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

using SixLabors.ImageSharp.Memory;
using SixLabors.ImageSharp.PixelFormats;
using System;
using System.Collections.Generic;

namespace SixLabors.ImageSharp.Drawing.Processing.Backends {
  /// <summary>
  /// Defines the contract for creating and rendering retained drawing scenes for canvas targets.
  /// </summary>
  public interface IDrawingBackend
  {
      /// <summary>
      /// Creates a retained backend scene from a prepared command batch.
      /// </summary>
      /// <param name="configuration">The active processing configuration.</param>
      /// <param name="targetBounds">The target bounds used for target-dependent scene data.</param>
      /// <param name="commandBatch">The scene commands in submission order.</param>
      /// <param name="ownedResources">The resources that must stay alive for the returned scene.</param>
      /// <returns>A retained backend scene.</returns>
      public DrawingBackendScene CreateScene(
          Configuration configuration,
          Rectangle targetBounds,
          DrawingCommandBatch commandBatch,
          IReadOnlyList<IDisposable>? ownedResources = null);

      /// <summary>
      /// Renders a retained backend scene into the target.
      /// </summary>
      /// <typeparam name="TPixel">The pixel format.</typeparam>
      /// <param name="configuration">The active processing configuration.</param>
      /// <param name="target">The target frame.</param>
      /// <param name="scene">The retained backend scene to render.</param>
      public void RenderScene<TPixel>(
          Configuration configuration,
          ICanvasFrame<TPixel> target,
          DrawingBackendScene scene)
          where TPixel : unmanaged, IPixel<TPixel>;

      /// <summary>
      /// Reads source pixels from the target into the destination region.
      /// </summary>
      /// <typeparam name="TPixel">The pixel format.</typeparam>
      /// <param name="configuration">The active processing configuration.</param>
      /// <param name="target">The target frame.</param>
      /// <param name="sourceRectangle">The source rectangle in target-local coordinates.</param>
      /// <param name="destination">The destination region that receives the copied pixels.</param>
      public void ReadRegion<TPixel>(
          Configuration configuration,
          ICanvasFrame<TPixel> target,
          Rectangle sourceRectangle,
          Buffer2DRegion<TPixel> destination)
          where TPixel : unmanaged, IPixel<TPixel>;
  }
}