Inital commit

src/FocusVolumeControl/AudioHelper.cs

@@ -0,0 +1,63 @@
+using CoreAudio;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace FocusVolumeControl
+{
+    internal class AudioHelper
+    {
+        ActiveAudioSessionWrapper GetSessionForProcess(Process process)
+        {
+            var deviceEnumerator = new MMDeviceEnumerator(Guid.NewGuid());
+
+            using var device = deviceEnumerator.GetDefaultAudioEndpoint(DataFlow.Render, Role.Multimedia);
+            using var manager = device.AudioSessionManager2;
+
+            var sessions = manager.Sessions;
+
+            foreach (var session in sessions)
+            {
+                var audioProcess = Process.GetProcessById((int)session.ProcessID);
+
+                if (session.ProcessID == process.Id || audioProcess?.ProcessName == process.ProcessName)
+                {
+                    var displayName = audioProcess.MainModule.FileVersionInfo.FileDescription;
+                    var path = audioProcess.MainModule.FileName;
+                    return new ActiveAudioSessionWrapper()
+                    {
+                        DisplayName = displayName,
+                        ExecutablePath = path,
+                        Volume = session.SimpleAudioVolume
+                    };
+                }
+            }
+            return null;
+        }
+
+        internal ActiveAudioSessionWrapper GetActiveSession()
+        {
+            const int nChars = 256;
+            IntPtr handle = IntPtr.Zero;
+            StringBuilder Buff = new StringBuilder(nChars);
+            handle = Native.GetForegroundWindow();
+
+            if (handle == IntPtr.Zero)
+            {
+                //todo: return system or something like that?
+                return null;
+            }
+
+            var tid = Native.GetWindowThreadProcessId(handle, out var pid);
+            var process = Process.GetProcessById(pid);
+
+            return GetSessionForProcess(process);
+        }
+
+
+    }
+}