#include "vulkan-game.hpp"

#include <iostream>

#include "consts.hpp"
#include "logger.hpp"

#include "vulkan-utils.hpp"

using namespace std;

VulkanGame::VulkanGame() {
   gui = nullptr;
   window = nullptr;
}

VulkanGame::~VulkanGame() {
}

void VulkanGame::run(int width, int height, unsigned char guiFlags) {
   cout << "DEBUGGING IS " << (ENABLE_VALIDATION_LAYERS ? "ON" : "OFF") << endl;

   cout << "Vulkan Game" << endl;

   // This gets the runtime version, use SDL_VERSION() for the comppile-time version
   // TODO: Create a game-gui function to get the gui version and retrieve it that way
   SDL_GetVersion(&sdlVersion);

   // TODO: Refactor the logger api to be more flexible,
   // esp. since gl_log() and gl_log_err() have issues printing anything besides stirngs
   restart_gl_log();
   gl_log("starting SDL\n%s.%s.%s",
      to_string(sdlVersion.major).c_str(),
      to_string(sdlVersion.minor).c_str(),
      to_string(sdlVersion.patch).c_str());

   open_log();
   get_log() << "starting SDL" << endl;
   get_log() <<
      (int)sdlVersion.major << "." <<
      (int)sdlVersion.minor << "." <<
      (int)sdlVersion.patch << endl;

   if (initWindow(width, height, guiFlags) == RTWO_ERROR) {
      return;
   }

   initVulkan();
   mainLoop();
   cleanup();

   close_log();
}

// TODO: Make some more initi functions, or call this initUI if the
// amount of things initialized here keeps growing
bool VulkanGame::initWindow(int width, int height, unsigned char guiFlags) {
   // TODO: Put all fonts, textures, and images in the assets folder
   gui = new GameGui_SDL();

   if (gui->init() == RTWO_ERROR) {
      // TODO: Also print these sorts of errors to the log
      cout << "UI library could not be initialized!" << endl;
      cout << gui->getError() << endl;
      return RTWO_ERROR;
   }

   window = (SDL_Window*) gui->createWindow("Vulkan Game", width, height, guiFlags & GUI_FLAGS_WINDOW_FULLSCREEN);
   if (window == nullptr) {
      cout << "Window could not be created!" << endl;
      cout << gui->getError() << endl;
      return RTWO_ERROR;
   }

   cout << "Target window size: (" << width << ", " << height << ")" << endl;
   cout << "Actual window size: (" << gui->getWindowWidth() << ", " << gui->getWindowHeight() << ")" << endl;

   renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
   if (renderer == nullptr) {
      cout << "Renderer could not be created!" << endl;
      cout << gui->getError() << endl;
      return RTWO_ERROR;
   }

   return RTWO_SUCCESS;
}

void VulkanGame::initVulkan() {
   const vector<const char*> validationLayers = {
      "VK_LAYER_KHRONOS_validation"
   };

   createVulkanInstance(validationLayers);
   setupDebugMessenger();
}

void VulkanGame::mainLoop() {
   UIEvent e;
   bool quit = false;

   SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);

   while (!quit) {
      gui->processEvents();

      while (gui->pollEvent(&e)) {
         switch(e.type) {
            case UI_EVENT_QUIT:
               cout << "Quit event detected" << endl;
               quit = true;
               break;
            case UI_EVENT_WINDOW:
               cout << "Window event detected" << endl;
               // Currently unused
               break;
            case UI_EVENT_KEY:
               if (e.key.keycode == SDL_SCANCODE_ESCAPE) {
                  quit = true;
               } else {
                  cout << "Key event detected" << endl;
               }
               break;
            case UI_EVENT_MOUSEBUTTONDOWN:
               cout << "Mouse button down event detected" << endl;
               break;
            case UI_EVENT_MOUSEBUTTONUP:
               cout << "Mouse button up event detected" << endl;
               break;
            case UI_EVENT_MOUSEMOTION:
               break;
            default:
               cout << "Unhandled UI event: " << e.type << endl;
         }
      }

      SDL_RenderClear(renderer);
      SDL_RenderPresent(renderer);
   }
}

void VulkanGame::cleanup() {
   if (ENABLE_VALIDATION_LAYERS) {
      VulkanUtils::destroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);
   }
   vkDestroyInstance(instance, nullptr);

   SDL_DestroyRenderer(renderer);
   renderer = nullptr;

   gui->destroyWindow();
   gui->shutdown();
   delete gui;
}

void VulkanGame::createVulkanInstance(const vector<const char*> &validationLayers) {
   if (ENABLE_VALIDATION_LAYERS && !VulkanUtils::checkValidationLayerSupport(validationLayers)) {
      throw runtime_error("validation layers requested, but not available!");
   }

   VkApplicationInfo appInfo = {};
   appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
   appInfo.pApplicationName = "Vulkan Game";
   appInfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);
   appInfo.pEngineName = "No Engine";
   appInfo.engineVersion = VK_MAKE_VERSION(1, 0, 0);
   appInfo.apiVersion = VK_API_VERSION_1_0;

   VkInstanceCreateInfo createInfo = {};
   createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
   createInfo.pApplicationInfo = &appInfo;

   vector<const char*> extensions = gui->getRequiredExtensions();
   if (ENABLE_VALIDATION_LAYERS) {
      extensions.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
   }

   createInfo.enabledExtensionCount = static_cast<uint32_t>(extensions.size());
   createInfo.ppEnabledExtensionNames = extensions.data();

   cout << endl << "Extensions:" << endl;
   for (const char* extensionName : extensions) {
      cout << extensionName << endl;
   }
   cout << endl;

   VkDebugUtilsMessengerCreateInfoEXT debugCreateInfo;
   if (ENABLE_VALIDATION_LAYERS) {
      createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
      createInfo.ppEnabledLayerNames = validationLayers.data();

      populateDebugMessengerCreateInfo(debugCreateInfo);
      createInfo.pNext = &debugCreateInfo;
   } else {
      createInfo.enabledLayerCount = 0;

      createInfo.pNext = nullptr;
   }

   if (vkCreateInstance(&createInfo, nullptr, &instance) != VK_SUCCESS) {
      throw runtime_error("failed to create instance!");
   }
}

void VulkanGame::setupDebugMessenger() {
   if (!ENABLE_VALIDATION_LAYERS) return;

   VkDebugUtilsMessengerCreateInfoEXT createInfo;
   populateDebugMessengerCreateInfo(createInfo);

   if (VulkanUtils::createDebugUtilsMessengerEXT(instance, &createInfo, nullptr, &debugMessenger) != VK_SUCCESS) {
      throw runtime_error("failed to set up debug messenger!");
   }
}

void VulkanGame::populateDebugMessengerCreateInfo(VkDebugUtilsMessengerCreateInfoEXT& createInfo) {
   createInfo = {};
   createInfo.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;
   createInfo.messageSeverity = VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT;
   createInfo.messageType = VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT;
   createInfo.pfnUserCallback = debugCallback;
}

VKAPI_ATTR VkBool32 VKAPI_CALL VulkanGame::debugCallback(
      VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
      VkDebugUtilsMessageTypeFlagsEXT messageType,
      const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData,
      void* pUserData) {
   cerr << "validation layer: " << pCallbackData->pMessage << endl;

   return VK_FALSE;
}