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

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;

namespace SixLabors.Fonts {
  /// <summary>
  /// Represents a readonly collection of font metrics.
  /// The interface uses compiler pattern matching to provide enumeration capabilities.
  /// </summary>
  internal interface IReadOnlyFontMetricsCollection
  {
      /// <summary>
      /// Gets the specified font metrics matching the given culture and font family name.
      /// </summary>
      /// <param name="name">The font family name.</param>
      /// <param name="culture">The culture to use when searching for a match.</param>
      /// <param name="style">The font style to use when searching for a match.</param>
      /// <param name="metrics">
      /// When this method returns, contains the metrics associated with the specified name,
      /// if the name is found; otherwise, the default value for the type of the family parameter.
      /// This parameter is passed uninitialized.
      /// </param>
      /// <returns>
      /// <see langword="true"/> if the <see cref="IReadOnlyFontMetricsCollection"/> contains font metrics
      /// with the specified name; otherwise, <see langword="false"/>.
      /// </returns>
      /// <exception cref="ArgumentNullException"><paramref name="name"/> is <see langword="null"/></exception>
      public bool TryGetMetrics(string name, CultureInfo culture, FontStyle style, [NotNullWhen(true)] out FontMetrics? metrics);

      /// <summary>
      /// Gets the collection of available font metrics for a given culture and font family name.
      /// </summary>
      /// <param name="name">The font family name.</param>
      /// <param name="culture">The culture to use when searching for a match.</param>
      /// <returns>The <see cref="IEnumerable{FontMetrics}"/>.</returns>
      /// <exception cref="ArgumentNullException"><paramref name="name"/> is <see langword="null"/></exception>
      public IEnumerable<FontMetrics> GetAllMetrics(string name, CultureInfo culture);

      /// <summary>
      /// Gets the collection of available font styles for a given culture and font family name.
      /// </summary>
      /// <param name="name">The font family name.</param>
      /// <param name="culture">The culture to use when searching for a match.</param>
      /// <returns>A read-only memory region containing the available font styles.</returns>
      /// <exception cref="ArgumentNullException"><paramref name="name"/> is <see langword="null"/></exception>
      public ReadOnlyMemory<FontStyle> GetAllStyles(string name, CultureInfo culture);

      /// <inheritdoc cref="IEnumerable{T}.GetEnumerator"/>
      public IEnumerator<FontMetrics> GetEnumerator();
  }
}