#include "android_host_interface.h"
#include "android_gles_host_display.h"
#include "common/assert.h"
#include "common/audio_stream.h"
#include "common/log.h"
#include "common/string.h"
#include "core/controller.h"
#include "core/game_list.h"
#include "core/gpu.h"
#include "core/host_display.h"
#include "core/system.h"
#include "frontend-common/ini_settings_interface.h"
#include <android/native_window_jni.h>
#include <cmath>
#include <imgui.h>
Log_SetChannel(AndroidHostInterface);

static JavaVM* s_jvm;
static jclass s_AndroidHostInterface_class;
static jmethodID s_AndroidHostInterface_constructor;
static jfieldID s_AndroidHostInterface_field_nativePointer;

// helper for retrieving the current per-thread jni environment
static JNIEnv* GetJNIEnv()
{
  JNIEnv* env;
  if (s_jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK)
    return nullptr;
  else
    return env;
}

static AndroidHostInterface* GetNativeClass(JNIEnv* env, jobject obj)
{
  return reinterpret_cast<AndroidHostInterface*>(
    static_cast<uintptr_t>(env->GetLongField(obj, s_AndroidHostInterface_field_nativePointer)));
}

static std::string JStringToString(JNIEnv* env, jstring str)
{
  if (str == nullptr)
    return {};

  jsize length = env->GetStringUTFLength(str);
  if (length == 0)
    return {};

  const char* data = env->GetStringUTFChars(str, nullptr);
  Assert(data != nullptr);

  std::string ret(data, length);
  env->ReleaseStringUTFChars(str, data);

  return ret;
}

AndroidHostInterface::AndroidHostInterface(jobject java_object) : m_java_object(java_object) {}

AndroidHostInterface::~AndroidHostInterface()
{
  ImGui::DestroyContext();
  GetJNIEnv()->DeleteGlobalRef(m_java_object);
}

bool AndroidHostInterface::Initialize()
{
  if (!HostInterface::Initialize())
    return false;

  return true;
}

void AndroidHostInterface::Shutdown()
{
  HostInterface::Shutdown();
}

void AndroidHostInterface::ReportError(const char* message)
{
  HostInterface::ReportError(message);
}

void AndroidHostInterface::ReportMessage(const char* message)
{
  HostInterface::ReportMessage(message);
}

void AndroidHostInterface::SetUserDirectory()
{
  // TODO: Should this be customizable or use an API-determined path?
  m_user_directory = "/sdcard/duckstation";
}

void AndroidHostInterface::LoadSettings()
{
  // check settings version, if invalid set defaults, then load settings
  INISettingsInterface settings_interface(GetSettingsFileName());
  CheckSettings(settings_interface);
  UpdateSettings([this, &settings_interface]() { m_settings.Load(settings_interface); });
}

bool AndroidHostInterface::StartEmulationThread(ANativeWindow* initial_surface, SystemBootParameters boot_params)
{
  Assert(!IsEmulationThreadRunning());

  Log_DevPrintf("Starting emulation thread...");
  m_emulation_thread_stop_request.store(false);
  m_emulation_thread =
    std::thread(&AndroidHostInterface::EmulationThreadEntryPoint, this, initial_surface, std::move(boot_params));
  m_emulation_thread_started.Wait();
  if (!m_emulation_thread_start_result.load())
  {
    m_emulation_thread.join();
    Log_ErrorPrint("Failed to start emulation in thread");
    return false;
  }

  return true;
}

void AndroidHostInterface::StopEmulationThread()
{
  Assert(IsEmulationThreadRunning());
  Log_InfoPrint("Stopping emulation thread...");
  m_emulation_thread_stop_request.store(true);
  m_emulation_thread.join();
  Log_InfoPrint("Emulation thread stopped");
}

void AndroidHostInterface::RunOnEmulationThread(std::function<void()> function, bool blocking)
{
  if (!IsEmulationThreadRunning())
  {
    function();
    return;
  }

  m_callback_mutex.lock();
  m_callback_queue.push_back(std::move(function));

  if (blocking)
  {
    // TODO: Don't spin
    for (;;)
    {
      if (m_callback_queue.empty())
        break;

      m_callback_mutex.unlock();
      m_callback_mutex.lock();
    }
  }

  m_callback_mutex.unlock();
}

void AndroidHostInterface::EmulationThreadEntryPoint(ANativeWindow* initial_surface, SystemBootParameters boot_params)
{
  CreateImGuiContext();

