// 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.Immutable;
using System.Composition;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Text;

namespace Microsoft.CodeAnalysis;

[ExportWorkspaceService(typeof(IDocumentTextDifferencingService), ServiceLayer.Default), Shared]
internal sealed class DefaultDocumentTextDifferencingService : IDocumentTextDifferencingService
{
    [ImportingConstructor]
    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
    public DefaultDocumentTextDifferencingService()
    {
    }

    public Task<ImmutableArray<TextChange>> GetTextChangesAsync(Document oldDocument, Document newDocument, CancellationToken cancellationToken)
        => GetTextChangesAsync(oldDocument, newDocument, TextDifferenceTypes.Word, cancellationToken);

    public async Task<ImmutableArray<TextChange>> GetTextChangesAsync(Document oldDocument, Document newDocument, TextDifferenceTypes preferredDifferenceType, CancellationToken cancellationToken)
    {
        var changes = await newDocument.GetTextChangesAsync(oldDocument, cancellationToken).ConfigureAwait(false);
        return [.. changes];
    }
}