/* AbiSource Application Framework
 * Copyright (C) 2001 AbiSource, Inc.
 * Copyright (C) 2001 Dom Lachowicz <cinamod@hotmail.com> 
 *
 * 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.
 */

#include "xap_ModuleManager.h"
#include "xap_Module.h"

#include "ut_string_class.h"
#include "ut_vector.h"
#include "ut_assert.h"

#include "ut_debugmsg.h"

// the loader manages instances of one of these target classes

#if defined (WIN32)
  #include "xap_Win32Module.h"
  #define MODULE_CLASS XAP_Win32Module

#elif defined (__BEOS__)
  #include "xap_BeOSModule.h"
  #define MODULE_CLASS XAP_BeOSModule

#elif defined (__QNXNTO__)
  #include "xap_QNXModule.h"
  #define MODULE_CLASS XAP_QNXModule

#elif defined (__APPLE__) && defined (XP_MAC_TARGET_MACOSX)
	#if defined (XP_MAC_TARGET_CARBON)
		#include <ConditionalMacros.h>
		#if defined(TARGET_RT_MAC_CFM) && (TARGET_RT_MAC_CFM == 1)
			#include "xap_MacCFMModule.h"
			#define MODULE_CLASS XAP_MacModule
		#elif defined (TARGET_RT_MAC_MACHO) && (TARGET_RT_MAC_MACHO == 1)
			#include "xap_MacModule.h"
			#define MODULE_CLASS XAP_MacModule
		#else
			#error Unknown Apple architecture
		#endif
	#elif defined (XP_TARGET_COCOA)
		#include "xap_CocoaModule.h"
		#define MODULE_CLASS XAP_CocoaModule	
	#endif
#else
  // *NIX
  #include "xap_UnixModule.h"
  #define MODULE_CLASS XAP_UnixModule

#endif

// TODO: get this from some auto-generated place
static const UT_uint32 major   = 1;
static const UT_uint32 minor   = 0;
static const UT_uint32 release = 0;

/*!
 * Protected destructor creates an instance of this module class
 */
XAP_ModuleManager::XAP_ModuleManager ()	
{
	m_modules = new UT_Vector (11);
}

/*!
 * Private destructor
 */
XAP_ModuleManager::~XAP_ModuleManager ()
{
	UT_VECTOR_PURGEALL (MODULE_CLASS *, (*m_modules));
	delete m_modules;
}

/*!
 * Acquire a handle to an instance of this module loader class
 */
XAP_ModuleManager & XAP_ModuleManager::instance ()
{
	static XAP_ModuleManager me;
	return me;
}

/*!
 * Request that the ModuleManager load the module represented by
 * szFilename. Returns a valid XAP_Module on success, 0 on failure
 *
 * \param szFilename   - the .bundle on your system that you wish to load
 * \param szBundlename - basename of szFilename (must be "*.bundle")
 * \return a valid XAP_Module or 0
 */
bool XAP_ModuleManager::loadBundle (const char * szFilename, const char * szBundlename)
{
	UT_ASSERT (szFilename);
	UT_ASSERT (szBundlename);

	if (!szFilename || !szBundlename) // be a *little* forgiving
	{
		UT_DEBUGMSG(("Attempt to load a null filename should fail\n"));
		return false;
	}

	char * szRelPath = UT_strdup (szBundlename);
	if (szRelPath == 0) return false;

	/* This assumes "*.bundle" - TODO: make this more xp
	 */
	strcpy (szRelPath,"/lib");
	strncat (szRelPath,szBundlename,strlen(szBundlename)-7);
	strcat (szRelPath,".so");

	UT_String plugin(szFilename);
	plugin += szRelPath;

	free (szRelPath);

	if (loadModule (plugin.c_str()))
	{
		XAP_Module * pModule = (XAP_Module *) m_modules->getLastItem();
		int (*setPath) (const char * szBundlePath) = 0;
		if (pModule->resolveSymbol ("abi_plugin_bundle_path", (void **)&setPath))
		{
			UT_DEBUGMSG(("FJF: Setting bundle path...\n"));
			setPath (szFilename);
		}
		return true;
	}

	return false;
}

/*!
 * Request that the ModuleManager load the module represented by
 * szFilename. Returns a valid XAP_Module on success, 0 on failure
 *
 * \param szFilename - the .dll or .so on your system that you wish to load
 * \return a valid XAP_Module or 0
 */
bool XAP_ModuleManager::loadModule (const char * szFilename)
{
	UT_ASSERT (szFilename);

	if (!szFilename) // be a *little* forgiving
	{
		UT_DEBUGMSG(("Attempt to load a null filename should fail\n"));
		return false;
	}

	XAP_Module * pModule = new MODULE_CLASS;
	UT_ASSERT (pModule);

	char * errorMsg;

	if (!pModule->load (szFilename))
	{		
		UT_DEBUGMSG (("Failed to load module %s\n", szFilename));
		
		if (pModule->getErrorMsg (&errorMsg))
		{	
			UT_DEBUGMSG (("Reason: %s\n", errorMsg));
			FREEP (errorMsg);
		}
		
		delete pModule;
		return false;
	}

	// assign the module's creator to be us
	pModule->setLoaded (true);
	pModule->setCreator (this);

	if (!pModule->registerThySelf ())
	{
		UT_DEBUGMSG (("Failed to register module %s\n", szFilename));
		
		if (pModule->getErrorMsg (&errorMsg))
		{	
			UT_DEBUGMSG (("Reason: %s\n", errorMsg));
			FREEP (errorMsg);
		}

		pModule->unload ();
		delete pModule;
		return false;
	}

	// TODO: we probably should turn this code on
	if (!pModule->supportsAbiVersion (major, minor, release))
	{
		UT_DEBUGMSG (("Plugin does not support AbiWord version %d.%d.%d\n",
					   major, minor, release));

		pModule->unregisterThySelf ();
		pModule->unload ();
		delete pModule;
		return false;
	}

	// we (somehow :^) got here. count our blessings and return
	m_modules->addItem (pModule);
	return true;
}

/*!
 * When passed a valid XAP_Module that this class loaded, this method
 * will unload the module from memory
 *
 * \param pModule - a valid module that you want to unload
 * \return true if we could register the module, false if not
 */
bool XAP_ModuleManager::unloadModule (XAP_Module * pModule)
{
	UT_ASSERT (pModule);
	UT_ASSERT (pModule->getCreator () == this);

	int ndx = m_modules->findItem (pModule);

	if (ndx != -1)
	{
		m_modules->deleteNthItem (ndx);

		// we're less picky when unloading than we are when loading
		// the (necessarily true) assumptions are that
		//
		// 1) we were the one who loaded the module
		// 2) registerThySelf() worked
		//
		// so it had better damn well work in the opposite direction!

		UT_ASSERT (pModule->unregisterThySelf ());
		pModule->setLoaded (false);
		UT_ASSERT (pModule->unload ());
		delete pModule;

		return true;
	}
	else
	{
		// how the heck did this happen?? something is *clearly* wrong
		UT_ASSERT (UT_SHOULD_NOT_HAPPEN);
		UT_DEBUGMSG (("Could not unload module\n"));
		return false;
	}
}

/*!
 * Enumerate the modules loaded thus far
 *
 * \return a vector containing XAP_Module*'s
 */
const UT_Vector * XAP_ModuleManager::enumModules () const
{
	// TODO: perhaps we should clone this
	return m_modules;
}