#!/bin/sh

############################################################################
#
# MODULE:       wms.request for GRASS 6
# AUTHOR(S):    Cedric Shock (cedric AT shockfamily.net)
#               Based on r.in.onearth by Soeren Gebbert and Markus Neteler
#               And on r.in.wms by Jachym Cepicky
# PURPOSE:      Builds requests for downloading data from web mapping servers
# COPYRIGHT:    (C) 2005, 2006 by the GRASS Development Team
#
#               This program is free software under the GNU General Public
#               License (>=v2). Read the file COPYING that comes with GRASS
#               for details.
#
#############################################################################

#%Module
#%  description: Builds download requests for WMS servers.
#%  keywords: wms
#%End
#%flag
#% key: o
#% description: Don't request transparent data
#%end
#%flag
#% key: c
#% description: Clean out existing data
#%end
#%flag
#% key: t
#% description: Use 
#%end
#%flag
#% key: p
#% description: This projection is the srs projection.
#%end
#%option
#% key: folder
#% type: string
#% description: Folder in which to save downloaded files
#% required : yes
#%end
#%option
#% key: prefix
#% type: string
#% description: Prefix file names with this
#% required : yes
#%end
#%option
#% key: region
#% type: string
#% description: Named region that defines the tileset.
#% required : no
#%end
#%option
#% key: mapserver
#% type: string
#% description: Mapserver to request data from
#% required: yes
#%end
#%option
#% key: layers
#% type: string
#% description: Layers to request from map server
#% multiple: yes
#% required: yes
#%end
#%option
#% key: styles
#% type: string
#% description: Styles to request from map server
#% multiple: yes
#% required: no
#%end
#%option
#% key: srs
#% type: string
#% description: Source projection to request from server
#% answer:EPSG:4326
#%end
#%option
#% key: format
#% type: string
#% description: Image format requested from the server
#% options: geotiff,tiff,jpeg,gif,png
#% answer: geotiff
#% required: no
#%end
#%option
#% key: maxcols
#% type: integer
#% description: Maximum columns to request at a time. 
#% answer: 1024
#% required : no
#%end
#%option
#% key: maxrows
#% type: integer
#% description: Maximum rows to request at a time
#% answer: 1024
#% required : no
#%end
#%option
#% key: tileoptions
#% type: string
#% description: Additional options for r.tileset
#% required : no
#%end
#%option
#% key: wmsquery
#% type:string
#% description: Addition query options for server
#% answer: version=1.1.1
#%end
# FIXME: Remove before GRASS 7 is released
#%option
#% key: v
#% type: integer
#% description: Verbosity level
#% answer: 1
#%end

if  [ -z "$GISBASE" ] ; then
    echo "You must be in GRASS GIS to run this program." 1>&2
    exit 1
fi

if [ "$1" != "@ARGS_PARSED@" ] ; then
  exec g.parser "$0" "$@"
fi

g.message -d "[wms.request]"


# Remember the intial field seperator
defaultIFS="$IFS"


####################################
# name:     message
# purpose:  displays messages to the user
# usage: message level text

message () {
	if [ $1 -lt $GIS_OPT_V ] ; then
		shift
		echo "$@"  
	fi
}


BC="bc"
BCARGS="-l"

####################################
# name: calculate
# purpose: perform calculations
# usage: varname "expr"

calculate() {
	message 3 "$2"
	c_tmp=`echo "$2" | $BC $BCARGS`
	eval $1=$c_tmp
}

####################################
# Calculate the number of tiles!!
# Download and them
GetTiles() {
  g.message "Calculating tiles"

  #################################################
  # ############## TILE SETTINGS ################ #
  #################################################
  MAXCOLS=${GIS_OPT_MAXCOLS} #The maximum cols of the biggest tile 
  MAXROWS=${GIS_OPT_MAXROWS} #The maximum rows of the biggest tile 


  #Calculate the number of tiles and set up the arrays
  message 1 "r.tileset -g sourceproj=\"$PROJ4_SRS\" sourcescale=\"$SRS_SCALE\" overlap=2 maxcols=${MAXCOLS} maxrows=${MAXROWS} $TILESET_OPTIONS"
  TILES=`eval "GRASS_VERBOSE=1 r.tileset -g sourceproj=\"$PROJ4_SRS\" sourcescale=\"$SRS_SCALE\" overlap=2 maxcols=${MAXCOLS} maxrows=${MAXROWS} $TILESET_OPTIONS"`
  if [ $? -ne 0 ] ; then
     g.message -e "r.tileset failure"
     exit 1
  fi

  NUMBER_OF_TILES=0 #The number of the tiles 
  #Calculate the number of tiles
  for i in $TILES ; do
	NUMBER_OF_TILES=`expr $NUMBER_OF_TILES + 1`
  done

  g.message "Requesting ${NUMBER_OF_TILES} tiles."
  if [ "$NUMBER_OF_TILES" -gt 200 ] ; then
     g.message -w "Proceed with care. This number of tiles may exceed \
       the maximum command line argument length available from your \
       operating system and cause an error later on in the r.in.gdalwarp \
       step. In addition it may be considered abusive behavior by the \
       server provider - check their terms of use."
  fi

