// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <array>
#include <memory>
#include <utility>
#include <vector>

#include <fmt/format.h>

#include "common/microprofile.h"
#include "common/socket_types.h"
#include "core/core.h"
#include "core/hle/kernel/k_thread.h"
#include "core/hle/service/ipc_helpers.h"
#include "core/hle/service/sockets/bsd.h"
#include "core/hle/service/sockets/sockets_translate.h"
#include "core/internal_network/network.h"
#include "core/internal_network/socket_proxy.h"
#include "core/internal_network/sockets.h"
#include "network/network.h"

using Common::Expected;
using Common::Unexpected;

namespace Service::Sockets {

namespace {

bool IsConnectionBased(Type type) {
    switch (type) {
    case Type::STREAM:
        return true;
    case Type::DGRAM:
        return false;
    default:
        UNIMPLEMENTED_MSG("Unimplemented type={}", type);
        return false;
    }
}

} // Anonymous namespace

void BSD::PollWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->PollImpl(write_buffer, read_buffer, nfds, timeout);
}

void BSD::PollWork::Response(HLERequestContext& ctx) {
    if (write_buffer.size() > 0) {
        ctx.WriteBuffer(write_buffer);
    }

    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
}

void BSD::AcceptWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->AcceptImpl(fd, write_buffer);
}

void BSD::AcceptWork::Response(HLERequestContext& ctx) {
    if (write_buffer.size() > 0) {
        ctx.WriteBuffer(write_buffer);
    }

    IPC::ResponseBuilder rb{ctx, 5};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
    rb.Push<u32>(static_cast<u32>(write_buffer.size()));
}

void BSD::ConnectWork::Execute(BSD* bsd) {
    bsd_errno = bsd->ConnectImpl(fd, addr);
}

void BSD::ConnectWork::Response(HLERequestContext& ctx) {
    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(bsd_errno == Errno::SUCCESS ? 0 : -1);
    rb.PushEnum(bsd_errno);
}

void BSD::RecvWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->RecvImpl(fd, flags, message);
}

void BSD::RecvWork::Response(HLERequestContext& ctx) {
    ctx.WriteBuffer(message);

    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
}

void BSD::RecvFromWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->RecvFromImpl(fd, flags, message, addr);
}

void BSD::RecvFromWork::Response(HLERequestContext& ctx) {
    ctx.WriteBuffer(message, 0);
    if (!addr.empty()) {
        ctx.WriteBuffer(addr, 1);
    }

    IPC::ResponseBuilder rb{ctx, 5};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
    rb.Push<u32>(static_cast<u32>(addr.size()));
}

void BSD::SendWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->SendImpl(fd, flags, message);
}

void BSD::SendWork::Response(HLERequestContext& ctx) {
    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
}

void BSD::SendToWork::Execute(BSD* bsd) {
    std::tie(ret, bsd_errno) = bsd->SendToImpl(fd, flags, message, addr);
}

void BSD::SendToWork::Response(HLERequestContext& ctx) {
    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
}

void BSD::RegisterClient(HLERequestContext& ctx) {
    LOG_WARNING(Service, "(STUBBED) called");

    IPC::ResponseBuilder rb{ctx, 3};

    rb.Push(ResultSuccess);
    rb.Push<s32>(0); // bsd errno
}

void BSD::StartMonitoring(HLERequestContext& ctx) {
    LOG_WARNING(Service, "(STUBBED) called");

    IPC::ResponseBuilder rb{ctx, 2};

    rb.Push(ResultSuccess);
}

void BSD::Socket(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const u32 domain = rp.Pop<u32>();
    const u32 type = rp.Pop<u32>();
    const u32 protocol = rp.Pop<u32>();

    LOG_DEBUG(Service, "called. domain={} type={} protocol={}", domain, type, protocol);

    const auto [fd, bsd_errno] = SocketImpl(static_cast<Domain>(domain), static_cast<Type>(type),
                                            static_cast<Protocol>(protocol));

    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(fd);
    rb.PushEnum(bsd_errno);
}

void BSD::Select(HLERequestContext& ctx) {
    LOG_WARNING(Service, "(STUBBED) called");

    IPC::ResponseBuilder rb{ctx, 4};

    rb.Push(ResultSuccess);
    rb.Push<u32>(0); // ret
    rb.Push<u32>(0); // bsd errno
}

void BSD::Poll(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 nfds = rp.Pop<s32>();
    const s32 timeout = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. nfds={} timeout={}", nfds, timeout);

