// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

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

#include <fmt/ostream.h>

#include "common/common_paths.h"
#include "common/detached_tasks.h"
#include "common/file_util.h"
#include "common/logging/backend.h"
#include "common/logging/filter.h"
#include "common/logging/log.h"
#include "common/microprofile.h"
#include "common/scm_rev.h"
#include "common/scope_exit.h"
#include "common/string_util.h"
#include "common/telemetry.h"
#include "core/core.h"
#include "core/crypto/key_manager.h"
#include "core/file_sys/vfs_real.h"
#include "core/gdbstub/gdbstub.h"
#include "core/hle/service/filesystem/filesystem.h"
#include "core/loader/loader.h"
#include "core/settings.h"
#include "core/telemetry_session.h"
#include "video_core/renderer_base.h"
#include "yuzu_cmd/config.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2.h"
#include "yuzu_cmd/emu_window/emu_window_sdl2_gl.h"
#ifdef HAS_VULKAN
#include "yuzu_cmd/emu_window/emu_window_sdl2_vk.h"
#endif

#include "core/file_sys/registered_cache.h"

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

#include <shellapi.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

static void PrintHelp(const char* argv0) {
    std::cout << "Usage: " << argv0
              << " [options] <filename>\n"
                 "-g, --gdbport=NUMBER  Enable gdb stub on port NUMBER\n"
                 "-f, --fullscreen      Start in fullscreen mode\n"
                 "-h, --help            Display this help and exit\n"
                 "-v, --version         Output version information and exit\n"
                 "-p, --program         Pass following string as arguments to executable\n";
}

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

static void InitializeLogging() {
    Log::Filter log_filter(Log::Level::Debug);
    log_filter.ParseFilterString(Settings::values.log_filter);
    Log::SetGlobalFilter(log_filter);

    Log::AddBackend(std::make_unique<Log::ColorConsoleBackend>());

    const std::string& log_dir = Common::FS::GetUserPath(Common::FS::UserPath::LogDir);
    Common::FS::CreateFullPath(log_dir);
    Log::AddBackend(std::make_unique<Log::FileBackend>(log_dir + LOG_FILE));
#ifdef _WIN32
    Log::AddBackend(std::make_unique<Log::DebuggerBackend>());
#endif
}

/// Application entry point
int main(int argc, char** argv) {
    Common::DetachedTasks detached_tasks;
    Config config;

    int option_index = 0;
    bool use_gdbstub = Settings::values.use_gdbstub;
    u32 gdb_port = static_cast<u32>(Settings::values.gdbstub_port);

    InitializeLogging();

    char* endarg;
#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;

    bool fullscreen = false;

    static struct option long_options[] = {
        {"gdbport", required_argument, 0, 'g'}, {"fullscreen", no_argument, 0, 'f'},
        {"help", no_argument, 0, 'h'},          {"version", no_argument, 0, 'v'},
        {"program", optional_argument, 0, 'p'}, {0, 0, 0, 0},
    };

    while (optind < argc) {
        int arg = getopt_long(argc, argv, "g:fhvp::", long_options, &option_index);
        if (arg != -1) {
            switch (static_cast<char>(arg)) {
            case 'g':
                errno = 0;
                gdb_port = strtoul(optarg, &endarg, 0);
                use_gdbstub = true;
                if (endarg == optarg)
                    errno = EINVAL;
                if (errno != 0) {
                    perror("--gdbport");
                    exit(1);
                }
                break;
            case 'f':
                fullscreen = true;
                LOG_INFO(Frontend, "Starting in fullscreen mode...");
                break;
            case 'h':
                PrintHelp(argv[0]);
                return 0;
            case 'v':
                PrintVersion();
                return 0;
            case 'p':
                Settings::values.program_args = argv[optind];
                ++optind;
                break;
            }
        } else {
#ifdef _WIN32
            filepath = Common::UTF16ToUTF8(argv_w[optind]);
#else
            filepath = argv[optind];
#endif
            optind++;
        }
    }

#ifdef _WIN32
    LocalFree(argv_w);
#endif

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

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

    // Apply the command line arguments
    Settings::values.gdbstub_port = gdb_port;
    Settings::values.use_gdbstub = use_gdbstub;
    Settings::Apply();

    Core::System& system{Core::System::GetInstance()};

    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>(system, fullscreen);
        break;
    case Settings::RendererBackend::Vulkan:
#ifdef HAS_VULKAN
        emu_window = std::make_unique<EmuWindow_SDL2_VK>(system, fullscreen);
        break;
#else
        LOG_CRITICAL(Frontend, "Vulkan backend has not been compiled!");
        return 1;
#endif
    }

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

    const Core::System::ResultStatus load_result{system.Load(*emu_window, filepath)};

    switch (load_result) {
    case Core::System::ResultStatus::ErrorGetLoader:
        LOG_CRITICAL(Frontend, "Failed to obtain loader for {}!", filepath);
        return -1;
    case Core::System::ResultStatus::ErrorLoader:
        LOG_CRITICAL(Frontend, "Failed to load ROM!");
        return -1;
    case Core::System::ResultStatus::ErrorNotInitialized:
        LOG_CRITICAL(Frontend, "CPUCore not initialized");
        return -1;
    case Core::System::ResultStatus::ErrorVideoCore:
        LOG_CRITICAL(Frontend, "Failed to initialize VideoCore!");
        return -1;
    case Core::System::ResultStatus::Success:
        break; // Expected case
    default:
        if (static_cast<u32>(load_result) >
            static_cast<u32>(Core::System::ResultStatus::ErrorLoader)) {
            const u16 loader_id = static_cast<u16>(Core::System::ResultStatus::ErrorLoader);
            const u16 error_id = static_cast<u16>(load_result) - loader_id;
            LOG_CRITICAL(Frontend,
                         "While attempting to load the ROM requested, an error occured. 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));
        }
    }

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

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

    system.Renderer().Rasterizer().LoadDiskResources();

    std::thread render_thread([&emu_window] { emu_window->Present(); });
    system.Run();
    while (emu_window->IsOpen()) {
        std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }
    system.Pause();
    render_thread.join();

    system.Shutdown();

    detached_tasks.WaitForAllTasks();
    return 0;
}
