#ifndef option_types_hh_INCLUDED
#define option_types_hh_INCLUDED

#include "array_view.hh"
#include "coord.hh"
#include "exception.hh"
#include "flags.hh"
#include "hash_map.hh"
#include "option.hh"
#include "ranges.hh"
#include "string.hh"
#include "string_utils.hh"
#include "units.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>
std::enable_if_t<std::is_enum<Enum>::value, String>
option_type_name(Meta::Type<Enum>)
{
    return format("{}({})", with_bit_ops(Meta::Type<Enum>{}) ? "flags" : "enum",
                  join(enum_desc(Meta::Type<Enum>{}) |
                       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;
}
constexpr 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");
}
constexpr StringView option_type_name(Meta::Type<bool>) { return "bool"; }

inline String option_to_string(Codepoint opt) { return to_string(opt); }
inline void option_from_string(StringView str, Codepoint& opt)
{
    if (str.char_length() != 1)
        throw runtime_error{format("'{}' is not a single codepoint", str)};
    opt = str[0_char];
}
constexpr StringView option_type_name(Meta::Type<Codepoint>) { return "codepoint"; }

constexpr char list_separator = ':';

template<typename T, MemoryDomain domain>
String option_to_string(const Vector<T, domain>& opt)
{
    return join(opt | transform([](const T& t) { return option_to_string(t); }),
                list_separator);
}

template<typename T, MemoryDomain domain>
void option_list_postprocess(Vector<T, domain>& opt)
{}

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

template<typename T, MemoryDomain domain>
bool option_add(Vector<T, domain>& opt, StringView str)
{
    Vector<T, domain> vec;
    option_from_string(str, vec);
    opt.insert(opt.end(),
               std::make_move_iterator(vec.begin()),
               std::make_move_iterator(vec.end()));
    option_list_postprocess(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 = opt.begin(); it != opt.end(); ++it)
    {
        if (it != opt.begin())
            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>
bool option_add(HashMap<Key, Value, domain>& opt, StringView str)
{
    bool changed = false;
    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) });
        changed = true;
    }
    return changed;
}

template<typename Key, typename Value, MemoryDomain domain>
void option_from_string(StringView str, HashMap<Key, Value, domain>& opt)
{
    opt.clear();
    option_add(opt, str);
}

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"
                            : "too 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)
{
    throw runtime_error("no add operation supported for this option type");
}

class Context;

inline void option_update(WorstMatch, const Context&)
{
    throw runtime_error("no update 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);
}

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>
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);
}

}

#endif // option_types_hh_INCLUDED