// SPDX-FileCopyrightText: 2014 Citra Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <chrono>
#include <iostream>
#include <memory>
#include <regex>
#include <string>
#include <thread>

#include <fmt/ostream.h>

#include "common/detached_tasks.h"
#include "common/logging/backend.h"
#include "common/logging/log.h"
#include "common/microprofile.h"
#include "common/nvidia_flags.h"
#include "common/scm_rev.h"
#include "common/scope_exit.h"
#include "common/settings.h"
#include "common/string_util.h"
#include "common/telemetry.h"
#include "core/core.h"
#include "core/core_timing.h"
#include "core/cpu_manager.h"
#include "core/crypto/key_manager.h"
#include "core/file_sys/registered_cache.h"
#include "core/file_sys/vfs/vfs_real.h"
#include "core/hle/service/am/applet_manager.h"
#include "core/hle/service/filesystem/filesystem.h"
#include "core/loader/loader.h"
#include "core/telemetry_session.h"
#include "frontend_common/config.h"
#include "input_common/main.h"
#include "network/network.h"
#include "sdl_config.h"
#include "video_core/renderer_base.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2_gl.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2_null.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2_vk.h"

#ifdef _WIN32
// windows.h needs to be included before shellapi.h
#include <windows.h>

#include <shellapi.h>

#include "common/windows/timer_resolution.h"
#endif

#undef _UNICODE
#include <getopt.h>
#ifndef _MSC_VER
#include <unistd.h>
#endif

#ifdef _WIN32
extern "C" {
// tells Nvidia and AMD drivers to use the dedicated GPU by default on laptops with switchable
// graphics
__declspec(dllexport) unsigned long NvOptimusEnablement = 0x00000001;
__declspec(dllexport) int AmdPowerXpressRequestHighPerformance = 1;
}
#endif

#ifdef __unix__
#include "common/linux/gamemode.h"
#endif

static void PrintHelp(const char* argv0) {
    std::cout << "Usage: " << argv0
              << " [options] <filename>\n"
                 "-c, --config          Load the specified configuration file\n"
                 "-f, --fullscreen      Start in fullscreen mode\n"
                 "-g, --game            File path of the game to load\n"
                 "-h, --help            Display this help and exit\n"
                 "-m, --multiplayer=nick:password@address:port"
                 " Nickname, password, address and port for multiplayer\n"
                 "-p, --program         Pass following string as arguments to executable\n"
                 "-u, --user            Select a specific user profile from 0 to 7\n"
                 "-v, --version         Output version information and exit\n";
}

static void PrintVersion() {
    std::cout << "yuzu " << Common::g_scm_branch << " " << Common::g_scm_desc << std::endl;
}

static void OnStateChanged(const Network::RoomMember::State& state) {
    switch (state) {
    case Network::RoomMember::State::Idle:
        LOG_DEBUG(Network, "Network is idle");
        break;
    case Network::RoomMember::State::Joining:
        LOG_DEBUG(Network, "Connection sequence to room started");
        break;
    case Network::RoomMember::State::Joined:
        LOG_DEBUG(Network, "Successfully joined to the room");
        break;
    case Network::RoomMember::State::Moderator:
        LOG_DEBUG(Network, "Successfully joined the room as a moderator");
        break;
    default:
        break;
    }
}

