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

using System.Runtime.CompilerServices;

namespace SixLabors.PolygonClipper {
  /// <summary>
  /// Provides helper methods for querying <see cref="PathCommand"/> values.
  /// </summary>
  internal static class PathCommandExtensions
  {
      /// <summary>
      /// Returns whether the command emits a vertex coordinate.
      /// </summary>
      /// <param name="command">The command to evaluate.</param>
      /// <returns>
      /// <see langword="true"/> when the command is a vertex-emitting command; otherwise, <see langword="false"/>.
      /// </returns>
      [MethodImpl(MethodImplOptions.AggressiveInlining)]
      public static bool Vertex(this PathCommand command) => command is >= PathCommand.MoveTo and < PathCommand.EndPoly;

      /// <summary>
      /// Returns whether the command is <see cref="PathCommand.Stop"/>.
      /// </summary>
      /// <param name="command">The command to evaluate.</param>
      /// <returns><see langword="true"/> if the command is stop; otherwise, <see langword="false"/>.</returns>
      [MethodImpl(MethodImplOptions.AggressiveInlining)]
      public static bool Stop(this PathCommand command) => command == PathCommand.Stop;

      /// <summary>
      /// Returns whether the command is <see cref="PathCommand.MoveTo"/>.
      /// </summary>
      /// <param name="command">The command to evaluate.</param>
      /// <returns><see langword="true"/> if the command is move-to; otherwise, <see langword="false"/>.</returns>
      [MethodImpl(MethodImplOptions.AggressiveInlining)]
      public static bool MoveTo(this PathCommand command) => command == PathCommand.MoveTo;

      /// <summary>
      /// Returns whether the masked command type is <see cref="PathCommand.EndPoly"/>.
      /// </summary>
      /// <param name="command">The command to evaluate.</param>
      /// <returns><see langword="true"/> if the command type is end-poly; otherwise, <see langword="false"/>.</returns>
      [MethodImpl(MethodImplOptions.AggressiveInlining)]
      public static bool EndPoly(this PathCommand command) => (command & PathCommand.Mask) == PathCommand.EndPoly;

      /// <summary>
      /// Extracts the close-path flag from the command.
      /// </summary>
      /// <param name="command">The command to evaluate.</param>
      /// <returns>The command value masked with <see cref="PathFlags.Close"/>.</returns>
      [MethodImpl(MethodImplOptions.AggressiveInlining)]
      public static int GetCloseFlag(this PathCommand command) => (int)command & (int)PathFlags.Close;
  }
}