    ExecuteWork(ctx, PollWork{
                         .nfds = nfds,
                         .timeout = timeout,
                         .read_buffer = ctx.ReadBuffer(),
                         .write_buffer = std::vector<u8>(ctx.GetWriteBufferSize()),
                     });
}

void BSD::Accept(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={}", fd);

    ExecuteWork(ctx, AcceptWork{
                         .fd = fd,
                         .write_buffer = std::vector<u8>(ctx.GetWriteBufferSize()),
                     });
}

void BSD::Bind(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} addrlen={}", fd, ctx.GetReadBufferSize());
    BuildErrnoResponse(ctx, BindImpl(fd, ctx.ReadBuffer()));
}

void BSD::Connect(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} addrlen={}", fd, ctx.GetReadBufferSize());

    ExecuteWork(ctx, ConnectWork{
                         .fd = fd,
                         .addr = ctx.ReadBuffer(),
                     });
}

void BSD::GetPeerName(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={}", fd);

    std::vector<u8> write_buffer(ctx.GetWriteBufferSize());
    const Errno bsd_errno = GetPeerNameImpl(fd, write_buffer);

    ctx.WriteBuffer(write_buffer);

    IPC::ResponseBuilder rb{ctx, 5};
    rb.Push(ResultSuccess);
    rb.Push<s32>(bsd_errno != Errno::SUCCESS ? -1 : 0);
    rb.PushEnum(bsd_errno);
    rb.Push<u32>(static_cast<u32>(write_buffer.size()));
}

void BSD::GetSockName(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={}", fd);

    std::vector<u8> write_buffer(ctx.GetWriteBufferSize());
    const Errno bsd_errno = GetSockNameImpl(fd, write_buffer);

    ctx.WriteBuffer(write_buffer);

    IPC::ResponseBuilder rb{ctx, 5};
    rb.Push(ResultSuccess);
    rb.Push<s32>(bsd_errno != Errno::SUCCESS ? -1 : 0);
    rb.PushEnum(bsd_errno);
    rb.Push<u32>(static_cast<u32>(write_buffer.size()));
}

void BSD::GetSockOpt(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();
    const u32 level = rp.Pop<u32>();
    const auto optname = static_cast<OptName>(rp.Pop<u32>());

    std::vector<u8> optval(ctx.GetWriteBufferSize());

    LOG_DEBUG(Service, "called. fd={} level={} optname=0x{:x} len=0x{:x}", fd, level, optname,
              optval.size());

    const Errno err = GetSockOptImpl(fd, level, optname, optval);

    ctx.WriteBuffer(optval);

    IPC::ResponseBuilder rb{ctx, 5};
    rb.Push(ResultSuccess);
    rb.Push<s32>(err == Errno::SUCCESS ? 0 : -1);
    rb.PushEnum(err);
    rb.Push<u32>(static_cast<u32>(optval.size()));
}

void BSD::Listen(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();
    const s32 backlog = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} backlog={}", fd, backlog);

    BuildErrnoResponse(ctx, ListenImpl(fd, backlog));
}

void BSD::Fcntl(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();
    const s32 cmd = rp.Pop<s32>();
    const s32 arg = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} cmd={} arg={}", fd, cmd, arg);

    const auto [ret, bsd_errno] = FcntlImpl(fd, static_cast<FcntlCmd>(cmd), arg);

    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<s32>(ret);
    rb.PushEnum(bsd_errno);
}

void BSD::SetSockOpt(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const s32 fd = rp.Pop<s32>();
    const u32 level = rp.Pop<u32>();
    const OptName optname = static_cast<OptName>(rp.Pop<u32>());

    const auto buffer = ctx.ReadBuffer();
    const u8* optval = buffer.empty() ? nullptr : buffer.data();
    size_t optlen = buffer.size();

    std::array<u64, 2> values;
    if ((optname == OptName::SNDTIMEO || optname == OptName::RCVTIMEO) && buffer.size() == 8) {
        std::memcpy(values.data(), buffer.data(), sizeof(values));
        optlen = sizeof(values);
        optval = reinterpret_cast<const u8*>(values.data());
    }

