#!/bin/sh

############################################################################
#
# MODULE:       wms.download 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:      Downloads data from 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: Downloads data from servers.
#%  keywords: wms
#%End
#%flag
#% key: g
#% label: Use GET method instead of POST data method
#% description: This may be needed to connect to servers which lack POST capability
#%end
#%option
#% key: requestfile
#% type: string
#% description: File that lists the tiles to download
#% required : yes
#%end
#%option
#% key: wgetoptions
#% type: string
#% description: Additional options for wget
#% answer: -c -t 5
#% required : no
#%end
#%option
#% key: curloptions
#% type: string
#% description: Additional options for curl
#% answer: -C - --retry 5
#% required : no
#%end
#%option
# FIXME: Remove before GRASS 7 is released
#% 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.download]"

#### setup temporary file
TEMPFILE="`g.tempfile pid=$$`"
if [ $? -ne 0 ] || [ -z "$TEMPFILE" ] ; then
    g.message -e "Unable to create temporary files"
    exit 1
fi

# check if we have wget or curl
if [ ! -x "`which wget`" ] ; then
    if [ ! -x "`which curl`" ] ; then
        g.message -e "one of wget or curl is required, please install either first" 
        exit 1
    else
        USE_CURL=1
    fi
else
    USE_WGET=1
fi

# Remember the intial field seperator
defaultIFS=$IFS

#######################################################################
# name:     exitprocedure
# purpose:  removes all temporary files
#
exitprocedure()
{
    g.message -e 'User break!'
    rm -f "$TEMPFILE"*
    exit 1
}
trap "exitprocedure" 2 3 15

BC="bc"
BCARGS="-l"

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

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

################################################################
# Download the tiles!!
GetTiles() {
    g.message "Downloading tiles"

    # init POST-data vs. GET URL method variable
    if [ "$GIS_FLAG_G" -eq 0 ] ; then
	POST_DATA_OK=1
    else
	POST_DATA_OK=0
    fi

    NUMBER_OF_TILES=0

    while read line ; do
	g.message -d message="wget command: [$line]" debug=2
	if [ -z "$line" ] ; then
	    continue
	fi

	eval "$line"

	emptyness=`file "$OUTPUT_FILE" | grep empty$`

	if [ -f "$OUTPUT_FILE" ] && [ -z "$emptyness" ] ; then
	   g.message "Tile already downloaded"
	else
	   GetData
	   if [ $? -ne 0 ] ; then
		NUMBER_OF_TILES=`expr $NUMBER_OF_TILES + 1`
           fi
	fi
    done < "$REQUESTFILE"

    if [ "$NUMBER_OF_TILES" -ne 0 ] ; then
	g.message -w "$NUMBER_OF_TILES tiles failed to download"
	return 1
    else
	g.message "All tiles downloaded successfully"
	return 0
    fi
}

##################################
#Get the data from the WMS server
GetData() {
   g.message "Downloading data"
   g.message -v message="Requesting data from <$SERVER>:"
   g.message -v message="$STRING"

   if [ "$POST_DATA_OK" -eq 1 ] ; then
      #download the File from the Server
      if [ "$USE_WGET" ] ; then
         wget --progress=dot:mega $WGET_OPTIONS --post-data="$STRING" \
	    "$SERVER" -O "$OUTPUT_FILE"
      else
         curl $CURL_OPTIONS -o "$OUTPUT_FILE" -d "$STRING" "$SERVER"
      fi
      if [ $? -ne 0 ] ; then
         g.message -e "Failed while downloading the data"
         return 1
      fi
      if [ ! -f "$OUTPUT_FILE" ] ; then 
         g.message -e "Not able to download the data"
         return 1
      fi

       # work-around for brain-dead ArcIMS servers which want POST-data as part of the GET URL
       #   (this is technically allowed by OGC WMS def v1.3.0 Sec6.3.4)
      if [ `wc -c < "$OUTPUT_FILE"` -eq 0 ] ; then
         g.message -w "Downloaded image file was empty -- trying another method"
         POST_DATA_OK=0
      fi
   fi  # no else!

   if [ "$POST_DATA_OK" -eq 0 ] ; then
      g.message -v message=""
      if [ "$USE_WGET" ] ; then
	 wget $WGET_OPTIONS "${SERVER}?${STRING}" -O "$OUTPUT_FILE"
      else
	 curl $CURL_OPTIONS -o "$OUTPUT_FILE" "${SERVER}?${STRING}"
      fi
      if [ $? -ne 0 ] ; then
         g.message -e "Failed while downloading the data"
         return 1
      fi
      if [ ! -f "$OUTPUT_FILE" ] || [ `wc -c < "$OUTPUT_FILE"` -eq 0 ] ; then 
         g.message -e "Not able to download the data"
         return 1
      fi
   fi

   return 0
}

# Initialize variables:
#wget has many options
WGET_OPTIONS="$GIS_OPT_WGETOPTIONS"
CURL_OPTIONS="$GIS_OPT_CURLOPTIONS"
REQUESTFILE="$GIS_OPT_REQUESTFILE"

#Get all the data
GetTiles

# Clean up:
rm -f "$TEMPFILE"*