/*
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// Main windowed and fullscreen graphics interface module. This module
// is used for both the software and OpenGL rendering versions of the
// Quake refresh engine.

#define SO_FILE "/etc/quake2.conf"

#include <errno.h>
#include <assert.h>
#include <dlfcn.h> // ELF dl loader
#include <sys/stat.h>
#include <unistd.h>

#include "../client/client.h"

#include "../linux/rw_linux.h"

// Structure containing functions exported from refresh DLL
refexport_t	re;

#ifdef REF_HARD_LINKED
refexport_t GetRefAPI (refimport_t rimp);
#endif

// Console variables that we need to access from this module
cvar_t		*vid_gamma;
cvar_t		*vid_ref;			// Name of Refresh DLL loaded
cvar_t		*vid_xpos;			// X coordinate of window position
cvar_t		*vid_ypos;			// Y coordinate of window position
cvar_t		*vid_fullscreen;

// Global variables used internally by this module
viddef_t	viddef;				// global video state; used by other modules
void		*reflib_library;		// Handle to refresh DLL 
qboolean	reflib_active = 0;

#define VID_NUM_MODES ( sizeof( vid_modes ) / sizeof( vid_modes[0] ) )

/** KEYBOARD **************************************************************/

void Do_Key_Event(int key, qboolean down);

void (*KBD_Update_fp)(void);
void (*KBD_Init_fp)(Key_Event_fp_t fp);
void (*KBD_Close_fp)(void);

/** MOUSE *****************************************************************/

in_state_t in_state;

void (*RW_IN_Init_fp)(in_state_t *in_state_p);
void (*RW_IN_Shutdown_fp)(void);
void (*RW_IN_Activate_fp)(qboolean active);
void (*RW_IN_Commands_fp)(void);
void (*RW_IN_Move_fp)(usercmd_t *cmd);
void (*RW_IN_Frame_fp)(void);

void Real_IN_Init (void);

/*
==========================================================================

DLL GLUE

==========================================================================
*/

#define	MAXPRINTMSG	4096
void VID_Printf (int print_level, char *fmt, ...)
{
	va_list		argptr;
	char		msg[MAXPRINTMSG];
	static qboolean	inupdate;
	
	va_start (argptr,fmt);
	vsprintf (msg,fmt,argptr);
	va_end (argptr);

	if (print_level == PRINT_ALL)
		Com_Printf ("%s", msg);
	else
		Com_DPrintf ("%s", msg);
}

void VID_Error (int err_level, char *fmt, ...)
{
	va_list		argptr;
	char		msg[MAXPRINTMSG];
	static qboolean	inupdate;
	
	va_start (argptr,fmt);
	vsprintf (msg,fmt,argptr);
	va_end (argptr);

	Com_Error (err_level,"%s", msg);
}

//==========================================================================

/*
============
VID_Restart_f

Console command to re-start the video mode and refresh DLL. We do this
simply by setting the modified flag for the vid_ref variable, which will
cause the entire video mode and refresh DLL to be reset on the next frame.
============
*/
void VID_Restart_f (void)
{
	vid_ref->modified = true;
}

/*
** VID_GetModeInfo
*/
typedef struct vidmode_s
{
	const char *description;
	int         width, height;
	int         mode;
} vidmode_t;

vidmode_t vid_modes[] =
{
	{ "Mode 0: 320x240",   320, 240,   0 },
	{ "Mode 1: 400x300",   400, 300,   1 },
	{ "Mode 2: 512x384",   512, 384,   2 },
	{ "Mode 3: 640x480",   640, 480,   3 },
	{ "Mode 4: 800x600",   800, 600,   4 },
	{ "Mode 5: 960x720",   960, 720,   5 },
	{ "Mode 6: 1024x768",  1024, 768,  6 },
	{ "Mode 7: 1152x864",  1152, 864,  7 },
	{ "Mode 8: 1280x1024",  1280, 1024, 8 },
	{ "Mode 9: 1600x1200", 1600, 1200, 9 },
	{ "Mode 10: 2048x1536", 2048, 1536, 10 }
};

qboolean VID_GetModeInfo( int *width, int *height, int mode )
{
	if ( mode < 0 || mode >= VID_NUM_MODES )
		return false;

	*width  = vid_modes[mode].width;
	*height = vid_modes[mode].height;

	return true;
}

/*
** VID_NewWindow
*/
void VID_NewWindow ( int width, int height)
{
	viddef.width  = width;
	viddef.height = height;
}

void VID_FreeReflib (void)
{
	if (reflib_library) {
		if (KBD_Close_fp)
			KBD_Close_fp();
		if (RW_IN_Shutdown_fp)
			RW_IN_Shutdown_fp();
#ifndef REF_HARD_LINKED
		dlclose(reflib_library);
#endif
	}

