#ifndef option_types_hh_INCLUDED
#define option_types_hh_INCLUDED

#include "exception.hh"
#include "string.hh"
#include "units.hh"
#include "coord.hh"
#include "array_view.hh"
#include "hash_map.hh"
#include "flags.hh"
#include "enum.hh"

#include <tuple>
#include <vector>

namespace Kakoune
{

template<typename T>
constexpr decltype(T::option_type_name) option_type_name(Meta::Type<T>)
{
    return T::option_type_name;
}

template<typename Enum>
typename std::enable_if<std::is_enum<Enum>::value, String>::type
option_type_name(Meta::Type<Enum>)
{
    constexpr StringView type = with_bit_ops(Meta::Type<Enum>{}) ? "flags" : "enum";
    auto name = enum_desc(Meta::Type<Enum>{});
    return type + "(" + join(name | transform(std::mem_fn(&EnumDesc<Enum>::name)), '|') + ")";
}

inline String option_to_string(int opt) { return to_string(opt); }
inline void option_from_string(StringView str, int& opt) { opt = str_to_int(str); }
inline bool option_add(int& opt, StringView str)
{
    auto val = str_to_int(str);
    opt += val;
    return val != 0;
}
inline StringView option_type_name(Meta::Type<int>) { return "int"; }

inline String option_to_string(size_t opt) { return to_string(opt); }
inline void option_from_string(StringView str, size_t& opt) { opt = str_to_int(str); }

inline String option_to_string(bool opt) { return opt ? "true" : "false"; }
inline void option_from_string(StringView str, bool& opt)
{
    if (str == "true" or str == "yes")
        opt = true;
    else if (str == "false" or str == "no")
        opt = false;
    else
        throw runtime_error("boolean values are either true, yes, false or no");
}
inline StringView option_type_name(Meta::Type<bool>) { return "bool"; }

constexpr char list_separator = ':';

template<typename T, MemoryDomain domain>
String option_to_string(const Vector<T, domain>& opt)
{
    String res;
    for (size_t i = 0; i < opt.size(); ++i)
    {
        res += escape(option_to_string(opt[i]), list_separator, '\\');
        if (i != opt.size() - 1)
            res += list_separator;
    }
    return res;
}

template<typename T, MemoryDomain domain>
void option_from_string(StringView str, Vector<T, domain>& opt)
{
    opt.clear();
    Vector<String> elems = split(str, list_separator, '\\');
    for (auto& elem: elems)
    {
        T opt_elem;
        option_from_string(elem, opt_elem);
        opt.push_back(opt_elem);
    }
}

template<typename T, MemoryDomain domain>
bool option_add(Vector<T, domain>& opt, StringView str)
{
    Vector<T, domain> vec;
    option_from_string(str, vec);
    std::copy(std::make_move_iterator(vec.begin()),
              std::make_move_iterator(vec.end()),
              back_inserter(opt));
    return not vec.empty();
}

template<typename T, MemoryDomain D>
String option_type_name(Meta::Type<Vector<T, D>>)
{
    return option_type_name(Meta::Type<T>{}) + StringView{"-list"};
}

template<typename Key, typename Value, MemoryDomain domain>
String option_to_string(const HashMap<Key, Value, domain>& opt)
{
    String res;
    for (auto it = begin(opt); it != end(opt); ++it)
    {
        if (it != begin(opt))
            res += list_separator;
        String elem = escape(option_to_string(it->key), '=', '\\') + "=" +
                      escape(option_to_string(it->value), '=', '\\');
        res += escape(elem, list_separator, '\\');
    }
    return res;
}

template<typename Key, typename Value, MemoryDomain domain>
void option_from_string(StringView str, HashMap<Key, Value, domain>& opt)
{
    opt.clear();
    for (auto& elem : split(str, list_separator, '\\'))
    {
        Vector<String> pair_str = split(elem, '=', '\\');
        if (pair_str.size() != 2)
            throw runtime_error("map option expects key=value");
        Key key;
        Value value;
        option_from_string(pair_str[0], key);
        option_from_string(pair_str[1], value);
        opt.insert({ std::move(key), std::move(value) });
    }
}