    LOG_DEBUG(Service, "called. fd={} level={} optname=0x{:x} optlen={}", fd, level,
              static_cast<u32>(optname), optlen);

    BuildErrnoResponse(ctx, SetSockOptImpl(fd, level, optname, optlen, optval));
}

void BSD::Shutdown(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const s32 fd = rp.Pop<s32>();
    const s32 how = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} how={}", fd, how);

    BuildErrnoResponse(ctx, ShutdownImpl(fd, how));
}

void BSD::Recv(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const s32 fd = rp.Pop<s32>();
    const u32 flags = rp.Pop<u32>();

    LOG_DEBUG(Service, "called. fd={} flags=0x{:x} len={}", fd, flags, ctx.GetWriteBufferSize());

    ExecuteWork(ctx, RecvWork{
                         .fd = fd,
                         .flags = flags,
                         .message = std::vector<u8>(ctx.GetWriteBufferSize()),
                     });
}

void BSD::RecvFrom(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const s32 fd = rp.Pop<s32>();
    const u32 flags = rp.Pop<u32>();

    LOG_DEBUG(Service, "called. fd={} flags=0x{:x} len={} addrlen={}", fd, flags,
              ctx.GetWriteBufferSize(0), ctx.GetWriteBufferSize(1));

    ExecuteWork(ctx, RecvFromWork{
                         .fd = fd,
                         .flags = flags,
                         .message = std::vector<u8>(ctx.GetWriteBufferSize(0)),
                         .addr = std::vector<u8>(ctx.GetWriteBufferSize(1)),
                     });
}

void BSD::Send(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const s32 fd = rp.Pop<s32>();
    const u32 flags = rp.Pop<u32>();

    LOG_DEBUG(Service, "called. fd={} flags=0x{:x} len={}", fd, flags, ctx.GetReadBufferSize());

    ExecuteWork(ctx, SendWork{
                         .fd = fd,
                         .flags = flags,
                         .message = ctx.ReadBuffer(),
                     });
}

void BSD::SendTo(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();
    const u32 flags = rp.Pop<u32>();

    LOG_DEBUG(Service, "called. fd={} flags=0x{} len={} addrlen={}", fd, flags,
              ctx.GetReadBufferSize(0), ctx.GetReadBufferSize(1));

    ExecuteWork(ctx, SendToWork{
                         .fd = fd,
                         .flags = flags,
                         .message = ctx.ReadBuffer(0),
                         .addr = ctx.ReadBuffer(1),
                     });
}

void BSD::Write(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={} len={}", fd, ctx.GetReadBufferSize());

    ExecuteWork(ctx, SendWork{
                         .fd = fd,
                         .flags = 0,
                         .message = ctx.ReadBuffer(),
                     });
}

void BSD::Read(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_WARNING(Service, "(STUBBED) called. fd={} len={}", fd, ctx.GetWriteBufferSize());

    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.Push<u32>(0); // ret
    rb.Push<u32>(0); // bsd errno
}

void BSD::Close(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const s32 fd = rp.Pop<s32>();

    LOG_DEBUG(Service, "called. fd={}", fd);

    BuildErrnoResponse(ctx, CloseImpl(fd));
}

void BSD::DuplicateSocket(HLERequestContext& ctx) {
    struct InputParameters {
        s32 fd;
        u64 reserved;
    };
    static_assert(sizeof(InputParameters) == 0x10);

    struct OutputParameters {
        s32 ret;
        Errno bsd_errno;
    };
    static_assert(sizeof(OutputParameters) == 0x8);

    IPC::RequestParser rp{ctx};
    auto input = rp.PopRaw<InputParameters>();

    Expected<s32, Errno> res = DuplicateSocketImpl(input.fd);
    IPC::ResponseBuilder rb{ctx, 4};
    rb.Push(ResultSuccess);
    rb.PushRaw(OutputParameters{
        .ret = res.value_or(0),
        .bsd_errno = res ? Errno::SUCCESS : res.error(),
    });
}

void BSD::EventFd(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    const u64 initval = rp.Pop<u64>();
    const u32 flags = rp.Pop<u32>();

    LOG_WARNING(Service, "(STUBBED) called. initval={}, flags={}", initval, flags);

