using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RailLocalMeter
{
    public class ImageZip
    {
        #region 按比例压缩
        /// <summary>
        /// 将byte转换为图像
        /// </summary>
        /// <param name="Bytes"></param>
        /// <returns></returns>
        public static Bitmap BytesToBitmap(byte[] Bytes)
        {

            if (Bytes.Length == 0 || Bytes.Length == 1)
            {
                return null;
            }
            try
            {
                MemoryStream ImageMem = new MemoryStream(Bytes, true);
                ImageMem.Write(Bytes, 0, Bytes.Length);
                Bitmap _Image = new Bitmap(ImageMem);
                return _Image;
            }
            catch (Exception ex)
            {
                Debug.Print(ex.Message);
                return null;
            }
        }

        /// <summary>
        /// 图像保存转化为数组
        /// </summary>
        /// <param name="strFileName">传入图像文件名称</param>
        /// <returns></returns>
        public static byte[] ZipImageByte(string strImagePath)
        {
            try
            {
                long Dest_Size = 55296;
                Bitmap img = null;
                if (System.IO.File.Exists(strImagePath))
                {
                    img = new Bitmap(strImagePath);
                }
                else
                {
                    return new byte[1];
                }

                MemoryStream bmpStream = new MemoryStream();
                img.Save(bmpStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                if (bmpStream.ToArray().Length < Dest_Size)
                {
                    img.Dispose();
                    return bmpStream.ToArray();
                }
                else
                {
                    ImageFormat __format;
                    System.Drawing.Imaging.Encoder __encoder;
                    EncoderParameter __encoderParameter;
                    EncoderParameters __encoderParameters;
                    ImageCodecInfo __imageCodecInfo;

                    __imageCodecInfo = DoGetEncoderInfo("image/jpeg");

                    __encoder = System.Drawing.Imaging.Encoder.Quality;
                    __encoderParameters = new EncoderParameters(1);

                    long dLevel = 30L;
                    long Len = Dest_Size;

                    __encoderParameter = new EncoderParameter(__encoder, dLevel); //图片质量 
                    __encoderParameters.Param[0] = __encoderParameter;
                    bmpStream = new MemoryStream();
                    img.Save(bmpStream, __imageCodecInfo, __encoderParameters);
                    Len = bmpStream.ToArray().Length;

                    img.Dispose();
                    return bmpStream.ToArray();
                }
            }
            catch (Exception exp)
            {
                Debug.Print(exp.Message);
                return new byte[1];
            }
        }

        /// <summary>
        /// 获取图片文件的编码与解码
        /// </summary>
        /// <param name="MYmimeType"></param>
        /// <returns></returns>
        public static ImageCodecInfo DoGetEncoderInfo(string MYmimeType)
        {
            int i = 0;
            System.Drawing.Imaging.ImageCodecInfo[] encoders = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders();
            for (i = 0; i < encoders.Length; i++)
            {
                if (encoders[i].MimeType == MYmimeType)
                {
                    return encoders[i];
                }
            }
            return null;
        }


        /// <summary>
        /// 图片压缩
        /// </summary>
        /// <param name="imagePath">图片文件路径</param>
        /// <param name="targetFolder">保存位置</param>
        /// <param name="quality">压缩质量</param>
        /// <param name="fileSuffix">压缩后的文件名后缀（防止直接覆盖原文件）</param>
        public static void CompressionImage(Image img, string targetFolder, long quality = 100, string fileSuffix = "compress")
        {
            var fileFullName = targetFolder;

            var imageByte = CompressionImage(img, quality);
            var ms = new MemoryStream(imageByte);
            var image = Image.FromStream(ms);
            image.Save(fileFullName);
            ms.Close();
            ms.Dispose();
            image.Dispose();
        }

        private static byte[] CompressionImage(Image img, long quality)
        {
            using (var bitmap = new Bitmap(img))
            {
                var codecInfo = GetEncoder(img.RawFormat);
                var myEncoder = System.Drawing.Imaging.Encoder.Quality;
                var myEncoderParameters = new EncoderParameters(1);
                var myEncoderParameter = new EncoderParameter(myEncoder, quality);
                myEncoderParameters.Param[0] = myEncoderParameter;
                using (var ms = new MemoryStream())
                {
                    bitmap.Save(ms, codecInfo, myEncoderParameters);
                    myEncoderParameters.Dispose();
                    myEncoderParameter.Dispose();
                    return ms.ToArray();
                }
            }
        }

        private static ImageCodecInfo GetEncoder(ImageFormat format)
        {
            var codecs = ImageCodecInfo.GetImageDecoders();
            return codecs.FirstOrDefault(codec => codec.FormatID == format.Guid);
        }
        #endregion
    }
}