#include "externals.hh"
#include "sync.hh"
#include "globals.hh"

namespace {

const std::map< std::string , T_SyncSegment::E_SegmentType > SegmentTypes_( ([] {
	std::map< std::string , T_SyncSegment::E_SegmentType > t;
	t.emplace( "linear" , T_SyncSegment::LINEAR );
	t.emplace( "ramp" , T_SyncSegment::RAMP );
	t.emplace( "smooth" , T_SyncSegment::SMOOTH );
	return t;
})());

}


/*= T_SyncTime ===============================================================*/

void T_SyncTime::setDuration(
		__rd__ const float uDuration ,
		__rd__ const uint32_t iDuration )
{
	this->uDuration = std::max( 1e-3f , uDuration );
	this->iDuration = std::max( 1u , iDuration );
	time = std::min( time , duration( ) );
}


/*= T_SyncCurves =============================================================*/

void T_SyncCurves::clear( )
{
	curves.clear( );
	positions.clear( );
}

void T_SyncCurves::setCurve( __rd__ T_SyncCurve curve )
{
	const auto p( positions.find( curve.name ) );
	if ( p == positions.end( ) ) {
		positions.emplace( curve.name , curves.size( ) );
		curves.emplace_back( std::move( curve ) );
	} else {
		curves[ p->second ] = std::move( curve );
	}
}

int32_t T_SyncCurves::indexOf( __rd__ std::string const& name )
{
	const auto p( positions.find( name ) );
	return p == positions.end( ) ? -1 : p->second;
}


/*= T_SyncCurveCache =========================================================*/

T_SyncCurveCache::T_SyncCurveCache(
		__rd__ T_SyncTime const& time ,
		__rd__ T_SyncCurves const& curves ,
		__rd__ const uint32_t curve ) noexcept
	: curve( curve ) , curPos( 0 )
{
	auto const& c( curves.curves[ curve ] );
	const auto ns( c.segments.size( ) );
	assert( ns > 0 );

	uint32_t s = 0;
	for ( auto i = 0u ; i < ns ; i ++ ) {
		auto const& v( c.segments[ i ] );
		assert( v.nPoints >= 2 );
		assert( v.durations.size( ) == v.nPoints - 1 );

		const auto nd( v.nPoints - 1 );
		for ( auto j = 0u ; j < nd ; j ++ ) {
			const auto sStart( s * time.uDuration );
			if ( time.time >= sStart ) {
				curPos = segStarts.size( );
			}
			segStarts.push_back( sStart );
			segRefs.push_back( std::make_pair( i , j ) );
			s += v.durations[ j ];
			segEnds.push_back( std::min( s , time.iDuration ) * time.uDuration );
			if ( s > time.iDuration ) {
				return;
			}
		}
	}
}

/*----------------------------------------------------------------------------*/

uint32_t T_SyncCurveCache::findSegment(
		__rd__ const float time ) const noexcept
{
	const auto ns( segStarts.size( ) );
	for ( auto i = 0u ; i < ns ; i ++ ) {
		if ( segStarts[ i ] <= time && segEnds[ i ] > time ) {
			return i;
		}
	}
	return ns;
}

/*----------------------------------------------------------------------------*/

float T_SyncCurveCache::valueAt(
		__rd__ T_SyncTime const& time ,
		__rd__ T_SyncCurves const& curves ,
		__rd__ const float position ) const noexcept
{
	return segmentValue( time.time , findSegment( position ) ,
			curves.curves[ curve ].segments );
}

float T_SyncCurveCache::value(
		__rd__ T_SyncTime const& time ,
		__rd__ T_SyncCurves const& curves ) noexcept
{
	const auto t( time.time );

	// Check / update curPos
	const float ss0( curPos == segStarts.size( )
			? time.duration( )
			: segStarts[ curPos ] );
	if ( ss0 > t ) {
		curPos = findSegment( t );
	} else {
		while ( curPos < segStarts.size( ) && t >= segEnds[ curPos ] ) {
			curPos ++;
		}
	}

	// We got the actual index in curPos, now compute the value.
	return segmentValue( t , curPos , curves.curves[ curve ].segments );
}

