/*
 * AlgorithmRegistry.cpp
 *
 *  Created on: 19. 8. 2017
 *	  Author: Jan Travnicek
 */

#include <abstraction/AlgorithmRegistry.hpp>
#include <abstraction/CastRegistry.hpp>
#include <global/GlobalData.h>
#include <foreach>

namespace abstraction {

ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > AlgorithmRegistry::dynamicReturnType ( ) {
	return ext::make_pair ( std::string ( "dynamic return type" ), ext::set < ParamQualifiers::ParamQualifier > { } );
}

bool AlgorithmRegistry::isRegistered ( const std::string & algorithm, AlgorithmCategories::AlgorithmCategory category, const ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > > & params ) {
	auto & group = getEntries ( ) [ algorithm ];

	for ( const ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > >, ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > & entry : group )
		if ( std::get < 0 > ( entry ) == category && std::get < 1 > ( entry ) == params )
			return true;

	return false;
}

void AlgorithmRegistry::registerInternal ( std::string algorithm, AlgorithmCategories::AlgorithmCategory category, ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > result, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > > params, std::shared_ptr < Entry > value ) {
	auto & group = getEntries ( ) [ algorithm ];

	ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > entryValue = ext::make_pair ( std::move ( result ), std::move ( value ) );
	group.push_back ( ext::make_tuple ( category, std::move ( params ), entryValue ) );
}

std::shared_ptr < abstraction::OperationAbstraction > AlgorithmRegistry::getAbstraction ( const std::string & name, const ext::vector < std::string > & paramTypes, AlgorithmCategories::AlgorithmCategory ) {
	auto group = getEntries ( ).find ( name );
	if ( group == getEntries ( ).end ( ) ) {
		for ( auto iter = getEntries ( ).begin ( ); iter != getEntries ( ).end ( ); ++ iter ) {
			if ( ext::is_same_type ( name, iter->first ) ) {
				if ( group == getEntries ( ).end ( ) )
					group = iter;
				else
					throw exception::CommonException ( "Name " + name + " is ambigous " );
			}
		}
	}
	if ( group == getEntries ( ).end ( ) )
		throw exception::CommonException ( "Entry " + name + " not available" );

	auto incompatibleLambda = [ ] ( const ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > & compatibility ) {
		return std::get < 0 > ( compatibility ) == MatchType::INCOMPATIBLE;
	};

	auto castLambda = [ ] ( const ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > & compatibility ) {
		return std::get < 0 > ( compatibility ) == MatchType::CAST;
	};

	auto exactLambda = [ ] ( const ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > & compatibility ) {
		return std::get < 0 > ( compatibility ) == MatchType::EXACT;
	};

	// determine how one can actually map what we have ( paramTypes ) as params to what is available as overloads ( group->second )
	std::vector < std::pair < ext::vector < ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > >, std::pair < std::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > > compatibilityData;
	for ( const ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > >, ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > & entry : group->second ) {
		if ( std::get < 1 > ( entry ).size ( ) != paramTypes.size ( ) )
			continue;

		ext::vector < ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > > compatibilityVector;
		for ( unsigned i = 0; i < paramTypes.size ( ); ++ i ) {
			MatchType matchType;
			if ( std::get < 0 > ( std::get < 1 > ( entry ) [ i ] ) == paramTypes [ i ] ) {
				matchType = MatchType::EXACT;
			} else if ( abstraction::CastRegistry::castAvailable ( std::get < 0 > ( std::get < 1 > ( entry ) [ i ] ), paramTypes [ i ] ) ) {
				matchType = MatchType::CAST;
			} else {
				matchType = MatchType::INCOMPATIBLE;
			}

			compatibilityVector.push_back ( ext::make_tuple ( matchType, std::get < 0 > ( std::get < 1 > ( entry ) [ i ] ), std::get < 1 > ( std::get < 1 > ( entry ) [ i ] ) ) );
		}

		// clear incompatibilities are fitered out
		if ( std::none_of ( compatibilityVector.begin ( ), compatibilityVector.end ( ), incompatibleLambda ) )
			compatibilityData.push_back ( std::make_pair ( std::move ( compatibilityVector ), std::get < 2 > ( entry ) ) );
	}

