// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
#nullable disable
 
using Microsoft.Extensions.EnvironmentAbstractions;
 
namespace Microsoft.DotNet.Cli.BuildServer;
 
internal class RazorPidFile(FilePath path, int processId, FilePath serverPath, string pipeName)
{
    public const string RazorServerType = "rzc";
    public const string FilePrefix = "rzc-";
 
    public FilePath Path { get; } = path;
 
    public int ProcessId = processId;
 
    public FilePath ServerPath { get; } = serverPath;
 
    public string PipeName { get; } = pipeName ?? throw new ArgumentNullException(pipeName);
 
    public static RazorPidFile Read(FilePath path, IFileSystem fileSystem = null)
    {
        fileSystem ??= FileSystemWrapper.Default;
 
        using (var stream = fileSystem.File.OpenFile(
            path.Value,
            FileMode.Open,
            FileAccess.Read,
            FileShare.Write | FileShare.Delete,
            4096,
            FileOptions.None))
        using (var reader = new StreamReader(stream, Encoding.UTF8))
        {
            if (!int.TryParse(reader.ReadLine(), out var processId))
            {
                return null;
            }
 
            if (reader.ReadLine() != RazorServerType)
            {
                return null;
            }
 
            var serverPath = reader.ReadLine();
            if (string.IsNullOrEmpty(serverPath))
            {
                return null;
            }
 
            var pipeName = reader.ReadLine();
            if (string.IsNullOrEmpty(pipeName))
            {
                return null;
            }
 
            return new RazorPidFile(path, processId, new FilePath(serverPath), pipeName);
        }
    }
}