/*
 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
 *
 * Copyright (C) 2005, Evan Battaglia <viking@greentorch.org>
 * UTM multi-zone stuff by Kit Transue <notlostyet@didactek.com>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#define MAX_SHRINKFACTOR 8.0000001 /* zoom 1 viewing 8-tiles */
#define MIN_SHRINKFACTOR 0.0312499 /* zoom 32 viewing 1-tiles */

#include <gtk/gtk.h>
#include <gdk-pixbuf/gdk-pixdata.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "globals.h"
#include "coords.h"
#include "vikcoord.h"
#include "viktreeview.h"
#include "vikviewport.h"
#include "viklayer.h"
#include "vikmapslayer.h"
#include "vikmapslayer_pixmap.h"

#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "mapcache.h"
/* only for dialog.h -- ugh */
#include "vikwaypoint.h"
#include "dialog.h"

#include "vikstatus.h"
#include "background.h"

#include "vikaggregatelayer.h"
#include "viklayerspanel.h"

#include "mapcoord.h"
#include "terraserver.h"
#include "googlemaps.h"
#include "google.h"
#include "khmaps.h"
#include "expedia.h"
#include "usgs.h"

typedef struct {
  guint8 uniq_id;
  guint16 tilesize_x;
  guint16 tilesize_y;
  guint drawmode;
  gboolean (*coord_to_mapcoord) ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );
  void (*mapcoord_to_center_coord) ( MapCoord *src, VikCoord *dest );
  void (*download) ( MapCoord *src, const gchar *dest_fn );
  /* TODO: constant size (yay!) */
} VikMapsLayer_MapType;


/****** MAP TYPES ******/

static const VikMapsLayer_MapType __map_types[] = {

{ 2, 200, 200, VIK_VIEWPORT_DRAWMODE_UTM, terraserver_topo_coord_to_mapcoord, terraserver_mapcoord_to_center_coord, terraserver_topo_download },
{ 1, 200, 200, VIK_VIEWPORT_DRAWMODE_UTM, terraserver_aerial_coord_to_mapcoord, terraserver_mapcoord_to_center_coord, terraserver_aerial_download },
{ 4, 200, 200, VIK_VIEWPORT_DRAWMODE_UTM, terraserver_urban_coord_to_mapcoord, terraserver_mapcoord_to_center_coord, terraserver_urban_download },
{ 5, 0, 0, VIK_VIEWPORT_DRAWMODE_EXPEDIA, expedia_coord_to_mapcoord, expedia_mapcoord_to_center_coord, expedia_download },
{ 9, 128, 128, VIK_VIEWPORT_DRAWMODE_GOOGLE, googlemaps_coord_to_mapcoord, googlemaps_mapcoord_to_center_coord, googlemaps_download },
{ 6, 800, 600, VIK_VIEWPORT_DRAWMODE_UTM, usgs_coord_to_mapcoord, usgs_mapcoord_to_center_coord, usgs_download },
{ 8, 256, 256, VIK_VIEWPORT_DRAWMODE_KH, khmaps_coord_to_mapcoord, khmaps_mapcoord_to_center_coord, khmaps_download },
{ 7, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_download },
{ 10, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_trans_download },
{ 11, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_kh_download },
};

#define NUM_MAP_TYPES (sizeof(__map_types)/sizeof(__map_types[0]))

/******** MAPZOOMS *********/

static gchar *params_mapzooms[] = { "Use Viking Zoom Level", "0.25", "1", "2", "4", "8", "16", "32", "64", "128", "256", "512", "1024", "USGS 10k", "USGS 24k", "USGS 25k", "USGS 50k", "USGS 100k", "USGS 200k", "USGS 250k" };
static gdouble __mapzooms_x[] = { 0.0, 0.25, 1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 1.016, 2.4384, 2.54, 5.08, 10.16, 20.32, 25.4 };
static gdouble __mapzooms_y[] = { 0.0, 0.25, 1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0, 512.0, 1024.0, 1.016, 2.4384, 2.54, 5.08, 10.16, 20.32, 25.4 };

static gchar *params_maptypes[] = { "Terraserver Topos", "Terraserver Aerials", "Terraserver Urban Areas", "Expedia (Street Maps)", "Google Maps (Street)", "USGS", "KH Maps", "New (Mercator) Google", "Transparent Google", "New (Mercator) KH" };
static guint params_maptypes_ids[] = { 2, 1, 4, 5, 9, 6, 8, 7, 10, 11 };
#define NUM_MAPZOOMS (sizeof(params_mapzooms)/sizeof(params_mapzooms[0]))

