#include <efsw/FileWatcherKqueue.hpp>

#if EFSW_PLATFORM == EFSW_PLATFORM_KQUEUE || EFSW_PLATFORM == EFSW_PLATFORM_FSEVENTS

#include <dirent.h>
#include <efsw/Debug.hpp>
#include <efsw/FileSystem.hpp>
#include <efsw/Lock.hpp>
#include <efsw/System.hpp>
#include <efsw/WatcherGeneric.hpp>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>

namespace efsw {

FileWatcherKqueue::FileWatcherKqueue( FileWatcher* parent ) :
	FileWatcherImpl( parent ),
	mLastWatchID( 0 ),
	mThread( NULL ),
	mFileDescriptorCount( 1 ),
	mAddingWatcher( false ) {
	mTimeOut.tv_sec = 0;
	mTimeOut.tv_nsec = 0;
	mInitOK = true;
}

FileWatcherKqueue::~FileWatcherKqueue() {
	WatchMap::iterator iter = mWatches.begin();

	for ( ; iter != mWatches.end(); ++iter ) {
		efSAFE_DELETE( iter->second );
	}

	mWatches.clear();

	mInitOK = false;

	efSAFE_DELETE( mThread );
}

WatchID FileWatcherKqueue::addWatch( const std::string& directory, FileWatchListener* watcher,
									 bool recursive ) {
	static bool s_ug = false;

	std::string dir( directory );

	FileSystem::dirAddSlashAtEnd( dir );

	FileInfo fi( dir );

	if ( !fi.isDirectory() ) {
		return Errors::Log::createLastError( Errors::FileNotFound, dir );
	} else if ( !fi.isReadable() ) {
		return Errors::Log::createLastError( Errors::FileNotReadable, dir );
	} else if ( pathInWatches( dir ) ) {
		return Errors::Log::createLastError( Errors::FileRepeated, directory );
	}

	std::string curPath;
	std::string link( FileSystem::getLinkRealPath( dir, curPath ) );

	if ( "" != link ) {
		if ( pathInWatches( link ) ) {
			return Errors::Log::createLastError( Errors::FileRepeated, directory );
		} else if ( !linkAllowed( curPath, link ) ) {
			return Errors::Log::createLastError( Errors::FileOutOfScope, dir );
		} else {
			dir = link;
		}
	}

	/// Check first if are enough file descriptors available to create another kqueue watcher,
	/// otherwise it creates a generic watcher
	if ( availablesFD() ) {
		mAddingWatcher = true;

		WatcherKqueue* watch = new WatcherKqueue( ++mLastWatchID, dir, watcher, recursive, this );

		{
			Lock lock( mWatchesLock );
			mWatches.insert( std::make_pair( mLastWatchID, watch ) );
		}

		watch->addAll();

		// if failed to open the directory... erase the watcher
		if ( !watch->initOK() ) {
			int le = watch->lastErrno();

			mWatches.erase( watch->ID );

			efSAFE_DELETE( watch );

			mLastWatchID--;

			// Probably the folder has too many files, create a generic watcher
			if ( EACCES != le ) {
				WatcherGeneric* genericWatch =
					new WatcherGeneric( ++mLastWatchID, dir, watcher, this, recursive );

				Lock lock( mWatchesLock );
				mWatches.insert( std::make_pair( mLastWatchID, genericWatch ) );
			} else {
				return Errors::Log::createLastError( Errors::Unspecified, link );
			}
		}

		mAddingWatcher = false;
	} else {
		if ( !s_ug ) {
			efDEBUG( "Started using generic watcher, file descriptor limit reached: %ld\n",
					 mFileDescriptorCount );
			s_ug = true;
		}

		WatcherGeneric* watch = new WatcherGeneric( ++mLastWatchID, dir, watcher, this, recursive );

		Lock lock( mWatchesLock );
		mWatches.insert( std::make_pair( mLastWatchID, watch ) );
	}

	return mLastWatchID;
}

void FileWatcherKqueue::removeWatch( const std::string& directory ) {
	Lock lock( mWatchesLock );

	WatchMap::iterator iter = mWatches.begin();

	for ( ; iter != mWatches.end(); ++iter ) {
		if ( directory == iter->second->Directory ) {
			removeWatch( iter->first );
			return;
		}
	}
}

void FileWatcherKqueue::removeWatch( WatchID watchid ) {
	Lock lock( mWatchesLock );

	WatchMap::iterator iter = mWatches.find( watchid );

	if ( iter == mWatches.end() )
		return;

	Watcher* watch = iter->second;

	mWatches.erase( iter );

	efSAFE_DELETE( watch );
}

bool FileWatcherKqueue::isAddingWatcher() const {
	return mAddingWatcher;
}

void FileWatcherKqueue::watch() {
	if ( NULL == mThread ) {
		mThread = new Thread( &FileWatcherKqueue::run, this );
		mThread->launch();
	}
}

void FileWatcherKqueue::run() {
	do {
		{
			Lock lock( mWatchesLock );

			for ( WatchMap::iterator it = mWatches.begin(); it != mWatches.end(); ++it ) {
				it->second->watch();
			}
		}

		System::sleep( 500 );
	} while ( mInitOK );
}

void FileWatcherKqueue::handleAction( Watcher* /*watch*/, const std::string& /*filename*/,
									  unsigned long /*action*/, std::string /*oldFilename*/ ) {}

std::list<std::string> FileWatcherKqueue::directories() {
	std::list<std::string> dirs;

	Lock lock( mWatchesLock );

	WatchMap::iterator it = mWatches.begin();

	for ( ; it != mWatches.end(); ++it ) {
		dirs.push_back( it->second->Directory );
	}

	return dirs;
}

bool FileWatcherKqueue::pathInWatches( const std::string& path ) {
	WatchMap::iterator it = mWatches.begin();

	for ( ; it != mWatches.end(); ++it ) {
		if ( it->second->Directory == path ) {
			return true;
		}
	}

	return false;
}

void FileWatcherKqueue::addFD() {
	mFileDescriptorCount++;
}

void FileWatcherKqueue::removeFD() {
	mFileDescriptorCount--;
}

bool FileWatcherKqueue::availablesFD() {
	return mFileDescriptorCount <= (Int64)System::getMaxFD() - 500;
}

} // namespace efsw

#endif
