/* -*- C++ -*-
 * Copyright ©2005 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#include "plugins.h"

#include <sys/types.h>
#include <dirent.h>
#include <dlfcn.h>
#include <cstring>

#include "contentgroup.h"
#include "magellan/options.h"

#include <errno.h>

std::list<PluginInfo_Map*> map_plugins;
std::list<PluginInfo_Orbit*> orbit_plugins;
std::list<PluginInfo_Content*> content_plugins;
std::list<PluginInfo_Output*> output_plugins;
std::list<PluginInfo_Viewport*> viewport_plugins;
std::list<PluginInfo_Display*> display_plugins;

typedef PluginInfo* (*InitFunction)(int);

template <class T>
bool try_insert(std::list<T*>& container, PluginInfo* p)
{
	T* cast = dynamic_cast<T*>(p);
	if(cast != NULL)
	{
		for(typename std::list<T*>::const_iterator it = container.begin();
			it != container.end();
			it++)
		{
			if((*it)->name == cast->name)
			{
				if(opts->debug_plugin() >= 1)
				{
					std::cerr << "Plugin from " << cast->file
							  << " has same name (" << cast->name
							  << ") as previously-loaded plugin from "
							  << (*it)->file << ". Skipping." << std::endl;
				}
				return true; // Falsely claim that everything is OK.
			}
		}
		// If we've got here, we've not seen the plugin before, so
		// load it
		container.push_back(cast);
	}

	return cast != NULL;
}

void load_plugins(void)
{
	for(Options::psearch_it it = opts->plugin_dir_start();
		it != opts->plugin_dir_end();
		it++)
	{
		DIR* dir = opendir(it->c_str());
		if(dir == NULL)
		{
			if(opts->debug_plugin() >= 1)
			{
				std::cerr << "Plugin loader: can't open " << *it << ": " 
						  << strerror(errno) << std::endl;
			}
			continue;
		}

		if(opts->debug_plugin() >= 1)
			std::cerr << "Opening plugin dir " << *it << std::endl;

		struct dirent* file;
		// For each entry in the directory
		while(file = readdir(dir))
		{
			// Check that it's a .so
			if(opts->debug_plugin() >= 2)
				std::cerr << "Checking file " << file->d_name << std::endl;
			if(strncmp(file->d_name + strlen(file->d_name)-3, ".so", 3) != 0)
				continue;
			
			// Open the library
			std::string fname = *it;
			fname += file->d_name;
			void* lib = dlopen(fname.c_str(), RTLD_LAZY | RTLD_GLOBAL);
			if(opts->debug_plugin() >= 2)
				std::cerr << "  (opened)" << std::endl;
			if(lib != NULL)
			{
				void *symbol;
				PluginInfo* (*init)(int);
				symbol = dlsym(lib, "getmodules");
				if(symbol == NULL)
				{
					std::cerr << "Plugin " << fname
							  << " doesn't have getmodules() function"
							  << std::endl;
					continue;
				}
				init = (InitFunction)(symbol);
				
				PluginInfo* res;
				int i=0;
				while(res = init(i++))
				{
					res->file = fname;

					if(try_insert(map_plugins, res)
					   || try_insert(orbit_plugins, res)
					   || try_insert(content_plugins, res)
					   || try_insert(output_plugins, res)
					   || try_insert(viewport_plugins, res)
						)
					{
					}
					else
					{
						std::cerr << "Plugin " << fname
								  << " not a recognised plugin type?"
								  << std::endl;
						continue;
					}
					if(opts->debug_plugin() >= 1)
					{
						std::cout << "Loaded: " << res->name << " v";
						std::cout << (res->version>>16 & 0xff) << ".";
						std::cout << (res->version>>8 & 0xff) << ".";
						std::cout << (res->version & 0xff);
						std::cout << " (" << file->d_name << ")" << std::endl;
					}
				}
			}
			else
			{
				if(opts->debug_plugin() >= 2)
					std::cerr << "  Error dlopen()ing the file" << std::endl;
				std::cout << dlerror() << std::endl;
			}
		}
		closedir(dir);
	}

	PluginInfo_Content* contentgroup = 
		dynamic_cast<PluginInfo_Content*>(ContentGroup::getmodules(0));
	ContentGroup::set_content_plugins(&content_plugins);
	content_plugins.push_back(contentgroup);

	PluginInfo_Viewport* vp = 
		dynamic_cast<PluginInfo_Viewport*>(XfView::getmodules(0));
	viewport_plugins.push_back(vp);

	PluginInfo_Display* di = 
		dynamic_cast<PluginInfo_Display*>(MDisplay::getmodules(0));
	display_plugins.push_back(di);
}

template <class Iterator>
void unload_plugins(Iterator start, Iterator end)
{
	for(Iterator it = start; it != end;	++it)
	{
		/* FIXME: Uninitialised pointer use here
		if((*it)->library != NULL)
		{
			dlclose((*it)->library);
		}
		*/
		delete (*it);
	}
}

void unload_plugins(void)
{
	unload_plugins(map_plugins.begin(), map_plugins.end());
	unload_plugins(orbit_plugins.begin(), orbit_plugins.end());
	unload_plugins(content_plugins.begin(), content_plugins.end());
	unload_plugins(output_plugins.begin(), output_plugins.end());
	unload_plugins(viewport_plugins.begin(), viewport_plugins.end());
	unload_plugins(display_plugins.begin(), display_plugins.end());

	map_plugins.clear();
	orbit_plugins.clear();
	content_plugins.clear();
	output_plugins.clear();
	viewport_plugins.clear();
	display_plugins.clear();
}