/**************************/


static VikMapsLayer *maps_layer_copy ( VikMapsLayer *vml, VikViewport *vvp );
static gboolean maps_layer_set_param ( VikMapsLayer *vml, guint16 id, VikLayerParamData data, VikViewport *vvp );
static VikLayerParamData maps_layer_get_param ( VikMapsLayer *vml, guint16 id );
static void maps_layer_draw ( VikMapsLayer *vml, VikViewport *vvp );
static VikMapsLayer *maps_layer_new ( VikViewport *vvp );
static void maps_layer_free ( VikMapsLayer *vml );
static gboolean maps_layer_download_release ( VikMapsLayer *vml, GdkEventButton *event, VikViewport *vvp );
static gboolean maps_layer_download_click ( VikMapsLayer *vml, GdkEventButton *event, VikViewport *vvp );
static void maps_layer_set_cache_dir ( VikMapsLayer *vml, const gchar *dir );
static void start_download_thread ( VikMapsLayer *vml, VikViewport *vvp, const VikCoord *ul, const VikCoord *br, gint redownload );
static void maps_layer_add_menu_items ( VikMapsLayer *vml, GtkMenu *menu, VikLayersPanel *vlp );


static VikLayerParamScale params_scales[] = {
  /* min, max, step, digits (decimal places) */
 { 0, 255, 3, 0 }, /* alpha */
};

VikLayerParam maps_layer_params[] = {
  { "mode", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, "Map Type:", VIK_LAYER_WIDGET_RADIOGROUP, params_maptypes, params_maptypes_ids },
  { "directory", VIK_LAYER_PARAM_STRING, VIK_LAYER_GROUP_NONE, "Maps Directory (Optional):", VIK_LAYER_WIDGET_FILEENTRY },
  { "alpha", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, "Alpha:", VIK_LAYER_WIDGET_HSCALE, params_scales },
  { "autodownload", VIK_LAYER_PARAM_BOOLEAN, VIK_LAYER_GROUP_NONE, "Autodownload maps:", VIK_LAYER_WIDGET_CHECKBUTTON },
  { "mapzoom", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, "Zoom Level:", VIK_LAYER_WIDGET_COMBOBOX, params_mapzooms },
};

enum { PARAM_MAPTYPE=0, PARAM_CACHE_DIR, PARAM_ALPHA, PARAM_AUTODOWNLOAD, PARAM_MAPZOOM, NUM_PARAMS };

static VikToolInterface maps_tools[] = {
  { "Maps Download", (VikToolInterfaceFunc) maps_layer_download_click, (VikToolInterfaceFunc) maps_layer_download_release },
};

VikLayerInterface vik_maps_layer_interface = {
  "Map",
  &mapslayer_pixbuf,

  maps_tools,
  sizeof(maps_tools) / sizeof(maps_tools[0]),

  maps_layer_params,
  NUM_PARAMS,
  NULL,
  0,

  (VikLayerFuncCreate)                  maps_layer_new,
  (VikLayerFuncRealize)                 NULL,
  (VikLayerFuncPostRead)                NULL,
  (VikLayerFuncFree)                    maps_layer_free,

  (VikLayerFuncProperties)              NULL,
  (VikLayerFuncDraw)                    maps_layer_draw,
  (VikLayerFuncChangeCoordMode)         NULL,

  (VikLayerFuncAddMenuItems)            maps_layer_add_menu_items,
  (VikLayerFuncSublayerAddMenuItems)    NULL,

  (VikLayerFuncSublayerRenameRequest)   NULL,
  (VikLayerFuncSublayerToggleVisible)   NULL,

  (VikLayerFuncCopy)                    maps_layer_copy,

  (VikLayerFuncSetParam)                maps_layer_set_param,
  (VikLayerFuncGetParam)                maps_layer_get_param,

  (VikLayerFuncReadFileData)            NULL,
  (VikLayerFuncWriteFileData)           NULL,

  (VikLayerFuncCopyItem)                NULL,
  (VikLayerFuncPasteItem)               NULL,
  (VikLayerFuncFreeCopiedItem)          NULL,
};

struct _VikMapsLayer {
  VikLayer vl;
  guint maptype;
  gchar *cache_dir;
  guint8 alpha;
  guint mapzoom_id;
  gdouble xmapzoom, ymapzoom;

  gboolean autodownload;

  gint dl_tool_x, dl_tool_y;

  GtkMenu *dl_right_click_menu;
  VikCoord redownload_ul, redownload_br; /* right click menu only */
  VikViewport *redownload_vvp;
};

enum { REDOWNLOAD_NONE = 0, REDOWNLOAD_BAD, REDOWNLOAD_ALL };


/****************************************/
/******** CACHE DIR STUFF ***************/
/****************************************/

#ifdef WINDOWS
#define MAPS_CACHE_DIR "C:\\VIKING-MAPS\\"
#define DIRSTRUCTURE "%st%ds%dz%d\\%d\\%d"
#else /* POSIX */

