// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <thread>
#include <boost/asio/io_context.hpp>

#include "common/assert.h"
#include "common/debug.h"
#include "common/elf_info.h"
#include "common/logging/log.h"
#include "common/polyfill_thread.h"
#include "common/thread.h"
#include "common/va_ctx.h"
#include "core/file_sys/fs.h"
#include "core/libraries/error_codes.h"
#include "core/libraries/kernel/debug.h"
#include "core/libraries/kernel/equeue.h"
#include "core/libraries/kernel/file_system.h"
#include "core/libraries/kernel/kernel.h"
#include "core/libraries/kernel/memory.h"
#include "core/libraries/kernel/orbis_error.h"
#include "core/libraries/kernel/posix_error.h"
#include "core/libraries/kernel/process.h"
#include "core/libraries/kernel/threads.h"
#include "core/libraries/kernel/threads/exception.h"
#include "core/libraries/kernel/time.h"
#include "core/libraries/libs.h"
#include "core/libraries/network/sys_net.h"

#ifdef _WIN64
#include <Rpc.h>
#else
#include <uuid/uuid.h>
#endif
#include <common/singleton.h>
#include <core/libraries/network/net_error.h>
#include <core/libraries/network/sockets.h>
#include "aio.h"

namespace Libraries::Kernel {

static u64 g_stack_chk_guard = 0xDEADBEEF54321ABC; // dummy return

boost::asio::io_context io_context;
static std::mutex m_asio_req;
static std::condition_variable_any cv_asio_req;
static std::atomic<u32> asio_requests;
static std::jthread service_thread;

void KernelSignalRequest() {
    std::unique_lock lock{m_asio_req};
    ++asio_requests;
    cv_asio_req.notify_one();
}

static void KernelServiceThread(std::stop_token stoken) {
    Common::SetCurrentThreadName("shadPS4:KernelServiceThread");

    while (!stoken.stop_requested()) {
        HLE_TRACE;
        {
            std::unique_lock lock{m_asio_req};
            Common::CondvarWait(cv_asio_req, lock, stoken, [] { return asio_requests != 0; });
        }
        if (stoken.stop_requested()) {
            break;
        }

        io_context.run();
        io_context.restart();

        asio_requests = 0;
    }
}

static PS4_SYSV_ABI void stack_chk_fail() {
    UNREACHABLE();
}

static thread_local s32 g_posix_errno = 0;

s32* PS4_SYSV_ABI __Error() {
    return &g_posix_errno;
}

void ErrSceToPosix(s32 error) {
    g_posix_errno = error - ORBIS_KERNEL_ERROR_UNKNOWN;
}

s32 ErrnoToSceKernelError(s32 error) {
    return error + ORBIS_KERNEL_ERROR_UNKNOWN;
}

s32 sceKernelError(int posix_error) {
    if (posix_error == 0) {
        return 0;
    }
    return posix_error + ORBIS_KERNEL_ERROR_UNKNOWN;
}

void SetPosixErrno(s32 e) {
    // Some error numbers are different between supported OSes
    switch (e) {
    case EPERM:
        g_posix_errno = POSIX_EPERM;
        break;
    case ENOENT:
        g_posix_errno = POSIX_ENOENT;
        break;
    case EDEADLK:
        g_posix_errno = POSIX_EDEADLK;
        break;
    case ENOMEM:
        g_posix_errno = POSIX_ENOMEM;
        break;
    case EACCES:
        g_posix_errno = POSIX_EACCES;
        break;
    case EFAULT:
        g_posix_errno = POSIX_EFAULT;
        break;
    case EINVAL:
        g_posix_errno = POSIX_EINVAL;
        break;
    case ENOSPC:
        g_posix_errno = POSIX_ENOSPC;
        break;
    case ERANGE:
        g_posix_errno = POSIX_ERANGE;
        break;
    case EAGAIN:
        g_posix_errno = POSIX_EAGAIN;
        break;
    case ETIMEDOUT:
        g_posix_errno = POSIX_ETIMEDOUT;
        break;
    default:
        LOG_WARNING(Kernel, "Unhandled errno {}", e);
        g_posix_errno = e;
    }
}

static u64 g_mspace_atomic_id_mask = 0;
static u64 g_mstate_table[64] = {0};

struct HeapInfoInfo {
    u64 size = sizeof(HeapInfoInfo);
    u32 flag;
    u32 getSegmentInfo;
    u64* mspace_atomic_id_mask;
    u64* mstate_table;
};

void PS4_SYSV_ABI sceLibcHeapGetTraceInfo(HeapInfoInfo* info) {
    info->mspace_atomic_id_mask = &g_mspace_atomic_id_mask;
    info->mstate_table = g_mstate_table;
    info->getSegmentInfo = 0;
}

