//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: Provides an interface to enable positional audio support in Mumble
//
//===========================================================================//

#if defined( WIN32 ) && !defined( _X360 )
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#elif defined( POSIX )
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#endif

#include "cbase.h"
#include "shareddefs.h"
#include "view.h"
#include "mumble.h"

#if !defined( _X360 ) && !defined( NO_STEAM )
#include "steam/isteamuser.h"
#include "steam/steam_api.h"
#endif

const char *COM_GetModDirectory(); // return the mod dir (rather than the complete -game param, which can be a path)

struct MumbleSharedMemory_t
{
#ifdef WIN32
	uint32	uiVersion;
	ulong	uiTick;
#else
	uint32_t uiVersion;
	uint32_t uiTick;
#endif
	float	fAvatarPosition[3];
	float	fAvatarFront[3];
	float	fAvatarTop[3];
	wchar_t	name[256];
	float	fCameraPosition[3];
	float	fCameraFront[3];
	float	fCameraTop[3];
	wchar_t	identity[256];
#ifdef WIN32
	uint32	context_len;
#else
	uint32_t context_len;
#endif
	unsigned char context[256];
	wchar_t description[2048];
};

MumbleSharedMemory_t *g_pMumbleMemory = NULL;
#ifdef WIN32
HANDLE g_hMapObject = NULL;
#endif

ConVar sv_mumble_positionalaudio( "sv_mumble_positionalaudio", "1", FCVAR_REPLICATED, "Allows players using Mumble to have support for positional audio." );

//-----------------------------------------------------------------------------
// Singleton
//-----------------------------------------------------------------------------
static CMumbleSystem g_MumbleSystem;

IGameSystem *MumbleSystem()
{
	return &g_MumbleSystem;
}

bool CMumbleSystem::Init()
{
	m_bHasSetPlayerUniqueId = false;
	m_nTeamSetInUniqueId = 0;
	m_szSteamIDCurrentServer[0] = '\0';
	m_cubSteamIDCurrentServer = 0;

	ListenForGameEvent( "server_spawn" );

	return true;
}

void CMumbleSystem::LevelInitPostEntity()
{
	if ( g_pMumbleMemory )
		return;

#if defined( WIN32 ) && !defined( _X360 )
	g_hMapObject = OpenFileMappingW( FILE_MAP_ALL_ACCESS, FALSE, L"MumbleLink" );
	if ( g_hMapObject == NULL )
		return;

	g_pMumbleMemory = (MumbleSharedMemory_t *) MapViewOfFile( g_hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, sizeof(MumbleSharedMemory_t) );
	if ( g_pMumbleMemory == NULL )
	{
		CloseHandle( g_hMapObject );
		g_hMapObject = NULL;
		return;
	}
#elif defined( POSIX )
	char memname[256];
	V_sprintf_safe( memname, "/MumbleLink.%d", getuid() );

	int shmfd = shm_open( memname, O_RDWR, S_IRUSR | S_IWUSR );

	if ( shmfd < 0 )
	{
		return;
	}

	g_pMumbleMemory = (MumbleSharedMemory_t *)( mmap( NULL, sizeof(struct MumbleSharedMemory_t), PROT_READ | PROT_WRITE, MAP_SHARED, shmfd,0 ) );

	if ( g_pMumbleMemory == (void *)(-1) )
	{
		g_pMumbleMemory = NULL;
		return;
	}
#endif
}

void CMumbleSystem::LevelShutdownPreEntity()
{
#if defined( WIN32 ) && !defined( _X360 )
	if ( g_hMapObject )
	{
		CloseHandle( g_hMapObject );
		g_pMumbleMemory = NULL;
		g_hMapObject = NULL;
	}
#elif defined( POSIX )
	if ( g_pMumbleMemory )
	{
		munmap( g_pMumbleMemory, sizeof(struct MumbleSharedMemory_t) );
		g_pMumbleMemory = NULL;
	}
#endif
}

void VectorToMumbleFloatArray( const Vector &vec, float *rgfl )
{
	// Traditional left-handed coordinate system
	rgfl[0] = vec.x; // X
	rgfl[1] = vec.z; // Y is up
	rgfl[2] = vec.y; // Z is into the screen
}

void CMumbleSystem::PostRender()
{
#ifndef NO_STEAM
	if ( !g_pMumbleMemory || !sv_mumble_positionalaudio.GetBool() )
		return;

	if ( g_pMumbleMemory->uiVersion != 2 )
	{
		V_wcscpy_safe( g_pMumbleMemory->name, L"Source engine: " );
		wchar_t wcsGameDir[MAX_PATH];
		Q_UTF8ToUnicode( COM_GetModDirectory(), wcsGameDir, sizeof(wcsGameDir) );
		V_wcscat_safe( g_pMumbleMemory->name, wcsGameDir );

