#include <KaizenGui.hpp>
#include <backend/Core.hpp>
#include <ImGuiImpl/GUI.hpp>
#include <ImGuiImpl/ProgressIndicators.hpp>
#include <ImGuiImpl/StatusBar.hpp>
#include <resources/gamecontrollerdb.h>

KaizenGui::KaizenGui() noexcept : window("Kaizen", 800, 600), settingsWindow(window), vulkanWidget(window.getHandle()), emuThread(fpsCounter, settingsWindow) {
  gui::Initialize(n64::Core::GetInstance().parallel.wsi, window.getHandle());
  SDL_InitSubSystem(SDL_INIT_GAMEPAD);

  SDL_AddGamepadMapping(gamecontrollerdb_str);
}

KaizenGui::~KaizenGui() {
  gui::Cleanup();
  SDL_Quit();
}

void KaizenGui::QueryDevices(const SDL_Event &event) {
  switch (event.type) {
  case SDL_EVENT_GAMEPAD_ADDED:
    if (!gamepad) {
      const auto index = event.gdevice.which;

      gamepad = SDL_OpenGamepad(index);
      info("Found controller!");
      info("Name: {}", SDL_GetGamepadName(gamepad));
      info("Vendor: {}", SDL_GetGamepadVendor(gamepad));
    }
    break;
  case SDL_EVENT_GAMEPAD_REMOVED:
    if (gamepad)
      SDL_CloseGamepad(gamepad);
    break;
  default: break;
  }
}

void KaizenGui::HandleInput(const SDL_Event &event) {
  const n64::Core& core = n64::Core::GetInstance();
  n64::PIF &pif = n64::Core::GetMem().mmio.si.pif;
  switch(event.type) {
    case SDL_EVENT_GAMEPAD_AXIS_MOTION:
      if(!gamepad)
        break;
      {
        pif.UpdateButton(0, n64::Controller::Key::Z, SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_LEFT_TRIGGER) == SDL_JOYSTICK_AXIS_MAX);
        pif.UpdateButton(0, n64::Controller::Key::CUp, SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_RIGHTY) <= -127);
        pif.UpdateButton(0, n64::Controller::Key::CDown, SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_RIGHTY) >= 127);
        pif.UpdateButton(0, n64::Controller::Key::CLeft, SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_RIGHTX) <= -127);
        pif.UpdateButton(0, n64::Controller::Key::CRight, SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_RIGHTX) >= 127);

        float xclamped = SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_LEFTX);
        if (xclamped < 0) {
          xclamped /= static_cast<float>(std::abs(SDL_JOYSTICK_AXIS_MAX));
        } else {
          xclamped /= SDL_JOYSTICK_AXIS_MAX;
        }

        xclamped *= 86;

        float yclamped = SDL_GetGamepadAxis(gamepad, SDL_GAMEPAD_AXIS_LEFTY);
        if (yclamped < 0) {
          yclamped /= static_cast<float>(std::abs(SDL_JOYSTICK_AXIS_MIN));
        } else {
          yclamped /= SDL_JOYSTICK_AXIS_MAX;
        }

        yclamped *= 86;

        pif.UpdateAxis(0, n64::Controller::Axis::Y, static_cast<s8>(-yclamped));
        pif.UpdateAxis(0, n64::Controller::Axis::X, static_cast<s8>( xclamped));
      }
      break;
    case SDL_EVENT_GAMEPAD_BUTTON_DOWN:
    case SDL_EVENT_GAMEPAD_BUTTON_UP:
      if(!gamepad)
        break;
    