template<typename K, typename V, MemoryDomain D>
String option_type_name(Meta::Type<HashMap<K, V, D>>)
{
    return format("{}-to-{}-map", option_type_name(Meta::Type<K>{}),
                  option_type_name(Meta::Type<V>{}));
}

constexpr char tuple_separator = '|';

template<size_t I, typename... Types>
struct TupleOptionDetail
{
    static String to_string(const std::tuple<Types...>& opt)
    {
        return TupleOptionDetail<I-1, Types...>::to_string(opt) +
               tuple_separator + escape(option_to_string(std::get<I>(opt)), tuple_separator, '\\');
    }

    static void from_string(ConstArrayView<String> elems, std::tuple<Types...>& opt)
    {
        option_from_string(elems[I], std::get<I>(opt));
        TupleOptionDetail<I-1, Types...>::from_string(elems, opt);
    }
};

template<typename... Types>
struct TupleOptionDetail<0, Types...>
{
    static String to_string(const std::tuple<Types...>& opt)
    {
        return option_to_string(std::get<0>(opt));
    }

    static void from_string(ConstArrayView<String> elems, std::tuple<Types...>& opt)
    {
        option_from_string(elems[0], std::get<0>(opt));
    }
};

template<typename... Types>
String option_to_string(const std::tuple<Types...>& opt)
{
    return TupleOptionDetail<sizeof...(Types)-1, Types...>::to_string(opt);
}

template<typename... Types>
void option_from_string(StringView str, std::tuple<Types...>& opt)
{
    auto elems = split(str, tuple_separator, '\\');
    if (elems.size() != sizeof...(Types))
        throw runtime_error(elems.size() < sizeof...(Types) ?
                              "not enough elements in tuple"
                            : "to many elements in tuple");
    TupleOptionDetail<sizeof...(Types)-1, Types...>::from_string(elems, opt);
}

template<typename RealType, typename ValueType>
inline String option_to_string(const StronglyTypedNumber<RealType, ValueType>& opt)
{
    return to_string(opt);
}

template<typename RealType, typename ValueType>
inline void option_from_string(StringView str, StronglyTypedNumber<RealType, ValueType>& opt)
{
     opt = StronglyTypedNumber<RealType, ValueType>{str_to_int(str)};
}

template<typename RealType, typename ValueType>
inline bool option_add(StronglyTypedNumber<RealType, ValueType>& opt,
                       StringView str)
{
    int val = str_to_int(str);
    opt += val;
    return val != 0;
}

struct WorstMatch { template<typename T> WorstMatch(T&&) {} };

inline bool option_add(WorstMatch, StringView str)
{
    throw runtime_error("no add operation supported for this option type");
}

template<typename EffectiveType, typename LineType, typename ColumnType>
inline void option_from_string(StringView str, LineAndColumn<EffectiveType, LineType, ColumnType>& opt)
{
    auto vals = split(str, ',');
    if (vals.size() != 2)
        throw runtime_error("expected <line>,<column>");
    opt.line = str_to_int(vals[0]);
    opt.column = str_to_int(vals[1]);
}

template<typename EffectiveType, typename LineType, typename ColumnType>
inline String option_to_string(const LineAndColumn<EffectiveType, LineType, ColumnType>& opt)
{
    return format("{},{}", opt.line, opt.column);
}

enum class DebugFlags
{
    None  = 0,
    Hooks = 1 << 0,
    Shell = 1 << 1,
    Profile = 1 << 2,
    Keys = 1 << 3,
};

