/*
 * COPYRIGHT:            See COPYING in the top level directory
 * PROJECT:              ReactOS kernel
 * FILE:                 lib/opengl32/opengl32.c
 * PURPOSE:              OpenGL32 lib
 * PROGRAMMER:           Anich Gregor (blight), Royce Mitchell III
 * UPDATE HISTORY:
 *                       Feb 1, 2004: Created
 */

#include "opengl32.h"

/* function prototypes */
static void OPENGL32_AppendICD( GLDRIVERDATA *icd );
static void OPENGL32_RemoveICD( GLDRIVERDATA *icd );
static GLDRIVERDATA *OPENGL32_LoadDriver( LPCWSTR regKey );
static DWORD OPENGL32_InitializeDriver( GLDRIVERDATA *icd );
static BOOL OPENGL32_UnloadDriver( GLDRIVERDATA *icd );
static DWORD OPENGL32_RegGetDriverInfo( LPCWSTR driver, GLDRIVERDATA *icd );


/* global vars */
/* Do not assume it have the free value MAXDWORD set, any value can be in here */
DWORD OPENGL32_tls = MAXDWORD;
GLPROCESSDATA OPENGL32_processdata;


static BOOL
OPENGL32_ThreadAttach( void )
{
    GLTHREADDATA* lpData = NULL;
    PROC *dispatchTable = NULL;
    TEB *teb = NULL;

    dispatchTable = (PROC*)HeapAlloc( GetProcessHeap(),
                                      HEAP_GENERATE_EXCEPTIONS | HEAP_ZERO_MEMORY,
                                      sizeof (((ICDTable *)(0))->dispatch_table) );
    if (dispatchTable == NULL)
    {
        DBGPRINT( "Error: Couldn't allocate GL dispatch table" );
        return FALSE;
    }

    lpData = (GLTHREADDATA*)HeapAlloc( GetProcessHeap(),
                                       HEAP_GENERATE_EXCEPTIONS | HEAP_ZERO_MEMORY,
                                       sizeof (GLTHREADDATA) );
    if (lpData == NULL)
    {
        DBGPRINT( "Error: Couldn't allocate GLTHREADDATA" );
        HeapFree( GetProcessHeap(), 0, dispatchTable );
        return FALSE;
    }

    teb = NtCurrentTeb();

    /* initialize dispatch table with empty functions */
    #define X(func, ret, typeargs, args, icdidx, tebidx, stack)            \
        dispatchTable[icdidx] = (PROC)glEmptyFunc##stack;                  \
        if (tebidx >= 0)                                                   \
            teb->glDispatchTable[tebidx] = (PVOID)glEmptyFunc##stack;
    GLFUNCS_MACRO
    #undef X

    teb->glTable = dispatchTable;
    TlsSetValue( OPENGL32_tls, lpData );

    return TRUE;
}


static void
OPENGL32_ThreadDetach( void )
{
    GLTHREADDATA* lpData = NULL;
    PROC *dispatchTable = NULL;

    rosglMakeCurrent( NULL, NULL );

    lpData = (GLTHREADDATA*)TlsGetValue( OPENGL32_tls );
    if (lpData != NULL)
    {
        if (!HeapFree( GetProcessHeap(), 0, lpData ))
            DBGPRINT( "Warning: HeapFree() on GLTHREADDATA failed (%d)",
                      GetLastError() );
        lpData = NULL;
    }

    dispatchTable = NtCurrentTeb()->glTable;
    if (dispatchTable != NULL)
    {
        if (!HeapFree( GetProcessHeap(), 0, dispatchTable ))
            DBGPRINT( "Warning: HeapFree() on dispatch table failed (%d)",
                      GetLastError() );
    }
}


static BOOL
OPENGL32_ProcessAttach( void )
{
    SECURITY_ATTRIBUTES attrib = { sizeof (SECURITY_ATTRIBUTES), /* nLength */
                                   NULL, /* lpSecurityDescriptor */
                                   TRUE /* bInheritHandle */ };

    OPENGL32_tls = TlsAlloc();
    if (OPENGL32_tls == MAXDWORD)
        return FALSE;

    memset( &OPENGL32_processdata, 0, sizeof (OPENGL32_processdata) );

