/******************************************************************************/
/* SRD - PARSER DEFINITIONS ***************************************************/
/******************************************************************************/

#ifndef _H_LW_LIB_SRDDEFINITIONS
#define _H_LW_LIB_SRDDEFINITIONS
#include <lw/lib/SRDData.hh>
#include <lw/lib/HashTables.hh>
namespace lw {


/*= DEFINITION DATA ==========================================================*/

// Full definition -> {contexts}, default context, {enums}
// Context -> name, {rules}
// Rule -> Accepted input, [context, [init], [exit]], [executor]
// Input def ->   Word
//		| Enum
//		| Token type
//		| Alternatives
//		| Repetition
// Alternatives -> {input def}
// Repetition -> Input sequence, min count, max count

// Forward declarations
struct T_SRDParserData;

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

// F_SRDHandler - Parser callbacks
using F_SRDHandler = std::function< bool( T_SRDParserData const& ) >;

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

// T_SRDEnum - an enumeration
// i.e. set of words with associated sequence of integers, that can be
// recognized as a single input token.
class T_SRDEnum
{
private:
	T_String name_;
	T_HashIndex index_;
	T_Array< T_String > words_;

public:
	T_SRDEnum( ) = delete;

	T_SRDEnum( T_String name );
	T_SRDEnum( T_SRDEnum const& ) = default;
	T_SRDEnum( T_SRDEnum && ) = default;

	T_SRDEnum & operator <<( T_String && word );
	T_SRDEnum & operator <<( char const* word );

	T_String const& name( ) const;
	auto size( ) const;

	T_String const& operator[]( int index ) const;
	T_String const& operator[]( uint32_t index ) const;

	uint32_t operator[]( T_String const& word ) const;
	uint32_t operator[]( char const* word ) const;

	bool contains( T_String const& word ) const;
	bool contains( char const* word ) const;
};

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

// E_SRDInputItem - Possible types for input definition elements
enum class E_SRDInputItem
{
	WORD ,		// A specific word
	ENUM ,		// A word from an enumeration
	TOKEN ,		// An arbitrary token
	ALTERNATIVE ,	// A set of alternative rules
	REPETITION ,	// Repetition of a sequence
};

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

// T_SRDInputItem - An element from an input definition
class T_SRDInputItem
{
public:
	struct T_ListHelper {
		T_Array< T_SRDInputItem > items;
		T_ListHelper( );
		T_ListHelper& operator <<( T_SRDInputItem item );
	};

private:
	E_SRDInputItem type_;
	T_String word_;
	E_SRDTokenType token_;
	T_Array< T_SRDInputItem > items_;
	uint32_t min_ , max_;

public:
	// Construct an ALTERNATIVE input element
	T_SRDInputItem( );
	// Construct either a WORD or an ENUM input element
	T_SRDInputItem( T_String wordOrName , bool isWord );
	// Construct a WORD from a C string
	T_SRDInputItem( char const* cString );
	// Construct a TOKEN input element
	T_SRDInputItem( E_SRDTokenType type );
	// Construct a REPETITION input element
	T_SRDInputItem( uint32_t min , uint32_t max );

	friend void swap( T_SRDInputItem & lhs , T_SRDInputItem & rhs ) noexcept;

	T_SRDInputItem( T_SRDInputItem const& ) = default;
	T_SRDInputItem( T_SRDInputItem && ) noexcept = default;
	T_SRDInputItem & operator=( T_SRDInputItem const& ) = default;
	T_SRDInputItem & operator=( T_SRDInputItem && ) = default;

	E_SRDInputItem type( ) const;
	T_String const& word( ) const;
	E_SRDTokenType token( ) const;
	T_Array< T_SRDInputItem > items( ) const;
	uint32_t min( ) const;
	uint32_t max( ) const;

	T_SRDInputItem & operator <<( T_SRDInputItem item );
	T_SRDInputItem& operator <<( T_ListHelper list );

	// This operator is not actually used. It's only here to make the template
	// instantiation happy. It actually returns false.
	bool operator ==( T_SRDInputItem const& other ) const;
};
void swap( T_SRDInputItem & lhs , T_SRDInputItem & rhs ) noexcept;
T_StringBuilder & operator <<( T_StringBuilder & sb , T_SRDInputItem const& item );

T_Array< T_SRDInputItem >& operator <<( T_Array< T_SRDInputItem > & items ,
		T_SRDInputItem::T_ListHelper& list );

extern template class T_Array< T_SRDInputItem >;

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

// T_SRDInputRule - A full rule from a context
class T_SRDInputRule
{
public:
	struct T_SetContextExecutor {
		const bool exit;
		const F_SRDHandler executor;
		T_SetContextExecutor( bool exit , F_SRDHandler executor );
	};
	struct T_SetContext {
		const T_String name;
		T_SetContext( T_String string );
	};

private:
	F_SRDHandler executor_;
	T_Array< T_SRDInputItem > items_;