constexpr bool with_bit_ops(Meta::Type<DebugFlags>) { return true; }

constexpr Array<EnumDesc<DebugFlags>, 4> enum_desc(Meta::Type<DebugFlags>)
{
    return { {
        { DebugFlags::Hooks, "hooks" },
        { DebugFlags::Shell, "shell" },
        { DebugFlags::Profile, "profile" },
        { DebugFlags::Keys, "keys" }
    } };
}

template<typename Flags, typename = decltype(enum_desc(Meta::Type<Flags>{}))>
EnableIfWithBitOps<Flags, String> option_to_string(Flags flags)
{
    constexpr auto desc = enum_desc(Meta::Type<Flags>{});
    String res;
    for (int i = 0; i < desc.size(); ++i)
    {
        if (not (flags & desc[i].value))
            continue;
        if (not res.empty())
            res += "|";
        res += desc[i].name;
    }
    return res;
}

template<typename Enum, typename = decltype(enum_desc(Meta::Type<Enum>{}))>
EnableIfWithoutBitOps<Enum, String> option_to_string(Enum e)
{
    constexpr auto desc = enum_desc(Meta::Type<Enum>{});
    auto it = find_if(desc, [e](const EnumDesc<Enum>& d) { return d.value == e; });
    if (it != desc.end())
        return it->name.str();
    kak_assert(false);
    return {};
}

template<typename Flags, typename = decltype(enum_desc(Meta::Type<Flags>{}))>
EnableIfWithBitOps<Flags> option_from_string(StringView str, Flags& flags)
{
    constexpr auto desc = enum_desc(Meta::Type<Flags>{});
    flags = Flags{};
    for (auto s : str | split<StringView>('|'))
    {
        auto it = find_if(desc, [s](const EnumDesc<Flags>& d) { return d.name == s; });
        if (it == desc.end())
            throw runtime_error(format("invalid flag value '{}'", s));
        flags |= it->value;
    }
}

template<typename Enum, typename = decltype(enum_desc(Meta::Type<Enum>{}))>
EnableIfWithoutBitOps<Enum> option_from_string(StringView str, Enum& e)
{
    constexpr auto desc = enum_desc(Meta::Type<Enum>{});
    auto it = find_if(desc, [str](const EnumDesc<Enum>& d) { return d.name == str; });
    if (it == desc.end())
        throw runtime_error(format("invalid enum value '{}'", str));
    e = it->value;
}

template<typename Flags, typename = decltype(enum_desc(Meta::Type<Flags>{}))>
EnableIfWithBitOps<Flags, bool> option_add(Flags& opt, StringView str)
{
    Flags res = Flags{};
    option_from_string(str, res);
    opt |= res;
    return res != (Flags)0;
}

template<typename P, typename T>
struct PrefixedList
{
    P prefix;
    Vector<T, MemoryDomain::Options> list;
};

template<typename P, typename T>
inline bool operator==(const PrefixedList<P, T>& lhs, const PrefixedList<P, T>& rhs)
{
    return lhs.prefix == rhs.prefix and lhs.list == rhs.list;
}

template<typename P, typename T>
inline bool operator!=(const PrefixedList<P, T>& lhs, const PrefixedList<P, T>& rhs)
{
    return not (lhs == rhs);
}

template<typename P, typename T>
inline String option_to_string(const PrefixedList<P, T>& opt)
{
    return format("{}:{}", opt.prefix, option_to_string(opt.list));
}

template<typename P, typename T>
inline void option_from_string(StringView str, PrefixedList<P, T>& opt)
{
    auto it = find(str, ':');
    option_from_string(StringView{str.begin(), it}, opt.prefix);
    if (it != str.end())
        option_from_string({it+1, str.end()}, opt.list);
}

template<typename P, typename T>
inline bool option_add(PrefixedList<P, T>& opt, StringView str)
{
    return option_add(opt.list, str);
}

template<typename T>
using TimestampedList = PrefixedList<size_t, T>;

}

#endif // option_types_hh_INCLUDED