    /* create driver, glrc & dcdata list mutex */
    OPENGL32_processdata.driver_mutex = CreateMutex( &attrib, FALSE, NULL );
    if (OPENGL32_processdata.driver_mutex == NULL)
    {
        DBGPRINT( "Error: Couldn't create driver_list mutex (%d)",
                  GetLastError() );
        return FALSE;
    }
    OPENGL32_processdata.glrc_mutex = CreateMutex( &attrib, FALSE, NULL );
    if (OPENGL32_processdata.glrc_mutex == NULL)
    {
        DBGPRINT( "Error: Couldn't create glrc_list mutex (%d)",
                  GetLastError() );
        return FALSE;
    }
    OPENGL32_processdata.dcdata_mutex = CreateMutex( &attrib, FALSE, NULL );
    if (OPENGL32_processdata.dcdata_mutex == NULL)
    {
        DBGPRINT( "Error: Couldn't create dcdata_list mutex (%d)",
                  GetLastError() );
        return FALSE;
    }

    return TRUE;
}


static void
OPENGL32_ProcessDetach( void )
{
    GLDRIVERDATA *icd, *icd2;
    GLDCDATA *dcdata, *dcdata2;
    GLRC *glrc, *glrc2;

    /* free lists */
    for (dcdata = OPENGL32_processdata.dcdata_list; dcdata != NULL;)
    {
        dcdata2 = dcdata;
        dcdata = dcdata->next;
        if (!HeapFree( GetProcessHeap(), 0, dcdata2 ))
            DBGPRINT( "Warning: HeapFree() on DCDATA 0x%08x failed (%d)",
                      dcdata2, GetLastError() );
    }

    for (glrc = OPENGL32_processdata.glrc_list; glrc != NULL;)
    {
        glrc2 = glrc;
        glrc = glrc->next;
        if (!HeapFree( GetProcessHeap(), 0, glrc2 ))
            DBGPRINT( "Warning: HeapFree() on GLRC 0x%08x failed (%d)",
                      glrc2, GetLastError() );
    }

    for (icd = OPENGL32_processdata.driver_list; icd != NULL;)
    {
        icd2 = icd;
        icd = icd->next;
        if (!HeapFree( GetProcessHeap(), 0, icd2 ))
            DBGPRINT( "Warning: HeapFree() on DRIVERDATA 0x%08x failed (%d)",
                      icd2, GetLastError() );
    }

    /* free mutexes */
    if (OPENGL32_processdata.driver_mutex != NULL)
        CloseHandle( OPENGL32_processdata.driver_mutex );
    if (OPENGL32_processdata.glrc_mutex != NULL)
        CloseHandle( OPENGL32_processdata.glrc_mutex );
    if (OPENGL32_processdata.dcdata_mutex != NULL)
        CloseHandle( OPENGL32_processdata.dcdata_mutex );

    /* free TLS */
    if (OPENGL32_tls != MAXDWORD)
        TlsFree(OPENGL32_tls);
}


BOOL WINAPI
DllMain(HINSTANCE hInstance, DWORD Reason, LPVOID Reserved)
{
    DBGPRINT( "Info: Called!" );
    switch ( Reason )
    {
    /* The DLL is loading due to process
     * initialization or a call to LoadLibrary.
     */
    case DLL_PROCESS_ATTACH:
        DBGTRACE( "Process attach" );
        if (!OPENGL32_ProcessAttach())
            return FALSE;
        /* No break: Initialize the index for first thread. */

    /* The attached process creates a new thread. */
    case DLL_THREAD_ATTACH:
        DBGTRACE( "Thread attach" );
        if (!OPENGL32_ThreadAttach())
            return FALSE;
        break;

    /* The thread of the attached process terminates. */
    case DLL_THREAD_DETACH:
        DBGTRACE( "Thread detach" );
        /* Release the allocated memory for this thread.*/
        OPENGL32_ThreadDetach();
        break;

    /* DLL unload due to process termination or FreeLibrary. */
    case DLL_PROCESS_DETACH:
        DBGTRACE( "Process detach" );
        OPENGL32_ThreadDetach();
        OPENGL32_ProcessDetach();
        break;
    }

    return TRUE;
}


/*! \brief Append ICD to linked list.
 *
 * \param icd  GLDRIVERDATA to append to list
 *
 * \note Only call this when you hold the driver_mutex.
 */
static void
OPENGL32_AppendICD( GLDRIVERDATA *icd )
{
    if (OPENGL32_processdata.driver_list == NULL)
        OPENGL32_processdata.driver_list = icd;
    else
    {
        GLDRIVERDATA *p = OPENGL32_processdata.driver_list;
        while (p->next != NULL)
            p = p->next;
        p->next = icd;
    }
}


