#pragma once

#include <type_traits>
#include <limits>
#include <utility>
#include <functional>
#include <unordered_map>
#include <map>
#include <string>
#include <cstdio>

#include "libipc/def.h"

#include "libipc/memory/alloc.h"
#include "libipc/memory/wrapper.h"
#include "libipc/platform/detail.h"

namespace ipc {
namespace mem {

//using async_pool_alloc = static_wrapper<variable_wrapper<async_wrapper<
//    detail::fixed_alloc<
//        variable_alloc                           <sizeof(void*) * 1024 * 256>, 
//        fixed_expand_policy<sizeof(void*) * 1024, sizeof(void*) * 1024 * 256>
//    >, 
//    default_recycler >>>;
using async_pool_alloc = ipc::mem::static_alloc;

template <typename T>
using allocator = allocator_wrapper<T, async_pool_alloc>;

} // namespace mem

namespace {

constexpr char const * pf(int)                { return "%d"  ; }
constexpr char const * pf(long)               { return "%ld" ; }
constexpr char const * pf(long long)          { return "%lld"; }
constexpr char const * pf(unsigned int)       { return "%u"  ; }
constexpr char const * pf(unsigned long)      { return "%lu" ; }
constexpr char const * pf(unsigned long long) { return "%llu"; }
constexpr char const * pf(float)              { return "%f"  ; }
constexpr char const * pf(double)             { return "%f"  ; }
constexpr char const * pf(long double)        { return "%Lf" ; }

} // internal-linkage

template <typename T>
struct hash : public std::hash<T> {};

template <typename Key, typename T>
using unordered_map = std::unordered_map<
    Key, T, ipc::hash<Key>, std::equal_to<Key>, ipc::mem::allocator<std::pair<Key const, T>>
>;

template <typename Key, typename T>
using map = std::map<
    Key, T, std::less<Key>, ipc::mem::allocator<std::pair<Key const, T>>
>;

template <typename Char>
using basic_string = std::basic_string<
    Char, std::char_traits<Char>, ipc::mem::allocator<Char>
>;

using string  = basic_string<char>;
using wstring = basic_string<wchar_t>;

template <> struct hash<string> {
    std::size_t operator()(string const &val) const noexcept {
        return std::hash<char const *>{}(val.c_str());
    }
};

template <> struct hash<wstring> {
    std::size_t operator()(wstring const &val) const noexcept {
        return std::hash<wchar_t const *>{}(val.c_str());
    }
};

template <typename T>
ipc::string to_string(T val) {
    char buf[std::numeric_limits<T>::digits10 + 1] {};
    if (std::snprintf(buf, sizeof(buf), pf(val), val) > 0) {
        return buf;
    }
    return {};
}

/// \brief Check string validity.
constexpr bool is_valid_string(char const *str) noexcept {
    return (str != nullptr) && (str[0] != '\0');
}

/// \brief Make a valid string.
inline ipc::string make_string(char const *str) {
    return is_valid_string(str) ? ipc::string{str} : ipc::string{};
}

/// \brief Combine prefix from a list of strings.
inline ipc::string make_prefix(ipc::string prefix, std::initializer_list<ipc::string> args) {
    prefix += "__IPC_SHM__";
    for (auto const &txt: args) {
        if (txt.empty()) continue;
        prefix += txt;
    }
    return prefix;
}

} // namespace ipc