#include <stdio.h>

#include "tile.h"
#include "tile_pvt.h"
#include "tile_cache.h"
#include "tile_manager.h"
#include "tile_swap.h"


static void tile_destroy (Tile *tile);

int tile_count = 0;

void
tile_sanitize_rowhints (Tile *tile)
{
  int height, y;

  /*  If tile has rowhints array already, do nothing.  */
  if (tile->rowhint)
    return;

  height = tile->eheight;
  
  tile->rowhint = g_new (TileRowHint, height);
  
  for (y=0; y<height; y++)
    {
      tile->rowhint[y] = TILEROWHINT_UNKNOWN;
    }
}

TileRowHint
tile_get_rowhint (Tile *tile, int yoff)
{
#ifdef HINTS_SANITY
  if (yoff < tile_eheight(tile) && yoff>=0)
    {
      return tile->rowhint[yoff];
    }
  else
    g_error("GET_ROWHINT OUT OF RANGE");
  return TILEROWHINT_OUTOFRANGE;
#else
  return tile->rowhint[yoff];  
#endif
}

void
tile_set_rowhint (Tile *tile, int yoff, TileRowHint rowhint)
{
#ifdef HINTS_SANITY
  if (yoff < tile_eheight(tile) && yoff>=0)
    {
      tile->rowhint[yoff] = rowhint;
    }
  else
    g_error("SET_ROWHINT OUT OF RANGE");
#else
  tile->rowhint[yoff] = rowhint;
#endif
}

void
tile_init (Tile *tile,
	   int   bpp)
{
  tile->ref_count = 0;
  tile->write_count = 0;
  tile->share_count = 0;
  tile->dirty = FALSE;
  tile->valid = FALSE;
  tile->data = NULL;
  tile->ewidth = TILE_WIDTH;
  tile->eheight = TILE_HEIGHT;
  tile->bpp = bpp;
  tile->swap_num = 1;
  tile->swap_offset = -1;
  tile->tlink = NULL;
  tile->next = tile->prev = NULL;
  tile->listhead = NULL;
  tile->rowhint = NULL;

#ifdef USE_PTHREADS
  {
    pthread_mutex_init(&tile->mutex, NULL);
  }
  tile_count++;
#endif
}

int tile_ref_count = 0;
int tile_share_count = 0;
int tile_active_count = 0;

#ifdef HINTS_SANITY
int tile_exist_peak = 0;
int tile_exist_count = 0;
#endif

void
tile_lock (Tile *tile)
{
  /* Increment the global reference count.
   */
  tile_ref_count += 1;

  /* Increment this tile's reference count.
   */

  TILE_MUTEX_LOCK (tile);
  tile->ref_count += 1;

  if (tile->ref_count == 1) 
    {
      if (tile->listhead) 
	{
	  /* remove from cache, move to main store */
	  tile_cache_flush (tile);
	}
      tile_active_count ++;
    }
  if (tile->data == NULL)
    {
      /* There is no data, so the tile must be swapped out */
      tile_swap_in (tile);
    }

  TILE_MUTEX_UNLOCK (tile);

  /* Call 'tile_manager_validate' if the tile was invalid.
   */
  if (!tile->valid)
    {
      /* an invalid tile should never be shared, so this should work */
      tile_manager_validate ((TileManager*) tile->tlink->tm, tile);
    }


}


void
tile_release (Tile *tile, int dirty)
{
  /* Decrement the global reference count.
   */
  tile_ref_count -= 1;

  TILE_MUTEX_LOCK(tile);

  /* Decrement this tile's reference count.
   */
  tile->ref_count -= 1;

  /* Decrement write ref count if dirtying
   */
  if (dirty)
    {
      int y;

      tile->write_count -= 1;

      if (tile->rowhint)
	{
	  for (y = 0; y < tile->eheight; y++)
	    {
	      tile->rowhint[y] = TILEROWHINT_UNKNOWN;
	    }
	}
    }

  if (tile->ref_count == 0)
    {
      tile_active_count--;
      if (tile->share_count == 0)
	{
	  /* tile is truly dead */
	  tile_destroy (tile);
	  return;			/* skip terminal unlock */
	}
      else 
	{
	  /* last reference was just released, so move the tile to the
	     tile cache */
	  tile_cache_insert (tile);
	}
    }