  NUMBER_OF_TILES=0 #The number of the tiles 

  mkdir -p "${GIS_OPT_FOLDER}"

  FOLDERPLUS="${GIS_OPT_FOLDER}/${GIS_OPT_PREFIX}_${GIS_OPT_REGION}"

  if [ $GIS_FLAG_C -eq 1 ] ; then
    g.message -v message="Removing files <${FOLDERPLUS}*>"
    rm -f "$FOLDERPLUS"*
  fi

  if [ -x "`which wget`" ] ; then
    REQUESTFILE="${FOLDERPLUS}.wget"
  else
    REQUESTFILE="${FOLDERPLUS}.curl"
  fi

  #reset the requestfile
  echo > "${REQUESTFILE}"

  echo "$PROJ4_SRS" > "${FOLDERPLUS}.proj4"

  for i in $TILES ; do
	eval "$i"
	SIZE="bbox=$w,$s,$e,$n&width=$cols&height=$rows"
	message 1 "$SIZE"
	IMAGEFILE="${FOLDERPLUS}_${NUMBER_OF_TILES}"
	OUTPUT_FILE="${IMAGEFILE}${FILE_EXTENT}"
	# We could add world files here to help out gdalwarp.
	# And here it is:
	# Displacement from top left cell to the one to the right of it and to the one below it:
	calculate xres "($e - $w) / $cols"
	calculate nyres "($s - $n) / $rows"
	# Center of top left cell:
	calculate top_left_cell_center_x "$w + $xres / 2"
	calculate top_left_cell_center_y "$n + $nyres / 2"
	#Write the world file:
	echo "$xres" > "${IMAGEFILE}${WORLDFILE}"
	echo "0.0" >> "${IMAGEFILE}${WORLDFILE}"
	echo "0.0" >> "${IMAGEFILE}${WORLDFILE}"
	echo "$nyres" >> "${IMAGEFILE}${WORLDFILE}"
	echo "$top_left_cell_center_x" >> "${IMAGEFILE}${WORLDFILE}"
	echo "$top_left_cell_center_y" >> "${IMAGEFILE}${WORLDFILE}"
	#Make the requestt for data:
	STRING="request=GetMap&layers=${GIS_OPT_LAYERS}&styles=${GIS_OPT_STYLES}&srs=${SRS}&${SIZE}&format=${FORMAT}&${TRANSPARENCY}&${WMS_QUERY}"
	echo "OUTPUT_FILE=\"${OUTPUT_FILE}\";SERVER=\"${SERVER}\";STRING=\"${STRING}\"" >> "${REQUESTFILE}"

	NUMBER_OF_TILES=`expr $NUMBER_OF_TILES + 1`
  done
}


# Initialize variables:

SERVER="${GIS_OPT_MAPSERVER}"
SRS="${GIS_OPT_SRS}"
# use `tr '[:upper:]' '[:lower:]'` instead?
SRS_lower=`echo $SRS | sed "y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"`


# If the user asserts that this projection is the same as the source
# use this projection as the source to get a trivial tiling from r.tileset
if [ $GIS_FLAG_P -eq 1 ] ; then

    PROJ4_SRS=`g.proj -j | (
	PROJ4_SRS=
	while read line ; do
	    PROJ4_SRS="$PROJ4_SRS '$line'"
	done
	echo "$PROJ4_SRS"
    )`

    eval `g.proj -p | grep ^meters | sed "s/\\s*:\\s*/=/"`
    SRS_SCALE=$meters;
else
    PROJ4_SRS="+init=$SRS_lower"
    SRS_SCALE=1
fi

WMS_QUERY="${GIS_OPT_WMSQUERY}"

if [ -z "$GIS_OPT_REGION" ] ; then
	TILESET_OPTIONS="$GIS_OPT_TILEOPTIONS"
else
	TILESET_OPTIONS="region=$GIS_OPT_REGION $GIS_OPT_TILEOPTIONS"
fi

if [ $GIS_FLAG_O -eq 1 ] ; then
	TRANSPARENCY="transparent=FALSE"
else
	TRANSPARENCY="transparent=TRUE"
fi

case "${GIS_OPT_FORMAT}" in
    "geotiff") FORMAT="image/geotiff"
               WORLDFILE=".tfw"
               FILE_EXTENT=".geotiff"
               ;;
    "tiff") FORMAT="image/tiff"
               WORLDFILE=".tfw"
               FILE_EXTENT=".tiff"
               ;;
    "png") FORMAT="image/png"
               WORLDFILE=".pgw"
               FILE_EXTENT=".png"
               ;;
    "jpeg") FORMAT="image/jpeg"
               WORLDFILE=".jgw"
               FILE_EXTENT=".jpeg"
               ;;
    "gif") FORMAT="image/gif"
               WORLDFILE=".gfw"
               FILE_EXTENT=".gif"
               ;;
esac

GetTiles

exit