static void OnNetworkError(const Network::RoomMember::Error& error) {
    switch (error) {
    case Network::RoomMember::Error::LostConnection:
        LOG_DEBUG(Network, "Lost connection to the room");
        break;
    case Network::RoomMember::Error::CouldNotConnect:
        LOG_ERROR(Network, "Error: Could not connect");
        exit(1);
        break;
    case Network::RoomMember::Error::NameCollision:
        LOG_ERROR(
            Network,
            "You tried to use the same nickname as another user that is connected to the Room");
        exit(1);
        break;
    case Network::RoomMember::Error::IpCollision:
        LOG_ERROR(Network, "You tried to use the same fake IP-Address as another user that is "
                           "connected to the Room");
        exit(1);
        break;
    case Network::RoomMember::Error::WrongPassword:
        LOG_ERROR(Network, "Room replied with: Wrong password");
        exit(1);
        break;
    case Network::RoomMember::Error::WrongVersion:
        LOG_ERROR(Network,
                  "You are using a different version than the room you are trying to connect to");
        exit(1);
        break;
    case Network::RoomMember::Error::RoomIsFull:
        LOG_ERROR(Network, "The room is full");
        exit(1);
        break;
    case Network::RoomMember::Error::HostKicked:
        LOG_ERROR(Network, "You have been kicked by the host");
        break;
    case Network::RoomMember::Error::HostBanned:
        LOG_ERROR(Network, "You have been banned by the host");
        break;
    case Network::RoomMember::Error::UnknownError:
        LOG_ERROR(Network, "UnknownError");
        break;
    case Network::RoomMember::Error::PermissionDenied:
        LOG_ERROR(Network, "PermissionDenied");
        break;
    case Network::RoomMember::Error::NoSuchUser:
        LOG_ERROR(Network, "NoSuchUser");
        break;
    }
}

static void OnMessageReceived(const Network::ChatEntry& msg) {
    std::cout << std::endl << msg.nickname << ": " << msg.message << std::endl << std::endl;
}

static void OnStatusMessageReceived(const Network::StatusMessageEntry& msg) {
    std::string message;
    switch (msg.type) {
    case Network::IdMemberJoin:
        message = fmt::format("{} has joined", msg.nickname);
        break;
    case Network::IdMemberLeave:
        message = fmt::format("{} has left", msg.nickname);
        break;
    case Network::IdMemberKicked:
        message = fmt::format("{} has been kicked", msg.nickname);
        break;
    case Network::IdMemberBanned:
        message = fmt::format("{} has been banned", msg.nickname);
        break;
    case Network::IdAddressUnbanned:
        message = fmt::format("{} has been unbanned", msg.nickname);
        break;
    }
    if (!message.empty())
        std::cout << std::endl << "* " << message << std::endl << std::endl;
}

/// Application entry point
int main(int argc, char** argv) {
#ifdef _WIN32
    if (AttachConsole(ATTACH_PARENT_PROCESS)) {
        freopen("CONOUT$", "wb", stdout);
        freopen("CONOUT$", "wb", stderr);
    }
#endif

    Common::Log::Initialize();
    Common::Log::SetColorConsoleBackendEnabled(true);
    Common::Log::Start();
    Common::DetachedTasks detached_tasks;

    int option_index = 0;
#ifdef _WIN32
    int argc_w;
    auto argv_w = CommandLineToArgvW(GetCommandLineW(), &argc_w);

    if (argv_w == nullptr) {
        LOG_CRITICAL(Frontend, "Failed to get command line arguments");
        return -1;
    }
#endif
    std::string filepath;
    std::optional<std::string> config_path;
    std::string program_args;
    std::optional<int> selected_user;

    bool use_multiplayer = false;
    bool fullscreen = false;
    std::string nickname{};
    std::string password{};
    std::string address{};
    u16 port = Network::DefaultRoomPort;

    static struct option long_options[] = {
        // clang-format off
        {"config", required_argument, 0, 'c'},
        {"fullscreen", no_argument, 0, 'f'},
        {"help", no_argument, 0, 'h'},
        {"game", required_argument, 0, 'g'},
        {"multiplayer", required_argument, 0, 'm'},
        {"program", optional_argument, 0, 'p'},
        {"user", required_argument, 0, 'u'},
        {"version", no_argument, 0, 'v'},
        {0, 0, 0, 0},
        // clang-format on
    };