/*! \brief Remove ICD from linked list.
 *
 * \param icd  GLDRIVERDATA to remove from list
 *
 * \note Only call this when you hold the driver_mutex.
 */
static void
OPENGL32_RemoveICD( GLDRIVERDATA *icd )
{
    if (icd == OPENGL32_processdata.driver_list)
        OPENGL32_processdata.driver_list = icd->next;
    else
    {
        GLDRIVERDATA *p = OPENGL32_processdata.driver_list;
        while (p != NULL)
        {
            if (p->next == icd)
            {
                p->next = icd->next;
                return;
            }
            p = p->next;
        }
        DBGPRINT( "Error: ICD 0x%08x not found in list!", icd );
    }
}


/*! \brief  Load an ICD.
 *
 * \param driver  Name of installable client driver.
 *
 * \return Pointer to an allocated GLDRIVERDATA struct.
 * \retval NULL  Failure.
 *
 * \todo Call SetLastError() where appropriate.
 */
static GLDRIVERDATA *
OPENGL32_LoadDriver( LPCWSTR driver )
{
    LONG ret;
    GLDRIVERDATA *icd;

    DBGPRINT( "Info: Loading driver %ws...", driver );

    /* allocate driver data */
    icd = (GLDRIVERDATA*)HeapAlloc( GetProcessHeap(),
                                    HEAP_GENERATE_EXCEPTIONS | HEAP_ZERO_MEMORY,
                                    sizeof (GLDRIVERDATA) );
    if (icd == NULL)
    {
        DBGPRINT( "Error: Couldn't allocate GLDRIVERDATA! (%d)", GetLastError() );
        return NULL;
    }

    ret = OPENGL32_RegGetDriverInfo( driver, icd );
    if (ret != ERROR_SUCCESS)
    {
        DBGPRINT( "Error: Couldn't query driver information (%d)", ret );
        if (!HeapFree( GetProcessHeap(), 0, icd ))
            DBGPRINT( "Error: HeapFree() returned false, error code = %d",
                      GetLastError() );
        return NULL;
    }

    DBGPRINT( "Info: Dll = %ws", icd->dll );
    DBGPRINT( "Info: Version = 0x%08x", icd->version );
    DBGPRINT( "Info: DriverVersion = 0x%08x", icd->driver_version );
    DBGPRINT( "Info: Flags = 0x%08x", icd->flags );

    /* load/initialize ICD */
    ret = OPENGL32_InitializeDriver( icd );
    if (ret != ERROR_SUCCESS)
    {
        DBGPRINT( "Error: Couldnt initialize ICD!" );
        if (!HeapFree( GetProcessHeap(), 0, icd ))
            DBGPRINT( "Error: HeapFree() returned false, error code = %d",
                      GetLastError() );
        return NULL;
    }

    /* append ICD to list */
    OPENGL32_AppendICD( icd );
    DBGPRINT( "Info: ICD loaded." );

    return icd;
}


/*! \brief Initialize a driver (Load DLL and DrvXxx procs)
 *
 * \param icd  ICD to initialize with the dll, version, driverVersion
 *             and flags already filled.
 * \return Error code.
 * \retval ERROR_SUCCESS  Success
 */
#define LOAD_DRV_PROC( icd, proc, required ) \
    *(char**)&icd->proc = (char*)GetProcAddress( icd->handle, #proc ); \
    if (required && icd->proc == NULL) { \
        DBGPRINT( "Error: GetProcAddress(\"%s\") failed!", #proc ); \
        FreeLibrary( icd->handle ); \
        return GetLastError(); \
    }

static DWORD
OPENGL32_InitializeDriver( GLDRIVERDATA *icd )
{
    /* check version */
    if (icd->version > 2)
        DBGPRINT( "Warning: ICD version > 2 (%d)", icd->version );

    /* load dll */
    icd->handle = LoadLibraryW( icd->dll );
    if (icd->handle == NULL)
    {
        DWORD err = GetLastError();
        DBGPRINT( "Error: Couldn't load DLL! (%d)", err );
        return err;
    }

    /* validate version */
    if (icd->driver_version > 1)
    {
        LOAD_DRV_PROC(icd, DrvValidateVersion, FALSE);
        if (icd->DrvValidateVersion != NULL)
        {
            if (!icd->DrvValidateVersion( icd->driver_version ))
            {
                DBGPRINT( "Error: DrvValidateVersion failed!" );
                DBGBREAK();
                FreeLibrary( icd->handle );
                return ERROR_INVALID_FUNCTION; /* FIXME: use better error code */
            }
        }
        else
            DBGPRINT( "Info: DrvValidateVersion not exported by ICD" );
    }

