#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <ws2tcpip.h>
#else
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#endif
#include "prx/libc/include/general/VabiMacros.hpp"
#include <cstdint>
#include <array>
#include <cstring>
#include <cstdlib>
#include <cerrno>
#include <new>
#include <string>
#include <vector>
#include "GuestResolver.hpp"

extern "C" int* APS5_VABI sceNetErrnoLoc();

namespace {
struct HostLookup {
    GuestResolver::HostEntry entry{};
    std::string name;
    std::vector<std::string> aliasNames;
    std::vector<char*> aliases;
    std::vector<std::string> addressBytes;
    std::vector<char*> addresses;
};

bool NumericAddress(const char* name, std::array<unsigned char, 4>& address) {
    std::array<unsigned char, 3> parts{};
    std::size_t count = 0;
    std::uint64_t value;
    bool digit;
    for (;;) {
        if (*name < '0' || *name > '9') return false;
        value = 0;
        int base = 10;
        digit = false;
        if (*name == '0') {
            ++name;
            if (*name == 'x' || *name == 'X') { base = 16; ++name; }
            else { base = 8; digit = true; }
        }
        for (;;) {
            const int next = *name >= '0' && *name <= '9' ? *name - '0' :
                *name >= 'a' && *name <= 'f' ? *name - 'a' + 10 :
                *name >= 'A' && *name <= 'F' ? *name - 'A' + 10 : -1;
            if (next < 0 || next >= base) break;
            value = value * base + next;
            digit = true;
            ++name;
        }
        if (*name != '.') break;
        if (count == parts.size() || value > 255) return false;
        parts[count++] = static_cast<unsigned char>(value);
        ++name;
    }
    if (!digit) return false;
    if (*name != '\0' && *name != ' ' && *name != '\t' && *name != '\n' &&
        *name != '\r' && *name != '\f' && *name != '\v') return false;
    if (count && value >= (std::uint64_t{1} << (8 * (4 - count)))) return false;
    auto result = static_cast<std::uint32_t>(value);
    for (std::size_t i = 0; i < count; ++i)
        result |= static_cast<std::uint32_t>(parts[i]) << (24 - 8 * i);
    for (std::size_t i = 0; i < address.size(); ++i)
        address[i] = static_cast<unsigned char>(result >> (24 - 8 * i));
    return true;
}

bool Ready() {
#ifdef _WIN32
    static const int status = [] { WSADATA data{}; return WSAStartup(MAKEWORD(2, 2), &data); }();
    return status == 0;
#else
    return true;
#endif
}
int GuestError(int error) {
    if (error == 0) return 0;
    if (error == EAI_AGAIN) return 2;
    if (error == EAI_BADFLAGS) return 3;
    if (error == EAI_FAMILY) return 5;
    if (error == EAI_MEMORY) return 6;
    if (error == EAI_NONAME) return 8;
    if (error == EAI_SERVICE) return 9;
    if (error == EAI_SOCKTYPE) return 10;
#ifdef _WIN32
    if (error == WSAEFAULT) return 14;
#else
    if (error == EAI_OVERFLOW) return 14;
#endif
    return 4;
}
}

extern "C" {
GuestResolver::HostEntry* APS5_VABI gethostbyname_nid_postfix(const char* name) {
    if (!name || !Ready()) { *sceNetErrnoLoc() = 3; return nullptr; }
    try {
        std::array<unsigned char, 4> numericAddress{};
        char* numericAliases[]{nullptr};
        char* numericAddresses[]{reinterpret_cast<char*>(numericAddress.data()), nullptr};
        hostent nativeEntry{const_cast<char*>(name), numericAliases, AF_INET, 4, numericAddresses};
        hostent* native = &nativeEntry;
        const bool numeric = NumericAddress(name, numericAddress);
#ifdef _WIN32
        if (!numeric) native = ::gethostbyname(name);
        if (!native) {
            const auto error = WSAGetLastError();
            *sceNetErrnoLoc() = error == WSAHOST_NOT_FOUND ? 1 : error == WSATRY_AGAIN ? 2 : error == WSANO_DATA ? 4 : 3;
            return nullptr;
        }
#else
        std::vector<char> buffer;
        int hostError = 0;
        int error = 0;
        if (!numeric) {
            buffer.resize(1024);
            while ((error = ::gethostbyname_r(name, &nativeEntry, buffer.data(), buffer.size(), &native, &hostError)) == ERANGE)
                buffer.resize(buffer.size() * 2);
        }
        if (error != 0 || !native) {
            *sceNetErrnoLoc() = hostError != 0 ? hostError : 3;
            if (hostError == -1) errno = error == EAGAIN ? 35 : error;
            return nullptr;
        }
#endif
        static thread_local HostLookup lookup;
        lookup.name = native->h_name;
        lookup.aliasNames.clear();
        lookup.aliases.clear();
        lookup.addressBytes.clear();
        lookup.addresses.clear();
        for (auto** alias = native->h_aliases; *alias; ++alias) lookup.aliasNames.emplace_back(*alias);
        for (auto& alias : lookup.aliasNames) lookup.aliases.push_back(alias.data());
        lookup.aliases.push_back(nullptr);
        for (auto** address = native->h_addr_list; *address; ++address)
            lookup.addressBytes.emplace_back(*address, native->h_length);
        for (auto& address : lookup.addressBytes) lookup.addresses.push_back(address.data());
        lookup.addresses.push_back(nullptr);
        lookup.entry = {lookup.name.data(), lookup.aliases.data(), native->h_addrtype == AF_INET6 ? 28 : 2,
            native->h_length, lookup.addresses.data()};
        if (numeric) *sceNetErrnoLoc() = 0;
        return &lookup.entry;
    } catch (const std::bad_alloc&) {
        *sceNetErrnoLoc() = -1;
        errno = ENOMEM;
        return nullptr;
    }
}