    while (optind < argc) {
        int arg = getopt_long(argc, argv, "g:fhvp::c:u:", long_options, &option_index);
        if (arg != -1) {
            switch (static_cast<char>(arg)) {
            case 'c':
                config_path = optarg;
                break;
            case 'f':
                fullscreen = true;
                LOG_INFO(Frontend, "Starting in fullscreen mode...");
                break;
            case 'h':
                PrintHelp(argv[0]);
                return 0;
            case 'g': {
                const std::string str_arg(optarg);
                filepath = str_arg;
                break;
            }
            case 'm': {
                use_multiplayer = true;
                const std::string str_arg(optarg);
                // regex to check if the format is nickname:password@ip:port
                // with optional :password
                const std::regex re("^([^:]+)(?::(.+))?@([^:]+)(?::([0-9]+))?$");
                if (!std::regex_match(str_arg, re)) {
                    std::cout << "Wrong format for option --multiplayer\n";
                    PrintHelp(argv[0]);
                    return 0;
                }

                std::smatch match;
                std::regex_search(str_arg, match, re);
                ASSERT(match.size() == 5);
                nickname = match[1];
                password = match[2];
                address = match[3];
                if (!match[4].str().empty()) {
                    port = static_cast<u16>(std::strtoul(match[4].str().c_str(), nullptr, 0));
                }
                std::regex nickname_re("^[a-zA-Z0-9._\\- ]+$");
                if (!std::regex_match(nickname, nickname_re)) {
                    std::cout
                        << "Nickname is not valid. Must be 4 to 20 alphanumeric characters.\n";
                    return 0;
                }
                if (address.empty()) {
                    std::cout << "Address to room must not be empty.\n";
                    return 0;
                }
                break;
            }
            case 'p':
                program_args = argv[optind];
                ++optind;
                break;
            case 'u':
                selected_user = atoi(optarg);
                break;
            case 'v':
                PrintVersion();
                return 0;
            }
        } else {
#ifdef _WIN32
            filepath = Common::UTF16ToUTF8(argv_w[optind]);
#else
            filepath = argv[optind];
#endif
            optind++;
        }
    }

    SdlConfig config{config_path};

    // apply the log_filter setting
    // the logger was initialized before and doesn't pick up the filter on its own
    Common::Log::Filter filter;
    filter.ParseFilterString(Settings::values.log_filter.GetValue());
    Common::Log::SetGlobalFilter(filter);

    if (!program_args.empty()) {
        Settings::values.program_args = program_args;
    }

    if (selected_user.has_value()) {
        Settings::values.current_user = std::clamp(*selected_user, 0, 7);
    }

#ifdef _WIN32
    LocalFree(argv_w);
#endif

    MicroProfileOnThreadCreate("EmuThread");
    SCOPE_EXIT({ MicroProfileShutdown(); });

    Common::ConfigureNvidiaEnvironmentFlags();

    if (filepath.empty()) {
        LOG_CRITICAL(Frontend, "Failed to load ROM: No ROM specified");
        return -1;
    }

    Core::System system{};
    system.Initialize();

    InputCommon::InputSubsystem input_subsystem{};

    // Apply the command line arguments
    system.ApplySettings();

    std::unique_ptr<EmuWindow_SDL2> emu_window;
    switch (Settings::values.renderer_backend.GetValue()) {
    case Settings::RendererBackend::OpenGL:
        emu_window = std::make_unique<EmuWindow_SDL2_GL>(&input_subsystem, system, fullscreen);
        break;
    case Settings::RendererBackend::Vulkan:
        emu_window = std::make_unique<EmuWindow_SDL2_VK>(&input_subsystem, system, fullscreen);
        break;
    case Settings::RendererBackend::Null:
        emu_window = std::make_unique<EmuWindow_SDL2_Null>(&input_subsystem, system, fullscreen);
        break;
    }