#include <stdlib.h>

#define MAPS_CACHE_DIR maps_layer_default_dir()
#define GLOBAL_MAPS_DIR "/var/cache/maps/"
#define DIRSTRUCTURE "%st%ds%dz%d/%d/%d"

static gchar *maps_layer_default_dir ()
{
  static gchar defaultdir[512];
  static gboolean already_run = 0;
  if ( ! already_run )
  {
    /* Thanks to Mike Davison for the $VIKING_MAPS usage */
    gchar *mapdir = getenv("VIKING_MAPS");
    if ( mapdir && strlen(mapdir) < 497 ) {
      strcpy ( defaultdir, mapdir );
    } else if ( access ( GLOBAL_MAPS_DIR, W_OK ) == 0 ) {
      strcpy ( defaultdir, GLOBAL_MAPS_DIR );
    } else {
      gchar *home = getenv("HOME");
      if ( home && strlen(home) < 497 )
      {
        strcpy ( defaultdir, home );
        strcat ( defaultdir, "/.viking-maps/" );
      }
      else
      {
        strcpy ( defaultdir, ".viking-maps/" );
      }
    }
    already_run = 1;
  }
  return defaultdir;
}

#endif

static void maps_layer_mkdir_if_default_dir ( VikMapsLayer *vml )
{
  if ( vml->cache_dir && strcmp ( vml->cache_dir, MAPS_CACHE_DIR ) == 0 && access ( vml->cache_dir, F_OK ) != 0 )
  {
#ifdef WINDOWS
    mkdir ( vml->cache_dir );
#else
    mkdir ( vml->cache_dir, 0777 );
#endif
  }
}

static void maps_layer_set_cache_dir ( VikMapsLayer *vml, const gchar *dir )
{
  guint len;
  g_assert ( vml != NULL);
  if ( vml->cache_dir )
    g_free ( vml->cache_dir );

  if ( dir == NULL || dir[0] == '\0' )
    vml->cache_dir = g_strdup ( MAPS_CACHE_DIR );
  else
  {
    len = strlen(dir);
    if ( dir[len-1] != VIKING_FILE_SEP )
    {
      vml->cache_dir = g_malloc ( len+2 );
      strncpy ( vml->cache_dir, dir, len );
      vml->cache_dir[len] = VIKING_FILE_SEP;
      vml->cache_dir[len+1] = '\0';
    }
    else
      vml->cache_dir = g_strdup ( dir );
  }
  maps_layer_mkdir_if_default_dir ( vml );
}

/****************************************/
/******** GOBJECT STUFF *****************/
/****************************************/

GType vik_maps_layer_get_type ()
{
  static GType vml_type = 0;

  if (!vml_type)
  {
    static const GTypeInfo vml_info =
    {
      sizeof (VikMapsLayerClass),
      NULL, /* base_init */
      NULL, /* base_finalize */
      NULL, /* class init */
      NULL, /* class_finalize */
      NULL, /* class_data */
      sizeof (VikMapsLayer),
      0,
      NULL /* instance init */
    };
    vml_type = g_type_register_static ( VIK_LAYER_TYPE, "VikMapsLayer", &vml_info, 0 );
  }

  return vml_type;
}

/****************************************/
/************** PARAMETERS **************/
/****************************************/

static guint map_index_to_uniq_id (guint8 index)
{
  g_assert ( index < NUM_MAP_TYPES );
  return __map_types[index].uniq_id;
}

static guint map_uniq_id_to_index ( guint uniq_id )
{
  gint i;
  for ( i = 0; i < NUM_MAP_TYPES; i++ )
    if ( __map_types[i].uniq_id == uniq_id )
      return i;
  return NUM_MAP_TYPES; /* no such thing */
}

static gboolean maps_layer_set_param ( VikMapsLayer *vml, guint16 id, VikLayerParamData data, VikViewport *vvp )
{
  switch ( id )
  {
    case PARAM_CACHE_DIR: maps_layer_set_cache_dir ( vml, data.s ); break;
    case PARAM_MAPTYPE: {
      gint maptype = map_uniq_id_to_index(data.u);
      if ( maptype == NUM_MAP_TYPES ) g_warning("Unknown map type");
      else vml->maptype = maptype;
      break;
    }
    case PARAM_ALPHA: if ( data.u <= 255 ) vml->alpha = data.u; break;
    case PARAM_AUTODOWNLOAD: vml->autodownload = data.b; break;
    case PARAM_MAPZOOM: if ( data.u < NUM_MAPZOOMS ) {
                          vml->mapzoom_id = data.u;
                          vml->xmapzoom = __mapzooms_x [data.u];
                          vml->ymapzoom = __mapzooms_y [data.u];
                        }else g_warning ("Unknown Map Zoom"); break;
  }
  return TRUE;
}

static VikLayerParamData maps_layer_get_param ( VikMapsLayer *vml, guint16 id )
{
  VikLayerParamData rv;
  switch ( id )
  {
    case PARAM_CACHE_DIR: rv.s = (vml->cache_dir && strcmp(vml->cache_dir, MAPS_CACHE_DIR) != 0) ? vml->cache_dir : ""; break;
    case PARAM_MAPTYPE: rv.u = map_index_to_uniq_id ( vml->maptype ); break;
    case PARAM_ALPHA: rv.u = vml->alpha; break;
    case PARAM_AUTODOWNLOAD: rv.u = vml->autodownload; break;
    case PARAM_MAPZOOM: rv.u = vml->mapzoom_id; break;
  }
  return rv;
}