      pif.UpdateButton(0, n64::Controller::Key::A, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_SOUTH));
      pif.UpdateButton(0, n64::Controller::Key::B, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_WEST));
      pif.UpdateButton(0, n64::Controller::Key::Start, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_START));
      pif.UpdateButton(0, n64::Controller::Key::DUp, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_DPAD_UP));
      pif.UpdateButton(0, n64::Controller::Key::DDown, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_DPAD_DOWN));
      pif.UpdateButton(0, n64::Controller::Key::DLeft, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_DPAD_LEFT));
      pif.UpdateButton(0, n64::Controller::Key::DRight, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_DPAD_RIGHT));
      pif.UpdateButton(0, n64::Controller::Key::LT, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_LEFT_SHOULDER));
      pif.UpdateButton(0, n64::Controller::Key::RT, SDL_GetGamepadButton(gamepad, SDL_GAMEPAD_BUTTON_RIGHT_SHOULDER));      
      break;
    case SDL_EVENT_KEY_DOWN:
    case SDL_EVENT_KEY_UP:
      {
        const auto keys = SDL_GetKeyboardState(nullptr);
        if((keys[SDL_SCANCODE_LCTRL] || keys[SDL_SCANCODE_RCTRL]) && keys[SDL_SCANCODE_O]) {
          fileDialogOpen = true;
        }

        fastForward = keys[SDL_SCANCODE_SPACE];
        if(!unlockFramerate)
          core.parallel.SetFramerateUnlocked(fastForward);

        if(core.romLoaded) {
          if(keys[SDL_SCANCODE_P]) {
            emuThread.TogglePause();
          }
  
          if(keys[SDL_SCANCODE_R]) {
            emuThread.Reset();
          }

          if(keys[SDL_SCANCODE_Q]) {
            emuThread.Stop();
          }
        }

        if(gamepad)
          break;

        pif.UpdateButton(0, n64::Controller::Key::Z, keys[SDL_SCANCODE_Z]);
        pif.UpdateButton(0, n64::Controller::Key::CUp, keys[SDL_SCANCODE_HOME]);
        pif.UpdateButton(0, n64::Controller::Key::CDown, keys[SDL_SCANCODE_END]);
        pif.UpdateButton(0, n64::Controller::Key::CLeft, keys[SDL_SCANCODE_DELETE]);
        pif.UpdateButton(0, n64::Controller::Key::CRight, keys[SDL_SCANCODE_PAGEDOWN]);
        pif.UpdateButton(0, n64::Controller::Key::A, keys[SDL_SCANCODE_X]);
        pif.UpdateButton(0, n64::Controller::Key::B, keys[SDL_SCANCODE_C]);
        pif.UpdateButton(0, n64::Controller::Key::Start, keys[SDL_SCANCODE_RETURN]);
        pif.UpdateButton(0, n64::Controller::Key::DUp, keys[SDL_SCANCODE_I]);
        pif.UpdateButton(0, n64::Controller::Key::DDown, keys[SDL_SCANCODE_K]);
        pif.UpdateButton(0, n64::Controller::Key::DLeft, keys[SDL_SCANCODE_J]);
        pif.UpdateButton(0, n64::Controller::Key::DRight, keys[SDL_SCANCODE_L]);
        pif.UpdateButton(0, n64::Controller::Key::LT, keys[SDL_SCANCODE_A]);
        pif.UpdateButton(0, n64::Controller::Key::RT, keys[SDL_SCANCODE_S]);

        if (keys[SDL_SCANCODE_UP]) pif.UpdateAxis(0, n64::Controller::Axis::Y, 86);
        else pif.UpdateAxis(0, n64::Controller::Axis::Y, 0);

        if (keys[SDL_SCANCODE_DOWN]) pif.UpdateAxis(0, n64::Controller::Axis::Y, -86);
        else pif.UpdateAxis(0, n64::Controller::Axis::Y, 0);

        if (keys[SDL_SCANCODE_LEFT]) pif.UpdateAxis(0, n64::Controller::Axis::X, -86);
        else pif.UpdateAxis(0, n64::Controller::Axis::X, 0);

