/*
 * m_vpplug.c
 *
 * Manejo de Plug-ins (.dll en win32, .so en unix) para parametros
 * virtuales
 * spd@daphne.cps.unizar.es
 * Ultima modificacion: Sat Oct  4 23:12:26 GMT--1:00 1997
 */


#include <stdio.h>
#include <stdlib.h>


#ifndef WIN32
#	include <sys/param.h>
#	include <sys/types.h>
#	if defined(DIRENT)
#		include <dirent.h>
		typedef struct dirent dir_type;
#	else
#		include <sys/dir.h>
		typedef struct direct dir_type;
#	endif
#	include <unistd.h>     /* chdir */
#	include <limits.h>
#	include <dlfcn.h>

#else
#	include <io.h>
#	include <time.h>
#	include <direct.h>

#	include <malloc.h>


#	ifdef MAXPATHLEN
#		undefine MAXPATHLEN
#	endif
#	define MAXPATHLEN _MAX_PATH
	
#	define getcwd _getcwd
#	define chdir _chdir
#endif


#include "vpplug.h"
#include "m_vpplug.h"

/*
 * Globales
 */

M_PLUG *vp_plug;
unsigned vp_plug_idx;

/*
 */

int	m_vpplug_init(void);
{
	char *vppath, *path, *argt, po;
    char cwd[MAXPATHLEN];

	vp_plug_idx=0;
	vp_plug=NULL;

	if ((vppath=getenv(M_VPPATH))==NULL)
		return M_VPERR_NOPATH;
	
	if ((path = strdup(vppath))==NULL)
		return M_VPERR_NOMEM;

   	if (getcwd(cwd, sizeof(cwd)) != NULL)
	{
		argt = strtok( path, PATH_LIM );
		while(argt!=NULL)
		{
			if ( -1 != chdir( argt ))
			{
#ifndef WIN32
				DIR			*dir;
				dir_type	*sd;
				char		*po;

				if ( NULL == (dir = opendir( "." )))
				{
					perror("opendir");
					continue;
				}
				else
				{
					while ( NULL != ( sd = readdir( dir )))
					{
						po=strrchr(sd->d_name, '.');
						if (
							(po != NULL) &&
							( 0 == strcmp ( po, PLUG_EXT ))
							)
							if ( 0!= m_vpplug_add(sd->d_name,-1))
								fprintf(stderr, "Can't load %s", sd->d_name);
					}
					closedir( dir );
				}
#else
				struct _finddata_t c_file;
				long hFile;

				/* Find first file in current directory */
				if( (hFile = _findfirst( "*"PLUG_EXT, &c_file )) == -1L )
					continue;
				else
				{
					do
					{
						if ( !( c_file.attrib & _A_SUBDIR ))
						if ( 0!= m_vpplug_add(c_file.name,-1))
							fprintf(stderr, "Can't load %s", c_file.name);
					}
					while( _findnext( hFile, &c_file ) == 0 );
					_findclose( hFile );
				}
#endif
			}
			argt = strtok( NULL, PATH_LIM );
		}
		
		chdir(cwd);
	}
	else
		perror("getcwd");

	return M_VPERR_NOERR;
}


int	m_vpplug_add(char *path, int which);
{
	int		result=M_VPERR_NOERR;
#ifndef WIN32
	void	*hLib;
#else
	HINSTANCE hLib;
#	define	dlsym	GetProcAddress
#endif
	char	**name;
	short	*magic;
	VP_PTR	fun;
	VP_INIT	init;

	if (NULL==(hLib=
#ifndef WIN32
		dlopen(path, RTLD_NOW)
#else
		LoadLibrary( path )
#endif
		))
		return 1;

	if ( which >= vp_plug_idx )
		return M_VPERR_BADPAR;
	
	if ( which < 0 )
		which = vp_plug_idx;
	
	if (!(
		(NULL==(magic=(short *)dlsym(hLib, VPPLUGIN_MAGIC))) ||
		( *magic != VPPLUGIN_MAGIC_VALUE ) ||
		(NULL==(name=(char **)dlsym(hLib, VPPLUGIN_NAME))) ||
		(NULL==(fun=(VP_PTR)dlsym(hLib, VPPLUGIN_MAIN))) 
		))

	{
		if (( which == vp_plug_idx ) && ( vp_plug_idx % M_PLUG_ADD == 0))
			vp_plug = realloc ( vp_plug, sizeof(M_PLUG)*M_PLUG_ADD ));

		if ( vp_plug != NULL )
		{
			vp_plug[which].type=M_PLUG_T_VP;
			vp_plug[which].name=*name;
			vp_plug[which].function=fun;
			vp_plug[which].path=strdup(path);
			vp_plug[which].lib=hLib;
			if ( which == vp_plug_idx )
				++vp_plug_idx;
		}
		else
			result=M_VPERR_NOMEM;

		if (NULL!=(init=(VP_INIT)dlsym(hLib, VPPLUGIN_INIT)))
			init();
	}

	return result;
}

int	m_vpplug_free(int which);
{
	VP_INIT	flush;

	if (NULL!=(flush=(VP_INIT)dlsym(hLib, VPPLUGIN_FLUSH)))
		flush();

	vp_plug[which].function=NULL;
	if (vp_plug[which].path)
		free(vp_plug[which].path);

#ifndef WIN32
	dlclose(vp_plug[which].lib);
#else
	FreeLibrary(vp_plug[which].lib);
#endif
	return M_VPERR_NOMEM;

}

int	m_vpplug_reload(int which)
{
	char path[MAXPATHLEN];
	
	strcpy(path, vp_plug[which].path)
	m_vpplug_free(which);

	return m_vpplug_add( path, which );
}