	KBD_Init_fp = NULL;
	KBD_Update_fp = NULL;
	KBD_Close_fp = NULL;
	RW_IN_Init_fp = NULL;
	RW_IN_Shutdown_fp = NULL;
	RW_IN_Activate_fp = NULL;
	RW_IN_Commands_fp = NULL;
	RW_IN_Move_fp = NULL;
	RW_IN_Frame_fp = NULL;

	memset (&re, 0, sizeof(re));
	reflib_library = NULL;
	reflib_active  = false;
}

/*
==============
VID_LoadRefresh
==============
*/
qboolean VID_LoadRefresh( char *name )
{
	refimport_t	ri;
#ifndef REF_HARD_LINKED
	GetRefAPI_t	GetRefAPI;
#endif
	char	fn[MAX_OSPATH];
	struct stat st;
	extern uid_t saved_euid;
	QFile *fp;
	char	*path;
	char	curpath[MAX_OSPATH];

	if ( reflib_active )
	{
		if (KBD_Close_fp)
			KBD_Close_fp();
		if (RW_IN_Shutdown_fp)
			RW_IN_Shutdown_fp();
		KBD_Close_fp = NULL;
		RW_IN_Shutdown_fp = NULL;
		re.Shutdown();
		VID_FreeReflib ();
	}

#ifndef REF_HARD_LINKED
	getcwd(curpath, sizeof(curpath));
	
	Com_Printf( "------- Loading %s -------\n", name );

	// now run through the search paths
	path = NULL;
	while (1)
	{
		path = FS_NextPath (path);
		if (!path)
			return NULL;		// couldn't find one anywhere
		sprintf (fn, "%s/%s/%s", curpath, path, name);
		Com_Printf ("Trying to load library (%s)\n", fn);

		reflib_library = dlopen( fn, RTLD_NOW );
		if (reflib_library)
		{
			Com_DPrintf ("LoadLibrary (%s)\n",name);
			break;
		}
	}

#endif

	ri.Cmd_AddCommand = Cmd_AddCommand;
	ri.Cmd_RemoveCommand = Cmd_RemoveCommand;
	ri.Cmd_Argc = Cmd_Argc;
	ri.Cmd_Argv = Cmd_Argv;
	ri.Cmd_ExecuteText = Cbuf_ExecuteText;
	ri.Con_Printf = VID_Printf;
	ri.Sys_Error = VID_Error;
	ri.FS_LoadFile = FS_LoadFile;
	ri.FS_FreeFile = FS_FreeFile;
	ri.FS_Gamedir = FS_Gamedir;
	ri.Cvar_Get = Cvar_Get;
	ri.Cvar_Set = Cvar_Set;
	ri.Cvar_SetValue = Cvar_SetValue;
	ri.Vid_GetModeInfo = VID_GetModeInfo;
	ri.Vid_MenuInit = VID_MenuInit;
	ri.Vid_NewWindow = VID_NewWindow;

#ifndef REF_HARD_LINKED
	if ( ( GetRefAPI = (void *) dlsym( reflib_library, "GetRefAPI" ) ) == 0 )
		Com_Error( ERR_FATAL, "dlsym failed on %s", name );
#endif
	re = GetRefAPI( ri );

	if (re.api_version != API_VERSION)
	{
		VID_FreeReflib ();
		Com_Error (ERR_FATAL, "%s has incompatible api_version", name);
	}

	/* Init IN (Mouse) */
	in_state.IN_CenterView_fp = IN_CenterView;
	in_state.Key_Event_fp = Do_Key_Event;
	in_state.viewangles = cl.viewangles;
	in_state.in_strafe_state = &in_strafe.state;

#ifndef REF_HARD_LINKED
	if ((RW_IN_Init_fp = dlsym(reflib_library, "RW_IN_Init")) == NULL ||
		(RW_IN_Shutdown_fp = dlsym(reflib_library, "RW_IN_Shutdown")) == NULL ||
		(RW_IN_Activate_fp = dlsym(reflib_library, "RW_IN_Activate")) == NULL ||
		(RW_IN_Commands_fp = dlsym(reflib_library, "RW_IN_Commands")) == NULL ||
		(RW_IN_Move_fp = dlsym(reflib_library, "RW_IN_Move")) == NULL ||
		(RW_IN_Frame_fp = dlsym(reflib_library, "RW_IN_Frame")) == NULL)
		Sys_Error("No RW_IN functions in REF.\n");
#else
	{
	    void RW_IN_Init(in_state_t *in_state_p);
	    void RW_IN_Shutdown(void);
	    void RW_IN_Commands (void);
	    void RW_IN_Move (usercmd_t *cmd);
	    void RW_IN_Frame (void);
	    void RW_IN_Activate(void);

	    RW_IN_Init_fp = RW_IN_Init;
	    RW_IN_Shutdown_fp = RW_IN_Shutdown;
	    RW_IN_Activate_fp = RW_IN_Activate;
	    RW_IN_Commands_fp = RW_IN_Commands;
	    RW_IN_Move_fp = RW_IN_Move;
	    RW_IN_Frame_fp = RW_IN_Frame;
	}
#endif

	if ( re.Init( 0, 0 ) == -1 )
	{
		re.Shutdown();
		VID_FreeReflib ();
		return false;
	}

	// give up root now
	setreuid(getuid(), getuid());
	setegid(getgid());

