#include "SQLParser.h"

#include <stdio.h>

#include <string>

#include "parser/bison_parser.h"

#include "parser/flex_lexer.h"

namespace hsql {

SQLParser::SQLParser() { fprintf(stderr, "SQLParser only has static methods atm! Do not initialize!\n"); }

// static

bool SQLParser::parse(const std::string& sql, SQLParserResult* result) {

  yyscan_t scanner;

  YY_BUFFER_STATE state;

  if (hsql_lex_init(&scanner)) {

    // Couldn't initialize the lexer.

    fprintf(stderr, "SQLParser: Error when initializing lexer!\n");

    return false;

  }

  const char* text = sql.c_str();

  state = hsql__scan_string(text, scanner);

  // Parse the tokens.

  // If parsing fails, the result will contain an error object.

  int ret = hsql_parse(result, scanner);

  bool success = (ret == 0);

  result->setIsValid(success);

  hsql__delete_buffer(state, scanner);

  hsql_lex_destroy(scanner);

  return true;

}

// static

bool SQLParser::parseSQLString(const char* sql, SQLParserResult* result) { return parse(sql, result); }

bool SQLParser::parseSQLString(const std::string& sql, SQLParserResult* result) { return parse(sql, result); }

// static

bool SQLParser::tokenize(const std::string& sql, std::vector<int16_t>* tokens) {

  // Initialize the scanner.

  yyscan_t scanner;

  if (hsql_lex_init(&scanner)) {

    fprintf(stderr, "SQLParser: Error when initializing lexer!\n");

    return false;

  }

  YY_BUFFER_STATE state;

  state = hsql__scan_string(sql.c_str(), scanner);

  YYSTYPE yylval;

  YYLTYPE yylloc;

  // Step through the string until EOF is read.

  // Note: hsql_lex returns int, but we know that its range is within 16 bit.

  int16_t token = hsql_lex(&yylval, &yylloc, scanner);

  while (token != 0) {

    tokens->push_back(token);

    token = hsql_lex(&yylval, &yylloc, scanner);

    if (token == SQL_IDENTIFIER || token == SQL_STRING) {

      free(yylval.sval);

    }

  }

  hsql__delete_buffer(state, scanner);

  hsql_lex_destroy(scanner);

  return true;

}

}  // namespace hsql