    BuildErrnoResponse(ctx, Errno::SUCCESS);
}

template <typename Work>
void BSD::ExecuteWork(HLERequestContext& ctx, Work work) {
    work.Execute(this);
    work.Response(ctx);
}

std::pair<s32, Errno> BSD::SocketImpl(Domain domain, Type type, Protocol protocol) {
    if (type == Type::SEQPACKET) {
        UNIMPLEMENTED_MSG("SOCK_SEQPACKET errno management");
    } else if (type == Type::RAW && (domain != Domain::INET || protocol != Protocol::ICMP)) {
        UNIMPLEMENTED_MSG("SOCK_RAW errno management");
    }

    [[maybe_unused]] const bool unk_flag = (static_cast<u32>(type) & 0x20000000) != 0;
    UNIMPLEMENTED_IF_MSG(unk_flag, "Unknown flag in type");
    type = static_cast<Type>(static_cast<u32>(type) & ~0x20000000);

    const s32 fd = FindFreeFileDescriptorHandle();
    if (fd < 0) {
        LOG_ERROR(Service, "No more file descriptors available");
        return {-1, Errno::MFILE};
    }

    file_descriptors[fd] = FileDescriptor{};
    FileDescriptor& descriptor = *file_descriptors[fd];
    // ENONMEM might be thrown here

    LOG_INFO(Service, "New socket fd={}", fd);

    auto room_member = room_network.GetRoomMember().lock();
    if (room_member && room_member->IsConnected()) {
        descriptor.socket = std::make_shared<Network::ProxySocket>(room_network);
    } else {
        descriptor.socket = std::make_shared<Network::Socket>();
    }

    descriptor.socket->Initialize(Translate(domain), Translate(type), Translate(protocol));
    descriptor.is_connection_based = IsConnectionBased(type);

    return {fd, Errno::SUCCESS};
}

std::pair<s32, Errno> BSD::PollImpl(std::vector<u8>& write_buffer, std::span<const u8> read_buffer,
                                    s32 nfds, s32 timeout) {
    if (write_buffer.size() < nfds * sizeof(PollFD)) {
        return {-1, Errno::INVAL};
    }

    if (nfds == 0) {
        // When no entries are provided, -1 is returned with errno zero
        return {-1, Errno::SUCCESS};
    }

    const size_t length = std::min(read_buffer.size(), write_buffer.size());
    std::vector<PollFD> fds(nfds);
    std::memcpy(fds.data(), read_buffer.data(), length);

    if (timeout >= 0) {
        const s64 seconds = timeout / 1000;
        const u64 nanoseconds = 1'000'000 * (static_cast<u64>(timeout) % 1000);

        if (seconds < 0) {
            return {-1, Errno::INVAL};
        }
        if (nanoseconds > 999'999'999) {
            return {-1, Errno::INVAL};
        }
    } else if (timeout != -1) {
        return {-1, Errno::INVAL};
    }

    for (PollFD& pollfd : fds) {
        ASSERT(False(pollfd.revents));

        if (pollfd.fd > static_cast<s32>(MAX_FD) || pollfd.fd < 0) {
            LOG_ERROR(Service, "File descriptor handle={} is invalid", pollfd.fd);
            pollfd.revents = PollEvents{};
            return {0, Errno::SUCCESS};
        }

        const std::optional<FileDescriptor>& descriptor = file_descriptors[pollfd.fd];
        if (!descriptor) {
            LOG_ERROR(Service, "File descriptor handle={} is not allocated", pollfd.fd);
            pollfd.revents = PollEvents::Nval;
            return {0, Errno::SUCCESS};
        }
    }

    std::vector<Network::PollFD> host_pollfds(fds.size());
    std::transform(fds.begin(), fds.end(), host_pollfds.begin(), [this](PollFD pollfd) {
        Network::PollFD result;
        result.socket = file_descriptors[pollfd.fd]->socket.get();
        result.events = Translate(pollfd.events);
        result.revents = Network::PollEvents{};
        return result;
    });

    const auto result = Network::Poll(host_pollfds, timeout);

    const size_t num = host_pollfds.size();
    for (size_t i = 0; i < num; ++i) {
        fds[i].revents = Translate(host_pollfds[i].revents);
    }
    std::memcpy(write_buffer.data(), fds.data(), length);

    return Translate(result);
}

std::pair<s32, Errno> BSD::AcceptImpl(s32 fd, std::vector<u8>& write_buffer) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }

    const s32 new_fd = FindFreeFileDescriptorHandle();
    if (new_fd < 0) {
        LOG_ERROR(Service, "No more file descriptors available");
        return {-1, Errno::MFILE};
    }

