#ifndef LLMR_STYLE_VALUE
#define LLMR_STYLE_VALUE

#include <llmr/util/variant.hpp>
#include <llmr/util/pbf.hpp>

namespace llmr {

typedef util::variant<bool, int64_t, uint64_t, double, std::string> Value;

std::string toString(const Value &value);

inline std::string& operator+=(std::string& out, const Value& value) {
    out += toString(value);
    return out;
}


Value parseValue(pbf data);

namespace util {

namespace detail {

inline int string_to_bool(std::string str) {
    std::transform(str.begin(), str.end(), str.begin(), ::tolower);
    if (str == "0" || str == "0.0" || str == "false" || str == "null" || !str.length()) return 0;
    else if (str == "true") return 1;
    else return -1;
}

template <typename T>
struct string_to_number {};

template <> struct string_to_number<bool> {
    bool operator()(const std::string &str) const {
        // Converts 0 => false, 1 => true and -1 => true.
        return string_to_bool(str);
    }
};

template <> struct string_to_number<double> {
    double operator()(std::string const &str) const {
        int val = string_to_bool(str);
        return val < 0 ? std::stod(str) : val;
    }
};

template <> struct string_to_number<int64_t> {
    int64_t operator()(std::string const &str) const {
        int val = string_to_bool(str);
        return val < 0 ? std::stoll(str) : val;
    }
};

template <> struct string_to_number<uint64_t> {
    uint64_t operator()(std::string const &str) const {
        int val = string_to_bool(str);
        return val < 0 ? std::stoull(str) : val;
    }
};

template <typename Operator>
struct relaxed_operator_visitor {
    bool operator()(bool lhs, bool rhs) const { return Operator()(lhs, rhs); }

    template <typename T, class = typename std::enable_if<std::is_arithmetic<T>::value>::type>
    bool operator()(bool lhs, T rhs) const { return Operator()(lhs, bool(rhs)); }

    template <typename T, class = typename std::enable_if<std::is_arithmetic<T>::value>::type>
    bool operator()(T lhs, bool rhs) const { return Operator()(bool(lhs), rhs); }

    bool operator()(int64_t lhs, uint64_t rhs) const { return lhs < 0 ? false : Operator()(uint64_t(lhs), rhs); }
    bool operator()(uint64_t lhs, int64_t rhs) const { return rhs < 0 ? false : Operator()(lhs, uint64_t(rhs)); }

    template <typename T, class = typename std::enable_if<std::is_arithmetic<T>::value>::type>
    bool operator()(const std::string &lhs, T rhs) const try { return Operator()(string_to_number<T>()(lhs), rhs); }
    catch(...) { return false; }

    template <typename T, class = typename std::enable_if<std::is_arithmetic<T>::value>::type>
    bool operator()(T lhs, const std::string &rhs) const try { return Operator()(lhs, string_to_number<T>()(rhs)); }
    catch(...) { return false; }

    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return Operator()(lhs, rhs); }
};

struct relaxed_equal_operator {
    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return lhs == rhs; }
};

struct relaxed_greater_operator {
    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return lhs > rhs; }
};

struct relaxed_greater_equal_operator {
    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return lhs >= rhs; }
};

struct relaxed_less_operator {
    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return lhs < rhs; }
};

struct relaxed_less_equal_operator {
    template <typename T0, typename T1>
    bool operator()(T0 lhs, T1 rhs) const { return lhs <= rhs; }
};


} // end namespace detail

inline bool relaxed_equal(Value const &lhs, Value const &rhs) {
    return apply_visitor(lhs, rhs, detail::relaxed_operator_visitor<detail::relaxed_equal_operator>());
}

inline bool relaxed_greater(Value const &lhs, Value const &rhs) {
    return apply_visitor(lhs, rhs, detail::relaxed_operator_visitor<detail::relaxed_greater_operator>());
}

inline bool relaxed_greater_equal(Value const &lhs, Value const &rhs) {
    return apply_visitor(lhs, rhs, detail::relaxed_operator_visitor<detail::relaxed_greater_equal_operator>());
}

inline bool relaxed_less(Value const &lhs, Value const &rhs) {
    return apply_visitor(lhs, rhs, detail::relaxed_operator_visitor<detail::relaxed_less_operator>());
}

inline bool relaxed_less_equal(Value const &lhs, Value const &rhs) {
    return apply_visitor(lhs, rhs, detail::relaxed_operator_visitor<detail::relaxed_less_equal_operator>());
}

}


template <typename T>
T toNumber(const Value &value) {
    if (value.is<std::string>()) return util::detail::string_to_number<T>()(value.get<std::string>());
    else if (value.is<bool>()) return value.get<bool>();
    else if (value.is<int64_t>()) return value.get<int64_t>();
    else if (value.is<uint64_t>()) return value.get<uint64_t>();
    else if (value.is<double>()) return value.get<double>();
    else return 0;
}

}

#endif