#include "opast.hh"

using namespace ebcl;
using namespace opast;


/*= A_Node ===================================================================*/

A_Node::A_Node( const E_Type type ,
		A_Node* const parent ) noexcept
	: type_( type ) , parent_( parent )
{
	assert( ( type == ROOT && !parent ) || ( type != ROOT && parent ) );
}

A_Node::~A_Node( ) { }

T_RootNode& A_Node::root( ) const noexcept
{
	A_Node const* node( this );
	while ( node->parent_ ) {
		node = node->parent_;
	}
	assert( node );
	assert( node->type_ == ROOT );
	return *dynamic_cast< T_RootNode* >(
			const_cast< A_Node* >( node ) );
}

/*= A_FuncNode ===============================================================*/

A_FuncNode::A_FuncNode(
		const bool isInit ,
		T_RootNode* const root ) noexcept
	: A_Node( isInit ? DECL_INIT : DECL_FRAME , root ) ,
		name_( isInit ? "*init*" : "*frame*" )
{ }

A_FuncNode::A_FuncNode(
		T_String const& name ,
		T_RootNode* const root ) noexcept
	: A_Node( DECL_FN , root ) , name_( name )
{ }


/*= T_RootNode ===============================================================*/

T_RootNode::T_RootNode( ) noexcept
	: A_Node( ROOT , nullptr ) , functions_(
			[]( T_OwnPtr< A_FuncNode > const& f ) {
				return f->name( );
			} )
{ }


T_RootNode::T_AddFunctionResult T_RootNode::addFunction(
		T_OwnPtr< A_FuncNode >& function ) noexcept
{
	T_String const& fn( function->name( ) );
	auto const* const pf( functions_.get( fn ) );
	if ( !pf ) {
		auto* const rv( function.get( ) );
		functions_.add( std::move( function ) );
		return *rv;
	}

	T_String dfn;
	uint32_t dupCtr( 0 );
	do {
		T_StringBuilder fnsb;
		fnsb << fn << " dup " << dupCtr ++;
		dfn = std::move( fnsb );
	} while ( functions_.contains( dfn ) );

	T_OwnPtr< A_FuncNode > df( NewOwned< T_FuncNode >( dfn , *this ) );
	auto* const rv( df.get( ) );
	functions_.add( std::move( df ) );
	return T_AddFunctionResult{ *rv , (*pf)->location( ) };
}


/*= T_SpecialFuncNode ========================================================*/

T_SpecialFuncNode::T_SpecialFuncNode(
		bool isInit ,
		T_RootNode& parent ) noexcept
	: A_FuncNode( isInit , &parent )
{ }


/*= T_FuncNode ===============================================================*/

T_FuncNode::T_FuncNode(
		T_String const& name ,
		T_RootNode& parent ) noexcept
	: A_FuncNode( name , &parent )
{ }

T_Optional< T_SRDLocation > T_FuncNode::addArgument(
		T_SRDToken const& token ) noexcept
{
	assert( token.type( ) == E_SRDTokenType::WORD );
	assert( token.hasLocation( ) );

	const auto pnp( argNames_.indexOf( token.stringValue( ) ) );
	if ( pnp != -1 ) {
		return argLocations_[ pnp ];
	}
	argNames_.add( token.stringValue( ) );
	argLocations_.add( token.location( ) );
	return {};
}


/*= T_Parser =================================================================*/

namespace {

struct T_ParserImpl_
{
	T_OwnPtr< T_RootNode >& root;
	T_Array< T_SRDError >& errors;

	T_ParserImpl_( T_Array< T_SRDError >* errors ,
			T_OwnPtr< T_RootNode >* root ) noexcept;

	void parseFunction( T_SRDList const& funcList ) noexcept;
};

T_ParserImpl_::T_ParserImpl_(
		T_Array< T_SRDError >* const errors ,
		T_OwnPtr< T_RootNode >* const root ) noexcept
	: root( *root ) , errors( *errors )
{ }

void T_ParserImpl_::parseFunction(
		T_SRDList const& funcList ) noexcept
{
	assert( funcList.size( ) != 0 );

	auto const& fw( funcList[ 0 ] );
	if ( fw.type( ) != E_SRDTokenType::WORD
			|| ( fw.stringValue( ) != "init" && fw.stringValue( ) != "frame"
				&& fw.stringValue( ) != "fn" ) ) {
		errors.addNew( "init, frame or fn expected" , fw.location( ) );
		return;
	}

	T_String const& ftw( fw.stringValue( ) );
	T_OwnPtr< A_FuncNode > fn;
	if ( ftw == "fn" ) {
		if ( funcList.size( ) < 3 ) {
			errors.addNew( "function name and arguments expected" ,
					fw.location( ) );
			return;
		}
		if ( funcList[ 1 ].type( ) != E_SRDTokenType::WORD ) {
			errors.addNew( "function name expected" , funcList[ 1 ].location( ) );
			return;
		}

		fn = NewOwned< T_FuncNode >( funcList[ 1 ].stringValue( ) , *root );
		// TODO parseFunctionArguments( funcList[ 2 ] );
	} else {
		fn = NewOwned< T_SpecialFuncNode >( ftw == "init" , *root );
	}
	fn->location( ) = fw.location( );

	const auto af( root->addFunction( fn ) );
	if ( af.dupLocation.present( ) ) {
		T_StringBuilder esb( "duplicate " );
		switch ( fn->type( ) ) {
			case A_Node::DECL_FN:
				esb << "function '" << fn->name( ) << "'";
				break;
			case A_Node::DECL_INIT:
				esb << "initialisation function";
				break;
			case A_Node::DECL_FRAME:
				esb << "frame function";
				break;
			default: std::abort( );
		}
		esb << "; previous declaration: " << *af.dupLocation.target( );
		errors.addNew( std::move( esb ) , fw.location( ) );
	}

	// TODO parseInstructions( fn->instructions , funcList ,
	// 			ftw == "fn" ? 3 : 1 );
}

} // namespace

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

T_Parser::T_Parser( ) noexcept
	: A_PrivateImplementation( new T_ParserImpl_( &errors_ , &rootNode_ ) ) ,
		errors_( 64 ) , rootNode_{}
{}

bool T_Parser::parse(
		T_SRDList const& input ) noexcept
{
	errors_.clear( );
	rootNode_ = NewOwned< T_RootNode >( );

	for ( auto const& t : input ) {
		if ( t.type( ) == E_SRDTokenType::LIST && t.list( ).size( ) > 0 ) {
			p< T_ParserImpl_ >( ).parseFunction( t.list( ) );
		} else {
			errors_.addNew( "Function or special block expected" ,
					t.location( ) );
		}
	}

	return errors_.empty( );
}