	/* Init KBD */
#ifndef REF_HARD_LINKED
	if ((KBD_Init_fp = dlsym(reflib_library, "KBD_Init")) == NULL ||
		(KBD_Update_fp = dlsym(reflib_library, "KBD_Update")) == NULL ||
		(KBD_Close_fp = dlsym(reflib_library, "KBD_Close")) == NULL)
		Sys_Error("No KBD functions in REF.\n");
#else
	{
		void KBD_Init(void);
		void KBD_Update(void);
		void KBD_Close(void);

		KBD_Init_fp = KBD_Init;
		KBD_Update_fp = KBD_Update;
		KBD_Close_fp = KBD_Close;
	}
#endif
	KBD_Init_fp(Do_Key_Event);
	Real_IN_Init();

	Com_Printf( "------------------------------------\n");
	reflib_active = true;
	return true;
}

/*
============
VID_CheckChanges

This function gets called once just before drawing each frame, and it's sole purpose in life
is to check to see if any of the video mode parameters have changed, and if they have to 
update the rendering DLL and/or video mode to match.
============
*/
void VID_CheckChanges (void)
{
	char name[100];
	cvar_t *sw_mode;

	if ( vid_ref->modified )
	{
		S_StopAllSounds();
	}

	while (vid_ref->modified)
	{
		/*
		** refresh has changed
		*/
		vid_ref->modified = false;
		vid_fullscreen->modified = true;
		cl.refresh_prepped = false;
		cls.disable_screen = true;

		sprintf( name, "ref_%s.so", vid_ref->string );
		if ( !VID_LoadRefresh( name ) )
		{
		        if ( strcmp (vid_ref->string, "soft") == 0 ) {
			        Com_Printf("Refresh failed\n");
				sw_mode = Cvar_Get( "sw_mode", "0", 0 );
				if (sw_mode->value != 0) {
				        Com_Printf("Trying mode 0\n");
					Cvar_SetValue("sw_mode", 0);
					if ( !VID_LoadRefresh( name ) )
						Com_Error (ERR_FATAL, "Couldn't fall back to software refresh!");
				} else
					Com_Error (ERR_FATAL, "Couldn't fall back to software refresh!");
			}

			Cvar_Set( "vid_ref", "soft" );

			/*
			** drop the console if we fail to load a refresh
			*/
			if ( cls.key_dest != key_console )
			{
				Con_ToggleConsole_f();
			}
		}
		cls.disable_screen = false;
	}

}

/*
============
VID_Init
============
*/
void VID_Init (void)
{
	/* Create the video variables so we know how to start the graphics drivers */
        vid_ref = Cvar_Get ("vid_ref", "soft", CVAR_ARCHIVE);
	vid_xpos = Cvar_Get ("vid_xpos", "3", CVAR_ARCHIVE);
	vid_ypos = Cvar_Get ("vid_ypos", "22", CVAR_ARCHIVE);
	vid_fullscreen = Cvar_Get ("vid_fullscreen", "0", CVAR_ARCHIVE);
	vid_gamma = Cvar_Get( "vid_gamma", "1", CVAR_ARCHIVE );

	/* Add some console commands that we want to handle */
	Cmd_AddCommand ("vid_restart", VID_Restart_f);

	/* Disable the 3Dfx splash screen */
	putenv("FX_GLIDE_NO_SPLASH=0");
		
	/* Start the graphics mode and load refresh DLL */
	VID_CheckChanges();
}

/*
============
VID_Shutdown
============
*/
void VID_Shutdown (void)
{
	if ( reflib_active )
	{
		if (KBD_Close_fp)
			KBD_Close_fp();
		if (RW_IN_Shutdown_fp)
			RW_IN_Shutdown_fp();
		KBD_Close_fp = NULL;
		RW_IN_Shutdown_fp = NULL;
		re.Shutdown ();
		VID_FreeReflib ();
	}
}


/*****************************************************************************/
/* INPUT                                                                     */
/*****************************************************************************/

cvar_t	*in_joystick;

// This if fake, it's acutally done by the Refresh load
void IN_Init (void)
{
	in_joystick	= Cvar_Get ("in_joystick", "0", CVAR_ARCHIVE);
}

void Real_IN_Init (void)
{
	if (RW_IN_Init_fp)
		RW_IN_Init_fp(&in_state);
}

void IN_Shutdown (void)
{
	if (RW_IN_Shutdown_fp)
		RW_IN_Shutdown_fp();
}

void IN_Commands (void)
{
	if (RW_IN_Commands_fp)
		RW_IN_Commands_fp();
}

void IN_Move (usercmd_t *cmd)
{
	if (RW_IN_Move_fp)
		RW_IN_Move_fp(cmd);
}

void IN_Frame (void)
{
	if (RW_IN_Frame_fp)
		RW_IN_Frame_fp();
}

void IN_Activate (qboolean active)
{
	if (RW_IN_Activate_fp)
		RW_IN_Activate_fp(active);
}

void Do_Key_Event(int key, qboolean down)
{
	Key_Event(key, down, Sys_Milliseconds());
}