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

using System;

namespace SixLabors.Fonts.Unicode {
  /// <summary>
  /// Represents a Unicode grapheme cluster and metadata derived while enumerating it.
  /// </summary>
  public readonly ref struct GraphemeCluster
  {
      /// <summary>
      /// Initializes a new instance of the <see cref="GraphemeCluster"/> struct.
      /// </summary>
      /// <param name="span">The UTF-16 span containing the grapheme cluster.</param>
      /// <param name="utf16Offset">The UTF-16 offset of the cluster in the original source.</param>
      /// <param name="codePointCount">The number of Unicode scalar values in the cluster.</param>
      /// <param name="terminalCellWidth">The policy-resolved terminal cell width of the cluster.</param>
      /// <param name="flags">The cluster flags derived while scanning the cluster.</param>
      /// <param name="firstCodePoint">The first code point in the cluster.</param>
      public GraphemeCluster(
          ReadOnlySpan<char> span,
          int utf16Offset,
          int codePointCount,
          int terminalCellWidth,
          GraphemeClusterFlags flags,
          CodePoint firstCodePoint)
      {
          this.Span = span;
          this.Utf16Offset = utf16Offset;
          this.CodePointCount = codePointCount;
          this.Utf16Length = span.Length;
          this.TerminalCellWidth = terminalCellWidth;
          this.Flags = flags;
          this.FirstCodePoint = firstCodePoint;
      }

      /// <summary>
      /// Gets the UTF-16 span containing the grapheme cluster.
      /// </summary>
      public ReadOnlySpan<char> Span { get; }

      /// <summary>
      /// Gets the UTF-16 offset of the cluster in the original source.
      /// </summary>
      public int Utf16Offset { get; }

      /// <summary>
      /// Gets the UTF-16 length of the cluster.
      /// </summary>
      public int Utf16Length { get; }

      /// <summary>
      /// Gets the number of Unicode scalar values in the cluster.
      /// </summary>
      public int CodePointCount { get; }

      /// <summary>
      /// Gets the policy-resolved terminal cell width of the cluster.
      /// </summary>
      public int TerminalCellWidth { get; }

      /// <summary>
      /// Gets the cluster flags derived while scanning the cluster.
      /// </summary>
      public GraphemeClusterFlags Flags { get; }

      /// <summary>
      /// Gets the first code point in the cluster.
      /// </summary>
      public CodePoint FirstCodePoint { get; }
  }
}