    FileDescriptor& descriptor = *file_descriptors[fd];
    auto [result, bsd_errno] = descriptor.socket->Accept();
    if (bsd_errno != Network::Errno::SUCCESS) {
        return {-1, Translate(bsd_errno)};
    }

    file_descriptors[new_fd] = FileDescriptor{};
    FileDescriptor& new_descriptor = *file_descriptors[new_fd];
    new_descriptor.socket = std::move(result.socket);
    new_descriptor.is_connection_based = descriptor.is_connection_based;

    const SockAddrIn guest_addr_in = Translate(result.sockaddr_in);
    const size_t length = std::min(sizeof(guest_addr_in), write_buffer.size());
    std::memcpy(write_buffer.data(), &guest_addr_in, length);

    return {new_fd, Errno::SUCCESS};
}

Errno BSD::BindImpl(s32 fd, std::span<const u8> addr) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }
    ASSERT(addr.size() == sizeof(SockAddrIn));
    SockAddrIn addr_in;
    std::memcpy(&addr_in, addr.data(), sizeof(addr_in));

    return Translate(file_descriptors[fd]->socket->Bind(Translate(addr_in)));
}

Errno BSD::ConnectImpl(s32 fd, std::span<const u8> addr) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    UNIMPLEMENTED_IF(addr.size() != sizeof(SockAddrIn));
    SockAddrIn addr_in;
    std::memcpy(&addr_in, addr.data(), sizeof(addr_in));

    return Translate(file_descriptors[fd]->socket->Connect(Translate(addr_in)));
}

Errno BSD::GetPeerNameImpl(s32 fd, std::vector<u8>& write_buffer) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    const auto [addr_in, bsd_errno] = file_descriptors[fd]->socket->GetPeerName();
    if (bsd_errno != Network::Errno::SUCCESS) {
        return Translate(bsd_errno);
    }
    const SockAddrIn guest_addrin = Translate(addr_in);

    ASSERT(write_buffer.size() >= sizeof(guest_addrin));
    write_buffer.resize(sizeof(guest_addrin));
    std::memcpy(write_buffer.data(), &guest_addrin, sizeof(guest_addrin));
    return Translate(bsd_errno);
}

Errno BSD::GetSockNameImpl(s32 fd, std::vector<u8>& write_buffer) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    const auto [addr_in, bsd_errno] = file_descriptors[fd]->socket->GetSockName();
    if (bsd_errno != Network::Errno::SUCCESS) {
        return Translate(bsd_errno);
    }
    const SockAddrIn guest_addrin = Translate(addr_in);

    ASSERT(write_buffer.size() >= sizeof(guest_addrin));
    write_buffer.resize(sizeof(guest_addrin));
    std::memcpy(write_buffer.data(), &guest_addrin, sizeof(guest_addrin));
    return Translate(bsd_errno);
}

Errno BSD::ListenImpl(s32 fd, s32 backlog) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }
    return Translate(file_descriptors[fd]->socket->Listen(backlog));
}

std::pair<s32, Errno> BSD::FcntlImpl(s32 fd, FcntlCmd cmd, s32 arg) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }

    FileDescriptor& descriptor = *file_descriptors[fd];

    switch (cmd) {
    case FcntlCmd::GETFL:
        ASSERT(arg == 0);
        return {descriptor.flags, Errno::SUCCESS};
    case FcntlCmd::SETFL: {
        const bool enable = (arg & Network::FLAG_O_NONBLOCK) != 0;
        const Errno bsd_errno = Translate(descriptor.socket->SetNonBlock(enable));
        if (bsd_errno != Errno::SUCCESS) {
            return {-1, bsd_errno};
        }
        descriptor.flags = arg;
        return {0, Errno::SUCCESS};
    }
    default:
        UNIMPLEMENTED_MSG("Unimplemented cmd={}", cmd);
        return {-1, Errno::SUCCESS};
    }
}

Errno BSD::GetSockOptImpl(s32 fd, u32 level, OptName optname, std::vector<u8>& optval) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    if (level != static_cast<u32>(SocketLevel::SOCKET)) {
        UNIMPLEMENTED_MSG("Unknown getsockopt level");
        return Errno::SUCCESS;
    }

