// =============================================================================
// TeslaLauncher — system master volume (shared with vPOD)
// =============================================================================
// The Console's set_VolumeLevel ends here. Setter chain:
//   nircmd.exe (legacy, works everywhere incl. XP, if present in the games dir)
//     → Core Audio (Vista+) → winmm waveOutSetVolume (XP fallback).
//
// Like MiniZip.cs, this file is compiled into BOTH the launcher and vPOD
// (linked source): vPOD's "Actually set system volume" mode applies the
// console's volume commands through the exact code the real pod runs.
// =============================================================================

using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;

namespace Tesla.Launcher
{
    internal static class VolumeControl
    {
        /// <summary>Sets the system master volume to <paramref name="scalar"/>
        /// (clamped to 0.0–1.0). <paramref name="nircmdDir"/> is probed for
        /// nircmd.exe first (the legacy path used on the original pods); the
        /// Windows APIs are the fallback. Never throws.</summary>
        public static void SetMasterScalar(float scalar, string nircmdDir)
        {
            scalar = Math.Max(0f, Math.Min(1f, scalar));

            if (!string.IsNullOrEmpty(nircmdDir))
            {
                var nircmd = Path.Combine(nircmdDir, "nircmd.exe");
                if (File.Exists(nircmd))
                {
                    try
                    {
                        var p = Process.Start(nircmd, "setsysvolume " + (int)(scalar * 65535));
                        if (p != null) p.Dispose();
                        return;
                    }
                    catch { /* fall through to API */ }
                }
            }

            if (Environment.OSVersion.Version.Major >= 6)
            {
                try { CoreAudio.SetMasterScalar(scalar); return; }
                catch { /* fall through */ }
            }

            WinMmVolume.SetMasterScalar(scalar);
        }
    }

    // ── Windows Core Audio API — minimal COM interop (Vista+) ─────────────────
    // No external dependencies. Vtable slot order matches the SDK headers exactly.
    // Methods we don't call are declared as void stubs to preserve vtable offsets.
    // NOT available on XP — callers must gate on OS version.

    internal static class CoreAudio
    {
        internal static void SetMasterScalar(float scalar)
        {
            var ep = GetEndpointVolume();
            try     { var ctx = Guid.Empty; ep.SetMasterVolumeLevelScalar(scalar, ref ctx); }
            finally { Marshal.ReleaseComObject(ep); }
        }

        private static IAudioEndpointVolume GetEndpointVolume()
        {
            var enumerator = (IMMDeviceEnumerator)new MMAudioEnumeratorComClass();
            try
            {
                IMMDevice device;
                enumerator.GetDefaultAudioEndpoint(0 /*eRender*/, 1 /*eMultimedia*/, out device);
                try
                {
                    var iid = typeof(IAudioEndpointVolume).GUID;
                    object obj;
                    device.Activate(ref iid, 23 /*CLSCTX_ALL*/, IntPtr.Zero, out obj);
                    return (IAudioEndpointVolume)obj;
                }
                finally { Marshal.ReleaseComObject(device); }
            }
            finally { Marshal.ReleaseComObject(enumerator); }
        }
    }

    [ComImport, Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
    internal class MMAudioEnumeratorComClass { }

    [Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"),
     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IMMDeviceEnumerator
    {
        void _unused_EnumAudioEndpoints();  // slot 0 — not used
        [PreserveSig]
        int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice endpoint);
    }

    [Guid("D666063F-1587-4E43-81F1-B948E807363F"),
     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IMMDevice
    {
        [PreserveSig]
        int Activate(ref Guid iid, int clsCtx, IntPtr pActivationParams,
            [MarshalAs(UnmanagedType.IUnknown)] out object interfacePointer);
    }

    // Vtable order (after IUnknown): RegisterControlChangeNotify(0),
    // UnregisterControlChangeNotify(1), GetChannelCount(2),
    // SetMasterVolumeLevel(3), SetMasterVolumeLevelScalar(4),
    // GetMasterVolumeLevel(5), GetMasterVolumeLevelScalar(6)
    [Guid("5CDF2C82-841E-4546-9722-0CF74078229A"),
     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IAudioEndpointVolume
    {
        void _unused_RegisterControlChangeNotify();    // slot 0
        void _unused_UnregisterControlChangeNotify();  // slot 1
        void _unused_GetChannelCount();                // slot 2
        [PreserveSig] int SetMasterVolumeLevel(float levelDB, ref Guid ctx);
        [PreserveSig] int SetMasterVolumeLevelScalar(float level, ref Guid ctx);
        [PreserveSig] int GetMasterVolumeLevel(out float levelDB);
        [PreserveSig] int GetMasterVolumeLevelScalar(out float level);
    }

    // ── winmm wave-out volume (XP fallback) ───────────────────────────────────
    // waveOutSetVolume with device -1 sets the wave mixer level of the default
    // device: low 16 bits = left channel, high 16 bits = right channel.

    internal static class WinMmVolume
    {
        [DllImport("winmm.dll")]
        private static extern int waveOutSetVolume(IntPtr hwo, uint dwVolume);

        internal static void SetMasterScalar(float scalar)
        {
            uint level = (uint)(Math.Max(0f, Math.Min(1f, scalar)) * 0xFFFF);
            try { waveOutSetVolume(IntPtr.Zero, (level << 16) | level); } catch { }
        }
    }
}