#ifdef _WIN32
    Common::Windows::SetCurrentTimerResolutionToMaximum();
    system.CoreTiming().SetTimerResolutionNs(Common::Windows::GetCurrentTimerResolution());
#endif

    system.SetContentProvider(std::make_unique<FileSys::ContentProviderUnion>());
    system.SetFilesystem(std::make_shared<FileSys::RealVfsFilesystem>());
    system.GetFileSystemController().CreateFactories(*system.GetFilesystem());
    system.GetUserChannel().clear();

    Service::AM::FrontendAppletParameters load_parameters{
        .applet_id = Service::AM::AppletId::Application,
    };
    const Core::SystemResultStatus load_result{system.Load(*emu_window, filepath, load_parameters)};

    switch (load_result) {
    case Core::SystemResultStatus::ErrorGetLoader:
        LOG_CRITICAL(Frontend, "Failed to obtain loader for {}!", filepath);
        return -1;
    case Core::SystemResultStatus::ErrorLoader:
        LOG_CRITICAL(Frontend, "Failed to load ROM!");
        return -1;
    case Core::SystemResultStatus::ErrorNotInitialized:
        LOG_CRITICAL(Frontend, "CPUCore not initialized");
        return -1;
    case Core::SystemResultStatus::ErrorVideoCore:
        LOG_CRITICAL(Frontend, "Failed to initialize VideoCore!");
        return -1;
    case Core::SystemResultStatus::Success:
        break; // Expected case
    default:
        if (static_cast<u32>(load_result) >
            static_cast<u32>(Core::SystemResultStatus::ErrorLoader)) {
            const u16 loader_id = static_cast<u16>(Core::SystemResultStatus::ErrorLoader);
            const u16 error_id = static_cast<u16>(load_result) - loader_id;
            LOG_CRITICAL(Frontend,
                         "While attempting to load the ROM requested, an error occurred. Please "
                         "refer to the yuzu wiki for more information or the yuzu discord for "
                         "additional help.\n\nError Code: {:04X}-{:04X}\nError Description: {}",
                         loader_id, error_id, static_cast<Loader::ResultStatus>(error_id));
        }
        break;
    }

    system.TelemetrySession().AddField(Common::Telemetry::FieldType::App, "Frontend", "SDL");

    if (use_multiplayer) {
        if (auto member = system.GetRoomNetwork().GetRoomMember().lock()) {
            member->BindOnChatMessageReceived(OnMessageReceived);
            member->BindOnStatusMessageReceived(OnStatusMessageReceived);
            member->BindOnStateChanged(OnStateChanged);
            member->BindOnError(OnNetworkError);
            LOG_DEBUG(Network, "Start connection to {}:{} with nickname {}", address, port,
                      nickname);
            member->Join(nickname, address.c_str(), port, 0, Network::NoPreferredIP, password);
        } else {
            LOG_ERROR(Network, "Could not access RoomMember");
            return 0;
        }
    }

    // Core is loaded, start the GPU (makes the GPU contexts current to this thread)
    system.GPU().Start();
    system.GetCpuManager().OnGpuReady();

    if (Settings::values.use_disk_shader_cache.GetValue()) {
        system.Renderer().ReadRasterizer()->LoadDiskResources(
            system.GetApplicationProcessProgramID(), std::stop_token{},
            [](VideoCore::LoadCallbackStage, size_t value, size_t total) {});
    }

    system.RegisterExitCallback([&] {
        // Just exit right away.
        exit(0);
    });

#ifdef __unix__
    Common::Linux::StartGamemode();
#endif

    void(system.Run());
    if (system.DebuggerEnabled()) {
        system.InitializeDebugger();
    }
    while (emu_window->IsOpen()) {
        emu_window->WaitEvent();
    }
    system.DetachDebugger();
    void(system.Pause());
    system.ShutdownMainProcess();

#ifdef __unix__
    Common::Linux::StopGamemode();
#endif

    detached_tasks.WaitForAllTasks();
    return 0;
}
