// 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.Immutable;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using Microsoft.CodeAnalysis.PooledObjects;
 
namespace Microsoft.CodeAnalysis.Editor.EditorConfigSettings.Extensions;
 
internal static class SolutionExtensions
{
    public static ImmutableArray<Project> GetProjectsUnderEditorConfigFile(this Solution solution, string pathToEditorConfigFile)
    {
        var directoryPathToCheck = Path.GetDirectoryName(pathToEditorConfigFile);
        if (directoryPathToCheck is null)
        {
            // we have been given an invalid file path
            return [];
        }
 
        var directoryInfoToCheck = new DirectoryInfo(directoryPathToCheck);
        var builder = ArrayBuilder<Project>.GetInstance();
        foreach (var project in solution.Projects)
        {
            if (!TryGetFolderContainingProject(project, out var projectDirectory))
            {
                // Certain ASP.NET scenarios will create artificial projects that do not exist on disk
                continue;
            }
 
            if (ContainsPath(directoryInfoToCheck, projectDirectory))
            {
                builder.Add(project);
            }
        }
 
        return builder.ToImmutableAndFree();
 
        static bool TryGetFolderContainingProject(Project project, [NotNullWhen(true)] out DirectoryInfo? directoryInfo)
        {
            directoryInfo = null;
            if (project.FilePath is null)
            {
                return false;
            }
 
            var fileDirectoryInfo = new DirectoryInfo(project.FilePath);
            if (fileDirectoryInfo.Parent is null)
            {
                return false;
            }
 
            directoryInfo = fileDirectoryInfo.Parent;
            return true;
        }
 
        static bool ContainsPath(DirectoryInfo directoryContainingEditorConfig, DirectoryInfo projectDirectory)
        {
            if (directoryContainingEditorConfig.FullName == projectDirectory.FullName)
            {
                return true;
            }
 
            // walk up each folder for the project and see if it matches
            // example match:
            // C:\source\roslyn\.editorconfig
            // C:\source\roslyn\src\project.csproj
 
            while (projectDirectory.Parent is not null)
            {
                if (projectDirectory.Parent.FullName == directoryContainingEditorConfig.FullName)
                {
                    return true;
                }
 
                projectDirectory = projectDirectory.Parent;
            }
 
            return false;
        }
    }
}