SvgColor.cs

using System;
using System.Collections.Generic;

namespace RT.Coordinates;

/// <summary>Describes an SVG color with optional opacity information.</summary>
public struct SvgColor(string color = null, string opacity = null) : IEquatable<SvgColor>
{
    /// <summary>Determines the SVG color, or <c>null</c> to use a default color.</summary>
    public string SvgFillColor { get; private set; } = color;
    /// <summary>Determines the SVG fill opacity, or <c>null</c> to omit the attribute.</summary>
    public string SvgFillOpacity { get; private set; } = opacity;

    /// <inheritdoc/>
    public override readonly bool Equals(object obj) => obj is SvgColor other && SvgFillColor == other.SvgFillColor && SvgFillOpacity == other.SvgFillOpacity;
    /// <inheritdoc/>
    public readonly bool Equals(SvgColor other) => SvgFillColor == other.SvgFillColor && SvgFillOpacity == other.SvgFillOpacity;

    /// <inheritdoc/>
    public override readonly int GetHashCode()
    {
        var hashCode = 1413938657;
        hashCode = unchecked(hashCode * -1521134295 + EqualityComparer<string>.Default.GetHashCode(SvgFillColor));
        hashCode = unchecked(hashCode * -1521134295 + EqualityComparer<string>.Default.GetHashCode(SvgFillOpacity));
        return hashCode;
    }

    /// <summary>Deconstructor.</summary>
    public readonly void Deconstruct(out string color, out string opacity)
    {
        color = SvgFillColor;
        opacity = SvgFillOpacity;
    }

    /// <inheritdoc/>
    public override readonly string ToString() => $"{SvgFillColor}{(SvgFillOpacity == null ? "" : "/")}{SvgFillOpacity}";

    /// <summary>Implicitly converts a string (containing an SVG color) to an opaque <see cref="SvgColor"/>.</summary>
    public static implicit operator SvgColor(string color) => new(color: color);

    /// <summary>Equality operator.</summary>
    public static bool operator ==(SvgColor left, SvgColor right) => left.Equals(right);

    /// <summary>Inequality operator.</summary>
    public static bool operator !=(SvgColor left, SvgColor right) => !left.Equals(right);
}