// 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.Collections.Generic;
using System.Collections.Immutable;

namespace Microsoft.CodeAnalysis.Differencing;

/// <summary>
/// Calculates Longest Common Subsequence for immutable arrays.
/// </summary>
internal abstract class LongestCommonImmutableArraySubsequence<TElement> : LongestCommonSubsequence<ImmutableArray<TElement>>
{
    protected abstract bool Equals(TElement oldElement, TElement newElement);

    protected sealed override bool ItemsEqual(ImmutableArray<TElement> oldSequence, int oldIndex, ImmutableArray<TElement> newSequence, int newIndex)
        => Equals(oldSequence[oldIndex], newSequence[newIndex]);

    public IEnumerable<SequenceEdit> GetEdits(ImmutableArray<TElement> oldSequence, ImmutableArray<TElement> newSequence)
        => GetEdits(oldSequence, oldSequence.Length, newSequence, newSequence.Length);

    public double ComputeDistance(ImmutableArray<TElement> oldSequence, ImmutableArray<TElement> newSequence)
        => ComputeDistance(oldSequence, oldSequence.Length, newSequence, newSequence.Length);
}