromImage(b);
			try
			{
				//清空图片背景色
				g.Clear(Color.White);
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				DrawString(g, frist.ToString());
				DrawString(g, fuhao);
				DrawString(g, scoend.ToString());
				DrawString(g, " = ? ");
				//画图片的边框线
				//g.DrawRectangle(new Pen(Color.CornflowerBlue), 0, 0, _width - 1, _height - 1);
				//保存图片数据
				MemoryStream stream = new MemoryStream();
				b.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				return new Tuple<byte[], string>(stream.ToArray(), GetResult(fuhao, frist, scoend).ToString());
			}
			finally
			{
				g.Dispose();
				b.Dispose();
			}

			
		}

		public Tuple<Bitmap, string> DrawExpBitmap()
		{
			int frist = GetString();
			int scoend = GetString();
			string fuhao = _fuHao[RandomToInt(_fuHao.Count)];
			Bitmap b = GetMap(_width, _height);
			Graphics g = Graphics.FromImage(b);
			try
			{
				//清空图片背景色
				g.Clear(Color.White);
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				DrawString(g, frist.ToString());
				DrawString(g, fuhao);
				DrawString(g, scoend.ToString());
				DrawString(g, " = ? ");
				//画图片的边框线
				//g.DrawRectangle(new Pen(Color.CornflowerBlue), 0, 0, _width - 1, _height - 1);
				//保存图片数据
				MemoryStream stream = new MemoryStream();
				b.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				return new Tuple<Bitmap, string>(b, GetResult(fuhao, frist, scoend).ToString());
			}
			finally
			{
				g.Dispose();
				b.Dispose();
			}
		}

		public Tuple<Bitmap, string> DrawExp(HttpContext context)
		{
			
			int frist = GetString();
			int scoend = GetString();
			string fuhao = _fuHao[RandomToInt(_fuHao.Count)];
			Bitmap b = GetMap(_width, _height);
			Graphics g = Graphics.FromImage(b);
			try
			{
				g.Clear(Color.White);
				g.FillRectangle(Brushes.Gainsboro, 0, 0, _width, _height);
				DrawString(g, frist.ToString());
				DrawString(g, fuhao);
				DrawString(g, scoend.ToString());
				DrawString(g, "=？");
				//画图片的边框线
				g.DrawRectangle(new Pen(Color.DarkGray), 0, 0, _width - 1, _height - 1);
				//保存图片数据
				MemoryStream stream = new MemoryStream();
				b.Save(stream, ImageFormat.Jpeg);
				//输出图片流
				context.Response.Clear();
				context.Response.ContentType = "image/jpeg";
				context.Response.BinaryWrite(stream.ToArray());
			}
			finally
			{
				g.Dispose();
				b.Dispose();
			}
				
			return new Tuple<Bitmap,string>(b, GetResult(fuhao, frist, scoend).ToString());
		}
		/// <summary>
		/// 随机得到数字
		/// </summary>
		/// <returns></returns>
		private int GetString()
		{
			return RandomToInt(50);
		}
		private int GetResult(string fuhao, int frist, int scoend)
		{
			int result = frist + scoend;
			switch (fuhao)
			{
				case "加": result = frist + scoend; break;
				case "减": result = frist - scoend; break;
			}
			return result;
		}
	}
	
}