using System;
using System.Collections.Generic;
using System.Linq;
using System.DrawingCore;
using System.DrawingCore.Drawing2D;
using System.DrawingCore.Imaging;
using System.IO;
using Bowin.Common.Utility;

namespace Bowin.Common
{
    public class VerifyCodeHelper
    {
        public static string CreateRandomNum(int length = 5)
        {
            string numberString = "";

            //生成起始序列值
            int seed = unchecked((int)DateTime.Now.Ticks);
            Random rand = new Random();

            //生成随机数字
            for (int i = 0; i < length; i++)
            {
                numberString += rand.Next(0, 10);
            }
            return numberString;
        }

        public static byte[] CreateValidateGraphic(string vcode)
        {
            Bitmap image = new Bitmap((int)Math.Ceiling(vcode.Length * 12.0), 25);
            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", 12, (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(vcode, 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();
            }
        }

        public static VerifyCode GetCode(int length = 5)
        {
            string code = "";
            string codeBase64 = "";

            code = CreateRandomNum(length);

            var bytes = CreateValidateGraphic(code);

            codeBase64 = Convert.ToBase64String(bytes);

            return new VerifyCode { Code = code.MD5(), CodeBase64 = codeBase64 };
        }
    }

    public class VerifyCode
    {
        public string Code { get; set; }
        public string CodeBase64 { get; set; }
    }
}