/*
	Copyright © 2015 Gluzskiy Alexandr (sss)

    This file is part of Unknown Download Manager (UDM).

    UDM 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.

    UDM 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 UDM.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "modules_handler.h"
#include <unistd.h>
#include <dlfcn.h>
#include <string>

#include <boost/filesystem.hpp>


#include <iostream>

extern core_api *module_api;


void modules_handler::load_metadata_modules(const std::string &path)
{
	if(boost::filesystem::exists(path) && boost::filesystem::is_directory(path))
	{
		for(boost::filesystem::directory_iterator i(path), end = boost::filesystem::directory_iterator(); i != end; ++i)
		{
			void *lib = dlopen(i->path().generic_string().c_str(), RTLD_LAZY);
			if(!lib)
			{
				printf("failed to open library \"%s\" with error: %s\n", i->path().c_str(), dlerror());
				return;
			}
			void *fptr = dlsym(lib, "udm_metadata_module_load");
			if(!fptr)
			{
				printf("failed to find symbol \"udm_metadata_module_load\" in library %s with error %s\n", i->path().c_str(), dlerror());
				dlclose(lib);
				return;
			}
			void *(*f)(void);
			f = (void* (*)())fptr;
			//TODO: aditional sanity checks
			module_metadata_storage *m = static_cast<module_metadata_storage*>(f());
			m->load(module_api);
			metadata_modules.push_back(m);
		}
	}
}

void modules_handler::load_downloader_modules(const std::string &path)
{
	if(boost::filesystem::exists(path) && boost::filesystem::is_directory(path))
	{
		for(boost::filesystem::directory_iterator i(path), end = boost::filesystem::directory_iterator(); i != end; ++i)
		{
			void *lib = dlopen(i->path().generic_string().c_str(), RTLD_LAZY);
			if(!lib)
			{
				printf("failed to open library \"%s\" with error: %s\n", i->path().c_str(), dlerror());
				return;
			}
			void *fptr = dlsym(lib, "udm_downloader_module_load");
			if(!fptr)
			{
				printf("failed to find symbol \"udm_downloader_module_load\" in library %s with error %s\n", i->path().c_str(), dlerror());
				dlclose(lib);
				return;
			}
			void *(*f)(void);
			f = (void* (*)())fptr;
			//TODO: aditional sanity checks
			module_metadata_storage *m = static_cast<module_metadata_storage*>(f());
			m->load(module_api);
			metadata_modules.push_back(m);
		}
	}
}

std::string modules_handler::get_self_path()
{
	//TODO: dynamic buffer
	char buf[1024];
	readlink("/proc/self/exe", buf, 1023);
	std::string s (buf);
	return s;
}

std::string modules_handler::list_modules()
{
	std::string buf;
	buf += "Installed  metadata modules:\n";
	for(auto i = metadata_modules.begin(), end = metadata_modules.end(); i != end; ++i)
	{
        buf += "\t";
        buf += (*i)->get_module_info().name;
        buf += " (" + (*i)->get_module_info().description + ") ";
        buf += "v" + (*i)->get_module_info().version;
        buf += "\n";
	}
	buf += "Installed  downloader modules:\n";
	for(auto i = downloader_modules.begin(), end = downloader_modules.end(); i != end; ++i)
	{
        buf += "\t";
        buf += (*i)->get_module_info().name;
        buf += " (" + (*i)->get_module_info().description + ") ";
        buf += "v" + (*i)->get_module_info().version;
        buf += "\n";
	}
	return buf;
}


modules_handler::modules_handler()
{
	self_path = get_self_path();
	boost::filesystem::path p(self_path);
    std::string self_dir = p.parent_path().generic_string();
    load_metadata_modules(self_dir + "/modules/metadata");
    load_metadata_modules("~/.share/udm/modules/metadata");
    load_metadata_modules("/usr/lib/udm/modules/metadata");
    load_downloader_modules(self_dir + "/modules/downloader");
    load_downloader_modules("~/.share/udm/modules/downloader");
    load_downloader_modules("/usr/lib/udm/modules/downloader");
}

modules_handler::~modules_handler()
{
	//dtor
}