#ifndef __tree_sitter_parser_h__
#define __tree_sitter_parser_h__

#include "document.h"
#include <stdio.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef int TSState;
typedef struct {
    TSState state;
    TSSymbol symbol;
} TSStackEntry;

typedef struct {
    TSTree tree;
    const char *input;
    size_t position;
    TSSymbol lookahead_sym;
    TSState lex_state;
    TSStackEntry *stack;
    size_t stack_size;
} TSParser;

TSParser TSParserMake(const char *input);
void TSParserShift(TSParser *parser, TSState state);
void TSParserReduce(TSParser *parser, TSSymbol symbol, int child_count);
void TSParserError(TSParser *parser);
void TSParserAdvance(TSParser *parser, TSState lex_state);
TSState TSParserParseState(const TSParser *parser);
TSState TSParserLexState(const TSParser *parser);
void TSParserSetLexState(TSParser *parser, TSState state);
char TSParserLookaheadChar(const TSParser *parser);
TSSymbol TSParserLookaheadSym(const TSParser *parser);
void TSParserSetLookaheadSym(TSParser *parser, TSSymbol symbol);

#pragma mark - DSL

#define START_PARSER() \
TSParser p = TSParserMake(input),  *parser = &p; \
next_state: \
printf("parse state: %d, lookahead: %s\n", PARSE_STATE(), LOOKAHEAD_SYM_NAME());
    
#define LOOKAHEAD_SYM_NAME() \
ts_symbol_names[LOOKAHEAD_SYM()]

#define START_LEXER() \
if (parser->lookahead_sym > 0) return; \
next_state: \
printf("lex state: %d, lookahead: %c\n", LEX_STATE(), LOOKAHEAD_CHAR()); \
if (LOOKAHEAD_CHAR() == '\0') { \
  ACCEPT_TOKEN(ts_symbol___END__); \
} \

#define LOOKAHEAD_SYM() \
TSParserLookaheadSym(parser)

#define LOOKAHEAD_CHAR() \
TSParserLookaheadChar(parser)

#define PARSE_STATE() \
TSParserParseState(parser)

#define LEX_STATE() \
TSParserLexState(parser)

#define SHIFT(state) \
{ TSParserShift(parser, state); goto next_state; }

#define SET_LEX_STATE(state_index) \
{ TSParserSetLexState(parser, state_index); ts_lex(parser); }

#define ADVANCE(state_index) \
{ TSParserAdvance(parser, state_index); goto next_state; }

#define ACCEPT_INPUT() \
{ goto done; }

#define ACCEPT_TOKEN(symbol) \
{ TSParserSetLookaheadSym(parser, symbol); goto done; }

#define REDUCE(symbol, child_count) \
{ TSParserReduce(parser, symbol, child_count); goto next_state; }

#define PARSE_ERROR() \
{ TSParserError(parser); goto done; }

#define LEX_ERROR() \
{ TSParserError(parser); goto done; }

#define FINISH_PARSER() \
done: \
return parser->tree;

#define FINISH_LEXER() \
done:
    
#ifdef __cplusplus
}
#endif

#endif