  // Boot system.
  if (!BootSystem(boot_params))
  {
    Log_ErrorPrintf("Failed to boot system on emulation thread (file:%s).", boot_params.filename.c_str());
    DestroyImGuiContext();
    m_emulation_thread_start_result.store(false);
    m_emulation_thread_started.Signal();
    return;
  }

  // System is ready to go.
  m_emulation_thread_start_result.store(true);
  m_emulation_thread_started.Signal();

  ImGui::NewFrame();

  while (!m_emulation_thread_stop_request.load())
  {
    // run any events
    m_callback_mutex.lock();
    for (;;)
    {
      if (m_callback_queue.empty())
        break;

      auto callback = std::move(m_callback_queue.front());
      m_callback_queue.pop_front();
      m_callback_mutex.unlock();
      callback();
      m_callback_mutex.lock();
    }
    m_callback_mutex.unlock();

    // simulate the system if not paused
    if (m_system && !m_paused)
      m_system->RunFrame();

    // rendering
    {
      DrawImGuiWindows();

      if (m_system)
        m_system->GetGPU()->ResetGraphicsAPIState();

      m_display->Render();

      if (m_system)
      {
        m_system->GetGPU()->RestoreGraphicsAPIState();
        m_system->UpdatePerformanceCounters();

        if (m_speed_limiter_enabled)
          m_system->Throttle();
      }
    }
  }

  DestroySystem();
  DestroyImGuiContext();
}

bool AndroidHostInterface::AcquireHostDisplay()
{
  std::unique_ptr<HostDisplay> display = AndroidGLESHostDisplay::Create(m_surface);
  if (!display)
  {
    Log_ErrorPrintf("Failed to create GLES host display");
    return false;
  }

  m_display = display.release();
  return true;
}

void AndroidHostInterface::ReleaseHostDisplay()
{
  delete m_display;
  m_display = nullptr;
}

std::unique_ptr<AudioStream> AndroidHostInterface::CreateAudioStream(AudioBackend backend)
{
  std::unique_ptr<AudioStream> stream;

  switch (m_settings.audio_backend)
  {
    case AudioBackend::Cubeb:
      stream = AudioStream::CreateCubebAudioStream();
      break;

    default:
      stream = AudioStream::CreateNullAudioStream();
      break;
  }

  if (!stream)
  {
    ReportFormattedError("Failed to create %s audio stream, falling back to null",
                         Settings::GetAudioBackendName(m_settings.audio_backend));
    stream = AudioStream::CreateNullAudioStream();
  }

  return stream;
}

void AndroidHostInterface::SurfaceChanged(ANativeWindow* surface, int format, int width, int height)
{
  Log_InfoPrintf("SurfaceChanged %p %d %d %d", surface, format, width, height);
  if (m_surface == surface)
  {
    if (m_display)
      m_display->WindowResized(width, height);

    return;
  }

  m_surface = surface;
  if (m_display)
    m_display->ChangeRenderWindow(surface);
}

void AndroidHostInterface::CreateImGuiContext()
{
  ImGui::CreateContext();

  ImGui::GetIO().IniFilename = nullptr;
  // ImGui::GetIO().ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;
  // ImGui::GetIO().BackendFlags |= ImGuiBackendFlags_HasGamepad;
}

void AndroidHostInterface::DestroyImGuiContext()
{
  ImGui::DestroyContext();
}

void AndroidHostInterface::SetControllerType(u32 index, std::string_view type_name)
{
  ControllerType type =
    Settings::ParseControllerTypeName(std::string(type_name).c_str()).value_or(ControllerType::None);

  if (!IsEmulationThreadRunning())
  {
    m_settings.controller_types[index] = type;
    return;
  }

