#!/usr/bin/env grass-script
#!/bin/bash -xe
# greenland is (mostly) missing in the mn75 (7.5arcsec) data
# but island and and the south is there
# unfortunately greenland isn't marked with nodata
# idea is to compare 7.5" to 30" data
# to build a nodata mask for the 7.5" data

#echo "$@"
P="$1"

r.in.gdal -e input="$P/$3" output=mn75
g.region rast=mn75
#r.info mn75
#r.univar mn75

r.in.gdal input="$P/$2" output=mn30
g.region rast=mn30
#r.info mn30
#r.univar mn30

g.region rast=mn75
#r.resamp.stats -w input=mn30 output=mn30at75 method=maximum

g.region s=59:59:59.5N
r.resample input=mn30 output=mn30at75
r.info mn30at75
#r.univar mn30at75

r.mapcalc mn30at75_nonull='if(isnull(mn30at75),0,mn30at75)'
r.info mn30at75_nonull
#r.univar mn30at75_nonull

r.mapcalc mask='if((mn75==0)&&(mn30at75_nonull>0),0,1)'
r.info mask
#r.univar mask

r.buffer -z input=mask output=mask2 distances=1000
r.info mask2
#r.univar mask2

r.mapcalc mask3='if(isnull(mask2),1,0)'
r.info mask3
#r.univar mask3

r.buffer -z input=mask3 output=mask4 distances=20000
r.info mask4
#r.univar mask4

r.mapcalc mask5='if(isnull(mask4),null(),-32768)'
r.info mask5
#r.univar mask5
r.out.gdal input=mask5 output="$P/$4" format=GTiff createopt="TILED=YES,COMPRESS=DEFLATE,ZLEVEL=7,PREDICTOR=2"
