// 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.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
using Microsoft.CodeAnalysis.Text;
using Microsoft.CodeAnalysis.Shared.Extensions;
 
namespace Microsoft.CodeAnalysis.Navigation;
 
internal static class INavigableLocationExtensions
{
    public static async Task<bool> TryNavigateToAsync(
        this INavigableLocation? location, IThreadingContext threadingContext, NavigationOptions options, CancellationToken cancellationToken)
    {
        if (location == null)
            return false;
 
        // This switch is currently unnecessary.  However, it helps support a future where location.NavigateTo becomes
        // async and must be on the UI thread.
        await threadingContext.JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
        return await location.NavigateToAsync(options, cancellationToken).ConfigureAwait(false);
    }
}
 
internal static class IDocumentNavigationServiceExtensions
{
    public static async Task<bool> TryNavigateToSpanAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
    {
        var location = await service.GetLocationForSpanAsync(workspace, documentId, textSpan, allowInvalidSpan, cancellationToken).ConfigureAwait(false);
        return await location.TryNavigateToAsync(threadingContext, options, cancellationToken).ConfigureAwait(false);
    }
 
    public static async Task<bool> TryNavigateToSpanAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, CancellationToken cancellationToken)
    {
        var location = await service.GetLocationForSpanAsync(workspace, documentId, textSpan, cancellationToken).ConfigureAwait(false);
        return await location.TryNavigateToAsync(threadingContext, options, cancellationToken).ConfigureAwait(false);
    }
 
    public static async Task<bool> TryNavigateToSpanAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, TextSpan textSpan, CancellationToken cancellationToken)
    {
        var location = await service.GetLocationForSpanAsync(workspace, documentId, textSpan, cancellationToken).ConfigureAwait(false);
        return await location.TryNavigateToAsync(threadingContext, NavigationOptions.Default, cancellationToken).ConfigureAwait(false);
    }
 
    public static async Task<bool> TryNavigateToPositionAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, int position, int virtualSpace, bool allowInvalidPosition, NavigationOptions options, CancellationToken cancellationToken)
    {
        var location = await service.GetLocationForPositionAsync(workspace, documentId, position, virtualSpace, allowInvalidPosition, cancellationToken).ConfigureAwait(false);
        return await location.TryNavigateToAsync(threadingContext, options, cancellationToken).ConfigureAwait(false);
    }
 
    public static Task<bool> TryNavigateToPositionAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, int position, CancellationToken cancellationToken)
    {
        return service.TryNavigateToPositionAsync(threadingContext, workspace, documentId, position, NavigationOptions.Default, cancellationToken);
    }
 
    public static async Task<bool> TryNavigateToPositionAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, int position, NavigationOptions options, CancellationToken cancellationToken)
    {
        var location = await service.GetLocationForPositionAsync(
            workspace, documentId, position, cancellationToken).ConfigureAwait(false);
        return await location.TryNavigateToAsync(threadingContext, options, cancellationToken).ConfigureAwait(false);
    }
 
    public static async Task<bool> TryNavigateToLineAndOffsetAsync(
        this IDocumentNavigationService service, IThreadingContext threadingContext, Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
    {
        // Navigation should not change the context of linked files and Shared Projects.
        documentId = workspace.GetDocumentIdInCurrentContext(documentId);
 
        var document = workspace.CurrentSolution.GetDocument(documentId);
        if (document is null)
            return false;
 
        // DocumentId+Line+Column come from sources that are not snapshot based.  In other words, the data may
        // correspond to some point in time in the past.  As such, we have to try to clamp it against the current
        // view of the document text.
        var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
 
        var linePosition = new LinePosition(lineNumber, offset);
        var linePositionSpan = new LinePositionSpan(linePosition, linePosition);
        var clampedSpan = linePositionSpan.GetClampedTextSpan(text);
 
        // This operation is fundamentally racey.  Between getting the clamped span and navigating the document may
        // have changed.  So allow for invalid spans here.
        var location = await service.GetLocationForSpanAsync(
            workspace, documentId, clampedSpan, allowInvalidSpan: true, cancellationToken).ConfigureAwait(false);
 
        return location != null && await location.TryNavigateToAsync(threadingContext, options, cancellationToken).ConfigureAwait(false);
    }
}