// 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.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Host;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Shared.Extensions;
 
internal static partial class ProjectExtensions
{
    public static TLanguageService? GetLanguageService<TLanguageService>(this Project? project) where TLanguageService : class, ILanguageService
#if CODE_STYLE
        => project?.GetExtendedLanguageServices().GetService<TLanguageService>();
#else
        => project?.Services.GetService<TLanguageService>();
#endif
 
    public static TLanguageService GetRequiredLanguageService<TLanguageService>(this Project project) where TLanguageService : class, ILanguageService
#if CODE_STYLE
        => project.GetExtendedLanguageServices().GetRequiredService<TLanguageService>();
#else
        => project.Services.GetRequiredService<TLanguageService>();
#endif
 
#pragma warning disable RS0030 // Do not used banned API 'Project.LanguageServices', use 'GetExtendedLanguageServices' instead - allow in this helper.
    /// <summary>
    /// Gets extended host language services, which includes language services from <see cref="Project.LanguageServices"/>.
    /// </summary>
    public static HostLanguageServices GetExtendedLanguageServices(this Project project)
#if CODE_STYLE
        => project.Solution.Workspace.Services.GetExtendedLanguageServices(project.Language);
#else
        => project.Solution.Services.GetExtendedLanguageServices(project.Language);
#endif
 
#pragma warning restore RS0030 // Do not used banned APIs
 
    public static string? TryGetAnalyzerConfigPathForProjectConfiguration(this Project project)
        => TryGetAnalyzerConfigPathForProjectOrDiagnosticConfiguration(project, diagnostic: null);
 
    public static string? TryGetAnalyzerConfigPathForDiagnosticConfiguration(this Project project, Diagnostic diagnostic)
    {
        Debug.Assert(diagnostic != null);
        return TryGetAnalyzerConfigPathForProjectOrDiagnosticConfiguration(project, diagnostic);
    }
 
    private static string? TryGetAnalyzerConfigPathForProjectOrDiagnosticConfiguration(Project project, Diagnostic? diagnostic)
    {
        if (project.AnalyzerConfigDocuments.Any())
        {
            var diagnosticFilePath = PathUtilities.GetDirectoryName(diagnostic?.Location.SourceTree?.FilePath ?? project.FilePath);
            if (!PathUtilities.IsAbsolute(diagnosticFilePath))
            {
                return null;
            }
 
            // Currently, we use a simple heuristic to find existing .editorconfig file.
            // We start from the directory of the source file where the diagnostic was reported and walk up
            // the directory tree to find an .editorconfig file.
            // In future, we might change this algorithm, or allow end users to customize it based on options.
 
            var bestPath = string.Empty;
            AnalyzerConfigDocument? bestAnalyzerConfigDocument = null;
            foreach (var analyzerConfigDocument in project.AnalyzerConfigDocuments)
            {
                // Analyzer config documents always have full paths, so GetDirectoryName will not return null.
                var analyzerConfigDirectory = PathUtilities.GetDirectoryName(analyzerConfigDocument.FilePath)!;
                if (diagnosticFilePath.StartsWith(analyzerConfigDirectory) &&
                    analyzerConfigDirectory.Length > bestPath.Length)
                {
                    bestPath = analyzerConfigDirectory;
                    bestAnalyzerConfigDocument = analyzerConfigDocument;
                }
            }
 
            if (bestAnalyzerConfigDocument != null)
            {
                return bestAnalyzerConfigDocument.FilePath;
            }
        }
 
        // Did not find any existing .editorconfig, so create one at root of the solution, if one exists.
        // If project is not part of a solution, then use project path.
        var solutionOrProjectFilePath = project.Solution?.FilePath ?? project.FilePath;
        if (!PathUtilities.IsAbsolute(solutionOrProjectFilePath))
        {
            return null;
        }
 
        var solutionOrProjectDirectoryPath = PathUtilities.GetDirectoryName(solutionOrProjectFilePath);
        // Suppression should be removed or addressed https://github.com/dotnet/roslyn/issues/41636
        return PathUtilities.CombineAbsoluteAndRelativePaths(solutionOrProjectDirectoryPath!, ".editorconfig");
    }
 
    public static AnalyzerConfigDocument? TryGetExistingAnalyzerConfigDocumentAtPath(this Project project, string analyzerConfigPath)
    {
        Debug.Assert(analyzerConfigPath != null);
        Debug.Assert(PathUtilities.IsAbsolute(analyzerConfigPath));
 
        return project.AnalyzerConfigDocuments.FirstOrDefault(d => d.FilePath == analyzerConfigPath);
    }
 
    public static async Task<Compilation> GetRequiredCompilationAsync(this Project project, CancellationToken cancellationToken)
    {
        var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
        if (compilation == null)
        {
            throw new InvalidOperationException(string.Format(WorkspaceExtensionsResources.Compilation_is_required_to_accomplish_the_task_but_is_not_supported_by_project_0, project.Name));
        }
 
        return compilation;
    }
}