#include "FaceDBPool.h"
#include "logger.h"
#include "faceAPI.h"

#include <pthread.h>
#include <map>

#define PLP_MUTEX_LOCK(mut,_ret) if (mut != nullptr) {\
	int ret = pthread_mutex_lock((pthread_mutex_t*)mut); \
	if(ret != 0) \
	{ \
		LOG_ERROR << "pthread_mutex_lock " << #mut <<  ": " << ret; \
		return _ret; \
	} \
}

#define PLP_MUTEX_UNLOCK(mut,_ret) if (mut != nullptr) {\
	int ret = pthread_mutex_unlock((pthread_mutex_t*)mut); \
	if(ret != 0) \
	{ \
		LOG_ERROR << "pthread_mutex_unlock " << #mut <<  ": " << ret; \
		return _ret; \
	} \
}

struct MutexLocker
{
	pthread_mutex_t* mut;
	MutexLocker(pthread_mutex_t* _mut) : mut(_mut)
	{
		PLP_MUTEX_LOCK(mut,);
	}
	~MutexLocker()
	{
		PLP_MUTEX_UNLOCK(mut,);
	}
};

struct ThreadSafeFaceDB
{
	int dbid;
	pthread_mutex_t db_mutex;
	faceAPI* api;
	
	ThreadSafeFaceDB() : dbid(-1), db_mutex(), api(nullptr)
	{
		pthread_mutex_init(db_mutex, NULL);
	}
	
	~ThreadSafeFaceDB()
	{
		pthread_mutex_destroy(db_mutex);
	}
};

typedef std::map<int, ThreadSafeFaceDB*> facedb_map_t;

FaceDBPool::FaceDBPool() : 
	pool_mutex(nullptr), face_db_map(nullptr)
{
	pool_mutex = new pthread_mutex_t;
	pthread_mutex_init((pthread_mutex_t*)pool_mutex, NULL);
	
	face_db_map = new facedb_map_t();
}

FaceDBPool::~FaceDBPool()
{
	facedb_map_t* _face_db_map = (facedb_map_t*)face_db_map;
	for (facedb_map_t::iterator iter = _face_db_map->begin(); iter != _face_db_map->end(); ++iter)
	{
		iter->second.api->db_save();
		delete iter->second.api;
		delete iter->second;
	}
	
	_face_db_map.clear();
	
	pthread_mutex_destroy((pthread_mutex_t*)pool_mutex);
	delete (pthread_mutex_t*)pool_mutex;
	pool_mutex = nullptr;
}

void FaceDBPool::manage(int dbid, faceAPI* db)
{
	if (dbid < 0 || db == nullptr)
		return;

	MutexLocker _ml(pool_mutex);
	
	facedb_map_t* _face_db_map = (facedb_map_t*)face_db_map;
	
	if (_face_db_map.find(dbid) != _face_db_map.end())
		return;
	
	ThreadSafeFaceDB* tsfdb = new ThreadSafeFaceDB;
	tsfdb.dbid = dbid;
	tsfdb.api = db;
	
	_face_db_map.insert(std::make_pair(dbid, tsfdb));
}

void FaceDBPool::unmanage(int dbid)
{
	MutexLocker _ml(pool_mutex);

	facedb_map_t* _face_db_map = (facedb_map_t*)face_db_map;
	facedb_map_t::iterator iter = _face_db_map.find(dbid);
	if (iter == _face_db_map.end())
		return;
	
	iter->second.api->db_save();
	delete iter->second.api;
	delete iter->second;
	
	_face_db_map.erase(iter);
}

faceAPI* FaceDBPool::get_free(int dbid)
{
	ThreadSafeFaceDB* tsfdb = nullptr;
	{
		//avoid dead lock
		MutexLocker _ml(pool_mutex);
		
		facedb_map_t* _face_db_map = (facedb_map_t*)face_db_map;
		if (_face_db_map.empty())
			return nullptr;
		
		facedb_map_t::iterator iter = _face_db_map.find(dbid);
		if (iter == _face_db_map.end())
			return nullptr;
		
		tsfdb = iter->second;
	}

	if (tsfdb != nullptr)
	{
		PLP_MUTEX_LOCK(tsfdb->db_mutex, nullptr);
		return tsfdb->api;
	}
}

void FaceDBPool::release(int dbid)
{
	ThreadSafeFaceDB* tsfdb = nullptr;
	{
		//avoid dead lock
		MutexLocker _ml(pool_mutex);
		
		facedb_map_t* _face_db_map = (facedb_map_t*)face_db_map;
		if (_face_db_map.empty())
			return;
		
		facedb_map_t::iterator iter = _face_db_map.find(dbid);
		if (iter == _face_db_map.end())
			return nullptr;
		
		tsfdb = iter->second;
	}
	
	if (tsfdb != nullptr)
	{
		PLP_MUTEX_UNLOCK(tsfdb->db_mutex,);
	}
}