#include "os.hpp"

#include <SDL3/SDL.h>
#include <SDL3/SDL_oldnames.h>
#include <SDL3/SDL_video.h>

#include <imgui.h>
#include <imgui_impl_sdl3.h>
#include <imgui_impl_sdlrenderer3.h>

#include <filesystem>
#include <locale>
#include <string>

namespace saura {
OS::OS() {
  root_window_ctx = std::make_unique<Window_Context>();
  root_window_ctx->title = "(Saura Studios) [Dev]";
  root_window_ctx->w = 1280;
  root_window_ctx->h = 720;

  std::locale::global(std::locale("en_US.UTF-8"));

  if (!SDL_Init(SDL_INIT_VIDEO)) {
    throw std::runtime_error("Failed SDL_Init!");
  }

  SDL_WindowFlags window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN;
  root_window_ctx->handle =
      SDL_CreateWindow(root_window_ctx->title.c_str(), root_window_ctx->w,
                       root_window_ctx->h, window_flags);
  if (root_window_ctx->handle == nullptr) {
    throw std::runtime_error("Failed SDL_CreateWindow!");
  }

  root_window_ctx->renderer =
      SDL_CreateRenderer(root_window_ctx->handle, nullptr);
  if (root_window_ctx->renderer == nullptr) {
    throw std::runtime_error("Failed SDL_CreateRenderer!");
  }
  SDL_SetRenderVSync(root_window_ctx->renderer, SDL_RENDERER_VSYNC_DISABLED);
  SDL_SetWindowPosition(root_window_ctx->handle, SDL_WINDOWPOS_CENTERED,
                        SDL_WINDOWPOS_CENTERED);
  SDL_ShowWindow(root_window_ctx->handle);

  // Setup imgui
  IMGUI_CHECKVERSION();
  ImGui::CreateContext();
  ImGuiIO &io = ImGui::GetIO();
  (void)io;
  io.ConfigFlags |=
      ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
  io.ConfigFlags |=
      ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls

  // Setup Dear ImGui style
  ImGui::StyleColorsDark();

  // Setup Platform/Renderer backends
  ImGui_ImplSDL3_InitForSDLRenderer(root_window_ctx->handle,
                                    root_window_ctx->renderer);
  ImGui_ImplSDLRenderer3_Init(root_window_ctx->renderer);
}

OS::~OS() {
  ImGui_ImplSDLRenderer3_Shutdown();
  ImGui_ImplSDL3_Shutdown();
  ImGui::DestroyContext();

  SDL_DestroyRenderer(root_window_ctx->renderer);
  SDL_DestroyWindow(root_window_ctx->handle);
  SDL_Quit();
}

void OS::draw_begin() {
  ImGui_ImplSDLRenderer3_NewFrame();
  ImGui_ImplSDL3_NewFrame();
  ImGui::NewFrame();
}

void OS::draw_end() {
  ImVec4 clear_color = {0.15f, 0.15f, 0.15f, 0.0f};
  ImGuiIO &io = ImGui::GetIO();
  (void)io;
  ImGui::Render();
  SDL_SetRenderScale(root_window_ctx->renderer, io.DisplayFramebufferScale.x,
                     io.DisplayFramebufferScale.y);
  SDL_SetRenderDrawColorFloat(root_window_ctx->renderer, clear_color.x,
                              clear_color.y, clear_color.z, clear_color.w);
  SDL_RenderClear(root_window_ctx->renderer);
  ImGui_ImplSDLRenderer3_RenderDrawData(ImGui::GetDrawData(),
                                        root_window_ctx->renderer);

  SDL_RenderPresent(root_window_ctx->renderer);
}

void OS::update() {
  int w, h = 0;
  SDL_GetWindowSize(root_window_ctx->handle, &w, &h);
  root_window_ctx->w = w;
  root_window_ctx->h = h;
}

bool OS::update_events() {
  SDL_Event event = {};
  while (SDL_PollEvent(&event)) {

    ImGui_ImplSDL3_ProcessEvent(&event);

    switch (event.type) {
    case SDL_EVENT_KEY_UP: {
      if (event.key.key == SDLK_ESCAPE) {
        return false;
      }
      break;
    }
    case SDL_EVENT_QUIT: {
      return false;
    }
    case SDL_EVENT_WINDOW_CLOSE_REQUESTED: {
      if (event.window.windowID == SDL_GetWindowID(root_window_ctx->handle)) {
        return false;
      }
      break;
    }
    }
  }
  return true;
}

void OS::sleep(double ms) { SDL_Delay((Uint32)ms * 1000); }

int OS::get_root_window_width() { return root_window_ctx->w; }

int OS::get_root_window_height() { return root_window_ctx->h; }

void OS::set_root_window_title(std::string title) {
    SDL_SetWindowTitle(root_window_ctx.get()->handle, title.c_str());
}

double OS::get_performance_frequency() {
  return (double)SDL_GetPerformanceFrequency();
}

double OS::get_performance_counter() {
  return (double)SDL_GetPerformanceCounter();
}

std::string OS::get_safe_getenv(const std::string key) {
  return SDL_getenv(key.c_str());
}

fs::path OS::get_home_config_path() {
  fs::path res = {};

#if defined(_WIN32)
  auto config = get_safe_getenv("APPDATA");

  if (config.empty()) {
    throw std::runtime_error("APPDATA environment variable not found");
  }

  res = fs::path(config);
#elif defined(__linux__)
  auto config = get_safe_getenv("HOME");

  if (config.empty()) {
    throw std::runtime_error("HOME environment variable not found");
  }

  res = fs::path(config) / ".config";
#endif

  return res;
}

std::string OS::get_user_name() { return get_safe_getenv("USERNAME"); }
} // namespace saura