/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2006,2007  Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/video.h>
#include <grub/types.h>
#include <grub/dl.h>

/* The list of video adapters registerd to system.  */
static grub_video_adapter_t grub_video_adapter_list;

/* Active video adapter.  */
static grub_video_adapter_t grub_video_adapter_active;

/* Register video driver.  */
void
grub_video_register (grub_video_adapter_t adapter)
{
  adapter->next = grub_video_adapter_list;
  grub_video_adapter_list = adapter;
}

/* Unregister video driver.  */
void
grub_video_unregister (grub_video_adapter_t adapter)
{
  grub_video_adapter_t *p, q;

  for (p = &grub_video_adapter_list, q = *p; q; p = &(q->next), q = q->next)
    if (q == adapter)
      {
        *p = q->next;
        break;
      }
}

/* Iterate thru all registered video drivers.  */
void
grub_video_iterate (int (*hook) (grub_video_adapter_t adapter))
{
  grub_video_adapter_t p;

  for (p = grub_video_adapter_list; p; p = p->next)
    if (hook (p))
      break;
}

/* Setup specified video mode.  */
grub_err_t
grub_video_setup (unsigned int width, unsigned int height,
                  unsigned int mode_type)
{
  grub_video_adapter_t p;

  /* De-activate last set video adapter.  */
  if (grub_video_adapter_active)
    {
      /* Finalize adapter.  */
      grub_video_adapter_active->fini ();
      if (grub_errno != GRUB_ERR_NONE)
        return grub_errno;

      /* Mark active adapter as not set.  */
      grub_video_adapter_active = 0;
    }

  /* Loop thru all possible video adapter trying to find requested mode.  */
  for (p = grub_video_adapter_list; p; p = p->next)
    {
      /* Try to initialize adapter, if it fails, skip to next adapter.  */
      p->init ();
      if (grub_errno != GRUB_ERR_NONE)
        {
          grub_errno = GRUB_ERR_NONE;
          continue;
        }

      /* Try to initialize video mode.  */
      p->setup (width, height, mode_type);
      if (grub_errno == GRUB_ERR_NONE)
        {
          /* Valid mode found from adapter, and it has been activated.
             Specify it as active adapter.  */
          grub_video_adapter_active = p;
          return GRUB_ERR_NONE;
        }
      else
        grub_errno = GRUB_ERR_NONE;

      /* No valid mode found in this adapter, finalize adapter.  */
      p->fini ();
      if (grub_errno != GRUB_ERR_NONE)
        return grub_errno;
    }

  /* We couldn't find suitable adapter for specified mode.  */
  return grub_error (GRUB_ERR_UNKNOWN_DEVICE, 
                     "Can't locate valid adapter for mode");
}

/* Restore back to initial mode (where applicaple).  */
grub_err_t
grub_video_restore (void)
{
  if (grub_video_adapter_active)
    {
      grub_video_adapter_active->fini ();
      if (grub_errno != GRUB_ERR_NONE)
        return grub_errno;

      grub_video_adapter_active = 0;
    }
  return GRUB_ERR_NONE;
}

/* Get information about active video mode.  */
grub_err_t
grub_video_get_info (struct grub_video_mode_info *mode_info)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->get_info (mode_info);
}

/* Determine optimized blitting formation for specified video mode info.  */
enum grub_video_blit_format
grub_video_get_blit_format (struct grub_video_mode_info *mode_info)
{
  /* Check if we have any known 32 bit modes.  */
  if (mode_info->bpp == 32)
    {
      if ((mode_info->red_mask_size == 8)
          && (mode_info->red_field_pos == 0)
          && (mode_info->green_mask_size == 8)
          && (mode_info->green_field_pos == 8)
          && (mode_info->blue_mask_size == 8)
          && (mode_info->blue_field_pos == 16)
          && (mode_info->reserved_mask_size == 8)
          && (mode_info->reserved_field_pos == 24))
        {
          return GRUB_VIDEO_BLIT_FORMAT_R8G8B8A8;
        }
    }

  /* Check if we have any known 24 bit modes.  */
  if (mode_info->bpp == 24)
    {
      if ((mode_info->red_mask_size == 8)
          && (mode_info->red_field_pos == 0)
          && (mode_info->green_mask_size == 8)
          && (mode_info->green_field_pos == 8)
          && (mode_info->blue_mask_size == 8)
          && (mode_info->blue_field_pos == 16))
        {
          return GRUB_VIDEO_BLIT_FORMAT_R8G8B8;
        }
    }