    Network::SocketBase* const socket = file_descriptors[fd]->socket.get();

    switch (optname) {
    case OptName::ERROR_: {
        auto [pending_err, getsockopt_err] = socket->GetPendingError();
        if (getsockopt_err == Network::Errno::SUCCESS) {
            Errno translated_pending_err = Translate(pending_err);
            ASSERT_OR_EXECUTE_MSG(
                optval.size() == sizeof(Errno), { return Errno::INVAL; },
                "Incorrect getsockopt option size");
            optval.resize(sizeof(Errno));
            memcpy(optval.data(), &translated_pending_err, sizeof(Errno));
        }
        return Translate(getsockopt_err);
    }
    default:
        UNIMPLEMENTED_MSG("Unimplemented optname={}", optname);
        return Errno::SUCCESS;
    }
}

Errno BSD::SetSockOptImpl(s32 fd, u32 level, OptName optname, size_t optlen, const void* optval) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    if (level != static_cast<u32>(SocketLevel::SOCKET)) {
        UNIMPLEMENTED_MSG("Unknown setsockopt level");
        return Errno::SUCCESS;
    }

    Network::SocketBase* const socket = file_descriptors[fd]->socket.get();

    if (optname == OptName::LINGER) {
        ASSERT(optlen == sizeof(Linger));
        Linger linger;
        std::memcpy(&linger, optval, sizeof(linger));
        ASSERT(linger.onoff == 0 || linger.onoff == 1);

        return Translate(socket->SetLinger(linger.onoff != 0, linger.linger));
    }

    ASSERT(optlen == sizeof(u32));
    u32 value;
    std::memcpy(&value, optval, sizeof(value));

    switch (optname) {
    case OptName::REUSEADDR:
        ASSERT(value == 0 || value == 1);
        return Translate(socket->SetReuseAddr(value != 0));
    case OptName::KEEPALIVE:
        ASSERT(value == 0 || value == 1);
        return Translate(socket->SetKeepAlive(value != 0));
    case OptName::BROADCAST:
        ASSERT(value == 0 || value == 1);
        return Translate(socket->SetBroadcast(value != 0));
    case OptName::SNDBUF:
        return Translate(socket->SetSndBuf(value));
    case OptName::RCVBUF:
        return Translate(socket->SetRcvBuf(value));
    case OptName::SNDTIMEO:
        return Translate(socket->SetSndTimeo(value));
    case OptName::RCVTIMEO:
        return Translate(socket->SetRcvTimeo(value));
    case OptName::NOSIGPIPE:
        LOG_WARNING(Service, "(STUBBED) setting NOSIGPIPE to {}", value);
        return Errno::SUCCESS;
    default:
        UNIMPLEMENTED_MSG("Unimplemented optname={}", optname);
        return Errno::SUCCESS;
    }
}

Errno BSD::ShutdownImpl(s32 fd, s32 how) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }
    const Network::ShutdownHow host_how = Translate(static_cast<ShutdownHow>(how));
    return Translate(file_descriptors[fd]->socket->Shutdown(host_how));
}

std::pair<s32, Errno> BSD::RecvImpl(s32 fd, u32 flags, std::vector<u8>& message) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }

    FileDescriptor& descriptor = *file_descriptors[fd];

    // Apply flags
    using Network::FLAG_MSG_DONTWAIT;
    using Network::FLAG_O_NONBLOCK;
    if ((flags & FLAG_MSG_DONTWAIT) != 0) {
        flags &= ~FLAG_MSG_DONTWAIT;
        if ((descriptor.flags & FLAG_O_NONBLOCK) == 0) {
            descriptor.socket->SetNonBlock(true);
        }
    }

    const auto [ret, bsd_errno] = Translate(descriptor.socket->Recv(flags, message));

    // Restore original state
    if ((descriptor.flags & FLAG_O_NONBLOCK) == 0) {
        descriptor.socket->SetNonBlock(false);
    }

    return {ret, bsd_errno};
}

std::pair<s32, Errno> BSD::RecvFromImpl(s32 fd, u32 flags, std::vector<u8>& message,
                                        std::vector<u8>& addr) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }

    FileDescriptor& descriptor = *file_descriptors[fd];

