MyAvaloniaDemo/AuroraDesk.Presentation/Converters/NodeCanvasConverters.cs

using Avalonia.Data.Converters;
using Avalonia.Media;
using Avalonia;
using AuroraDesk.Core.Entities;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;

namespace AuroraDesk.Presentation.Converters;

/// <summary>
/// 节点画布相关转换器
/// </summary>
public static class NodeCanvasConverters
{
    public static readonly IValueConverter BooleanToBorderBrushConverter = new BooleanToBorderBrushConverter();
    public static readonly IValueConverter BooleanToBorderThicknessConverter = new BooleanToBorderThicknessConverter();
    public static readonly IValueConverter NodeToSelectionTextConverter = new NodeToSelectionTextConverter();
    public static readonly IValueConverter IsNotNullConverter = new IsNotNullConverter();
    public static readonly IValueConverter IsNullConverter = new IsNullConverter();
    public static readonly IValueConverter DoubleToStringConverter = new DoubleToStringConverter();
    public static readonly IValueConverter ColorHexToBrushConverter = new ColorHexToBrushConverter();
    public static readonly IValueConverter ColorHexToColorConverter = new ColorHexToColorConverter();
    public static readonly IValueConverter ConnectorAttachmentModeToTextConverter = new ConnectorAttachmentModeToTextConverter();
    public static readonly IValueConverter ConnectionPointsToInputsConverter = new ConnectionPointsToInputsConverter();
    public static readonly IValueConverter ConnectionPointsToOutputsConverter = new ConnectionPointsToOutputsConverter();
    public static readonly IValueConverter ConnectorPlacementToTextConverter = new ConnectorPlacementToTextConverter();
    public static readonly IMultiValueConverter ConnectorPlacementMarginConverter = new ConnectorPlacementMarginConverter();
    public static readonly IValueConverter IndexToDisplayTextConverter = new IndexToDisplayTextConverter();
}

/// <summary>
/// 布尔值到边框颜色转换器（选中时显示蓝色边框）
/// </summary>
public class BooleanToBorderBrushConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool isSelected && isSelected)
        {
            // 使用 StaticResource 的颜色，如果无法获取则使用默认蓝色
            try
            {
                var color = Color.Parse("#3498DB"); // PrimaryBlue
                return new SolidColorBrush(color);
            }
            catch
            {
                return new SolidColorBrush(Color.FromRgb(52, 152, 219)); // #3498DB
            }
        }
        return new SolidColorBrush(Colors.Transparent);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 布尔值到边框厚度转换器（选中时显示边框）
/// </summary>
public class BooleanToBorderThicknessConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool isSelected && isSelected)
        {
            return new Thickness(2);
        }
        return new Thickness(0);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 过滤输入连接点转换器
/// </summary>
public class NodeToSelectionTextConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is Node node)
        {
            return $"已选中1个对象 (节点)";
        }
        return "未选中对象";
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 非空转换器（用于控制可见性）
/// </summary>
public class IsNotNullConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        return value != null;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 空值转换器（用于控制可见性）
/// </summary>
public class IsNullConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        return value == null;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 将附件圆模式枚举转换为中文描述
/// </summary>
public class ConnectorAttachmentModeToTextConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is ConnectorAttachmentMode mode)
        {
            return mode switch
            {
                ConnectorAttachmentMode.None => "不显示",
                ConnectorAttachmentMode.LeftOnly => "仅左侧",
                ConnectorAttachmentMode.RightOnly => "仅右侧",
                ConnectorAttachmentMode.Both => "左右两侧",
                _ => mode.ToString()
            };
        }

        return string.Empty;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 过滤节点输入连接点集合
/// </summary>
public class ConnectionPointsToInputsConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is IEnumerable<ConnectionPoint> points)
        {
            return points
                .Where(p => p.Type == ConnectionPointType.Input)
                .OrderBy(p => p.Index)
                .ToList();
        }

        return Array.Empty<ConnectionPoint>();
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 过滤节点输出连接点集合
/// </summary>
public class ConnectionPointsToOutputsConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is IEnumerable<ConnectionPoint> points)
        {
            return points
                .Where(p => p.Type == ConnectionPointType.Output)
                .OrderBy(p => p.Index)
                .ToList();
        }

        return Array.Empty<ConnectionPoint>();
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 将附件圆定位模式转换为显示文本
/// </summary>
public class ConnectorPlacementToTextConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is ConnectorPlacementMode placement)
        {
            return placement switch
            {
                ConnectorPlacementMode.Inside => "内侧",
                ConnectorPlacementMode.Outside => "外侧",
                _ => placement.ToString()
            };
        }

        return string.Empty;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 根据附件圆定位和尺寸计算 ItemsControl 外边距
/// </summary>
public class ConnectorPlacementMarginConverter : IMultiValueConverter
{
    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
    {
        if (values.Count < 2)
        {
            return new Thickness(0);
        }

        if (values[0] is ConnectorPlacementMode placement && values[1] is double size)
        {
            var side = parameter?.ToString() ?? string.Empty;
            
            // Outside 模式：圆在组件边界外侧
            // Inside 模式：圆在组件边界内侧
            if (placement == ConnectorPlacementMode.Outside)
            {
                return side switch
                {
                    "Left" => new Thickness(-size, 0, 0, 0),  // 左侧外侧：向左移动 size
                    "Right" => new Thickness(0, 0, -size, 0),  // 右侧外侧：使用负右边距
                    _ => new Thickness(0)
                };
            }
            else
            {
                // Inside 模式：不添加额外边距
                return new Thickness(0);
            }
        }

        return new Thickness(0);
    }

    public object? ConvertBack(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// Double 与字符串互转转换器
/// </summary>
public class DoubleToStringConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is double d)
        {
            return d.ToString("0.##", culture);
        }
        return string.Empty;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is string s && double.TryParse(s, NumberStyles.Float, culture, out var result))
        {
            return result;
        }
        return AvaloniaProperty.UnsetValue;
    }
}

/// <summary>
/// 将 Hex 字符串转换为 SolidColorBrush
/// </summary>
public class ColorHexToBrushConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is string hex && !string.IsNullOrWhiteSpace(hex))
        {
            try
            {
                var color = Color.Parse(hex);
                return new SolidColorBrush(color);
            }
            catch
            {
                // ignore parse error
            }
        }
        return new SolidColorBrush(Colors.Transparent);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 将 Hex 字符串与 Avalonia.Media.Color 互转
/// </summary>
public class ColorHexToColorConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is string hex && !string.IsNullOrWhiteSpace(hex))
        {
            try
            {
                return Color.Parse(hex);
            }
            catch
            {
                // ignore parse error
            }
        }

        return Colors.Transparent;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is Color color)
        {
            return $"#{color.R:X2}{color.G:X2}{color.B:X2}";
        }

        return AvaloniaProperty.UnsetValue;
    }
}

/// <summary>
/// 将零基索引转换为显示文本（圆 1、圆 2 ...）
/// </summary>
public class IndexToDisplayTextConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is int index)
        {
            return $"圆 {index + 1}";
        }

        return string.Empty;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}