/****************************************/
/****** CREATING, COPYING, FREEING ******/
/****************************************/

static VikMapsLayer *maps_layer_new ( VikViewport *vvp )
{
  VikMapsLayer *vml = VIK_MAPS_LAYER ( g_object_new ( VIK_MAPS_LAYER_TYPE, NULL ) );
  vik_layer_init ( VIK_LAYER(vml), VIK_LAYER_MAPS );
  vml->maptype = 0;
  vml->alpha = 255;
  vml->mapzoom_id = 0;
  vml->dl_tool_x = vml->dl_tool_y = -1;
  maps_layer_set_cache_dir ( vml, NULL );
  vml->autodownload = FALSE;

  vml->dl_right_click_menu = NULL;

  return vml;
}

static void maps_layer_free ( VikMapsLayer *vml )
{
  if ( vml->cache_dir )
    g_free ( vml->cache_dir );
  if ( vml->dl_right_click_menu )
    gtk_object_sink ( GTK_OBJECT(vml->dl_right_click_menu) );
}

static VikMapsLayer *maps_layer_copy ( VikMapsLayer *vml, VikViewport *vvp )
{
  VikMapsLayer *rv = maps_layer_new ( vvp );
  *rv = *vml;
  rv->cache_dir = g_strdup(rv->cache_dir);
  VIK_LAYER(rv)->name = NULL;
  return rv;
}

/*********************/
/****** DRAWING ******/
/*********************/

static GdkPixbuf *pixbuf_set_alpha ( GdkPixbuf *pixbuf, guint8 alpha )
{
  guchar *pixels;
  gint width, height, iii, jjj;

  if ( ! gdk_pixbuf_get_has_alpha ( pixbuf ) )
  {
    GdkPixbuf *tmp = gdk_pixbuf_add_alpha(pixbuf,FALSE,0,0,0);
    g_object_unref(G_OBJECT(pixbuf));
    pixbuf = tmp;
  }

  pixels = gdk_pixbuf_get_pixels(pixbuf);
  width = gdk_pixbuf_get_width(pixbuf);
  height = gdk_pixbuf_get_height(pixbuf);

  /* r,g,b,a,r,g,b,a.... */
  for (iii = 0; iii < width; iii++) for (jjj = 0; jjj < height; jjj++)
  {
    pixels += 3;
    *pixels++ = alpha;
  }
  return pixbuf;
}

static GdkPixbuf *pixbuf_shrink ( GdkPixbuf *pixbuf, gdouble xshrinkfactor, gdouble yshrinkfactor )
{
  GdkPixbuf *tmp;
  guint16 width = gdk_pixbuf_get_width(pixbuf), height = gdk_pixbuf_get_height(pixbuf);
  tmp = gdk_pixbuf_scale_simple(pixbuf, ceil(width * xshrinkfactor), ceil(height * yshrinkfactor), GDK_INTERP_BILINEAR);
  g_object_unref ( G_OBJECT(pixbuf) );
  return tmp;
}

static GdkPixbuf *get_pixbuf( VikMapsLayer *vml, gint mode, MapCoord *mapcoord, gchar *filename_buf, gint buf_len, gdouble xshrinkfactor, gdouble yshrinkfactor )
{
  GdkPixbuf *pixbuf;

  /* get the thing */
  pixbuf = a_mapcache_get ( mapcoord->x, mapcoord->y, mapcoord->z,
                            mode, mapcoord->scale, vml->alpha, xshrinkfactor, yshrinkfactor );

  if ( ! pixbuf ) {
    g_snprintf ( filename_buf, buf_len, DIRSTRUCTURE,
                     vml->cache_dir, mode,
                     mapcoord->scale, mapcoord->z, mapcoord->x, mapcoord->y );
    if ( access ( filename_buf, R_OK ) == 0) {
    {
      GError *gx = NULL;
      pixbuf = gdk_pixbuf_new_from_file ( filename_buf, &gx );

      if (gx)
      {
        if ( gx->domain != GDK_PIXBUF_ERROR || gx->code != GDK_PIXBUF_ERROR_CORRUPT_IMAGE )
          g_warning ( "Couldn't open image file: %s", gx->message );

          g_error_free ( gx );
          if ( pixbuf )
            g_object_unref ( G_OBJECT(pixbuf) );
          pixbuf = NULL;
        } else {
          if ( vml->alpha < 255 )
            pixbuf = pixbuf_set_alpha ( pixbuf, vml->alpha );
          if ( xshrinkfactor != 1.0 || yshrinkfactor != 1.0 )
            pixbuf = pixbuf_shrink ( pixbuf, xshrinkfactor, yshrinkfactor );

          a_mapcache_add ( pixbuf, mapcoord->x, mapcoord->y, 
              mapcoord->z, __map_types[vml->maptype].uniq_id, 
              mapcoord->scale, vml->alpha, xshrinkfactor, yshrinkfactor );
        }
      }
    }
  }
  return pixbuf;
}

