#!/usr/bin/env bash
# shellcheck disable=SC1090,SC1091

# set -xv
EUMETSAT_KEY="jdBM1PsDQUm0tCZfk9VXD6IaJoUa"
EUMETSAT_SECRET="SumkiqFMU3MAGpt_azb1KXKgjdMa"

error() {
	printf "\033[31m%s\033[0m\n" "$1"
	exit 1
}

# verify internet
ping -c1 1.1.1.1 >>/dev/null || error "couldn't establish an internet connection!"

# acquire the output directory
if command -v xdg-user-dir; then
	outdir="$(xdg-user-dir PICTURES)/eumetsat"
elif [ -z "$HOME" ]; then
	outdir="$HOME/.eumetsat"
else
	error "couldn't connect to either 'xdg-user-dir PICTURES' or '\$HOME'"
fi

# acquire the API key
key=$(
	curl -k -d "grant_type=client_credentials" \
		-H "Authorization: Basic $(printf "%s:%s" "$EUMETSAT_KEY" "$EUMETSAT_SECRET" | base64)" \
		https://api.eumetsat.int/token | jq -r '.["access_token"]'
)

# set url
url="https://view.eumetsat.int/geoserver/wms?"
url+="&service=WMS"
url+="&request=GetMap"
url+="&version=1.3.0"
url+="&layers=mtg_fd:rgb_geocolour"
url+="&width=1080&height=1080"
url+="&bbox=-6400000,-6400000,6400000,6400000"
url+="&crs=AUTO:42003,9001,0,0"
url+="&styles="
url+="&format=image/png"
url+="&access_token=$key"

# process incoming data
[ ! -d "$outdir" ] && { mkdir -p "$outdir" || error "failed to access '$outdir'!"; }
curl "$url" -o "$outdir/tmp.png" || error "failed to download from url='$url'!"
convert "$outdir/tmp.png" -alpha set -channel RGBA -fuzz 1% -fill none -floodfill +0+0 white "$outdir/curr.png"

# update the feh background
. "$HOME/.fehbg"