// 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.

#nullable enable

// NOTE: This code is derived from an implementation originally in dotnet/runtime:
// https://github.com/dotnet/runtime/blob/v8.0.3/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/IDictionaryDebugView.cs
//
// See the commentary in https://github.com/dotnet/roslyn/pull/50156 for notes on incorporating changes made to the
// reference implementation.

using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace Microsoft.CodeAnalysis.Collections.Internal
{
    internal sealed class IDictionaryDebugView<K, V>
        where K : notnull
    {
        private readonly IDictionary<K, V> _dict;

        public IDictionaryDebugView(IDictionary<K, V> dictionary)
        {
            _dict = dictionary ?? throw new ArgumentNullException(nameof(dictionary));
        }

        [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
        public KeyValuePair<K, V>[] Items
        {
            get
            {
                var items = new KeyValuePair<K, V>[_dict.Count];
                _dict.CopyTo(items, 0);
                return items;
            }
        }
    }

    internal sealed class DictionaryKeyCollectionDebugView<TKey, TValue>
    {
        private readonly ICollection<TKey> _collection;

        public DictionaryKeyCollectionDebugView(ICollection<TKey> collection)
        {
            _collection = collection ?? throw new ArgumentNullException(nameof(collection));
        }

        [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
        public TKey[] Items
        {
            get
            {
                var items = new TKey[_collection.Count];
                _collection.CopyTo(items, 0);
                return items;
            }
        }
    }

    internal sealed class DictionaryValueCollectionDebugView<TKey, TValue>
    {
        private readonly ICollection<TValue> _collection;

        public DictionaryValueCollectionDebugView(ICollection<TValue> collection)
        {
            _collection = collection ?? throw new ArgumentNullException(nameof(collection));
        }

        [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
        public TValue[] Items
        {
            get
            {
                var items = new TValue[_collection.Count];
                _collection.CopyTo(items, 0);
                return items;
            }
        }
    }
}