		V_wcscpy_safe( g_pMumbleMemory->description, L"Links Source engine games to Mumble." );
		g_pMumbleMemory->uiVersion = 2;
	}

	g_pMumbleMemory->uiTick++;

	Vector vecOriginPlayer, vecOriginCamera = MainViewOrigin();
	QAngle anglesPlayer, anglesCamera = MainViewAngles();

	C_BasePlayer *pPlayer = C_BasePlayer::GetLocalPlayer();
	if ( pPlayer )
	{
		vecOriginPlayer = pPlayer->EyePosition();
		anglesPlayer = pPlayer->GetAbsAngles();
	}
	else
	{
		vecOriginPlayer = vecOriginCamera;
		anglesPlayer = anglesCamera;
	}

	anglesPlayer.x = 0;

	Vector vecPlayerForward, vecPlayerUp, vecCameraForward, vecCameraUp;
	AngleVectors( anglesPlayer, &vecPlayerForward, NULL, &vecPlayerUp );
	AngleVectors( anglesCamera, &vecCameraForward, NULL, &vecCameraUp );

	// 1 Source unit is about one inch
	// 1 mumble unit = 1 meter
	vecOriginPlayer *= METERS_PER_INCH;
	vecOriginCamera *= METERS_PER_INCH;

	VectorToMumbleFloatArray( vecPlayerForward, g_pMumbleMemory->fAvatarFront );
	VectorToMumbleFloatArray( vecPlayerUp, g_pMumbleMemory->fAvatarTop );
	VectorToMumbleFloatArray( vecOriginPlayer, g_pMumbleMemory->fAvatarPosition );

	VectorToMumbleFloatArray( vecCameraForward, g_pMumbleMemory->fCameraFront );
	VectorToMumbleFloatArray( vecCameraUp, g_pMumbleMemory->fCameraTop );
	VectorToMumbleFloatArray( vecOriginCamera, g_pMumbleMemory->fCameraPosition );

	if ( pPlayer && m_bHasSetPlayerUniqueId && m_nTeamSetInUniqueId != pPlayer->GetTeamNumber() )
	{
		// Player changed team since we set the unique ID. Set it again.
		m_bHasSetPlayerUniqueId = false;
	}

	if ( !m_bHasSetPlayerUniqueId && steamapicontext && steamapicontext->SteamUser() )
	{
		CSteamID steamid = steamapicontext->SteamUser()->GetSteamID();
		if ( steamid.IsValid() )
		{
			int unTeam = pPlayer ? pPlayer->GetTeamNumber() : 0;
			char szSteamId[256];
			V_sprintf_safe( szSteamId, "universe:%u;account_type:%u;id:%u;instance:%u;team:%d", steamid.GetEUniverse(), steamid.GetEAccountType(), steamid.GetAccountID(), steamid.GetUnAccountInstance(), unTeam );

			wchar_t wcsSteamId[256];
			Q_UTF8ToUnicode( szSteamId, wcsSteamId, sizeof(wcsSteamId) );

			// Identifier which uniquely identifies a certain player in a context.
			V_wcscpy_safe( g_pMumbleMemory->identity, wcsSteamId );

			m_bHasSetPlayerUniqueId = true;
			m_nTeamSetInUniqueId = unTeam;
		}
	}

	// Context should be equal for players which should be able to hear each other positional and
	// differ for those who shouldn't (e.g. it could contain the server+port and team)
	memcpy( g_pMumbleMemory->context, &m_szSteamIDCurrentServer, m_cubSteamIDCurrentServer );
	g_pMumbleMemory->context_len = m_cubSteamIDCurrentServer;
#endif // NO_STEAM
}

void CMumbleSystem::FireGameEvent( IGameEvent *event )
{
#ifndef NO_STEAM
	const char *eventname = event->GetName();

	if ( !eventname || !eventname[0] )
		return;

	if ( !Q_strcmp( "server_spawn", eventname ) )
	{
		V_strcpy_safe( m_szSteamIDCurrentServer, event->GetString( "steamid", "" ) );
		m_cubSteamIDCurrentServer = strlen( m_szSteamIDCurrentServer ) + 1;
	}
#endif // NO_STEAM
}