    /* load DrvXXX procs */
    LOAD_DRV_PROC(icd, DrvCopyContext, TRUE);
    LOAD_DRV_PROC(icd, DrvCreateContext, FALSE);
    LOAD_DRV_PROC(icd, DrvCreateLayerContext, FALSE);
    LOAD_DRV_PROC(icd, DrvDeleteContext, TRUE);
    LOAD_DRV_PROC(icd, DrvDescribeLayerPlane, TRUE);
    LOAD_DRV_PROC(icd, DrvDescribePixelFormat, TRUE);
    LOAD_DRV_PROC(icd, DrvGetLayerPaletteEntries, TRUE);
    LOAD_DRV_PROC(icd, DrvGetProcAddress, TRUE);
    LOAD_DRV_PROC(icd, DrvReleaseContext, TRUE);
    LOAD_DRV_PROC(icd, DrvRealizeLayerPalette, TRUE);
    LOAD_DRV_PROC(icd, DrvSetContext, TRUE);
    LOAD_DRV_PROC(icd, DrvSetLayerPaletteEntries, TRUE);
    LOAD_DRV_PROC(icd, DrvSetPixelFormat, TRUE);
    LOAD_DRV_PROC(icd, DrvShareLists, TRUE);
    LOAD_DRV_PROC(icd, DrvSwapBuffers, TRUE);
    LOAD_DRV_PROC(icd, DrvSwapLayerBuffers, TRUE);

    /* we require at least one of DrvCreateContext and DrvCreateLayerContext */
    if (icd->DrvCreateContext == NULL && icd->DrvCreateLayerContext == NULL)
    {
        DBGPRINT( "Error: One of DrvCreateContext/DrvCreateLayerContext is required!" );
        FreeLibrary( icd->handle );
        return ERROR_INVALID_FUNCTION; /* FIXME: use better error code... */
    }

    return ERROR_SUCCESS;
}


/*! \brief Unload ICD.
 *
 * \retval  TRUE  Success.
 * \retval  FALSE Failure.
 */
static BOOL
OPENGL32_UnloadDriver( GLDRIVERDATA *icd )
{
    BOOL allOk = TRUE;

    DBGPRINT( "Info: Unloading driver %ws...", icd->driver_name );
    if (icd->refcount != 0)
        DBGPRINT( "Warning: ICD refcount = %d (should be 0)", icd->refcount );

    /* unload dll */
    if (!FreeLibrary( icd->handle ))
    {
        allOk = FALSE;
        DBGPRINT( "Warning: FreeLibrary on ICD %ws failed! (%d)", icd->dll,
                  GetLastError() );
    }

    /* free resources */
    OPENGL32_RemoveICD( icd );
    if (!HeapFree( GetProcessHeap(), 0, icd ))
    {
        allOk = FALSE;
        DBGPRINT( "Warning: HeapFree() returned FALSE, error code = %d",
                  GetLastError() );
    }

    return allOk;
}


/*! \brief Load ICD (shared ICD data)
 *
 * \return Pointer to an allocated GLDRIVERDATA on success.
 * \retval NULL  Failure.
 */
GLDRIVERDATA *
OPENGL32_LoadICD( LPCWSTR driver )
{
    GLDRIVERDATA *icd;

    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.driver_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return NULL; /* FIXME: do we have to expect such an error and handle it? */
    }

    /* look if ICD is already loaded */
    for (icd = OPENGL32_processdata.driver_list; icd; icd = icd->next)
    {
        if (!_wcsicmp( driver, icd->driver_name )) /* found */
        {
            /* release mutex */
            if (!ReleaseMutex( OPENGL32_processdata.driver_mutex ))
                DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );

            return icd;
        }
    }

    /* not found - try to load */
    icd = OPENGL32_LoadDriver( driver );

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.driver_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );

    return icd;
}


/*! \brief Unload ICD (shared ICD data)
 *
 * \retval TRUE   Success.
 * \retval FALSE  Failure.
 */
BOOL
OPENGL32_UnloadICD( GLDRIVERDATA *icd )
{
    BOOL ret = TRUE;

    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.driver_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return FALSE; /* FIXME: do we have to expect such an error and handle it? */
    }

    if (icd->refcount == 0)
        ret = OPENGL32_UnloadDriver( icd );

