#include <codecvt>
#include <locale>
#include <string>
#include <string_view>

#include <android/api-level.h>
#include <android/native_window_jni.h>

#include "common/detached_tasks.h"
#include "common/logging/backend.h"
#include "common/logging/log.h"
#include "common/microprofile.h"
#include "common/scm_rev.h"
#include "common/scope_exit.h"
#include "common/settings.h"
#include "core/core.h"
#include "core/cpu_manager.h"
#include "core/file_sys/registered_cache.h"
#include "core/file_sys/vfs_real.h"
#include "core/hle/service/filesystem/filesystem.h"
#include "core/perf_stats.h"
#include "jni/config.h"
#include "jni/emu_window/emu_window.h"
#include "jni/id_cache.h"
#include "video_core/rasterizer_interface.h"

namespace {

ANativeWindow* s_surf{};
std::unique_ptr<EmuWindow_Android> emu_window;
std::atomic<bool> stop_run{true};
Core::System system_;

std::string UTF16ToUTF8(std::u16string_view input) {
    std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> convert;
    return convert.to_bytes(input.data(), input.data() + input.size());
}

std::string GetJString(JNIEnv* env, jstring jstr) {
    if (!jstr) {
        return {};
    }

    const jchar* jchars = env->GetStringChars(jstr, nullptr);
    const jsize length = env->GetStringLength(jstr);
    const std::u16string_view string_view(reinterpret_cast<const char16_t*>(jchars), length);
    const std::string converted_string = UTF16ToUTF8(string_view);
    env->ReleaseStringChars(jstr, jchars);

    return converted_string;
}

} // Anonymous namespace

static Core::SystemResultStatus RunEmulation(const std::string& filepath) {
    Common::Log::Initialize();
    Common::Log::SetColorConsoleBackendEnabled(true);
    Common::Log::Start();
    Common::DetachedTasks detached_tasks;

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

    LOG_INFO(Frontend, "starting");

    if (filepath.empty()) {
        LOG_CRITICAL(Frontend, "failed to load: filepath empty!");
        return Core::SystemResultStatus::ErrorLoader;
    }

    // Loads the configuration.
    Config{};

    system_.Initialize();
    system_.ApplySettings();

    InputCommon::InputSubsystem input_subsystem{};

    emu_window = std::make_unique<EmuWindow_Android>(&input_subsystem, s_surf);

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

    const Core::SystemResultStatus load_result{system_.Load(*emu_window, filepath)};

    if (load_result != Core::SystemResultStatus::Success) {
        return load_result;
    }

    system_.GPU().Start();
    system_.GetCpuManager().OnGpuReady();
    system_.RegisterExitCallback([&] { exit(0); });

    void(system_.Run());

    if (system_.DebuggerEnabled()) {
        system_.InitializeDebugger();
    }

    stop_run = false;
    while (!stop_run) {
        std::this_thread::sleep_for(std::chrono::seconds(1));
    }

    system_.DetachDebugger();
    void(system_.Pause());
    system_.ShutdownMainProcess();

    detached_tasks.WaitForAllTasks();

    return Core::SystemResultStatus::Success;
}

extern "C" {

void Java_org_yuzu_yuzu_1emu_NativeLibrary_SurfaceChanged(JNIEnv* env,
                                                            [[maybe_unused]] jclass clazz,
                                                            jobject surf) {
    s_surf = ANativeWindow_fromSurface(env, surf);

    if (emu_window) {
        emu_window->OnSurfaceChanged(s_surf);
    }

    LOG_INFO(Frontend, "surface changed");
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_SurfaceDestroyed(JNIEnv* env,
                                                              [[maybe_unused]] jclass clazz) {
    ANativeWindow_release(s_surf);
    s_surf = nullptr;
    if (emu_window) {
        emu_window->OnSurfaceChanged(s_surf);
    }
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_DoFrame(JNIEnv* env, [[maybe_unused]] jclass clazz) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_NotifyOrientationChange(JNIEnv* env,
                                                                     [[maybe_unused]] jclass clazz,
                                                                     jint layout_option,
                                                                     jint rotation) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_SetUserDirectory(
    [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jclass clazz,
    [[maybe_unused]] jstring j_directory) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_UnPauseEmulation([[maybe_unused]] JNIEnv* env,
                                                              [[maybe_unused]] jclass clazz) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_PauseEmulation([[maybe_unused]] JNIEnv* env,
                                                            [[maybe_unused]] jclass clazz) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_StopEmulation([[maybe_unused]] JNIEnv* env,
                                                           [[maybe_unused]] jclass clazz) {}

jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_IsRunning([[maybe_unused]] JNIEnv* env,
                                                           [[maybe_unused]] jclass clazz) {
    return static_cast<jboolean>(!stop_run);
}

jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_onGamePadEvent([[maybe_unused]] JNIEnv* env,
                                                                [[maybe_unused]] jclass clazz,
                                                                [[maybe_unused]] jstring j_device,
                                                                jint j_button, jint action) {
    emu_window->OnGamepadEvent(j_button, action != 0);
    return static_cast<jboolean>(true);
}

jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_onGamePadMoveEvent([[maybe_unused]] JNIEnv* env,
                                                                    [[maybe_unused]] jclass clazz,
                                                                    jstring j_device, jint axis,
                                                                    jfloat x, jfloat y) {
    // Clamp joystick movement to supported minimum and maximum.
    x = std::clamp(x, -1.f, 1.f);
    y = std::clamp(-y, -1.f, 1.f);

    // Clamp the input to a circle.
    float r = x * x + y * y;
    if (r > 1.0f) {
        r = std::sqrt(r);
        x /= r;
        y /= r;
    }
    emu_window->OnGamepadMoveEvent(x, y);
    return static_cast<jboolean>(false);
}

jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_onGamePadAxisEvent([[maybe_unused]] JNIEnv* env,
                                                                    [[maybe_unused]] jclass clazz,
                                                                    jstring j_device, jint axis_id,
                                                                    jfloat axis_val) {
    return {};
}

jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_onTouchEvent([[maybe_unused]] JNIEnv* env,
                                                              [[maybe_unused]] jclass clazz,
                                                              jfloat x, jfloat y,
                                                              jboolean pressed) {
    return static_cast<jboolean>(emu_window->OnTouchEvent(x, y, pressed));
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_onTouchMoved([[maybe_unused]] JNIEnv* env,
                                                          [[maybe_unused]] jclass clazz, jfloat x,
                                                          jfloat y) {
    emu_window->OnTouchMoved(x, y);
}

jintArray Java_org_yuzu_yuzu_1emu_NativeLibrary_GetIcon([[maybe_unused]] JNIEnv* env,
                                                          [[maybe_unused]] jclass clazz,
                                                          [[maybe_unused]] jstring j_file) {
    return {};
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetTitle([[maybe_unused]] JNIEnv* env,
                                                         [[maybe_unused]] jclass clazz,
                                                         [[maybe_unused]] jstring j_filename) {
    return env->NewStringUTF("");
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetDescription([[maybe_unused]] JNIEnv* env,
                                                               [[maybe_unused]] jclass clazz,
                                                               jstring j_filename) {
    return j_filename;
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetGameId([[maybe_unused]] JNIEnv* env,
                                                          [[maybe_unused]] jclass clazz,
                                                          jstring j_filename) {
    return j_filename;
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetRegions([[maybe_unused]] JNIEnv* env,
                                                           [[maybe_unused]] jclass clazz,
                                                           [[maybe_unused]] jstring j_filename) {
    return env->NewStringUTF("");
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetCompany([[maybe_unused]] JNIEnv* env,
                                                           [[maybe_unused]] jclass clazz,
                                                           [[maybe_unused]] jstring j_filename) {
    return env->NewStringUTF("");
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetGitRevision([[maybe_unused]] JNIEnv* env,
                                                               [[maybe_unused]] jclass clazz) {
    return {};
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_CreateConfigFile
    [[maybe_unused]] (JNIEnv* env, [[maybe_unused]] jclass clazz) {
    Config{};
}

