// 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.Immutable;
using System.Diagnostics;

namespace Microsoft.CodeAnalysis.EditAndContinue;

internal readonly struct DocumentActiveStatementChanges
{
    public readonly ImmutableArray<UnmappedActiveStatement> OldStatements;
    public readonly ImmutableArray<ActiveStatement> NewStatements;
    public readonly ImmutableArray<ImmutableArray<SourceFileSpan>> NewExceptionRegions;

    public DocumentActiveStatementChanges(
        ImmutableArray<UnmappedActiveStatement> oldSpans,
        ImmutableArray<ActiveStatement> newStatements,
        ImmutableArray<ImmutableArray<SourceFileSpan>> newExceptionRegions)
    {
        Contract.ThrowIfFalse(oldSpans.Length == newStatements.Length);
        Contract.ThrowIfFalse(oldSpans.Length == newExceptionRegions.Length);

#if DEBUG
        for (var i = 0; i < oldSpans.Length; i++)
        {
            // old and new exception region counts must match:
            Debug.Assert(oldSpans[i].ExceptionRegions.Spans.Length == newExceptionRegions[i].Length);
        }
#endif

        OldStatements = oldSpans;
        NewStatements = newStatements;
        NewExceptionRegions = newExceptionRegions;
    }

    public void Deconstruct(
        out ImmutableArray<UnmappedActiveStatement> oldStatements,
        out ImmutableArray<ActiveStatement> newStatements,
        out ImmutableArray<ImmutableArray<SourceFileSpan>> newExceptionRegions)
    {
        oldStatements = OldStatements;
        newStatements = NewStatements;
        newExceptionRegions = NewExceptionRegions;
    }
}