/********************************************************************
** Copyright (c) 2018-2020 Guan Wenliang
** This file is part of the Berry default interpreter.
** skiars@qq.com, https://github.com/Skiars/berry
** See Copyright Notice in the LICENSE file or at
** https://github.com/Skiars/berry/blob/master/LICENSE
********************************************************************/
#include "macro_table.h"
#include <regex>
#include <fstream>
#include <sstream>

std::string macro_table::readfile(const std::string &filename)
{
    std::ifstream in(filename);
    std::ostringstream tmp;
    tmp << in.rdbuf();
    return tmp.str();
}

int macro_table::parse_value(std::string str)
{
    if (!str.length()) {
        return 1; /* defined a macro name but no content, considered true */
    }
    if (!(str[0] >= '0' && str[0] <= '9')) {
        return 1;
    }
    return atoi(str.c_str());
}

void macro_table::scan_file(const std::string &filename)
{
    std::string str(readfile(filename));
    std::regex reg("(?:\\n|$)\\s*#define\\s+(\\w+)[ \\t]+(\\w+)");
    std::sregex_iterator it(str.begin(), str.end(), reg);
    std::sregex_iterator end;
    while (it != end) {
        m_map[it->str(1)] = parse_value(it->str(2));
        ++it;
    }
}

bool macro_table::query(const std::string &str) const
{
    std::regex reg("(!?)(\\w+)");
    std::match_results<std::string::const_iterator> res;
    if (regex_match(str, res, reg)) {
        auto it = m_map.find(res[2]);
        int value = it == m_map.end() ? 0 : it->second;
        return res[1] == "!" ? value == 0 : value != 0;
    }
    return 0;
}

std::map<std::string, int> macro_table::table() const
{
    return m_map;
}