jint Java_org_yuzu_yuzu_1emu_NativeLibrary_DefaultCPUCore([[maybe_unused]] JNIEnv* env,
                                                            [[maybe_unused]] jclass clazz) {
    return {};
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_Run__Ljava_lang_String_2Ljava_lang_String_2Z(
    [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jclass clazz, [[maybe_unused]] jstring j_file,
    [[maybe_unused]] jstring j_savestate, [[maybe_unused]] jboolean j_delete_savestate) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_ReloadSettings([[maybe_unused]] JNIEnv* env,
                                                            [[maybe_unused]] jclass clazz) {
    Config{};
}

jstring Java_org_yuzu_yuzu_1emu_NativeLibrary_GetUserSetting([[maybe_unused]] JNIEnv* env,
                                                               [[maybe_unused]] jclass clazz,
                                                               jstring j_game_id, jstring j_section,
                                                               jstring j_key) {
    std::string_view game_id = env->GetStringUTFChars(j_game_id, 0);
    std::string_view section = env->GetStringUTFChars(j_section, 0);
    std::string_view key = env->GetStringUTFChars(j_key, 0);

    env->ReleaseStringUTFChars(j_game_id, game_id.data());
    env->ReleaseStringUTFChars(j_section, section.data());
    env->ReleaseStringUTFChars(j_key, key.data());

    return env->NewStringUTF("");
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_SetUserSetting([[maybe_unused]] JNIEnv* env,
                                                            [[maybe_unused]] jclass clazz,
                                                            jstring j_game_id, jstring j_section,
                                                            jstring j_key, jstring j_value) {
    std::string_view game_id = env->GetStringUTFChars(j_game_id, 0);
    std::string_view section = env->GetStringUTFChars(j_section, 0);
    std::string_view key = env->GetStringUTFChars(j_key, 0);
    std::string_view value = env->GetStringUTFChars(j_value, 0);

    env->ReleaseStringUTFChars(j_game_id, game_id.data());
    env->ReleaseStringUTFChars(j_section, section.data());
    env->ReleaseStringUTFChars(j_key, key.data());
    env->ReleaseStringUTFChars(j_value, value.data());
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_InitGameIni([[maybe_unused]] JNIEnv* env,
                                                         [[maybe_unused]] jclass clazz,
                                                         jstring j_game_id) {
    std::string_view game_id = env->GetStringUTFChars(j_game_id, 0);

    env->ReleaseStringUTFChars(j_game_id, game_id.data());
}

jdoubleArray Java_org_yuzu_yuzu_1emu_NativeLibrary_GetPerfStats([[maybe_unused]] JNIEnv* env,
                                                                  [[maybe_unused]] jclass clazz) {
    jdoubleArray j_stats = env->NewDoubleArray(4);

    if (!stop_run && system_.IsPoweredOn()) {
        const auto results = system_.GetAndResetPerfStats();

        // Converting the structure into an array makes it easier to pass it to the frontend
        double stats[4] = {results.system_fps, results.average_game_fps, results.frametime,
                           results.emulation_speed};

        env->SetDoubleArrayRegion(j_stats, 0, 4, stats);
    }

    return j_stats;
}

void Java_org_yuzu_yuzu_1emu_utils_DirectoryInitialization_SetSysDirectory(
    [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jclass clazz, jstring j_path) {}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_Run__Ljava_lang_String_2([[maybe_unused]] JNIEnv* env,
                                                                      [[maybe_unused]] jclass clazz,
                                                                      jstring j_path) {
    const std::string path = GetJString(env, j_path);

    if (!stop_run) {
        stop_run = true;
    }

    const Core::SystemResultStatus result{RunEmulation(path)};
    if (result != Core::SystemResultStatus::Success) {
        env->CallStaticVoidMethod(IDCache::GetNativeLibraryClass(),
                                  IDCache::GetExitEmulationActivity(), static_cast<int>(result));
    }
}

void Java_org_yuzu_yuzu_1emu_NativeLibrary_LogDeviceInfo([[maybe_unused]] JNIEnv* env,
                                                           [[maybe_unused]] jclass clazz) {
    LOG_INFO(Frontend, "yuzu Version: {}-{}", Common::g_scm_branch, Common::g_scm_desc);
    LOG_INFO(Frontend, "Host OS: Android API level {}", android_get_device_api_level());
}

} // extern "C"