// ============================================================================
// Copyright © 2026 Hexagon Technology Center GmbH. All Rights Reserved.
// 文件名: IntegralProcessor.cs
// 描述: 积分运算算子，计算积分图像
// 功能:
//   - 计算积分图像（累加和）
//   - 用于快速区域求和
//   - 支持归一化输出
// 算法: 积分图像算法
// 作者: 李伟 wei.lw.li@hexagon.com
// ============================================================================

using Emgu.CV;
using Emgu.CV.Structure;
using XP.ImageProcessing.Core;
using Serilog;
using System.Drawing;

namespace XP.ImageProcessing.Processors;

/// <summary>
/// 积分运算算子
/// </summary>
public class IntegralProcessor : ImageProcessorBase
{
    private static readonly ILogger _logger = Log.ForContext<IntegralProcessor>();

    public IntegralProcessor()
    {
        Name = LocalizationHelper.GetString("IntegralProcessor_Name");
        Description = LocalizationHelper.GetString("IntegralProcessor_Description");
    }

    protected override void InitializeParameters()
    {
        Parameters.Add("Normalize", new ProcessorParameter(
            "Normalize",
            LocalizationHelper.GetString("IntegralProcessor_Normalize"),
            typeof(bool),
            true,
            null,
            null,
            LocalizationHelper.GetString("IntegralProcessor_Normalize_Desc")));

        _logger.Debug("InitializeParameters");
    }

    public override Image<Gray, byte> Process(Image<Gray, byte> inputImage)
    {
        bool normalize = GetParameter<bool>("Normalize");

        int width = inputImage.Width;
        int height = inputImage.Height;

        // 使用double类型避免溢出
        var integralImage = new Image<Gray, double>(width, height);

        // 计算积分图像
        for (int y = 0; y < height; y++)
        {
            for (int x = 0; x < width; x++)
            {
                double sum = inputImage.Data[y, x, 0];

                if (x > 0)
                    sum += integralImage.Data[y, x - 1, 0];
                if (y > 0)
                    sum += integralImage.Data[y - 1, x, 0];
                if (x > 0 && y > 0)
                    sum -= integralImage.Data[y - 1, x - 1, 0];

                integralImage.Data[y, x, 0] = sum;
            }
        }

        var result = integralImage.Convert<Gray, float>();

        if (normalize)
        {
            double minVal = 0, maxVal = 0;
            Point minLoc = new Point();
            Point maxLoc = new Point();
            CvInvoke.MinMaxLoc(result, ref minVal, ref maxVal, ref minLoc, ref maxLoc);

            if (maxVal > minVal)
            {
                result = (result - minVal) * (255.0 / (maxVal - minVal));
            }
        }

        integralImage.Dispose();
        _logger.Debug("Process: Normalize = {Normalize}", normalize);
        return result.Convert<Gray, byte>();
    }
}