/*----------------------------------------------------------------------------*/

float T_SyncCurveCache::segmentValue(
		__rd__ float time ,
		__rd__ uint32_t segIndex ,
		__rd__ std::vector< T_SyncSegment > const& segments ) const noexcept
{
	const auto sss( segStarts.size( ) );
	if ( segIndex >= sss ) {
		assert( sss != 0 );
		segIndex = sss - 1;
		time = segEnds[ segIndex ];
	}

	auto const& idxp( segRefs[ segIndex ] );
	auto const& seg( segments[ idxp.first ] );

	// Interpolation factor
	const float st( segStarts[ segIndex ] );
	const float et( segEnds[ segIndex ] );
	const float v0 = ( time - st ) / ( et - st );
	float v = v0;
	if ( seg.type != T_SyncSegment::LINEAR ) {
		v *= v0;
		if ( seg.type == T_SyncSegment::SMOOTH ) {
			v *= 3 - 2 * v0;
		}
	}

	const auto pid( idxp.second );
	const float sv( seg.values[ pid ] );
	const float ev( seg.values[ pid + 1 ] );
#if 0
	printf( "[%.2f] gidx %d - seg %d idx %d - %f\n" , time , segIndex ,
			idxp.first , idxp.second , v * ( ev - sv ) + sv );
#endif
	return v * ( ev - sv ) + sv;
}


/*= T_SyncValues =============================================================*/

T_SyncValues::T_SyncValues( )
{
	values.push_back( 0 );
}

// ---------------------------------------------------------------------

void T_SyncValues::clear( )
{
	identifiers.clear( );
	values.clear( );
	overriden.clear( );
	positions.clear( );
	values.push_back( 0 );
}

bool T_SyncValues::addValue(
		__rd__ std::string const& name ,
		__rd__ const float initial )
{
	const auto np( positions.find( name ) );
	if ( np != positions.end( ) ) {
		return false;
	}
	const auto li( values.size( ) - 1 );
	positions.emplace( name , li );
	identifiers.push_back( name );
	values.push_back( initial );
	std::swap( values[ li ] , values[ li + 1 ] );
	overriden.push_back( false );
	return true;
}

uint32_t T_SyncValues::indexOf(
		__rd__ std::string const& name ) const
{
	const auto np( positions.find( name ) );
	if ( np == positions.end( ) ) {
		return values.size( ) - 1;
	} else {
		return np->second;
	}
}


/*= T_SyncManager ============================================================*/

void T_SyncManager::setDuration(
		__rd__ const float uDuration ,
		__rd__ const uint32_t iDuration )
{
	time_.setDuration( uDuration , iDuration );
	updateCurveCaches( );
}

void T_SyncManager::setTime(
		__rd__ const float time )
{
	time_.setTime( time );
	updateValues( );
}

/*----------------------------------------------------------------------------*/

void T_SyncManager::checkCurveFile( )
{
	if ( watcher_ ) {
		return;
	}

	printf( "CURVE INIT\n" );
	bool missing;
	if ( loadCurves_( missing ) || !missing ) {
		watcher_ = std::make_unique< T_WatchedFiles >(
				Globals::Watcher( ) ,
				[this] { curvesChanged_( ); } );
		watcher_->watch( "curves.json" );
	}
	printf( "INIT MISSING IS %c\n" , missing ? 'Y' : 'N' );
}

void T_SyncManager::clearCurves( )
{
	curves_.clear( );
	updateCurveCaches( );
}

void T_SyncManager::setCurve(
		__rd__ T_SyncCurve curve )
{
	curves_.setCurve( curve );
	updateCurveCaches( );
}

void T_SyncManager::curvesChanged_( )
{
	bool missing;
	if ( !loadCurves_( missing ) && missing ) {
		watcher_.reset( );
	}
}

bool T_SyncManager::loadCurves_(
		__wr__ bool& missing )
{
	using T_STI_ = std::istream_iterator< char >;
	std::ifstream file( "curves.json" );
	picojson::value root;
	try {
		missing = !file.is_open( );
		if ( missing ) {
			return false;
		}

		std::string errors;
		picojson::parse( root , T_STI_( file ) , T_STI_( ) , &errors );
		if ( !errors.empty( ) ) {
			printf( "Failed to parse 'curves.json':\n%s\n" , errors.c_str( ) );
			return false;
		}
	} catch ( std::ios_base::failure const& e ) {
		printf( "I/O error while reading 'curves.json'\n%s\n" , e.what( ) );
		missing = false;
		return false;
	}

