Toak/Audio/FfmpegAudioRecorder.cs

using System;
using System.Diagnostics;
using System.IO;

using Toak.Core;
using Toak.IO;
using Toak.Core.Interfaces;

namespace Toak.Audio;

public class FfmpegAudioRecorder : IAudioRecorder
{
    private readonly string WavPath = Constants.Paths.RecordingWavFile;
    private readonly IRecordingStateTracker _stateTracker;
    private readonly INotifications _notifications;

    public FfmpegAudioRecorder(IRecordingStateTracker stateTracker, INotifications notifications)
    {
        _stateTracker = stateTracker;
        _notifications = notifications;
    }

    public string GetWavPath() => WavPath;

    public void StartRecording()
    {
        if (File.Exists(WavPath))
        {
            Logger.LogDebug($"Deleting old audio file: {WavPath}");
            File.Delete(WavPath);
        }

        Logger.LogDebug("Starting ffmpeg to record audio...");

        var pInfo = new ProcessStartInfo
        {
            FileName = Constants.Commands.AudioFfmpeg,
            Arguments = $"-f pulse -i default -ac 1 -ar 16000 \"{WavPath}\"",
            UseShellExecute = false,
            CreateNoWindow = true,
            RedirectStandardOutput = true,
            RedirectStandardError = true
        };

        var process = Process.Start(pInfo);
        if (process != null)
        {
            _stateTracker.SetRecording(process.Id);
            _notifications.Notify("Recording Started (FFmpeg)");
        }
    }

    public void StopRecording()
    {
        var pid = _stateTracker.GetRecordingPid();
        if (pid.HasValue)
        {
            Logger.LogDebug($"Found active ffmpeg process with PID {pid.Value}. Attempting to stop...");
            try
            {
                var process = Process.GetProcessById(pid.Value);
                if (!process.HasExited)
                {
                    // Gracefully stop ffmpeg using SIGINT to ensure WAV headers are finalizing cleanly
                    Process.Start(new ProcessStartInfo
                    {
                        FileName = Constants.Commands.ProcessKill,
                        Arguments = $"-INT {pid.Value}",
                        CreateNoWindow = true,
                        UseShellExecute = false
                    })?.WaitForExit();
                    
                    process.WaitForExit(2000); // give it a moment to flush
                }
            }
            catch (Exception ex)
            {
                // Process might already be dead
                Console.WriteLine($"[FfmpegAudioRecorder] Error stopping ffmpeg: {ex.Message}");
            }
            finally
            {
                _stateTracker.ClearRecording();
            }
        }
    }
}