#include "settings.h"
#include <map>
#include <cstdlib>
#include <regex>

namespace settings {
    const std::map<std::string, std::string> dummySettings {
        {"weapon", "parser/items/weapons/"},
            {"armor", "parser/items/armor/"},
            {"spellcasting", "parser/spells/"},
            {"savedir", "~/.dmtool/"}
    };


    // Update the input string.
    // Obtained from https://stackoverflow.com/a/23442780
    void autoExpandEnvironmentVariables(std::string& text) {
        std::size_t tilde;
        while((tilde = text.find("~")) != std::string::npos) {
            text.replace(tilde, tilde+1, "${HOME}");
        }
        static std::regex env("\\$(?:\\{([^}]+)\\}|([^/]+))");
        std::smatch match;
        while(std::regex_search(text, match, env)) {
            std::string matchStr = match[1].str().empty()? match[2].str() : match[1].str();
            auto s = getenv(matchStr.c_str());
            const std::string var(s == NULL? "" : s);
            text.replace(match[0].first, match[0].second, var);
        }
    }

    // Returns the setting, or an empty string in the case of an error
    std::string getString(const std::string& key) {
        if(! dummySettings.contains(key)) {
            return "";
        }
        std::string ret = dummySettings.at(key);
        autoExpandEnvironmentVariables(ret);
        return ret;
    }
}