// 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.
 
#nullable disable
 
using System.IO;
using System.Threading;
using Microsoft.CodeAnalysis.LanguageService;
using Microsoft.CodeAnalysis.Text;
using Microsoft.VisualStudio.Language.Intellisense;
 
namespace Microsoft.CodeAnalysis.Editor.Implementation.Peek;
 
internal static class PeekHelpers
{
    internal static IDocumentPeekResult CreateDocumentPeekResult(string filePath, LinePositionSpan identifierLocation, LinePositionSpan entityOfInterestSpan, IPeekResultFactory peekResultFactory)
    {
        var fileName = Path.GetFileName(filePath);
        var label = string.Format("{0} - ({1}, {2})", fileName, identifierLocation.Start.Line + 1, identifierLocation.Start.Character + 1);
 
        var displayInfo = new PeekResultDisplayInfo(label: label, labelTooltip: filePath, title: fileName, titleTooltip: filePath);
 
        return CreateDocumentPeekResult(
            filePath,
            identifierLocation,
            entityOfInterestSpan,
            displayInfo,
            peekResultFactory,
            isReadOnly: false);
    }
 
    internal static IDocumentPeekResult CreateDocumentPeekResult(string filePath, LinePositionSpan identifierLocation, LinePositionSpan entityOfInterestSpan, PeekResultDisplayInfo displayInfo, IPeekResultFactory peekResultFactory, bool isReadOnly)
    {
        return peekResultFactory.Create(
            displayInfo,
            filePath: filePath,
            startLine: entityOfInterestSpan.Start.Line,
            startIndex: entityOfInterestSpan.Start.Character,
            endLine: entityOfInterestSpan.End.Line,
            endIndex: entityOfInterestSpan.End.Character,
            idLine: identifierLocation.Start.Line,
            idIndex: identifierLocation.Start.Character,
            isReadOnly: isReadOnly);
    }
 
    internal static LinePositionSpan GetEntityOfInterestSpan(ISymbol symbol, Workspace workspace, Location identifierLocation, CancellationToken cancellationToken)
    {
        // This is called on a background thread, but since we don't have proper asynchrony we must block
        var root = identifierLocation.SourceTree.GetRoot(cancellationToken);
        var node = root.FindToken(identifierLocation.SourceSpan.Start).Parent;
 
        var syntaxFactsService = workspace.Services.GetLanguageServices(root.Language).GetService<ISyntaxFactsService>();
 
        switch (symbol.Kind)
        {
            case SymbolKind.Event:
            case SymbolKind.Field:
            case SymbolKind.Method:
            case SymbolKind.Property:
                node = node.FirstAncestorOrSelf<SyntaxNode, ISyntaxFactsService>((node, syntaxFactsService) => syntaxFactsService.IsMethodLevelMember(node), syntaxFactsService) ?? node;
                break;
 
            case SymbolKind.NamedType:
            case SymbolKind.Namespace:
                node = node.FirstAncestorOrSelf<SyntaxNode, ISyntaxFactsService>((node, syntaxFactsService) => syntaxFactsService.IsTopLevelNodeWithMembers(node), syntaxFactsService) ?? node;
                break;
        }
 
        return identifierLocation.SourceTree.GetLocation(node.Span).GetMappedLineSpan().Span;
    }
}