struct OrbisKernelUuid {
    u32 timeLow;
    u16 timeMid;
    u16 timeHiAndVersion;
    u8 clockSeqHiAndReserved;
    u8 clockSeqLow;
    u8 node[6];
};
static_assert(sizeof(OrbisKernelUuid) == 0x10);

s32 PS4_SYSV_ABI sceKernelUuidCreate(OrbisKernelUuid* orbisUuid) {
    if (!orbisUuid) {
        return ORBIS_KERNEL_ERROR_EINVAL;
    }
#ifdef _WIN64
    UUID uuid;
    if (UuidCreate(&uuid) != RPC_S_OK) {
        return ORBIS_KERNEL_ERROR_EFAULT;
    }
#else
    uuid_t uuid;
    uuid_generate(uuid);
#endif
    std::memcpy(orbisUuid, &uuid, sizeof(OrbisKernelUuid));
    return ORBIS_OK;
}

s32 PS4_SYSV_ABI kernel_ioctl(s32 fd, u64 cmd, VA_ARGS) {
    auto* h = Common::Singleton<Core::FileSys::HandleTable>::Instance();
    auto* file = h->GetFile(fd);
    if (file == nullptr) {
        LOG_INFO(Lib_Kernel, "ioctl: fd = {:X} cmd = {:X} file == nullptr", fd, cmd);
        g_posix_errno = POSIX_EBADF;
        return -1;
    }
    if (file->type != Core::FileSys::FileType::Device) {
        LOG_WARNING(Lib_Kernel, "ioctl: fd = {:X} cmd = {:X} file->type != Device", fd, cmd);
        g_posix_errno = ENOTTY;
        return -1;
    }
    VA_CTX(ctx);
    s32 result = file->device->ioctl(cmd, &ctx);
    LOG_TRACE(Lib_Kernel, "ioctl: fd = {:X} cmd = {:X} result = {}", fd, cmd, result);
    if (result < 0) {
        ErrSceToPosix(result);
        return -1;
    }
    return result;
}

const char* PS4_SYSV_ABI sceKernelGetFsSandboxRandomWord() {
    const char* path = "sys";
    return path;
}

s32 PS4_SYSV_ABI _sigprocmask() {
    return ORBIS_OK;
}

s32 PS4_SYSV_ABI posix_getpagesize() {
    return 16_KB;
}

s32 PS4_SYSV_ABI posix_getsockname(Libraries::Net::OrbisNetId s,
                                   Libraries::Net::OrbisNetSockaddr* addr, u32* paddrlen) {
    auto* netcall = Common::Singleton<Libraries::Net::NetInternal>::Instance();
    auto sock = netcall->FindSocket(s);
    if (!sock) {
        *Libraries::Kernel::__Error() = ORBIS_NET_ERROR_EBADF;
        LOG_ERROR(Lib_Net, "socket id is invalid = {}", s);
        return -1;
    }
    s32 returncode = sock->GetSocketAddress(addr, paddrlen);
    if (returncode >= 0) {
        LOG_ERROR(Lib_Net, "return code : {:#x}", (u32)returncode);
        return 0;
    }
    *Libraries::Kernel::__Error() = 0x20;
    LOG_ERROR(Lib_Net, "error code returned : {:#x}", (u32)returncode);
    return -1;
}

// stubbed on non-devkit consoles
s32 PS4_SYSV_ABI sceKernelGetGPI() {
    LOG_DEBUG(Kernel, "called");
    return ORBIS_OK;
}

// stubbed on non-devkit consoles
s32 PS4_SYSV_ABI sceKernelSetGPO() {
    LOG_DEBUG(Kernel, "called");
    return ORBIS_OK;
}

s32 PS4_SYSV_ABI sceKernelGetSystemSwVersion(SwVersionStruct* ret) {
    if (ret == nullptr) {
        return ORBIS_OK; // but why?
    }
    ASSERT(ret->struct_size == 40);
    u32 fake_fw = Common::ElfInfo::Instance().RawFirmwareVer();
    ret->hex_representation = fake_fw;
    std::snprintf(ret->text_representation, 28, "%2x.%03x.%03x", fake_fw >> 0x18,
                  fake_fw >> 0xc & 0xfff, fake_fw & 0xfff); // why %2x?
    LOG_INFO(Lib_Kernel, "called, returned sw version: {}", ret->text_representation);
    return ORBIS_OK;
}

void RegisterLib(Core::Loader::SymbolsResolver* sym) {
    service_thread = std::jthread{KernelServiceThread};

