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

namespace MvvmScaffoldFrame48.DLL.ImageAlgorithm
{
    public static class ImageAlgorithmTools
    {
        /// <summary>
        /// 根据ROI裁剪图像
        /// </summary>
        /// <param name="sourceBitmap"></param>
        /// <param name="roi"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentException"></exception>
        public static Bitmap CropBitmap(Bitmap sourceBitmap, Rectangle roi)
        {
            // 检查边界
            if (roi.X < 0 || roi.Y < 0 ||
                roi.Right > sourceBitmap.Width ||
                roi.Bottom > sourceBitmap.Height)
            {
                throw new ArgumentException("ROI区域超出源图像边界");
            }

            // 创建目标位图
            Bitmap result = new Bitmap(roi.Width, roi.Height, sourceBitmap.PixelFormat);

            // 锁定位图数据
            BitmapData sourceData = sourceBitmap.LockBits(
                new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height),
                ImageLockMode.ReadOnly,
                sourceBitmap.PixelFormat);

            BitmapData resultData = result.LockBits(
                new Rectangle(0, 0, result.Width, result.Height),
                ImageLockMode.WriteOnly,
                result.PixelFormat);

            try
            {
                unsafe
                {
                    byte* sourcePtr = (byte*)sourceData.Scan0;
                    byte* resultPtr = (byte*)resultData.Scan0;

                    int pixelSize = Image.GetPixelFormatSize(sourceBitmap.PixelFormat) / 8;
                    int sourceStride = sourceData.Stride;
                    int resultStride = resultData.Stride;

                    for (int y = 0; y < roi.Height; y++)
                    {
                        byte* srcRow = sourcePtr + (roi.Y + y) * sourceStride + roi.X * pixelSize;
                        byte* dstRow = resultPtr + y * resultStride;

                        // 复制一行像素数据
                        for (int x = 0; x < roi.Width * pixelSize; x++)
                        {
                            dstRow[x] = srcRow[x];
                        }
                    }
                }
            }
            finally
            {
                sourceBitmap.UnlockBits(sourceData);
                result.UnlockBits(resultData);
            }

            return result;
        }

        /// <summary>
        /// Bitmap 转 BitmapImage 的辅助方法
        /// </summary>
        /// <param name="bitmap"></param>
        /// <returns></returns>
        public static BitmapImage ConvertToBitmapImage(Bitmap bitmap)
        {
            using (MemoryStream memory = new MemoryStream())
            {
                bitmap.Save(memory, System.Drawing.Imaging.ImageFormat.Png);
                memory.Position = 0;
                var bitmapImage = new BitmapImage();
                bitmapImage.BeginInit();
                bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
                bitmapImage.DecodePixelWidth = 1440; // 设置目标分辨率宽度
                bitmapImage.DecodePixelHeight = 1080; // 保持宽高比
                bitmapImage.StreamSource = memory;
                bitmapImage.EndInit();
                return bitmapImage;
            }
        }
    }
}