static void maps_layer_draw_section ( VikMapsLayer *vml, VikViewport *vvp, VikCoord *ul, VikCoord *br )
{
  MapCoord ulm, brm;
  gdouble xzoom = vik_viewport_get_xmpp ( vvp );
  gdouble yzoom = vik_viewport_get_ympp ( vvp );
  gdouble xshrinkfactor = 1.0, yshrinkfactor = 1.0;

  if ( vml->xmapzoom && (vml->xmapzoom != xzoom || vml->ymapzoom != yzoom) ) {
    xshrinkfactor = vml->xmapzoom / xzoom;
    yshrinkfactor = vml->ymapzoom / yzoom;
    if ( xshrinkfactor > MIN_SHRINKFACTOR && xshrinkfactor < MAX_SHRINKFACTOR &&
         yshrinkfactor > MIN_SHRINKFACTOR && yshrinkfactor < MAX_SHRINKFACTOR ) {
      xzoom = vml->xmapzoom;
      yzoom = vml->xmapzoom;
    } else {
      g_warning ( "Cowardly refusing to draw tiles at a shrinkfactor more than %.3f (zoomed out) or less than %.3f (zoomed in).", 1/MIN_SHRINKFACTOR, 1/MAX_SHRINKFACTOR );
    }
  }

  /* coord -> ID */
  if ( __map_types[vml->maptype].coord_to_mapcoord ( ul, xzoom, yzoom, &ulm ) &&
       __map_types[vml->maptype].coord_to_mapcoord ( br, xzoom, yzoom, &brm ) ) {

    /* loop & draw */
    gint x, y;
    gint xmin = MIN(ulm.x, brm.x), xmax = MAX(ulm.x, brm.x);
    gint ymin = MIN(ulm.y, brm.y), ymax = MAX(ulm.y, brm.y);
    gint mode = __map_types[vml->maptype].uniq_id;

    VikCoord coord;
    gint xx, yy, width, height;
    GdkPixbuf *pixbuf;

    guint max_path_len = strlen(vml->cache_dir) + 40;
    gchar *path_buf = g_malloc ( max_path_len * sizeof(char) );

    if ( vml->autodownload )
      start_download_thread ( vml, vvp, ul, br, REDOWNLOAD_NONE );

    if ( __map_types[vml->maptype].tilesize_x == 0 ) {
      for ( x = xmin; x <= xmax; x++ ) {
        for ( y = ymin; y <= ymax; y++ ) {
          ulm.x = x;
          ulm.y = y;
          pixbuf = get_pixbuf ( vml, mode, &ulm, path_buf, max_path_len, xshrinkfactor, yshrinkfactor );
          if ( pixbuf ) {
            width = gdk_pixbuf_get_width ( pixbuf );
            height = gdk_pixbuf_get_height ( pixbuf );

            __map_types[vml->maptype].mapcoord_to_center_coord ( &ulm, &coord );
            vik_viewport_coord_to_screen ( vvp, &coord, &xx, &yy );
            xx -= (width/2);
            yy -= (height/2);

            vik_viewport_draw_pixbuf ( vvp, pixbuf, 0, 0, xx, yy, width, height );
          }
        }
      }
    } else { /* tilesize is known, don't have to keep converting coords */
      gdouble tilesize_x = __map_types[vml->maptype].tilesize_x * xshrinkfactor;
      gdouble tilesize_y = __map_types[vml->maptype].tilesize_y * yshrinkfactor;
      /* ceiled so tiles will be maximum size in the case of funky shrinkfactor */
      gint tilesize_x_ceil = ceil ( tilesize_x );
      gint tilesize_y_ceil = ceil ( tilesize_y );
      gint8 xinc = (ulm.x == xmin) ? 1 : -1;
      gint8 yinc = (ulm.y == ymin) ? 1 : -1;
      gdouble xx, yy; gint xx_tmp, yy_tmp;
      gint base_yy, xend, yend;
      xend = (xinc == 1) ? (xmax+1) : (xmin-1);
      yend = (yinc == 1) ? (ymax+1) : (ymin-1);

      __map_types[vml->maptype].mapcoord_to_center_coord ( &ulm, &coord );
      vik_viewport_coord_to_screen ( vvp, &coord, &xx_tmp, &yy_tmp );
      xx = xx_tmp; yy = yy_tmp;
      /* above trick so xx,yy doubles. this is so shrinkfactors aren't rounded off
       * eg if tile size 128, shrinkfactor 0.333 */
      xx -= (tilesize_x/2);
      base_yy = yy - (tilesize_y/2);

      for ( x = ((xinc == 1) ? xmin : xmax); x != xend; x+=xinc ) {
        yy = base_yy;
        for ( y = ((yinc == 1) ? ymin : ymax); y != yend; y+=yinc ) {
          ulm.x = x;
          ulm.y = y;
          pixbuf = get_pixbuf ( vml, mode, &ulm, path_buf, max_path_len, xshrinkfactor, yshrinkfactor );
          if ( pixbuf )
            vik_viewport_draw_pixbuf ( vvp, pixbuf, 0, 0, xx, yy, tilesize_x_ceil, tilesize_y_ceil );

          yy += tilesize_y;
        }
        xx += tilesize_x;
      }
    }

    g_free ( path_buf );
  }
}

static void maps_layer_draw ( VikMapsLayer *vml, VikViewport *vvp )
{
  if ( __map_types[vml->maptype].drawmode == vik_viewport_get_drawmode ( vvp ) )
  {
    VikCoord ul, br;