	T_String context_;
	F_SRDHandler contextEnter_;
	F_SRDHandler contextExit_;

public:
	T_SRDInputRule & operator <<( T_SRDInputItem item );
	T_SRDInputRule & operator <<( F_SRDHandler executor );
	T_SRDInputRule & operator <<( T_SetContextExecutor sce );
	T_SRDInputRule & operator <<( T_SetContext sc );
	T_SRDInputRule & operator <<( T_SRDInputItem::T_ListHelper sc );

	F_SRDHandler const& handler( ) const;
	T_Array< T_SRDInputItem > const& rule( ) const;
	T_String const& context( ) const;
	F_SRDHandler const& onEnter( ) const;
	F_SRDHandler const& onExit( ) const;
};
T_StringBuilder & operator <<( T_StringBuilder & sb , T_SRDInputRule const& item );

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

// T_SRDContext - A set of rules that will share common data
class T_SRDContext
{
private:
	T_String name_;
	T_String parent_;
	T_Array< T_SRDInputRule > rules_;

public:
	T_SRDContext( ) = delete;

	explicit T_SRDContext( T_String name , T_String parent = T_String( ) );

	T_SRDContext & operator <<( T_SRDInputRule rule );

	T_String const& name( ) const;
	T_String const& parent( ) const;
	T_Array< T_SRDInputRule > const& rules( ) const;

	T_StringBuilder & dump( T_StringBuilder & sb , T_String const& separator );
};

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

// T_SRDParserDefs - All definitions for a parser
class T_SRDParserDefs
{
public:
	// SetHandler - Used to set start/end handlers
	struct SetHandler
	{
		const F_SRDHandler handler;
		const bool start;
		SetHandler( F_SRDHandler const& handler , bool start );
	};

private:
	T_String dfCtx_;
	T_ObjectTable< T_String , T_SRDContext > ctx_;
	T_ObjectTable< T_String , T_SRDEnum > enums_;

	F_SRDHandler onStart_;
	F_SRDHandler onFinish_;

public:
	T_SRDParserDefs( ) = delete;

	explicit T_SRDParserDefs( T_String defaultContext );
	explicit T_SRDParserDefs( char const* defaultContext );

	T_String const& defaultContext( ) const;
	void defaultContext( T_String const& name );
	void defaultContext( char const* name );

	T_SRDParserDefs & operator <<( SetHandler sh );
	F_SRDHandler const& onStart( ) const;
	F_SRDHandler const& onFinish( ) const;

	uint32_t contexts( ) const;
	T_SRDContext & operator[]( uint32_t idx );
	T_SRDContext const& operator[]( uint32_t idx ) const;

	uint32_t contextId( T_String const& name ) const;

	T_SRDContext & context( T_String const& name );
	T_SRDContext & context( char const* name );
	T_SRDContext & context( T_String const& name , T_String const& parent );
	T_SRDContext & context( char const* name , char const* parent );

	uint32_t enums( ) const;
	bool hasEnum( T_String const& name ) const;
	T_SRDEnum & enumeration( char const* name );
	T_SRDEnum & enumeration( T_String const& name );
	T_SRDEnum const& enumeration( T_String const& name ) const;
};
M_CLASS_POINTERS( SRDParserDefs );


/*= PARSER DEFINITIONS HELPERS ===============================================*/

namespace SRD {

T_SRDParserDefs::SetHandler OnStart( F_SRDHandler const& handler );
T_SRDParserDefs::SetHandler OnFinish( F_SRDHandler const& handler );

T_SRDContext Context( T_String name );
T_SRDContext Context( char const* name );

T_SRDContext Context( char const* name , char const* parent );
T_SRDContext Context( T_String name , T_String parent );

T_SRDInputRule Rule( );

T_SRDEnum CreateEnum( T_String name );
T_SRDEnum CreateEnum( char const* name );

T_SRDInputItem Word( T_String const& word );
T_SRDInputItem Word( char const* word );

T_SRDInputItem Word( );
T_SRDInputItem String( );
T_SRDInputItem Binary( );
T_SRDInputItem LStart( );
T_SRDInputItem LEnd( );
T_SRDInputItem Int32( );
T_SRDInputItem Int64( );
T_SRDInputItem Float( );

T_SRDInputItem Enum( T_String name );
T_SRDInputItem Enum( char const* name );

T_SRDInputItem::T_ListHelper List( );

T_SRDInputItem Alt( );

T_SRDInputItem Sub( );

T_SRDInputItem Opt( );
T_SRDInputItem Opt( T_SRDInputItem item );

T_SRDInputItem AtLeast( uint32_t n );
T_SRDInputItem AtMost( uint32_t n );
T_SRDInputItem Times( uint32_t n );
T_SRDInputItem Between( uint32_t a , uint32_t b );

T_SRDInputItem Integer( );
T_SRDInputItem Numeric( );
T_SRDInputItem Text( );

T_SRDInputRule::T_SetContext EnterContext( T_String name );
T_SRDInputRule::T_SetContext EnterContext( char const* name );

T_SRDInputRule::T_SetContextExecutor OnEnter( F_SRDHandler f );
T_SRDInputRule::T_SetContextExecutor OnExit( F_SRDHandler f );

} // namespace SRD


} // namespace
#include <lw/lib/inline/SRDDefinitions.hh>
#endif // _H_LW_LIB_SRDDEFINITIONS