void APS5_VABI freeaddrinfo_nid_postfix(GuestResolver::AddressInfo* first) {
    while (first) {
        auto* next = first->next;
        std::free(first->canonicalName);
        std::free(first->address);
        std::free(first);
        first = next;
    }
}

int APS5_VABI getaddrinfo_nid_postfix(const char* node, const char* service,
    const GuestResolver::AddressInfo* hints, GuestResolver::AddressInfo** output) {
    if (!output) return 4;
    *output = nullptr;
    addrinfo nativeHints{};
    if (hints) {
        if (hints->addressLength || hints->address || hints->canonicalName || hints->next) return 12;
        if ((hints->flags & ~0xd0f) != 0) return 3;
        if (hints->family != 0 && hints->family != 2 && hints->family != 28) return 5;
        if (hints->socketType != 0 && hints->socketType != 1 && hints->socketType != 2) return 10;
        nativeHints.ai_family = hints->family == 28 ? AF_INET6 : hints->family == 2 ? AF_INET : AF_UNSPEC;
        nativeHints.ai_socktype = hints->socketType == 1 ? SOCK_STREAM : hints->socketType == 2 ? SOCK_DGRAM : 0;
        nativeHints.ai_protocol = hints->protocol;
        if (hints->flags & 1) nativeHints.ai_flags |= AI_PASSIVE;
        if (hints->flags & 2) nativeHints.ai_flags |= AI_CANONNAME;
        if (hints->flags & 4) nativeHints.ai_flags |= AI_NUMERICHOST;
        if (hints->flags & 8) nativeHints.ai_flags |= AI_NUMERICSERV;
        if (hints->flags & 0x100) nativeHints.ai_flags |= AI_ALL;
        if (hints->flags & 0x400) nativeHints.ai_flags |= AI_ADDRCONFIG;
        if (hints->flags & 0x800) nativeHints.ai_flags |= AI_V4MAPPED;
    }
    if (!Ready()) return 4;
    addrinfo* native = nullptr;
    const auto error = ::getaddrinfo(node, service, &nativeHints, &native);
    if (error) return GuestError(error);
    GuestResolver::AddressInfo* first = nullptr;
    auto** tail = &first;
    int failure = 0;
    for (auto* item = native; item; item = item->ai_next) {
        if (item->ai_family != AF_INET && item->ai_family != AF_INET6) { failure = 5; break; }
        auto* converted = static_cast<GuestResolver::AddressInfo*>(std::calloc(1, sizeof(GuestResolver::AddressInfo)));
        if (!converted) { failure = 6; break; }
        *tail = converted;
        tail = &converted->next;
        converted->flags = hints ? hints->flags : 0;
        converted->family = item->ai_family == AF_INET ? 2 : 28;
        converted->socketType = item->ai_socktype == SOCK_STREAM ? 1 : item->ai_socktype == SOCK_DGRAM ? 2 : 0;
        converted->protocol = item->ai_protocol;
        converted->addressLength = item->ai_family == AF_INET ? 16 : 28;
        auto* bytes = static_cast<unsigned char*>(std::calloc(1, converted->addressLength));
        converted->address = bytes;
        if (!bytes) { failure = 6; break; }
        bytes[0] = static_cast<unsigned char>(converted->addressLength);
        bytes[1] = static_cast<unsigned char>(converted->family);
        if (item->ai_family == AF_INET) {
            const auto* v4 = reinterpret_cast<const sockaddr_in*>(item->ai_addr);
            std::memcpy(bytes + 2, &v4->sin_port, 2);
            std::memcpy(bytes + 4, &v4->sin_addr, 4);
        } else {
            const auto* v6 = reinterpret_cast<const sockaddr_in6*>(item->ai_addr);
            std::memcpy(bytes + 2, &v6->sin6_port, 2);
            std::memcpy(bytes + 4, &v6->sin6_flowinfo, 4);
            std::memcpy(bytes + 8, &v6->sin6_addr, 16);
            std::memcpy(bytes + 24, &v6->sin6_scope_id, 4);
        }
        if (item->ai_canonname) {
            const auto size = std::strlen(item->ai_canonname) + 1;
            converted->canonicalName = static_cast<char*>(std::malloc(size));
            if (!converted->canonicalName) { failure = 6; break; }
            std::memcpy(converted->canonicalName, item->ai_canonname, size);
        }
    }
    ::freeaddrinfo(native);
    if (failure) { freeaddrinfo_nid_postfix(first); return failure; }
    *output = first;
    return 0;
}