    Libraries::Kernel::RegisterFileSystem(sym);
    Libraries::Kernel::RegisterTime(sym);
    Libraries::Kernel::RegisterThreads(sym);
    Libraries::Kernel::RegisterKernelEventFlag(sym);
    Libraries::Kernel::RegisterMemory(sym);
    Libraries::Kernel::RegisterEventQueue(sym);
    Libraries::Kernel::RegisterProcess(sym);
    Libraries::Kernel::RegisterException(sym);
    Libraries::Kernel::RegisterAio(sym);
    Libraries::Kernel::RegisterDebug(sym);

    LIB_OBJ("f7uOxY9mM1U", "libkernel", 1, "libkernel", 1, 1, &g_stack_chk_guard);
    LIB_FUNCTION("D4yla3vx4tY", "libkernel", 1, "libkernel", 1, 1, sceKernelError);
    LIB_FUNCTION("Mv1zUObHvXI", "libkernel", 1, "libkernel", 1, 1, sceKernelGetSystemSwVersion);
    LIB_FUNCTION("PfccT7qURYE", "libkernel", 1, "libkernel", 1, 1, kernel_ioctl);
    LIB_FUNCTION("JGfTMBOdUJo", "libkernel", 1, "libkernel", 1, 1, sceKernelGetFsSandboxRandomWord);
    LIB_FUNCTION("6xVpy0Fdq+I", "libkernel", 1, "libkernel", 1, 1, _sigprocmask);
    LIB_FUNCTION("Xjoosiw+XPI", "libkernel", 1, "libkernel", 1, 1, sceKernelUuidCreate);
    LIB_FUNCTION("Ou3iL1abvng", "libkernel", 1, "libkernel", 1, 1, stack_chk_fail);
    LIB_FUNCTION("9BcDykPmo1I", "libkernel", 1, "libkernel", 1, 1, __Error);
    LIB_FUNCTION("k+AXqu2-eBc", "libkernel", 1, "libkernel", 1, 1, posix_getpagesize);
    LIB_FUNCTION("k+AXqu2-eBc", "libScePosix", 1, "libkernel", 1, 1, posix_getpagesize);
    LIB_FUNCTION("NWtTN10cJzE", "libSceLibcInternalExt", 1, "libSceLibcInternal", 1, 1,
                 sceLibcHeapGetTraceInfo);

    // network
    LIB_FUNCTION("XVL8So3QJUk", "libkernel", 1, "libkernel", 1, 1, Libraries::Net::sys_connect);
    LIB_FUNCTION("TU-d9PfIHPM", "libkernel", 1, "libkernel", 1, 1, Libraries::Net::sys_socketex);
    LIB_FUNCTION("KuOmgKoqCdY", "libkernel", 1, "libkernel", 1, 1, Libraries::Net::sys_bind);
    LIB_FUNCTION("pxnCmagrtao", "libkernel", 1, "libkernel", 1, 1, Libraries::Net::sys_listen);
    LIB_FUNCTION("3e+4Iv7IJ8U", "libkernel", 1, "libkernel", 1, 1, Libraries::Net::sys_accept);
    LIB_FUNCTION("TU-d9PfIHPM", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_socket);
    LIB_FUNCTION("oBr313PppNE", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_sendto);
    LIB_FUNCTION("lUk6wrGXyMw", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_recvfrom);
    LIB_FUNCTION("fFxGkxF2bVo", "libScePosix", 1, "libkernel", 1, 1,
                 Libraries::Net::sys_setsockopt);
    // LIB_FUNCTION("RenI1lL1WFk", "libScePosix", 1, "libkernel", 1, 1, posix_getsockname);
    LIB_FUNCTION("KuOmgKoqCdY", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_bind);
    LIB_FUNCTION("5jRCs2axtr4", "libScePosix", 1, "libkernel", 1, 1,
                 Libraries::Net::sceNetInetNtop); // TODO fix it to sys_ ...
    LIB_FUNCTION("4n51s0zEf0c", "libScePosix", 1, "libkernel", 1, 1,
                 Libraries::Net::sceNetInetPton); // TODO fix it to sys_ ...
    LIB_FUNCTION("XVL8So3QJUk", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_connect);
    LIB_FUNCTION("3e+4Iv7IJ8U", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_accept);
    LIB_FUNCTION("aNeavPDNKzA", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_sendmsg);
    LIB_FUNCTION("pxnCmagrtao", "libScePosix", 1, "libkernel", 1, 1, Libraries::Net::sys_listen);

    LIB_FUNCTION("4oXYe9Xmk0Q", "libkernel", 1, "libkernel", 1, 1, sceKernelGetGPI);
    LIB_FUNCTION("ca7v6Cxulzs", "libkernel", 1, "libkernel", 1, 1, sceKernelSetGPO);
}

} // namespace Libraries::Kernel