// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
using System.Collections;
using System.Collections.Generic;
using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Text;
 
namespace Microsoft.CodeAnalysis.ExternalAccess.AspNetCore.EmbeddedLanguages
{
    /// <inheritdoc cref="VirtualCharSequence"/>
    internal readonly struct AspNetCoreVirtualCharSequence
    {
        private readonly VirtualCharSequence _virtualCharSequence;
 
        internal AspNetCoreVirtualCharSequence(VirtualCharSequence virtualCharSequence)
        {
            _virtualCharSequence = virtualCharSequence;
        }
 
        /// <inheritdoc cref="VirtualCharSequence.Empty"/>
        public static readonly AspNetCoreVirtualCharSequence Empty = new(VirtualCharSequence.Empty);
 
        /// <inheritdoc cref="VirtualCharSequence.IsDefault"/>
        public bool IsDefault => _virtualCharSequence.IsDefault;
 
        /// <inheritdoc cref="VirtualCharSequence.Length"/>
        public int Length => _virtualCharSequence.Length;
 
        /// <inheritdoc cref="VirtualCharSequence.this"/>
        public AspNetCoreVirtualChar this[int index] => new(_virtualCharSequence[index]);
 
        /// <inheritdoc cref="VirtualCharSequence.GetSubSequence"/>
        public AspNetCoreVirtualCharSequence GetSubSequence(TextSpan span) => new(_virtualCharSequence.GetSubSequence(span));
 
        /// <inheritdoc cref="VirtualCharSequence.Find"/>
        public AspNetCoreVirtualChar? Find(int position) => (_virtualCharSequence.Find(position) is VirtualChar c) ? new(c) : null;
 
        /// <inheritdoc cref="VirtualCharSequence.CreateString"/>
        public string CreateString() => _virtualCharSequence.CreateString();
 
        /// <inheritdoc cref="VirtualCharSequence.FromBounds"/>
        public static AspNetCoreVirtualCharSequence FromBounds(
            AspNetCoreVirtualCharSequence chars1, AspNetCoreVirtualCharSequence chars2)
            => new(VirtualCharSequence.FromBounds(chars1._virtualCharSequence, chars2._virtualCharSequence));
 
        /// <inheritdoc cref="VirtualCharSequence.IndexOf"/>
        public int IndexOf(AspNetCoreVirtualChar @char)
            => _virtualCharSequence.IndexOf(@char.VirtualChar);
 
        /// <inheritdoc cref="VirtualCharSequence.Contains"/>
        public bool Contains(AspNetCoreVirtualChar @char)
            => _virtualCharSequence.Contains(@char.VirtualChar);
 
        /// <inheritdoc cref="VirtualCharSequence.GetEnumerator"/>
        public Enumerator GetEnumerator()
            => new Enumerator(_virtualCharSequence.GetEnumerator());
 
        /// <inheritdoc cref="VirtualCharSequence.Enumerator"/>
        public struct Enumerator : IEnumerator<AspNetCoreVirtualChar>
        {
            private VirtualCharSequence.Enumerator _enumerator;
 
            public Enumerator(VirtualCharSequence.Enumerator enumerator)
            {
                _enumerator = enumerator;
            }
 
            public bool MoveNext()
                => _enumerator.MoveNext();
 
            public readonly AspNetCoreVirtualChar Current
                => new(_enumerator.Current);
 
            public void Reset()
                => _enumerator.Reset();
 
            readonly object IEnumerator.Current
                => this.Current;
 
            public readonly void Dispose()
                => _enumerator.Dispose();
        }
    }
}