    Network::SockAddrIn addr_in{};
    Network::SockAddrIn* p_addr_in = nullptr;
    if (descriptor.is_connection_based) {
        // Connection based file descriptors (e.g. TCP) zero addr
        addr.clear();
    } else {
        p_addr_in = &addr_in;
    }

    // Apply flags
    using Network::FLAG_MSG_DONTWAIT;
    using Network::FLAG_O_NONBLOCK;
    if ((flags & FLAG_MSG_DONTWAIT) != 0) {
        flags &= ~FLAG_MSG_DONTWAIT;
        if ((descriptor.flags & FLAG_O_NONBLOCK) == 0) {
            descriptor.socket->SetNonBlock(true);
        }
    }

    const auto [ret, bsd_errno] = Translate(descriptor.socket->RecvFrom(flags, message, p_addr_in));

    // Restore original state
    if ((descriptor.flags & FLAG_O_NONBLOCK) == 0) {
        descriptor.socket->SetNonBlock(false);
    }

    if (p_addr_in) {
        if (ret < 0) {
            addr.clear();
        } else {
            ASSERT(addr.size() == sizeof(SockAddrIn));
            const SockAddrIn result = Translate(addr_in);
            std::memcpy(addr.data(), &result, sizeof(result));
        }
    }

    return {ret, bsd_errno};
}

std::pair<s32, Errno> BSD::SendImpl(s32 fd, u32 flags, std::span<const u8> message) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }
    return Translate(file_descriptors[fd]->socket->Send(message, flags));
}

std::pair<s32, Errno> BSD::SendToImpl(s32 fd, u32 flags, std::span<const u8> message,
                                      std::span<const u8> addr) {
    if (!IsFileDescriptorValid(fd)) {
        return {-1, Errno::BADF};
    }

    Network::SockAddrIn addr_in;
    Network::SockAddrIn* p_addr_in = nullptr;
    if (!addr.empty()) {
        ASSERT(addr.size() == sizeof(SockAddrIn));
        SockAddrIn guest_addr_in;
        std::memcpy(&guest_addr_in, addr.data(), sizeof(guest_addr_in));
        addr_in = Translate(guest_addr_in);
        p_addr_in = &addr_in;
    }

    return Translate(file_descriptors[fd]->socket->SendTo(flags, message, p_addr_in));
}

Errno BSD::CloseImpl(s32 fd) {
    if (!IsFileDescriptorValid(fd)) {
        return Errno::BADF;
    }

    const Errno bsd_errno = Translate(file_descriptors[fd]->socket->Close());
    if (bsd_errno != Errno::SUCCESS) {
        return bsd_errno;
    }

    LOG_INFO(Service, "Close socket fd={}", fd);

    file_descriptors[fd].reset();
    return bsd_errno;
}

Expected<s32, Errno> BSD::DuplicateSocketImpl(s32 fd) {
    if (!IsFileDescriptorValid(fd)) {
        return Unexpected(Errno::BADF);
    }

    const s32 new_fd = FindFreeFileDescriptorHandle();
    if (new_fd < 0) {
        LOG_ERROR(Service, "No more file descriptors available");
        return Unexpected(Errno::MFILE);
    }

    file_descriptors[new_fd] = file_descriptors[fd];
    return new_fd;
}

std::optional<std::shared_ptr<Network::SocketBase>> BSD::GetSocket(s32 fd) {
    if (!IsFileDescriptorValid(fd)) {
        return std::nullopt;
    }
    return file_descriptors[fd]->socket;
}

s32 BSD::FindFreeFileDescriptorHandle() noexcept {
    for (s32 fd = 0; fd < static_cast<s32>(file_descriptors.size()); ++fd) {
        if (!file_descriptors[fd]) {
            return fd;
        }
    }
    return -1;
}

bool BSD::IsFileDescriptorValid(s32 fd) const noexcept {
    if (fd > static_cast<s32>(MAX_FD) || fd < 0) {
        LOG_ERROR(Service, "Invalid file descriptor handle={}", fd);
        return false;
    }
    if (!file_descriptors[fd]) {
        LOG_ERROR(Service, "File descriptor handle={} is not allocated", fd);
        return false;
    }
    return true;
}

void BSD::BuildErrnoResponse(HLERequestContext& ctx, Errno bsd_errno) const noexcept {
    IPC::ResponseBuilder rb{ctx, 4};

    rb.Push(ResultSuccess);
    rb.Push<s32>(bsd_errno == Errno::SUCCESS ? 0 : -1);
    rb.PushEnum(bsd_errno);
}

void BSD::OnProxyPacketReceived(const Network::ProxyPacket& packet) {
    for (auto& optional_descriptor : file_descriptors) {
        if (!optional_descriptor.has_value()) {
            continue;
        }
        FileDescriptor& descriptor = *optional_descriptor;
        descriptor.socket.get()->HandleProxyPacket(packet);
    }
}