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.driver_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );

    return ret;
}


/*! \brief Enumerate OpenGLDrivers (from registry)
 *
 * \param idx    Index of the driver to get information about.
 * \param name   Pointer to an array of WCHARs (can be NULL)
 * \param cName  Pointer to a DWORD. Input is len of name array.
 *               Output is length of the drivername.
 *               Can be NULL if name is NULL.
 *
 * \return Error code
 * \retval ERROR_NO_MORE_ITEMS  End of driver list.
 * \retval ERROR_SUCCESS        Success.
 */
#if 0 /* unused */
DWORD
OPENGL32_RegEnumDrivers( DWORD idx, LPWSTR name, LPDWORD cName )
{
    HKEY hKey;
    LPCWSTR subKey = OPENGL_DRIVERS_SUBKEY;
    LONG ret;
    DWORD size;
    WCHAR driver[256];

    if (name == NULL)
        return ERROR_SUCCESS; /* nothing to do */

    if (cName == NULL)
        return ERROR_INVALID_FUNCTION; /* we need cName when name is given */

    /* open OpenGLDrivers registry key */
    ret = RegOpenKeyExW( HKEY_LOCAL_MACHINE, subKey, 0, KEY_READ, &hKey );
    if (ret != ERROR_SUCCESS)
    {
        DBGPRINT( "Error: Couldn't open registry key '%ws'", subKey );
        return ret;
    }

    /* get subkey name */
    size = sizeof (driver) / sizeof (driver[0]);
    ret = RegEnumKeyW( hKey, idx, name, *cName );
    if (ret != ERROR_SUCCESS)
    {
        DBGPRINT( "Error: Couldn't get OpenGLDrivers subkey name (%d)", ret );
        RegCloseKey( hKey );
        return ret;
    }
    *cName = wcslen( name );

    /* close key */
    RegCloseKey( hKey );
    return ERROR_SUCCESS;
}
#endif /* 0 -- unused */


/*! \brief Get registry values for a driver given a name.
 *
 * \param driver  Name of the driver to get information about.
 * \param icd     Pointer to GLDRIVERDATA.
 *
 * \return Error code.
 * \retval ERROR_SUCCESS  Success.
 *
 * \note On success the following fields of \a icd are filled: \a driver_name,
 *       \a dll, \a version, \a driver_version and \a flags.
 */
static DWORD
OPENGL32_RegGetDriverInfo( LPCWSTR driver, GLDRIVERDATA *icd )
{
    HKEY hKey;
    WCHAR subKey[1024] = OPENGL_DRIVERS_SUBKEY2;
    LONG ret;
    DWORD type, size;

    /* drivers registry values */
    DWORD version = 1, driverVersion = 0, flags = 0;
    WCHAR dll[256];

    /* open driver registry key */
    wcsncat( subKey, driver, 1024 );
    ret = RegOpenKeyExW( HKEY_LOCAL_MACHINE, subKey, 0, KEY_READ, &hKey );
    if (ret != ERROR_SUCCESS)
    {
        DBGPRINT( "Error: Couldn't open registry key '%ws'", subKey );
        return ret;
    }

    /* query values */
    size = sizeof (dll);
    ret = RegQueryValueExW( hKey, L"Dll", 0, &type, (LPBYTE)dll, &size );
    if (ret != ERROR_SUCCESS || type != REG_SZ)
    {
        DBGPRINT( "Error: Couldn't query Dll value or not a string" );
        RegCloseKey( hKey );
        return ret;
    }

    size = sizeof (DWORD);
    ret = RegQueryValueExW( hKey, L"Version", 0, &type, (LPBYTE)&version, &size );
    if (ret != ERROR_SUCCESS || type != REG_DWORD)
        DBGPRINT( "Warning: Couldn't query Version value or not a DWORD" );

    size = sizeof (DWORD);
    ret = RegQueryValueExW( hKey, L"DriverVersion", 0, &type,
                            (LPBYTE)&driverVersion, &size );
    if (ret != ERROR_SUCCESS || type != REG_DWORD)
        DBGPRINT( "Warning: Couldn't query DriverVersion value or not a DWORD" );

    size = sizeof (DWORD);
    ret = RegQueryValueExW( hKey, L"Flags", 0, &type, (LPBYTE)&flags, &size );
    if (ret != ERROR_SUCCESS || type != REG_DWORD)
        DBGPRINT( "Warning: Couldn't query Flags value or not a DWORD" );

    /* close key */
    RegCloseKey( hKey );

    /* output data */
    /* FIXME: NUL-terminate strings? */
    wcsncpy( icd->driver_name, driver,
             sizeof (icd->driver_name) / sizeof (icd->driver_name[0]) - 1 );
    wcsncpy( icd->dll, dll,
             sizeof (icd->dll) / sizeof (icd->dll[0]) );
    icd->version = version;
    icd->driver_version = driverVersion;
    icd->flags = flags;

    return ERROR_SUCCESS;
}

/* EOF */