// ============================================================================
// Copyright © 2026 Hexagon Technology Center GmbH. All Rights Reserved.
// 文件名: ThresholdProcessor.cs
// 描述: 阈值分割算子，用于图像二值化处理
// 功能:
//   - 固定阈值二值化
//   - Otsu自动阈值计算
//   - 可调节阈值和最大值
//   - 将灰度图像转换为二值图像
// 算法: 阈值分割、Otsu算法
// 作者: 李伟 wei.lw.li@hexagon.com
// ============================================================================

using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using XP.ImageProcessing.Core;
using Serilog;

namespace XP.ImageProcessing.Processors;

/// <summary>
/// 阈值分割算子
/// </summary>
public class ThresholdProcessor : ImageProcessorBase
{
    private static readonly ILogger _logger = Log.ForContext<ThresholdProcessor>();

    public ThresholdProcessor()
    {
        Name = LocalizationHelper.GetString("ThresholdProcessor_Name");
        Description = LocalizationHelper.GetString("ThresholdProcessor_Description");
    }

    protected override void InitializeParameters()
    {
        Parameters.Add("MinThreshold", new ProcessorParameter(
            "MinThreshold",
            LocalizationHelper.GetString("ThresholdProcessor_MinThreshold"),
            typeof(int),
            64,
            0,
            255,
            LocalizationHelper.GetString("ThresholdProcessor_MinThreshold_Desc")));

        Parameters.Add("MaxThreshold", new ProcessorParameter(
            "MaxThreshold",
            LocalizationHelper.GetString("ThresholdProcessor_MaxThreshold"),
            typeof(int),
            192,
            0,
            255,
            LocalizationHelper.GetString("ThresholdProcessor_MaxThreshold_Desc")));

        Parameters.Add("UseOtsu", new ProcessorParameter(
            "UseOtsu",
            LocalizationHelper.GetString("ThresholdProcessor_UseOtsu"),
            typeof(bool),
            false,
            null,
            null,
            LocalizationHelper.GetString("ThresholdProcessor_UseOtsu_Desc")));
        _logger.Debug("InitializeParameters");
    }

    public override Image<Gray, byte> Process(Image<Gray, byte> inputImage)
    {
        int minThreshold = GetParameter<int>("MinThreshold");
        int maxThreshold = GetParameter<int>("MaxThreshold");
        bool useOtsu = GetParameter<bool>("UseOtsu");

        var result = new Image<Gray, byte>(inputImage.Size);

        if (useOtsu)
        {
            // 使用Otsu算法
            CvInvoke.Threshold(inputImage, result, minThreshold, 255, ThresholdType.Otsu);
            _logger.Debug("Process: UseOtsu = true");
        }
        else
        {
            // 双阈值分割：介于MinThreshold和MaxThreshold之间的为前景(255)，其他为背景(0)
            byte[,,] inputData = inputImage.Data;
            byte[,,] outputData = result.Data;

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

            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    byte pixelValue = inputData[y, x, 0];
                    outputData[y, x, 0] = (pixelValue >= minThreshold && pixelValue <= maxThreshold)
                        ? (byte)255
                        : (byte)0;
                }
            }

            _logger.Debug("Process: MinThreshold = {MinThreshold}, MaxThreshold = {MaxThreshold}",
                minThreshold, maxThreshold);
        }

        return result;
    }
}