	// remaining compatible overloads are examined per parameter and the best option is remembered as overload index that achieved it
	ext::vector < ext::set < unsigned > > winnerList;
	for ( unsigned i = 0; i < paramTypes.size ( ); ++ i ) {
		ext::set < unsigned > best;

		unsigned overload = 0;
		for ( const std::pair < ext::vector < ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > >, std::pair < std::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > & data : compatibilityData ) {
			if ( exactLambda ( data.first [ i ] ) )
				best.insert ( overload );

			++ overload;
		}

		if ( best.size ( ) > 0 ) {
			winnerList.push_back ( std::move ( best ) );
			continue;
		}

		overload = 0;
		for ( const std::pair < ext::vector < ext::tuple < MatchType, std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > > >, std::pair < std::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > & data : compatibilityData ) {
			if ( castLambda ( data.first [ i ] ) )
				best.insert ( overload );

			++ overload;
		}

		winnerList.push_back ( std::move ( best ) );
	}

	// intersection of everything together finds indexes which are better or of the same quality for all params over all overloads
	ext::set < unsigned > winner { ext::sequence < unsigned > ( 0 ).begin ( ), ext::sequence < unsigned > ( compatibilityData.size ( ) ).end ( ) };
	for ( const ext::set < unsigned > & best : winnerList ) {
		ext::set < unsigned > filtered;
		std::set_intersection ( winner.begin ( ), winner.end ( ), best.begin ( ), best.end ( ), std::inserter ( filtered, filtered.end ( ) ) );
		winner = std::move ( filtered );
	}

	// if there is a sinle winner, return it
	std::shared_ptr < Entry > best;
	if ( winner.size ( ) == 1 ) {
		best = compatibilityData [ * winner.begin ( ) ].second.second;
	} else if ( winner.size ( ) > 1 ) {
		std::stringstream ss;
		ss << paramTypes;

//		throw exception::CommonException ( "Entry overload " + ss.str ( ) + " ambiguous." ); FIXME make better overload select algorithm
		best = compatibilityData [ * winner.begin ( ) ].second.second;

		if(common::GlobalData::verbose)
			common::Streams::err << "Entry overload " + ss.str ( ) + " ambiguous. First selected." << std::endl;
	} else {
		std::stringstream ss;
		ss << paramTypes;

		throw exception::CommonException ( "Entry overload " + ss.str ( ) + " not available." );
	}

	return best->getAbstraction ( );
}

ext::set < std::string > AlgorithmRegistry::listGroup ( const std::string & group ) {
	ext::set < std::string > res;

	for ( const std::pair < const std::string, ext::vector < ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > >, ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > > > & entry : getEntries ( ) )
		if ( entry.first.find ( group ) == 0 ) //found at the begining
			res.insert ( entry.first );

	return res;
}

ext::set < ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > > > > AlgorithmRegistry::listOverloads ( const std::string & algorithm ) {
	auto group = getEntries ( ).find ( algorithm );
	if ( group == getEntries ( ).end ( ) )
		throw exception::CommonException ( "Entry " + algorithm + " not available" );

	ext::set < ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > > > > res;
	for ( const ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > >, ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > & overloads : group->second )
		res.insert ( ext::make_tuple ( std::get < 0 > ( overloads ), std::get < 2 > ( overloads ).first, std::get < 1 > ( overloads ) ) );

	return res;
}

ext::set < std::string > AlgorithmRegistry::list ( ) {
	ext::set < std::string > res;

	for ( const std::pair < const std::string, ext::vector < ext::tuple < AlgorithmCategories::AlgorithmCategory, ext::vector < ext::tuple < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier >, std::string > >, ext::pair < ext::pair < std::string, ext::set < abstraction::ParamQualifiers::ParamQualifier > >, std::shared_ptr < Entry > > > > > & entry : getEntries ( ) )
		res.insert ( entry.first );

	return res;
}

} /* namespace abstraction */