#include "devices.h"
#include <string.h>
#include <unistd.h>

i32 console_open(void *data, u32 mode) {
  USED(mode);
  USED(data);
  /* Nothing to open — stdin/stdout are always available */
  return 0; /* Success */
}

i32 console_read(void *data, u8 *buffer, u32 size) {
  USED(data);
  for (u32 i = 0; i < size; i++) {
    u8 ch = getchar();
    if (ch == '\0')
      break;
    if (ch == '\n')
      break;
    buffer[i] = ch;
  }
  return 0;
}

i32 console_write(void *data, const u8 *buffer, u32 size) {
  USED(data);
  for (u32 i = 0; i < size; i++) {
    putchar(buffer[i]);
  }
  return 0;
}

i32 console_close(void *data) {
  USED(data);
  /* Nothing to close — stdin/stdout are process-owned */
  return 0;
}

i32 console_ioctl(void *data, u32 cmd, const u8 *buffer) {
  USED(data);
  USED(cmd);
  USED(buffer);
  return -1; /* Unsupported */
}

i32 screen_open(void *data, u32 mode) {
  USED(mode);
  ScreenDeviceData *screen = (ScreenDeviceData *)data;

  screen->window =
      SDL_CreateWindow("Reality Engine VM", SDL_WINDOWPOS_CENTERED,
                       SDL_WINDOWPOS_CENTERED, screen->width, screen->height,
                       SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI);

  if (!screen->window)
    return -1;

  screen->renderer = SDL_CreateRenderer(
      screen->window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
  if (!screen->renderer)
    return -1;

  screen->texture = SDL_CreateTexture(screen->renderer, SDL_PIXELFORMAT_RGB332,
                                      SDL_TEXTUREACCESS_STREAMING,
                                      screen->width, screen->height);
  if (!screen->texture)
    return -1;

  SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "0");
  return 0;
}

i32 screen_read(void *data, u8 *buffer, u32 size) {
  USED(data);
  USED(buffer);
  USED(size);
  return -1;
}

i32 screen_write(void *data, const u8 *buffer, u32 size) {
  ScreenDeviceData *screen = (ScreenDeviceData *)data;
  USED(buffer);

  if (size > screen->size * sizeof(u8)) {
    return -1;
  }

  if (screen->texture && screen->renderer) {
    SDL_UpdateTexture(screen->texture, nil, &buffer[screen->pos],
                      screen->width);

    SDL_RenderClear(screen->renderer);

    SDL_Rect output_rect;
    SDL_RenderGetViewport(screen->renderer, &output_rect);
    float scale_x = (float)output_rect.w / screen->width;
    float scale_y = (float)output_rect.h / screen->height;
    float scale = SDL_min(scale_x, scale_y);

    SDL_Rect dstrect = {(i32)((output_rect.w - screen->width * scale) / 2),
                        (i32)((output_rect.h - screen->height * scale) / 2),
                        (i32)(screen->width * scale),
                        (i32)(screen->height * scale)};

    SDL_RenderCopy(screen->renderer, screen->texture, nil, &dstrect);
    SDL_RenderPresent(screen->renderer);
  }

  return 0;
}

i32 screen_close(void *data) {
  ScreenDeviceData *screen = (ScreenDeviceData *)data;

  if (screen->texture) {
    SDL_DestroyTexture(screen->texture);
    screen->texture = NULL;
  }
  if (screen->renderer) {
    SDL_DestroyRenderer(screen->renderer);
    screen->renderer = NULL;
  }
  if (screen->window) {
    SDL_DestroyWindow(screen->window);
    screen->window = NULL;
  }
  return 0;
}

i32 screen_ioctl(void *data, u32 cmd, const u8 *buffer) {
  ScreenDeviceData *screen = (ScreenDeviceData *)data;

  switch (cmd) {
  case IOCTL_GET_INFO: {
    u8 *info = (u8 *)buffer;
    u32 size;
    memcpy(&size, &info[0], sizeof(u32));

    if (size < 16) {
      return -1;
    }
    
    memcpy(&info[4], &screen->pos, sizeof(u32));
    memcpy(&info[8], &screen->size, sizeof(u32));
    memcpy(&info[12], &screen->width, sizeof(u32));
    memcpy(&info[16], &screen->height, sizeof(u32));
    return 0;
  }

  default:
    return -1; // Error
  }
}

/* MOUSE */
i32 mouse_open(void *data, u32 mode) {
  USED(data);
  USED(mode);
  return 0;
}

i32 mouse_read(void *data, u8 *buffer, u32 size) {
  MouseDeviceData *mouse = (MouseDeviceData *)data;

  if (size < 12)
    return -1;

  SDL_PumpEvents();
  SDL_Event event;
  while (SDL_PollEvent(&event)) {
    switch (event.type) {
    case SDL_MOUSEMOTION:
      mouse->x = event.motion.x;
      mouse->y = event.motion.y;
      break;
    case SDL_MOUSEBUTTONDOWN:
      if (event.button.button == SDL_BUTTON_LEFT)
        mouse->btn1 = 1;
      if (event.button.button == SDL_BUTTON_RIGHT)
        mouse->btn2 = 1;
      if (event.button.button == SDL_BUTTON_MIDDLE)
        mouse->btn3 = 1;
      if (event.button.button == SDL_BUTTON_X1)
        mouse->btn4 = 1;
      break;
    case SDL_MOUSEBUTTONUP:
      if (event.button.button == SDL_BUTTON_LEFT)
        mouse->btn1 = 0;
      if (event.button.button == SDL_BUTTON_RIGHT)
        mouse->btn2 = 0;
      if (event.button.button == SDL_BUTTON_MIDDLE)
        mouse->btn3 = 0;
      if (event.button.button == SDL_BUTTON_X1)
        mouse->btn4 = 0;
      break;
    }
  }

  u8 *info = (u8 *)buffer;
  memcpy(&info[0], &mouse->x, sizeof(u32));
  memcpy(&info[4], &mouse->y, sizeof(u32));
  memcpy(&info[8], &mouse->btn1, sizeof(u8));
  memcpy(&info[9], &mouse->btn2, sizeof(u8));
  memcpy(&info[10], &mouse->btn3, sizeof(u8));
  memcpy(&info[11], &mouse->btn4, sizeof(u8));
  return 0;
}

i32 mouse_write(void *data, const u8 *buffer, u32 size) {
  USED(data);
  USED(buffer);
  USED(size);
  return -1;
}

i32 mouse_close(void *data) {
  USED(data);
  return 0;
}

i32 keyboard_open(void *data, u32 mode) {
  USED(data);
  USED(mode);
  return 0;
}

i32 keyboard_read(void *data, u8 *buffer, u32 size) {
  KeyboardDeviceData *kbd = (KeyboardDeviceData *)data;

  if (size < (u32)kbd->key_count)
    return -1;

  memcpy(buffer, kbd->keys, kbd->key_count);
  return 0;
}

i32 keyboard_write(void *data, const u8 *buffer, u32 size) {
  USED(data);
  USED(buffer);
  USED(size);
  return -1; /* not writable */
}

i32 keyboard_close(void *data) {
  USED(data);
  return 0;
}