/*
 * DBparser.h
 *
 *  Created on: 2014-6-20
 *      Author: liyouhuan
 */

#ifndef DBPARSER_H_
#define DBPARSER_H_

#include<string>
#include<vector>
#include<fstream>
#include<stdio.h>
#include "../Query/SPARQLquery.h"
#include "../Triple/Triple.h"
#include "SparqlParser.h"
#include "SparqlLexer.h"
using namespace std;

class DBparser{
private:

	int printNode(pANTLR3_BASE_TREE node,int depth=0);
	int parseNode(pANTLR3_BASE_TREE node, SPARQLquery& query,int depth=0);
	int parsePrefix(pANTLR3_BASE_TREE node,std::pair<std::string,std::string>& prefixPair);
	int parseString(pANTLR3_BASE_TREE node,std::string& str,int depth=0);
	int parseTriple(pANTLR3_BASE_TREE node,Triple& triple);
	int parseBasicQuery(pANTLR3_BASE_TREE node,BasicQuery& basicQuery);
	int parseVar(pANTLR3_BASE_TREE node,SPARQLquery& query);
	int replacePrefix(string& str);

	std::map<std::string,std::string> _prefix_map;

public:
	/* how many triples at most will be parsed out when call rdfParser() once
	 * when -1, it means parse all triples in the file into the triples set(array)
	 * */
	static const int TRIPLE_NUM_PER_GROUP = 10*1000*1000;

	DBparser();

	/* input sparql query string and parse query into SPARQLquery
	 * the returned string is set for log when error happen */
	string sparqlParser(const string& _sparql, SPARQLquery& _sparql_query);

	/* file stream _fin points to rdfFile
	 * that was opened previously in Database::encodeRDF
	 * rdfParser() will be called many times until all triples in the rdfFile is parsed
	 * and after each call, a group of triples will be parsed into the vector;
	 * the returned string is set for log when error happen;
	 */
	string rdfParser(ifstream& _fin, Triple* _triple_array, int& _triple_num);

private:
	/*
	 * used in readline of FILE, avoiding new memory each time
	 */
	static char* line_buf;
	static int buf_len;
};


#endif /* DBPARSER_H_ */