// 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.Diagnostics.CodeAnalysis;
using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
using Microsoft.CodeAnalysis.Text;
using Microsoft.CodeAnalysis.Text.Shared.Extensions;
using Microsoft.VisualStudio.Text;
 
namespace Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 
internal static partial class ITextBufferExtensions
{
    internal static bool IsInLspEditorContext(this ITextBuffer buffer)
    {
        if (buffer.TryGetWorkspace(out var workspace))
        {
            var workspaceContextService = workspace.Services.GetRequiredService<IWorkspaceContextService>();
            return workspaceContextService.IsInLspEditorContext();
        }
 
        return false;
    }
 
    internal static bool TryGetWorkspace(this ITextBuffer buffer, [NotNullWhen(true)] out Workspace? workspace)
        => Workspace.TryGetWorkspace(buffer.AsTextContainer(), out workspace);
 
    /// <summary>
    /// Checks if a buffer supports refactorings.
    /// </summary>
    internal static bool SupportsRefactorings(this ITextBuffer buffer)
        => TryGetSupportsFeatureService(buffer, out var service) && service.SupportsRefactorings(buffer);
 
    /// <summary>
    /// Checks if a buffer supports rename.
    /// </summary>
    internal static bool SupportsRename(this ITextBuffer buffer)
        => TryGetSupportsFeatureService(buffer, out var service) && service.SupportsRename(buffer);
 
    /// <summary>
    /// Checks if a buffer supports code fixes.
    /// </summary>
    internal static bool SupportsCodeFixes(this ITextBuffer buffer)
        => TryGetSupportsFeatureService(buffer, out var service) && service.SupportsCodeFixes(buffer);
 
    /// <summary>
    /// Checks if a buffer supports navigation.
    /// </summary>
    internal static bool SupportsNavigationToAnyPosition(this ITextBuffer buffer)
        => TryGetSupportsFeatureService(buffer, out var service) && service.SupportsNavigationToAnyPosition(buffer);
 
    private static bool TryGetSupportsFeatureService(ITextBuffer buffer, [NotNullWhen(true)] out ITextBufferSupportsFeatureService? service)
    {
        service = null;
        if (buffer.TryGetWorkspace(out var workspace))
        {
            service = workspace.Services.GetService<ITextBufferSupportsFeatureService>();
        }
 
        return service != null;
    }
 
    public static ITextSnapshot ApplyChange(this ITextBuffer buffer, TextChange change)
    {
        if (buffer.Properties.TryGetProperty<IContainedDocument>(typeof(IContainedDocument), out var containedDocument))
        {
            return containedDocument.ApplyChanges([change]);
        }
 
        using var edit = buffer.CreateEdit(EditOptions.DefaultMinimalChange, reiteratedVersionNumber: null, editTag: null);
        edit.Replace(change.Span.ToSpan(), change.NewText);
        return edit.Apply();
    }
 
    public static ITextSnapshot ApplyChanges(this ITextBuffer buffer, IEnumerable<TextChange> changes)
    {
        if (buffer.Properties.TryGetProperty<IContainedDocument>(typeof(IContainedDocument), out var containedDocument))
        {
            return containedDocument.ApplyChanges(changes);
        }
 
        using var edit = buffer.CreateEdit(EditOptions.DefaultMinimalChange, reiteratedVersionNumber: null, editTag: null);
        foreach (var change in changes)
        {
            edit.Replace(change.Span.ToSpan(), change.NewText);
        }
 
        return edit.Apply();
    }
}