  RunOnEmulationThread(
    [this, index, type]() {
      Log_InfoPrintf("Changing controller slot %d to %s", index, Settings::GetControllerTypeName(type));
      m_settings.controller_types[index] = type;
      m_system->UpdateControllers();
    },
    false);
}

void AndroidHostInterface::SetControllerButtonState(u32 index, s32 button_code, bool pressed)
{
  if (!IsEmulationThreadRunning())
    return;

  RunOnEmulationThread(
    [this, index, button_code, pressed]() {
      Controller* controller = m_system->GetController(index);
      if (!controller)
        return;

      controller->SetButtonState(button_code, pressed);
    },
    false);
}

extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved)
{
  Log::SetDebugOutputParams(true, nullptr, LOGLEVEL_DEV);
  s_jvm = vm;

  JNIEnv* env = GetJNIEnv();
  if ((s_AndroidHostInterface_class = env->FindClass("com/github/stenzek/duckstation/AndroidHostInterface")) == nullptr)
  {
    Log_ErrorPrint("AndroidHostInterface class lookup failed");
    return -1;
  }

  // Create global reference so it doesn't get cleaned up.
  s_AndroidHostInterface_class = static_cast<jclass>(env->NewGlobalRef(s_AndroidHostInterface_class));
  if (!s_AndroidHostInterface_class)
  {
    Log_ErrorPrint("Failed to get reference to AndroidHostInterface");
    return -1;
  }

  if ((s_AndroidHostInterface_constructor = env->GetMethodID(s_AndroidHostInterface_class, "<init>", "()V")) ==
        nullptr ||
      (s_AndroidHostInterface_field_nativePointer =
         env->GetFieldID(s_AndroidHostInterface_class, "nativePointer", "J")) == nullptr)
  {
    Log_ErrorPrint("AndroidHostInterface lookups failed");
    return -1;
  }

  return JNI_VERSION_1_6;
}

#define DEFINE_JNI_METHOD(return_type, name)                                                                           \
  extern "C" JNIEXPORT return_type JNICALL Java_com_github_stenzek_duckstation_##name(JNIEnv* env)

#define DEFINE_JNI_ARGS_METHOD(return_type, name, ...)                                                                 \
  extern "C" JNIEXPORT return_type JNICALL Java_com_github_stenzek_duckstation_##name(JNIEnv* env, __VA_ARGS__)

DEFINE_JNI_ARGS_METHOD(jobject, AndroidHostInterface_create, jobject unused)
{
  // initialize the java side
  jobject java_obj = env->NewObject(s_AndroidHostInterface_class, s_AndroidHostInterface_constructor);
  if (!java_obj)
  {
    Log_ErrorPrint("Failed to create Java AndroidHostInterface");
    return nullptr;
  }

  jobject java_obj_ref = env->NewGlobalRef(java_obj);
  Assert(java_obj_ref != nullptr);

  // initialize the C++ side
  AndroidHostInterface* cpp_obj = new AndroidHostInterface(java_obj_ref);
  if (!cpp_obj)
  {
    // TODO: Do we need to release the original java object reference?
    Log_ErrorPrint("Failed to create C++ AndroidHostInterface");
    env->DeleteGlobalRef(java_obj_ref);
    return nullptr;
  }

  env->SetLongField(java_obj, s_AndroidHostInterface_field_nativePointer,
                    static_cast<long>(reinterpret_cast<uintptr_t>(cpp_obj)));

  return java_obj;
}

DEFINE_JNI_ARGS_METHOD(jboolean, AndroidHostInterface_isEmulationThreadRunning, jobject obj)
{
  return GetNativeClass(env, obj)->IsEmulationThreadRunning();
}

DEFINE_JNI_ARGS_METHOD(jboolean, AndroidHostInterface_startEmulationThread, jobject obj, jobject surface,
                       jstring filename, jstring state_filename)
{
  ANativeWindow* native_surface = ANativeWindow_fromSurface(env, surface);
  if (!native_surface)
  {
    Log_ErrorPrint("ANativeWindow_fromSurface() returned null");
    return false;
  }

  std::string state_filename_str = JStringToString(env, state_filename);