  TILE_MUTEX_UNLOCK (tile);
}

void
tile_alloc (Tile *tile)
{
  if (tile->data)
    return;

  /* Allocate the data for the tile.
   */
  tile->data = g_new (guchar, tile_size (tile));

#ifdef HINTS_SANITY
  tile_exist_count++;
  if (tile_exist_count > tile_exist_peak)
    tile_exist_peak = tile_exist_count;
#endif
}

static void
tile_destroy (Tile *tile)
{
  if (tile->ref_count) 
    {
      g_warning ("tried to destroy a ref'd tile");
      return;
    }
  if (tile->share_count)
    {
      g_warning ("tried to destroy an attached tile");
      return;
    }
  if (tile->data) 
    {
      g_free (tile->data);
      tile->data = NULL;
    }
  if (tile->rowhint) 
    {
      g_free (tile->rowhint);
      tile->rowhint = NULL;
    }
  if (tile->swap_offset != -1)
    {
      /* If the tile is on disk, then delete its
       *  presence there.
       */
      tile_swap_delete (tile);
    }
  if (tile->listhead)
    tile_cache_flush (tile);
  
  TILE_MUTEX_UNLOCK (tile); 
  g_free (tile);
  tile_count --;

#ifdef HINTS_SANITY
  tile_exist_count--;
#endif
}


int
tile_size (Tile *tile)
{
  int size;
  /* Return the actual size of the tile data.
   *  (Based on its effective width and height).
   */
  size = tile->ewidth * tile->eheight * tile->bpp;
  return size;
}


int
tile_ewidth (Tile *tile)
{
  return tile->ewidth;
}


int
tile_eheight (Tile *tile)
{
  return tile->eheight;
}


int
tile_bpp (Tile *tile)
{
  return tile->bpp;
}


int 
tile_is_valid (Tile *tile)
{
  return tile->valid;
}


void
tile_mark_valid (Tile *tile)
{
  TILE_MUTEX_LOCK (tile);
  tile->valid = TRUE;
  TILE_MUTEX_UNLOCK (tile);
}


void
tile_attach (Tile *tile, void *tm, int tile_num)
{
  TileLink *tmp;

  if ((tile->share_count > 0) && (!tile->valid)) 
    {
      /* trying to share invalid tiles is problematic, not to mention silly */
      tile_manager_validate ((TileManager*) tile->tlink->tm, tile);
    }
  tile->share_count++;
  tile_share_count++;
#ifdef TILE_DEBUG
  g_print("tile_attach: %p -> (%p,%d) *%d\n", tile, tm, tile_num, tile->share_count);
#endif

  /* link this tile into the tile's tilelink chain */
  tmp = g_new (TileLink, 1);
  tmp->tm = tm;
  tmp->tile_num = tile_num;
  tmp->next = tile->tlink;
  tile->tlink = tmp;
}

void
tile_detach (Tile *tile, void *tm, int tile_num)
{
  TileLink **link;
  TileLink *tmp;

#ifdef TILE_DEBUG
  g_print("tile_detach: %p ~> (%p,%d) r%d *%d\n", tile, tm, tile_num,
	  tile->ref_count, tile->share_count);
#endif

  for (link = &tile->tlink;
       *link != NULL;
       link = &(*link)->next)
    {
      if (((*link)->tm == tm) && ((*link)->tile_num == tile_num))
	break;
    }

  if (*link == NULL) 
    {
      g_warning ("Tried to detach a nonattached tile -- TILE BUG!");
      return;
    }

  tmp = *link;
  *link = tmp->next;
  g_free (tmp);

  tile_share_count--;
  tile->share_count--;
 
  if (tile->share_count == 0 && tile->ref_count == 0)
    {
      tile_destroy (tile);
      return;
    }
  TILE_MUTEX_UNLOCK (tile);
}


void *
tile_data_pointer (Tile *tile, int xoff, int yoff)
{
  int offset = yoff * tile->ewidth + xoff;
  return (void *)(tile->data + offset * tile->bpp);
}