        if (keys[SDL_SCANCODE_RIGHT]) pif.UpdateAxis(0, n64::Controller::Axis::X, 86);
        else pif.UpdateAxis(0, n64::Controller::Axis::X, 0);
      }
      break;
    default: break;
  }
}

std::pair<std::optional<s64>, std::optional<Util::Error::MemoryAccess>> RenderErrorMessageDetails() {
  auto lastPC = Util::Error::GetLastPC();
  if(lastPC.has_value()) {
    ImGui::Text("%s", std::format("Occurred @ PC = {:016X}", Util::Error::GetLastPC().value()).c_str());
  }

  auto memoryAccess = Util::Error::GetMemoryAccess();
  if(memoryAccess.has_value()) {
    const auto [is_write, size, address, written_val] = memoryAccess.value();
    ImGui::Text("%s", std::format("{} {}-bit value @ {:08X}{}", is_write ? "Writing" : "Reading",
                                  static_cast<u8>(size), address,
                                  is_write ? std::format(" (value = 0x{:X})", written_val) : "")
                                  .c_str());
  }

  return {lastPC, memoryAccess};
}

void KaizenGui::RenderUI() {
  n64::Core& core = n64::Core::GetInstance();
  gui::StartFrame();

  if(ImGui::BeginMainMenuBar()) {
    if(ImGui::BeginMenu("File")) {
      if(ImGui::MenuItem("Open", "Ctrl-O")) {
        fileDialogOpen = true;
      }
      if(ImGui::MenuItem("Exit")) {
        quit = true;
        emuThread.Stop();
      }
      ImGui::EndMenu();
    }
    if(ImGui::BeginMenu("Emulation")) {
      ImGui::BeginDisabled(!core.romLoaded);
      
      if(ImGui::MenuItem(core.pause ? "Resume" : "Pause", "P")) {
        emuThread.TogglePause();
      }
      
      if(ImGui::MenuItem("Reset", "R")) {
        emuThread.Reset();
      }
      
      if(ImGui::MenuItem("Stop", "Q")) {
        emuThread.Stop();
        core.romLoaded = false;
      }
      
      if(ImGui::Checkbox("Unlock framerate", &unlockFramerate)) {
        core.parallel.SetFramerateUnlocked(unlockFramerate);
      }

      if(ImGui::MenuItem("Open Debugger")) {
        debugger.Open();
      }

      ImGui::EndDisabled();

      if(ImGui::MenuItem("Options")) {
        settingsWindow.isOpen = true;
      }
      ImGui::EndMenu();
    }
    if(ImGui::BeginMenu("Help")) {
      if(ImGui::MenuItem("About")) {
        aboutOpen = true;
      }
      
      ImGui::EndMenu();
    }
    ImGui::EndMainMenuBar();
  }

  if(!Util::Error::IsHandled()) {
    ImGui::OpenPopup(Util::Error::GetSeverity().as_c_str());
  }
  
  if(settingsWindow.isOpen) {
    ImGui::OpenPopup("Settings", ImGuiPopupFlags_None);
  }

  if(aboutOpen) {
    ImGui::OpenPopup("About Kaizen");
  }

  settingsWindow.render();
  debugger.render();

  const ImVec2 center = ImGui::GetMainViewport()->GetCenter();
  ImGui::SetNextWindowPos(center, ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));

  if (ImGui::BeginPopupModal("About Kaizen", &aboutOpen, ImGuiWindowFlags_AlwaysAutoResize)) {
    ImGui::Text("Kaizen is a Nintendo 64 emulator that strives");
    ImGui::Text("to offer a friendly user experience and compatibility.");
    ImGui::Text("Kaizen is licensed under the BSD 3-clause license.");
    ImGui::Text("Nintendo 64 is a registered trademark of Nintendo Co., Ltd.");
    if(ImGui::Button("OK")) {
      aboutOpen = false;
      ImGui::CloseCurrentPopup();
    }
    
