// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using SixLabors.ImageSharp.PixelFormats;
using System;
using System.Numerics;

namespace SixLabors.ImageSharp.Drawing.Processing {
  /// <summary>
  /// Represents a logical configuration of a brush which can be used to source pixel colors.
  /// </summary>
  /// <remarks>
  /// A brush creates a <see cref="BrushRenderer{TPixel}"/> that performs the logic for retrieving
  /// pixel values for specific locations.
  /// </remarks>
  public abstract class Brush : IEquatable<Brush>
  {
      /// <summary>
      /// Creates the prepared execution object for this brush.
      /// </summary>
      /// <typeparam name="TPixel">The pixel type.</typeparam>
      /// <param name="configuration">The configuration instance to use when performing operations.</param>
      /// <param name="options">The graphic options.</param>
      /// <param name="canvasWidth">The canvas width for the current render pass.</param>
      /// <param name="region">The region the brush will be applied to.</param>
      /// <returns>
      /// The <see cref="BrushRenderer{TPixel}"/> for this brush.
      /// </returns>
      /// <remarks>
      /// The <paramref name="region" /> when being applied to things like shapes would usually be the
      /// bounding box of the shape not necessarily the bounds of the whole image.
      /// </remarks>
      public abstract BrushRenderer<TPixel> CreateRenderer<TPixel>(
          Configuration configuration,
          GraphicsOptions options,
          int canvasWidth,
          RectangleF region)
          where TPixel : unmanaged, IPixel<TPixel>;

      /// <summary>
      /// Returns a new brush with its defining geometry transformed by the given matrix.
      /// </summary>
      /// <param name="matrix">The transformation matrix to apply.</param>
      /// <returns>A transformed brush, or <c>this</c> if the brush has no spatial parameters.</returns>
      public virtual Brush Transform(Matrix4x4 matrix) => this;

      /// <inheritdoc/>
      public abstract bool Equals(Brush? other);

      /// <inheritdoc/>
      public override bool Equals(object? obj) => this.Equals(obj as Brush);

      /// <inheritdoc/>
      public abstract override int GetHashCode();
  }
}