BSD::BSD(Core::System& system_, const char* name)
    : ServiceFramework{system_, name}, room_network{system_.GetRoomNetwork()} {
    // clang-format off
    static const FunctionInfo functions[] = {
        {0, &BSD::RegisterClient, "RegisterClient"},
        {1, &BSD::StartMonitoring, "StartMonitoring"},
        {2, &BSD::Socket, "Socket"},
        {3, nullptr, "SocketExempt"},
        {4, nullptr, "Open"},
        {5, &BSD::Select, "Select"},
        {6, &BSD::Poll, "Poll"},
        {7, nullptr, "Sysctl"},
        {8, &BSD::Recv, "Recv"},
        {9, &BSD::RecvFrom, "RecvFrom"},
        {10, &BSD::Send, "Send"},
        {11, &BSD::SendTo, "SendTo"},
        {12, &BSD::Accept, "Accept"},
        {13, &BSD::Bind, "Bind"},
        {14, &BSD::Connect, "Connect"},
        {15, &BSD::GetPeerName, "GetPeerName"},
        {16, &BSD::GetSockName, "GetSockName"},
        {17, &BSD::GetSockOpt, "GetSockOpt"},
        {18, &BSD::Listen, "Listen"},
        {19, nullptr, "Ioctl"},
        {20, &BSD::Fcntl, "Fcntl"},
        {21, &BSD::SetSockOpt, "SetSockOpt"},
        {22, &BSD::Shutdown, "Shutdown"},
        {23, nullptr, "ShutdownAllSockets"},
        {24, &BSD::Write, "Write"},
        {25, &BSD::Read, "Read"},
        {26, &BSD::Close, "Close"},
        {27, &BSD::DuplicateSocket, "DuplicateSocket"},
        {28, nullptr, "GetResourceStatistics"},
        {29, nullptr, "RecvMMsg"},
        {30, nullptr, "SendMMsg"},
        {31, &BSD::EventFd, "EventFd"},
        {32, nullptr, "RegisterResourceStatisticsName"},
        {33, nullptr, "Initialize2"},
    };
    // clang-format on

    RegisterHandlers(functions);

    if (auto room_member = room_network.GetRoomMember().lock()) {
        proxy_packet_received = room_member->BindOnProxyPacketReceived(
            [this](const Network::ProxyPacket& packet) { OnProxyPacketReceived(packet); });
    } else {
        LOG_ERROR(Service, "Network isn't initialized");
    }
}

BSD::~BSD() {
    if (auto room_member = room_network.GetRoomMember().lock()) {
        room_member->Unbind(proxy_packet_received);
    }
}

BSDCFG::BSDCFG(Core::System& system_) : ServiceFramework{system_, "bsdcfg"} {
    // clang-format off
    static const FunctionInfo functions[] = {
        {0, nullptr, "SetIfUp"},
        {1, nullptr, "SetIfUpWithEvent"},
        {2, nullptr, "CancelIf"},
        {3, nullptr, "SetIfDown"},
        {4, nullptr, "GetIfState"},
        {5, nullptr, "DhcpRenew"},
        {6, nullptr, "AddStaticArpEntry"},
        {7, nullptr, "RemoveArpEntry"},
        {8, nullptr, "LookupArpEntry"},
        {9, nullptr, "LookupArpEntry2"},
        {10, nullptr, "ClearArpEntries"},
        {11, nullptr, "ClearArpEntries2"},
        {12, nullptr, "PrintArpEntries"},
        {13, nullptr, "Unknown13"},
        {14, nullptr, "Unknown14"},
        {15, nullptr, "Unknown15"},
    };
    // clang-format on

    RegisterHandlers(functions);
}

BSDCFG::~BSDCFG() = default;

} // namespace Service::Sockets