	T_SyncCurves nCurves;
	if ( !loadCurvesData_( nCurves , root ) ) {
		return false;
	}
	curves_ = std::move( nCurves );
	updateCurveCaches( );
	return true;
}

bool T_SyncManager::loadCurvesData_(
		__wr__ T_SyncCurves& curves ,
		__rd__ picojson::value const& root )
{
	if ( !root.is< T_JSONObject >( ) ) {
		printf( "Curves data: root is not a JSON object\n" );
		return false;
	}

	auto const& r( root.get< T_JSONObject >( ) );
	bool ok( true );
	for ( auto const& item : r ) {
		if ( curves.indexOf( item.first ) != -1 ) {
			printf( "Curves data: duplicate curve '%s'\n" ,
					item.first.c_str( ) );
			ok = false;
			continue;
		}
		if ( !item.second.is< T_JSONArray >( ) ) {
			printf( "Curves data: entry for curve '%s' is not an array\n" ,
					item.first.c_str( ) );
			ok = false;
			continue;
		}

		T_SyncCurve nsc;
		nsc.name = item.first;

		bool segsOk( true );
		for ( auto const& v : item.second.get< T_JSONArray >( ) ) {
			if ( !v.is< T_JSONObject >( ) ) {
				printf( "Curves data: curve '%s': invalid segment\n" ,
						item.first.c_str( ) );
				segsOk = false;
				continue;
			}

			T_SyncSegment segment;
			try {
				if ( !loadSegmentData_( segment , nsc.name ,
						v.get< T_JSONObject >( ) ) ) {
					segsOk = false;
					continue;
				}
			} catch ( X_JsonGetFailed const& ) {
				printf( "Curves data: curve '%s': could not parse segment data\n" ,
						item.first.c_str( ) );
				segsOk = false;
				continue;
			}
			nsc.segments.emplace_back( std::move( segment ) );
		}

		ok = ok && segsOk;
		if ( nsc.segments.empty( ) && segsOk ) {
			printf( "Curves data: curve '%s': no segments\n" ,
					item.first.c_str( ) );
			ok = false;
		}
		curves.setCurve( std::move( nsc ) );
	}

	return ok;
}

bool T_SyncManager::loadSegmentData_(
		__wr__ T_SyncSegment& segment ,
		__rd__ std::string const& curve ,
		__rd__ T_JSONObject const& sd )
{
	auto const& sType( jsonGet< std::string >( sd , "type" ) );

	const auto p( SegmentTypes_.find( sType ) );
	if ( p == SegmentTypes_.end( ) ) {
		printf( "Curves data: curve '%s': invalid segment type '%s'\n" ,
				curve.c_str( ) , sType.c_str( ) );
		return false;
	}
	segment.type = p->second;

	auto const& vList( jsonGet< T_JSONArray >( sd , "values" ) );
	auto const& dList( jsonGet< T_JSONArray >( sd , "durations" ) );

	if ( vList.size( ) < 2 ) {
		printf( "Curves data: curve '%s': segment doesn't have enough values\n" ,
				curve.c_str( ) );
		return false;
	}
	if ( vList.size( ) != dList.size( ) + 1 ) {
		printf( "Curves data: curve '%s': segment values / durations count mismatch\n" ,
				curve.c_str( ) );
		return false;
	}

	for ( auto const& vv : vList ) {
		if ( !vv.is< double >( ) ) {
			printf( "Curves data: curve '%s': non-numeric entry in segment values\n" ,
					curve.c_str( ) );
			return false;
		}
		segment.values.push_back( float( vv.get< double >( ) ) );
	}