    /* get corner coords */
    if ( vik_viewport_get_coord_mode ( vvp ) == VIK_COORD_UTM && ! vik_viewport_is_one_zone ( vvp ) ) {
      /* UTM multi-zone stuff by Kit Transue */
      gchar leftmost_zone, rightmost_zone, i;
      leftmost_zone = vik_viewport_leftmost_zone( vvp );
      rightmost_zone = vik_viewport_rightmost_zone( vvp );
      for ( i = leftmost_zone; i <= rightmost_zone; ++i ) {
        vik_viewport_corners_for_zonen ( vvp, i, &ul, &br );
        maps_layer_draw_section ( vml, vvp, &ul, &br );
      }
    }
    else {
      vik_viewport_screen_to_coord ( vvp, 0, 0, &ul );
      vik_viewport_screen_to_coord ( vvp, vik_viewport_get_width(vvp), vik_viewport_get_height(vvp), &br );

      maps_layer_draw_section ( vml, vvp, &ul, &br );
    }
  }
}

/*************************/
/****** DOWNLOADING ******/
/*************************/

/* pass along data to thread, exists even if layer is deleted. */
typedef struct {
  gchar *cache_dir;
  gchar *filename_buf;
  gint x0, y0, xf, yf;
  MapCoord mapcoord;
  gint maptype;
  gint maxlen;
  gint mapstoget;
  gint redownload;
} MapDownloadInfo;

static void mdi_free ( MapDownloadInfo *mdi )
{
  g_free ( mdi->cache_dir );
  g_free ( mdi->filename_buf );
  g_free ( mdi );
}

static void map_download_thread ( MapDownloadInfo *mdi, gpointer threaddata )
{
  guint donemaps = 0;
  gint x, y;
  for ( x = mdi->x0; x <= mdi->xf; x++ )
  {
    for ( y = mdi->y0; y <= mdi->yf; y++ )
    {
      g_snprintf ( mdi->filename_buf, mdi->maxlen, DIRSTRUCTURE,
                     mdi->cache_dir, __map_types[mdi->maptype].uniq_id,
                     mdi->mapcoord.scale, mdi->mapcoord.z, x, y );

      if ( mdi->redownload == REDOWNLOAD_ALL)
        remove ( mdi->filename_buf );
      else if ( mdi->redownload == REDOWNLOAD_BAD && access ( mdi->filename_buf, F_OK ) == 0 )
      {
        /* see if this one is bad or what */
        GError *gx = NULL;
        GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file ( mdi->filename_buf, &gx );
        if (gx || (!pixbuf))
          remove ( mdi->filename_buf );
        if ( pixbuf )
          g_object_unref ( pixbuf );
        if ( gx )
          g_error_free ( gx );
      }

      if ( access ( mdi->filename_buf, F_OK ) != 0 )
      {
        mdi->mapcoord.x = x; mdi->mapcoord.y = y;
        __map_types[mdi->maptype].download ( &(mdi->mapcoord), mdi->filename_buf );
        mdi->mapcoord.x = mdi->mapcoord.y = 0; /* we're temporarily between downloads */

       if ( mdi->redownload !=- REDOWNLOAD_NONE )
         a_mapcache_remove_all_shrinkfactors ( x, y, mdi->mapcoord.z, mdi->maptype, mdi->mapcoord.scale );


        donemaps++;
        a_background_thread_progress ( threaddata, ((gdouble)donemaps) / mdi->mapstoget ); /* this also calls testcancel */
      }
    }
  }
}

static void mdi_cancel_cleanup ( MapDownloadInfo *mdi )
{
  if ( mdi->mapcoord.x || mdi->mapcoord.y )
  {
    g_snprintf ( mdi->filename_buf, mdi->maxlen, DIRSTRUCTURE,
                     mdi->cache_dir, __map_types[mdi->maptype].uniq_id,
                     mdi->mapcoord.scale, mdi->mapcoord.z, mdi->mapcoord.x, mdi->mapcoord.y );
    if ( access ( mdi->filename_buf, F_OK ) == 0)
    {
      remove ( mdi->filename_buf );
    }
  }
}

static void start_download_thread ( VikMapsLayer *vml, VikViewport *vvp, const VikCoord *ul, const VikCoord *br, gint redownload )
{
  gdouble xzoom = vml->xmapzoom ? vml->xmapzoom : vik_viewport_get_xmpp ( vvp );
  gdouble yzoom = vml->ymapzoom ? vml->ymapzoom : vik_viewport_get_ympp ( vvp );
  MapCoord ulm, brm;
  if ( __map_types[vml->maptype].coord_to_mapcoord ( ul, xzoom, yzoom, &ulm ) 
    && __map_types[vml->maptype].coord_to_mapcoord ( br, xzoom, yzoom, &brm ) )
  {
    MapDownloadInfo *mdi = g_malloc ( sizeof(MapDownloadInfo) );
    gint a, b;