int APS5_VABI getnameinfo_nid_postfix(const void* address, std::uint32_t length,
    char* host, std::uint32_t hostLength, char* service, std::uint32_t serviceLength, int flags) {
    // PS5 sockaddr begins with byte-sized length and family. The host's does not.
    if (!address || length < 2) return 5;
    if ((!host && hostLength) || (!service && serviceLength)) return 4;
    if ((flags & ~0x1f) != 0) return 3;
    const auto* bytes = static_cast<const unsigned char*>(address);
    sockaddr_storage native{};
    socklen_t nativeLength;
    if (bytes[1] == 2) {
        if (length < 16 || bytes[0] != 16) return 5;
        auto& v4 = reinterpret_cast<sockaddr_in&>(native);
        v4.sin_family = AF_INET;
        std::memcpy(&v4.sin_port, bytes + 2, 2);
        std::memcpy(&v4.sin_addr, bytes + 4, 4);
        nativeLength = sizeof(v4);
    } else if (bytes[1] == 28) {
        if (length < 28 || bytes[0] != 28) return 5;
        auto& v6 = reinterpret_cast<sockaddr_in6&>(native);
        v6.sin6_family = AF_INET6;
        std::memcpy(&v6.sin6_port, bytes + 2, 2);
        std::memcpy(&v6.sin6_flowinfo, bytes + 4, 4);
        std::memcpy(&v6.sin6_addr, bytes + 8, 16);
        std::memcpy(&v6.sin6_scope_id, bytes + 24, 4);
        nativeLength = sizeof(v6);
    } else return 5;
    int nativeFlags = 0;
    if (flags & 1) nativeFlags |= NI_NOFQDN;
    if (flags & 2) nativeFlags |= NI_NUMERICHOST;
    if (flags & 4) nativeFlags |= NI_NAMEREQD;
    if (flags & 8) nativeFlags |= NI_NUMERICSERV;
    if (flags & 16) nativeFlags |= NI_DGRAM;
    if (!Ready()) return 4;
    // Stage results so host-specific short-buffer errors do not leak into the
    // guest ABI, and neither guest output is partially modified on overflow.
    char resolvedHost[NI_MAXHOST]{};
    char resolvedService[NI_MAXSERV]{};
    const bool wantHost = host && hostLength;
    const bool wantService = service && serviceLength;
    const int error = ::getnameinfo(reinterpret_cast<const sockaddr*>(&native), nativeLength,
        wantHost ? resolvedHost : nullptr, wantHost ? sizeof(resolvedHost) : 0,
        wantService ? resolvedService : nullptr, wantService ? sizeof(resolvedService) : 0, nativeFlags);
    if (error) return GuestError(error);
    if ((wantHost && std::strlen(resolvedHost) >= hostLength) ||
        (wantService && std::strlen(resolvedService) >= serviceLength)) return 14;
    if (wantHost) std::memcpy(host, resolvedHost, std::strlen(resolvedHost) + 1);
    if (wantService) std::memcpy(service, resolvedService, std::strlen(resolvedService) + 1);
    return 0;
}

const char* APS5_VABI gai_strerror_nid_postfix(int error) {
    static const char* messages[] = {
        "Success", "Address family for hostname not supported", "Temporary failure in name resolution",
        "Invalid flags", "Name resolution failed", "Address family not supported",
        "Memory allocation failed", "No address for hostname", "Name or service not known",
        "Service not supported for socket type", "Socket type not supported", "System error",
        "Invalid hints", "Unknown protocol", "Buffer too small"
    };
    if (error < 0 || error >= static_cast<int>(sizeof(messages) / sizeof(messages[0])))
        return "Unknown address resolution error";
    return messages[error];
}
}