	for ( auto const& dv : dList ) {
		if ( !dv.is< double >( ) ) {
			printf( "Curves data: curve '%s': non-numeric entry in segment durations\n" ,
					curve.c_str( ) );
			return false;
		}

		const double dvn( dv.get< double >( ) );
		if ( fmod( dvn , 1.0 ) != 0.0 || dvn <= 0 ) {
			printf( "Curves data: curve '%s': invalid segment duration %f\n" ,
					curve.c_str( ) , dvn );
			return false;
		}
		segment.durations.push_back( uint32_t( dvn ) );
	}

	segment.nPoints = segment.values.size( );
	return true;
}

/*----------------------------------------------------------------------------*/

void T_SyncManager::updateCurveCaches( )
{
	curveCaches_.clear( );
	const uint32_t nv( values_.identifiers.size( ) );
	for ( auto i = 0u ; i < nv ; i ++ ) {
		auto const& id( values_.identifiers[ i ] );
		const auto cp( curves_.indexOf( id ) );
		if ( cp < 0 ) {
			curveCaches_.emplace_back( );
		} else {
			curveCaches_.emplace_back( new T_SyncCurveCache(
				time_ , curves_ , cp
			) );
		}
	}
	updateValues( );
}

void T_SyncManager::updateValues( )
{
	const auto nv( values_.identifiers.size( ) );
	assert( nv == curveCaches_.size( ) );
	for ( auto i = 0u ; i < nv ; i ++ ) {
		auto const& cc( curveCaches_[ i ] );
		if ( !cc || values_.overriden[ i ] ) {
			continue;
		}
		values_.values[ i ] = cc->value( time_ , curves_ );
	}
}

/*============================================================================*/

#if 0
void T_SyncManager::makeUI( )
{
	auto const& dspSize( ImGui::GetIO( ).DisplaySize );

	if ( wOverrides ) {
		ImGui::SetNextWindowSize( ImVec2( 300 , dspSize.y - 300 ) ,
				ImGuiSetCond_Once );
		ImGui::SetNextWindowPos( ImVec2( 0 , 150 ) ,
				ImGuiSetCond_Once );
		ImGui::Begin( "Input overrides" );
		displayOvSections( uiRoot , true );
		ImGui::End( );
	}
	if ( wCurves ) {
		ImGui::SetNextWindowSize( ImVec2( dspSize.x , 150 ) ,
				ImGuiSetCond_Once );
		ImGui::SetNextWindowPos( ImVec2( 0 , dspSize.y - 150 ) ,
				ImGuiSetCond_Once );
		ImGui::Begin( "Curve editor" );
		// XXX contents
		ImGui::End( );
	}
}

void T_SyncManager::displayOvSections(
		__rw__ T_SyncUISections& sections ,
		__rd__ const bool topLevel )
{
	for ( auto& s : sections ) {
		const bool display( topLevel
				? ImGui::CollapsingHeader( s->title.c_str( ) )
				: ImGui::TreeNode( s->title.c_str( ) ) );
		if ( !display ) {
			continue;
		}
		displayOvSections( s->subsections );
		if ( s->subsections.size( ) && s->overrides.size( ) ) {
			ImGui::Separator( );
		}
		displayOvControls( s->overrides );
		if ( !topLevel ) {
			ImGui::TreePop( );
		}
	}
}

void T_SyncManager::displayOvControls(
		__rw__ T_SyncUIOverrides& overrides )
{
	for ( auto& o : overrides ) {
		// XXX enable override checkbox should be selected and disabled
		// if there is no curve
		const bool changed( ImGui::Checkbox( "" , &o->enabled ) );
		if ( changed ) {
			// XXX mark the inputs as coming from the UI / the curves
		}
		ImGui::SameLine( );

		switch ( o->type ) {
			case T_SyncUIOverride::FLOAT:
			case T_SyncUIOverride::VEC2:
			case T_SyncUIOverride::VEC3:
			case T_SyncUIOverride::VEC4:
			case T_SyncUIOverride::INT:
			case T_SyncUIOverride::COLOR:
			case T_SyncUIOverride::COLOR_GRADING:
			case T_SyncUIOverride::CAMERA:
				break;
		}
	}
}
#endif