    /* cache_dir and buffer for dest filename */
    mdi->cache_dir = g_strdup ( vml->cache_dir );
    mdi->maxlen = strlen ( vml->cache_dir ) + 40;
    mdi->filename_buf = g_malloc ( mdi->maxlen * sizeof(gchar) );
    mdi->maptype = vml->maptype;

    mdi->mapcoord = ulm;

    mdi->redownload = redownload;

    mdi->x0 = MIN(ulm.x, brm.x);
    mdi->xf = MAX(ulm.x, brm.x);
    mdi->y0 = MIN(ulm.y, brm.y);
    mdi->yf = MAX(ulm.y, brm.y);

    mdi->mapstoget = 0;

    if ( mdi->redownload ) {
      mdi->mapstoget = (mdi->xf - mdi->x0 + 1) * (mdi->yf - mdi->y0 + 1);
    } else {
      /* calculate how many we need */
      for ( a = mdi->x0; a <= mdi->xf; a++ )
      {
        for ( b = mdi->y0; b <= mdi->yf; b++ )
        {
          g_snprintf ( mdi->filename_buf, mdi->maxlen, DIRSTRUCTURE,
                       vml->cache_dir, __map_types[vml->maptype].uniq_id, ulm.scale,
                       ulm.z, a, b );
          if ( access ( mdi->filename_buf, F_OK ) != 0)
            mdi->mapstoget++;
        }
      }
    }

    mdi->mapcoord.x = mdi->mapcoord.y = 0; /* for cleanup -- no current map */

    if ( mdi->mapstoget )
    {
      gchar *tmp = g_strdup_printf ( "%s %s%d %s %s...", redownload ? "Redownloading" : "Downloading", redownload == REDOWNLOAD_BAD ? "up to " : "", mdi->mapstoget, params_maptypes[vml->maptype], (mdi->mapstoget == 1) ? "map" : "maps" );

      /* launch the thread */
      a_background_thread ( VIK_GTK_WINDOW_FROM_LAYER(vml), /* parent window */
                            tmp,                                              /* description string */
                            (vik_thr_func) map_download_thread,               /* function to call within thread */
                            mdi,                                              /* pass along data */
                            (vik_thr_free_func) mdi_free,                     /* function to free pass along data */
                            (vik_thr_free_func) mdi_cancel_cleanup,
                            mdi->mapstoget );
      g_free ( tmp );
    }
    else
      mdi_free ( mdi );
  }
}

static void maps_layer_redownload_bad ( VikMapsLayer *vml )
{
  start_download_thread ( vml, vml->redownload_vvp, &(vml->redownload_ul), &(vml->redownload_br), REDOWNLOAD_BAD );
}
static void maps_layer_redownload_all ( VikMapsLayer *vml )
{
  start_download_thread ( vml, vml->redownload_vvp, &(vml->redownload_ul), &(vml->redownload_br), REDOWNLOAD_ALL );
}

static gboolean maps_layer_download_release ( VikMapsLayer *vml, GdkEventButton *event, VikViewport *vvp )
{

  if ( vml->dl_tool_x != -1 && vml->dl_tool_y != -1 )
  {
    if ( event->button == 1 )
    {
      VikCoord ul, br;
      vik_viewport_screen_to_coord ( vvp, MAX(0, MIN(event->x, vml->dl_tool_x)), MAX(0, MIN(event->y, vml->dl_tool_y)), &ul );
      vik_viewport_screen_to_coord ( vvp, MIN(vik_viewport_get_width(vvp), MAX(event->x, vml->dl_tool_x)), MIN(vik_viewport_get_height(vvp), MAX ( event->y, vml->dl_tool_y ) ), &br );
      start_download_thread ( vml, vvp, &ul, &br, REDOWNLOAD_NONE );
      vml->dl_tool_x = vml->dl_tool_y = -1;
      return TRUE;
    }
    else
    {
      vik_viewport_screen_to_coord ( vvp, MAX(0, MIN(event->x, vml->dl_tool_x)), MAX(0, MIN(event->y, vml->dl_tool_y)), &(vml->redownload_ul) );
      vik_viewport_screen_to_coord ( vvp, MIN(vik_viewport_get_width(vvp), MAX(event->x, vml->dl_tool_x)), MIN(vik_viewport_get_height(vvp), MAX ( event->y, vml->dl_tool_y ) ), &(vml->redownload_br) );

      vml->redownload_vvp = vvp;

      vml->dl_tool_x = vml->dl_tool_y = -1;