    ImGui::EndPopup();
  }

  ImGui::SetNextWindowPos(center, ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));

  if (ImGui::BeginPopupModal(Util::Error::GetSeverity().as_c_str(), nullptr, ImGuiWindowFlags_AlwaysAutoResize)) {
    emuThread.TogglePause();
    switch(Util::Error::GetSeverity().as_enum) {
      case Util::Error::Severity::WARN: {
        ImGui::PushStyleColor(ImGuiCol_TitleBg, 0x8054eae5);
        ImGui::PushStyleColor(ImGuiCol_Text, 0xff7be4e1);
        ImGui::Text("Warning of type: %s", Util::Error::GetType().as_c_str());
        ImGui::PopStyleColor();  
        ImGui::PopStyleColor();
        ImGui::Text(R"(Warning message: "%s")", Util::Error::GetError().c_str());
        RenderErrorMessageDetails();

        if(n64::Core::GetInstance().romLoaded && !n64::Core::GetInstance().pause) {
          const bool ignore = ImGui::Button("Try continuing"); ImGui::SameLine();
          const bool stop = ImGui::Button("Stop emulation"); ImGui::SameLine();
          const bool chooseAnother = ImGui::Button("Choose another ROM");
          if(ignore || stop || chooseAnother) {
            Util::Error::SetHandled();
            ImGui::CloseCurrentPopup();
          }

          if(ignore) {
            emuThread.TogglePause();
          }

          if(stop || chooseAnother) {
            emuThread.Stop();
          }
          
          if(chooseAnother) {
            fileDialogOpen = true;
          }
          break;
        }

        if(ImGui::Button("OK"))
          ImGui::CloseCurrentPopup();
      } break;
      case Util::Error::Severity::UNRECOVERABLE: {
        emuThread.Stop();
        ImGui::PushStyleColor(ImGuiCol_TitleBg, 0x800000ff);
        ImGui::PushStyleColor(ImGuiCol_Text, 0xff3b3bbf);
        ImGui::Text("An unrecoverable error has occurred! Emulation has been stopped...");
        ImGui::Text("Error of type: %s", Util::Error::GetType().as_c_str());
        ImGui::PopStyleColor();
        ImGui::PopStyleColor();
        ImGui::Text(R"(Error message: "%s")", Util::Error::GetError().c_str());
        RenderErrorMessageDetails();
        if(ImGui::Button("OK"))
          ImGui::CloseCurrentPopup();
      } break;
      case Util::Error::Severity::NON_FATAL: {
        ImGui::PushStyleColor(ImGuiCol_TitleBg, 0x800000ff);
        ImGui::PushStyleColor(ImGuiCol_Text, 0xff3b3bbf);
        ImGui::Text("An error has occurred!");
        ImGui::Text("Error of type: %s", Util::Error::GetType().as_c_str());
        ImGui::PopStyleColor();
        ImGui::PopStyleColor();
        ImGui::Text(R"(Error message: "%s")", Util::Error::GetError().c_str());
        auto [lastPC, memoryAccess] = RenderErrorMessageDetails();

        const bool ignore = ImGui::Button("Try continuing"); ImGui::SameLine();
        const bool stop = ImGui::Button("Stop emulation"); ImGui::SameLine();
        const bool chooseAnother = ImGui::Button("Choose another ROM");
        const bool openInDebugger = lastPC.has_value() ? ImGui::Button("Add breakpoint at this PC and open the debugger") : false;
        if(ignore || stop || chooseAnother || openInDebugger) {
          Util::Error::SetHandled();
          ImGui::CloseCurrentPopup();
        }

        if(ignore) {
          emuThread.TogglePause();
        }

        if(stop || chooseAnother) {
          emuThread.Stop();
        }
        
        if(chooseAnother) {
          fileDialogOpen = true;
        }

        if(openInDebugger) {
          if(!n64::Core::GetInstance().breakpoints.contains(lastPC.value()))
            n64::Core::GetInstance().ToggleBreakpoint(lastPC.value());
          
          debugger.Open();
          emuThread.Reset();
        }
      } break;
      default: break;
    }
    