  /* If there are more than 8 bits per color, assume RGB(A) mode.  */
  if (mode_info->bpp > 8)
    {
      if (mode_info->reserved_mask_size > 0)
        {
          return GRUB_VIDEO_BLIT_FORMAT_RGBA;
        }
      return GRUB_VIDEO_BLIT_FORMAT_RGB;
    }

  /* Assume as indexcolor mode.  */
  return GRUB_VIDEO_BLIT_FORMAT_INDEXCOLOR;
}

/* Set new indexed color palette entries.  */
grub_err_t
grub_video_set_palette (unsigned int start, unsigned int count,
                        struct grub_video_palette_data *palette_data)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->set_palette (start, count, palette_data);
}

/* Get indexed color palette entries.  */
grub_err_t
grub_video_get_palette (unsigned int start, unsigned int count,
                        struct grub_video_palette_data *palette_data)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->get_palette (start, count, palette_data);
}

/* Set viewport dimensions.  */
grub_err_t
grub_video_set_viewport (unsigned int x, unsigned int y,
                         unsigned int width, unsigned int height)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->set_viewport (x, y, width, height);
}

/* Get viewport dimensions.  */
grub_err_t
grub_video_get_viewport (unsigned int *x, unsigned int *y,
                         unsigned int *width, unsigned int *height)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->get_viewport (x, y, width, height);
}

/* Map color name to adapter specific color.  */
grub_video_color_t
grub_video_map_color (grub_uint32_t color_name)
{
  if (! grub_video_adapter_active)
    return 0;

  return grub_video_adapter_active->map_color (color_name);
}

/* Map RGB value to adapter specific color.  */
grub_video_color_t
grub_video_map_rgb (grub_uint8_t red, grub_uint8_t green, grub_uint8_t blue)
{
  if (! grub_video_adapter_active)
    return 0;

  return grub_video_adapter_active->map_rgb (red, green, blue);
}

/* Map RGBA value to adapter specific color.  */
grub_video_color_t
grub_video_map_rgba (grub_uint8_t red, grub_uint8_t green, grub_uint8_t blue,
                     grub_uint8_t alpha)
{
  if (! grub_video_adapter_active)
    return 0;

  return grub_video_adapter_active->map_rgba (red, green, blue, alpha);
}

/* Fill rectangle using specified color.  */
grub_err_t
grub_video_fill_rect (grub_video_color_t color, int x, int y,
                      unsigned int width, unsigned int height)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->fill_rect (color, x, y, width, height);
}

/* Blit glyph to screen using specified color.  */
grub_err_t
grub_video_blit_glyph (struct grub_font_glyph *glyph,
                       grub_video_color_t color, int x, int y)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->blit_glyph (glyph, color, x, y);
}

/* Blit bitmap to screen.  */
grub_err_t
grub_video_blit_bitmap (struct grub_video_bitmap *bitmap,
                        enum grub_video_blit_operators oper,
                        int x, int y, int offset_x, int offset_y,
                        unsigned int width, unsigned int height)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->blit_bitmap (bitmap, oper, x, y,
                                                 offset_x, offset_y,
                                                 width, height);
}

/* Blit render target to active render target.  */
grub_err_t
grub_video_blit_render_target (struct grub_video_render_target *target,
                               enum grub_video_blit_operators oper,
                               int x, int y, int offset_x, int offset_y,
                               unsigned int width, unsigned int height)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->blit_render_target (target, oper, x, y,
                                                        offset_x, offset_y,
                                                        width, height);
}

/* Scroll viewport and fill new areas with specified color.  */
grub_err_t
grub_video_scroll (grub_video_color_t color, int dx, int dy)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->scroll (color, dx, dy);
}

/* Swap buffers (swap active render target).  */
grub_err_t
grub_video_swap_buffers (void)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->swap_buffers ();
}

/* Create new render target.  */
grub_err_t
grub_video_create_render_target (struct grub_video_render_target **result,
                                 unsigned int width, unsigned int height,
                                 unsigned int mode_type)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->create_render_target (result,
                                                          width, height,
                                                          mode_type);
}

/* Delete render target.  */
grub_err_t
grub_video_delete_render_target (struct grub_video_render_target *target)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->delete_render_target (target);
}

/* Set active render target.  */
grub_err_t
grub_video_set_active_render_target (struct grub_video_render_target *target)
{
  if (! grub_video_adapter_active)
    return grub_error (GRUB_ERR_BAD_DEVICE, "No video mode activated");

  return grub_video_adapter_active->set_active_render_target (target);
}

/* Initialize Video API module.  */
GRUB_MOD_INIT(video_video)
{
  grub_video_adapter_active = 0;
  grub_video_adapter_list = 0;
}

/* Finalize Video API module.  */
GRUB_MOD_FINI(video_video)
{
}