#include "ParsodusLexer.h"
#include "Parsodus/inputparser.h"
#include "Parsodus/parser.h"
#include "Parsodus/util/parserType.h"
#include "Lexesis/inputparser.h"
#include <set>
#include <fstream>
#include <iostream>

namespace {
    std::set<std::string> getTerminals(std::string file) {
		std::fstream f(file);
		return lxs::input::InputParser::getTokens(f);
    }   

}

namespace pds {

    InputParserException::InputParserException(std::string what): m_what(what) {}  
    const char* InputParserException::what() const throw() {
            return m_what.c_str();
    }   
    Config InputParser::parseInput(std::istream& is) {
        ParsodusLexer lex(is);
        Parser parser(lex);
    
        Config cnf = *parser.parse();   
        if (!cnf.lexesisFile.empty()) {
            auto terminals = getTerminals(cnf.lexesisFile);
            for(auto& terminal : terminals)
                cnf.grammar.terminals.insert(terminal);
        }
    
		for(auto& rule : cnf.grammar.rules) {
			for(auto& tail_piece : rule->tail) {
				if (cnf.grammar.terminals.find(tail_piece) == cnf.grammar.terminals.end() &&
					cnf.grammar.variables.find(tail_piece) == cnf.grammar.variables.end())
					throw InputParserException("Found '" + tail_piece + "' in rule body while this isn't a variable or terminal");
			}
		}

		bool found_token;
		for(auto& term : cnf.grammar.terminals) {
			found_token = false;
			for(auto& rule : cnf.grammar.rules) {
				for(auto& tail_value : rule->tail) {
					if (tail_value == term) {
						found_token = true;
						break;
					}
				}
				if (found_token) break;
			}
			if (!found_token)
				std::cout << "Warning: Terminal '" << term << "' is not been used." << std::endl;
		}

        return cnf;
    }   
}