  SystemBootParameters boot_params;
  boot_params.filename = JStringToString(env, filename);

  return GetNativeClass(env, obj)->StartEmulationThread(native_surface, std::move(boot_params));
}

DEFINE_JNI_ARGS_METHOD(void, AndroidHostInterface_stopEmulationThread, jobject obj)
{
  GetNativeClass(env, obj)->StopEmulationThread();
}

DEFINE_JNI_ARGS_METHOD(void, AndroidHostInterface_surfaceChanged, jobject obj, jobject surface, jint format, jint width,
                       jint height)
{
  ANativeWindow* native_surface = ANativeWindow_fromSurface(env, surface);
  if (!native_surface)
    Log_ErrorPrint("ANativeWindow_fromSurface() returned null");

  AndroidHostInterface* hi = GetNativeClass(env, obj);
  hi->RunOnEmulationThread(
    [hi, native_surface, format, width, height]() { hi->SurfaceChanged(native_surface, format, width, height); }, true);
}

DEFINE_JNI_ARGS_METHOD(void, AndroidHostInterface_setControllerType, jobject obj, jint index, jstring controller_type)
{
  GetNativeClass(env, obj)->SetControllerType(index, JStringToString(env, controller_type));
}

DEFINE_JNI_ARGS_METHOD(void, AndroidHostInterface_setControllerButtonState, jobject obj, jint index, jint button_code,
                       jboolean pressed)
{
  GetNativeClass(env, obj)->SetControllerButtonState(index, button_code, pressed);
}

DEFINE_JNI_ARGS_METHOD(jint, AndroidHostInterface_getControllerButtonCode, jobject unused, jstring controller_type,
                       jstring button_name)
{
  std::optional<ControllerType> type = Settings::ParseControllerTypeName(JStringToString(env, controller_type).c_str());
  if (!type)
    return -1;

  std::optional<s32> code = Controller::GetButtonCodeByName(type.value(), JStringToString(env, button_name));
  return code.value_or(-1);
}

DEFINE_JNI_ARGS_METHOD(jarray, GameList_getEntries, jobject unused, jstring j_cache_path, jstring j_redump_dat_path,
                       jarray j_search_directories, jboolean search_recursively)
{
  // const std::string cache_path = JStringToString(env, j_cache_path);
  std::string redump_dat_path = JStringToString(env, j_redump_dat_path);

  // TODO: This should use the base HostInterface.
  GameList gl;
  if (!redump_dat_path.empty())
    gl.SetDatabaseFilename(std::move(redump_dat_path));

  const jsize search_directories_size = env->GetArrayLength(j_search_directories);
  for (jsize i = 0; i < search_directories_size; i++)
  {
    jobject search_dir_obj = env->GetObjectArrayElement(reinterpret_cast<jobjectArray>(j_search_directories), i);
    const std::string search_dir = JStringToString(env, reinterpret_cast<jstring>(search_dir_obj));
    if (!search_dir.empty())
      gl.AddDirectory(search_dir.c_str(), search_recursively);
  }

  jclass entry_class = env->FindClass("com/github/stenzek/duckstation/GameListEntry");
  Assert(entry_class != nullptr);

  jmethodID entry_constructor =
    env->GetMethodID(entry_class, "<init>",
                     "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;J)V");
  Assert(entry_constructor != nullptr);

  jobjectArray entry_array = env->NewObjectArray(gl.GetEntryCount(), entry_class, nullptr);
  Assert(entry_array != nullptr);

  u32 counter = 0;
  for (const GameListEntry& entry : gl.GetEntries())
  {
    jstring path = env->NewStringUTF(entry.path.c_str());
    jstring code = env->NewStringUTF(entry.code.c_str());
    jstring title = env->NewStringUTF(entry.title.c_str());
    jstring region = env->NewStringUTF(Settings::GetDiscRegionName(entry.region));
    jstring type = env->NewStringUTF(GameList::EntryTypeToString(entry.type));
    jlong size = entry.total_size;

    jobject entry_jobject = env->NewObject(entry_class, entry_constructor, path, code, title, region, type, size);

    env->SetObjectArrayElement(entry_array, counter++, entry_jobject);
  }

  return entry_array;
}