      if ( ! vml->dl_right_click_menu ) {
        GtkWidget *item;
        vml->dl_right_click_menu = GTK_MENU ( gtk_menu_new () );

        item = gtk_menu_item_new_with_label ( "Redownload bad map(s)" );
        g_signal_connect_swapped ( G_OBJECT(item), "activate", G_CALLBACK(maps_layer_redownload_bad), vml );
        gtk_menu_shell_append ( GTK_MENU_SHELL(vml->dl_right_click_menu), item );

        item = gtk_menu_item_new_with_label ( "Redownload all map(s)" );
        g_signal_connect_swapped ( G_OBJECT(item), "activate", G_CALLBACK(maps_layer_redownload_all), vml );
        gtk_menu_shell_append ( GTK_MENU_SHELL(vml->dl_right_click_menu), item );
      }

      gtk_menu_popup ( vml->dl_right_click_menu, NULL, NULL, NULL, NULL, event->button, event->time );
      gtk_widget_show_all ( GTK_WIDGET(vml->dl_right_click_menu) );
    }
  }
  return FALSE;
}

static gboolean maps_layer_download_click ( VikMapsLayer *vml, GdkEventButton *event, VikViewport *vvp )
{
  MapCoord tmp;
  if ( __map_types[vml->maptype].drawmode == vik_viewport_get_drawmode ( vvp ) &&
    __map_types[vml->maptype].coord_to_mapcoord ( vik_viewport_get_center ( vvp ),
           vml->xmapzoom ? vml->xmapzoom : vik_viewport_get_xmpp ( vvp ),
           vml->ymapzoom ? vml->ymapzoom : vik_viewport_get_ympp ( vvp ),
           &tmp ) ) {
    vml->dl_tool_x = event->x, vml->dl_tool_y = event->y;
    return TRUE;
  }
  return FALSE;

 
#if 0
  if ( __map_types[vml->maptype].drawmode == vik_viewport_get_drawmode ( vvp ) )
  {
    VikCoord coord;
    MapCoord mapcoord;
    vik_viewport_screen_to_coord ( vvp, event->x, event->y, &coord );
    if ( __map_types[vml->maptype].coord_to_mapcoord ( &coord,
                vml->xmapzoom ? vml->xmapzoom : vik_viewport_get_xmpp ( vvp ),
                vml->ymapzoom ? vml->ymapzoom : vik_viewport_get_ympp ( vvp ),
                &mapcoord ) ) {
      gchar *filename_buf = g_strdup_printf ( DIRSTRUCTURE,
                     vml->cache_dir, __map_types[vml->maptype].uniq_id,
                     mapcoord.scale, mapcoord.z, mapcoord.x, mapcoord.y );

      __map_types[vml->maptype].download ( &mapcoord, filename_buf );
      g_free ( filename_buf );
      vik_layer_emit_update ( VIK_LAYER(vml) );
      return TRUE;
    }
  }
  return FALSE;
#endif
}

static void maps_layer_download_onscreen_maps ( gpointer vml_vvp[2] )
{
  VikMapsLayer *vml = vml_vvp[0];
  VikViewport *vvp = vml_vvp[1];

  gdouble xzoom = vml->xmapzoom ? vml->xmapzoom : vik_viewport_get_xmpp ( vvp );
  gdouble yzoom = vml->ymapzoom ? vml->ymapzoom : vik_viewport_get_ympp ( vvp );

  VikCoord ul, br;
  MapCoord ulm, brm;

  vik_viewport_screen_to_coord ( vvp, 0, 0, &ul );
  vik_viewport_screen_to_coord ( vvp, vik_viewport_get_width(vvp), vik_viewport_get_height(vvp), &br );

  if ( __map_types[vml->maptype].drawmode == vik_viewport_get_drawmode ( vvp ) &&
       __map_types[vml->maptype].coord_to_mapcoord ( &ul, xzoom, yzoom, &ulm ) &&
       __map_types[vml->maptype].coord_to_mapcoord ( &br, xzoom, yzoom, &brm ) )
    start_download_thread ( vml, vvp, &ul, &br, REDOWNLOAD_NONE );
  else
    a_dialog_error_msg ( VIK_GTK_WINDOW_FROM_LAYER(vml), "Wrong drawmode / zoom level for this map." );

}

static void maps_layer_add_menu_items ( VikMapsLayer *vml, GtkMenu *menu, VikLayersPanel *vlp )
{
  static gpointer pass_along[2];
  GtkWidget *item;
  pass_along[0] = vml;
  pass_along[1] = vik_layers_panel_get_viewport( VIK_LAYERS_PANEL(vlp) );

  item = gtk_menu_item_new();
  gtk_menu_shell_append ( GTK_MENU_SHELL(menu), item );
  gtk_widget_show ( item );

  item = gtk_menu_item_new_with_label ( "Download Onscreen Maps" );
  g_signal_connect_swapped ( G_OBJECT(item), "activate", G_CALLBACK(maps_layer_download_onscreen_maps), pass_along );
  gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);
  gtk_widget_show ( item );
}