#region

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

#endregion

namespace CSFrameworkV5.Common
{
    /// <summary>
    ///     图片处理
    /// </summary>
    public class CImageLibrary
    {
        /// <summary>
        ///     检查图片返回的结果
        /// </summary>
        public enum ValidateImageResult
        {
            OK,
            InvalidFileSize,
            InvalidImageSize
        }

        /// <summary>
        ///     数组转换为图片
        /// </summary>
        /// .
        /// <param name="bs">数组</param>
        /// <returns></returns>
        public static Image FromBytes(byte[] bs)
        {
            if (bs == null) return null;

            using (var ms = new MemoryStream(bs))
            {
                return Image.FromStream(ms);
            }
        }

        /// <summary>
        ///     获取1x1像素的空图片
        /// </summary>
        /// <returns></returns>
        public static byte[] GetEmptyImageByte()
        {
            Bitmap bmp = null;

            try
            {
                using (bmp = new Bitmap(1, 1))
                {
                    return GetImageBytes(bmp, ImageFormat.Jpeg);
                }
            }
            finally
            {
                if (bmp != null) bmp.Dispose();
            }
        }

        /// <summary>
        ///     图片转换为数组
        /// </summary>
        /// <param name="imageFileName">图片文件</param>
        /// <returns></returns>
        public static byte[] GetImageBytes(string imageFileName,
            ImageFormat format)
        {
            var img = Image.FromFile(imageFileName);
            var bs = GetImageBytes(img, format);
            img.Dispose();
            return bs;
        }

        /// <summary>
        ///     图片转换为数组
        /// </summary>
        /// <param name="img">图片实例</param>
        /// <returns></returns>
        public static byte[] GetImageBytes(Image img, ImageFormat format)
        {
            if (img == null) return null;

            MemoryStream ms = null;
            Bitmap bmp = null;
            try
            {
                using (ms = new MemoryStream())
                {
                    using (bmp = new Bitmap(img))
                    {
                        bmp.Save(ms, format);
                        return ms.ToArray();
                    }
                }
            }
            finally
            {
                if (ms != null) ms.Dispose();

                if (bmp != null) bmp.Dispose();
            }
        }

        /// <summary>
        ///     按宽度比例缩小图片
        /// </summary>
        /// <param name="imgSource">原始图片</param>
        /// <param name="MAX_WIDTH">最大宽度</param>
        /// <returns></returns>
        public static Image ResizeImage(Image imgSource, int MAX_WIDTH,
            int MAX_HEIGHT)
        {
            var imgOutput = imgSource;

            var size = new Size(0, 0); //用于存储按比例计算后的宽和高参数

            if (imgSource.Width <= 3 ||
                imgSource.Height <= 3) return imgSource; //3X3大小的图片不转换

            //按宽度缩放图片
            if (imgSource.Width > MAX_WIDTH) //计算宽度
            {
                var rate = MAX_WIDTH / (double)imgSource.Width; //计算宽度比例因子

                size.Width = Convert.ToInt32(imgSource.Width * rate);
                size.Height = Convert.ToInt32(imgSource.Height * rate);
                imgOutput = imgSource.GetThumbnailImage(size.Width, size.Height,
                    null, IntPtr.Zero);
            }

            //按高度缩放图片
            if (imgOutput.Height > MAX_HEIGHT) //计算高度
            {
                var rate = MAX_HEIGHT / (double)imgOutput.Height; //计算宽度比例因子

                size.Width = Convert.ToInt32(imgOutput.Width * rate);
                size.Height = Convert.ToInt32(imgOutput.Height * rate);
                imgOutput = imgSource.GetThumbnailImage(size.Width, size.Height,
                    null, IntPtr.Zero);
            }

            return imgOutput;
        }

        /// <summary>
        ///     转换为BMP格式
        /// </summary>
        /// <param name="source">原图</param>
        /// <returns>返回BMP格式的图片</returns>
        public static Image ToBMP(Image source, string outFileName)
        {
            try
            {
                source.Save(outFileName, ImageFormat.Bmp);
            }
            catch (Exception ex)
            {
                throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
            }

            if (source.RawFormat == ImageFormat.Bmp)
                return source as Bitmap; //BMP格式不需要转换

            return Image.FromFile(outFileName); //加载存储的BMP文件.
        }

        /// <summary>
        ///     转换为JPG格式
        /// </summary>
        /// <param name="source">原图</param>
        /// <returns>返回JPG格式的图片</returns>
        public static Image ToJPG(Image source, string outFileName)
        {
            try
            {
                source.Save(outFileName, ImageFormat.Jpeg);
            }
            catch (Exception ex)
            {
                throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
            }

            if (source.RawFormat == ImageFormat.Jpeg)
                return source as Bitmap; //BMP格式不需要转换

            return Image.FromFile(outFileName); //加载存储的BMP文件.
        }

        /// <summary>
        ///     转换为PNG格式
        /// </summary>
        /// <param name="source">原图</param>
        /// <returns>返回PNG格式的图片</returns>
        public static Image ToPNG(Image source, string outFileName)
        {
            try
            {
                source.Save(outFileName, ImageFormat.Png);
            }
            catch (Exception ex)
            {
                throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
            }

            if (source.RawFormat == ImageFormat.Png)
                return source as Bitmap; //BMP格式不需要转换

            return Image.FromFile(outFileName); //加载存储的BMP文件.
        }

        /// <summary>
        ///     检查图片文件大小
        /// </summary>
        /// <param name="file">图片文件</param>
        /// <param name="MAX_FILE_SIZE">最大文件大小</param>
        /// <param name="MAX_WIDTH">最大宽度</param>
        /// <param name="MAX_HEIGHT">最大高度</param>
        /// <returns>返回检查结果</returns>
        public static ValidateImageResult ValidateImage(string file,
            int MAX_FILE_SIZE, int MAX_WIDTH, int MAX_HEIGHT)
        {
            var bs = File.ReadAllBytes(file);
            double size = bs.Length / 1024;

            //大于50KB
            if (size > MAX_FILE_SIZE)
                return ValidateImageResult.InvalidFileSize;

            Image img = null;
            try
            {
                img = Image.FromFile(file);
                if (img.Width > MAX_WIDTH || img.Height > MAX_HEIGHT)
                    return ValidateImageResult.InvalidImageSize;
                else
                    return ValidateImageResult.OK;
            }
            finally
            {
                img.Dispose();
            }
        }
    }
}