    ImGui::EndPopup();
  }
      
  if(ImGui::BeginMainStatusBar()) {
    ImGui::Text("FPS: %.2f", ImGui::GetIO().Framerate);
    ImGui::EndMainStatusBar();
  }

  if (shouldDisplaySpinner) {
    ImGui::SetNextWindowPos({static_cast<float>(width) * 0.5f, static_cast<float>(height) * 0.5f}, 0, ImVec2(0.5f, 0.5f));
    ImGui::PushStyleColor(ImGuiCol_WindowBg, IM_COL32_BLACK_TRANS);
    ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);

    ImGui::Begin("##spinnerContainer", nullptr, ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoDecoration);

    ImGui::Spinner("##spinner", 10.f, 4.f, ImGui::GetColorU32(ImGui::GetStyle().Colors[ImGuiCol_TitleBgActive]));
    ImGui::SameLine();

    ImGui::PushFont(nullptr, ImGui::GetStyle().FontSizeBase * 2.f);
    ImGui::Text("Loading \"%s\"...", fs::path(fileToLoad).filename().string().c_str());
    ImGui::PopFont();

    ImGui::End();

    ImGui::PopStyleVar();
    ImGui::PopStyleColor();
  }

  ImGui::Render();
  if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable) {
    ImGui::UpdatePlatformWindows();
    ImGui::RenderPlatformWindowsDefault();
  }

  if(fileDialogOpen) {
    fileDialogOpen = false;
    constexpr SDL_DialogFileFilter filters[] = {{"All files", "*"}, {"Nintendo 64 executable", "n64;z64;v64"}, {"Nintendo 64 executable archive", "rar;tar;zip;7z"}};
    SDL_ShowOpenFileDialog([](void *userdata, const char * const *filelist, int) {
      auto kaizen = static_cast<KaizenGui*>(userdata);
      
      if (!filelist) {
        panic("An error occured: {}", SDL_GetError());
      }

      if (!*filelist) {
        warn("The user did not select any file.");
        warn("Most likely, the dialog was canceled.");
        return;
      }

      kaizen->fileToLoad = *filelist;
      kaizen->shouldDisplaySpinner = true;

      std::thread fileWorker(&KaizenGui::FileWorker, kaizen);
      fileWorker.detach();
    }, this, window.getHandle(), filters, 3, nullptr, false);
  }

  if(minimized)
    return;

  if(core.romLoaded) {
    core.parallel.UpdateScreen<true>();
    return;
  }

  core.parallel.UpdateScreen<false>();
}

void KaizenGui::LoadROM(const std::string &path) noexcept {
  n64::Core& core = n64::Core::GetInstance();
  core.LoadROM(path);
  const auto gameNameDB = n64::Core::GetMem().rom.gameNameDB;
  SDL_SetWindowTitle(window.getHandle(), ("Kaizen - " + gameNameDB).c_str());
}

void KaizenGui::run() {
  while(!quit) {
    SDL_Event e;
    while (SDL_PollEvent(&e)) {
      ImGui_ImplSDL3_ProcessEvent(&e);
      switch(e.type) {
        case SDL_EVENT_QUIT:
          quit = true;
          emuThread.Stop();
          break;
        case SDL_EVENT_WINDOW_MINIMIZED:
          minimized = true;
          break;
        case SDL_EVENT_WINDOW_RESTORED:
          minimized = false;
          break;
        default:
      }
      QueryDevices(e);
      HandleInput(e);
    }

    SDL_GetWindowSize(window.getHandle(), &width, &height);

    emuThread.run();
    RenderUI();
  }
}

void KaizenGui::LoadTAS(const std::string &path) noexcept {
  n64::Core::GetInstance().LoadTAS(fs::path(path));
}