#!/usr/bin/env sh

interval=610
animate_speed=2
walldir="$HOME"/weatherbg
url_latest="http://radar.weather.gov/Conus/RadarImg/latest.gif"
url_animated="http://radar.weather.gov/Conus/Loop/NatLoop.gif"
dest_latest="$walldir"/latest-doppler.gif
dest_animated="$walldir"/animated-doppler.gif

mkdir -pv "$walldir"

function dl_doppler()
{
    echo "downloading latest doppler"
    wget -O "$dest_animated" "$url_animated"
    convertops="-coalesce"
    frames="$walldir"/frames.jpg
    convert "$dest_animated" "$convertops" "$frames"

        mkdir -pv "$walldir"/dark
    files=()
    for i in *.jpg ; do
        [[ -f "$i" ]] && convert "$i" -modulate 75 "$walldir"/dark/"$i"
    done


}

function loop_frames()
{
    files=()
    for i in *.jpg ; do
        [[ -f "$i" ]] && files+=("$i")
    done
    loop_time=${#files[@]}
    n_loops=$(($interval/$loop_time*animate_speed))
    echo "looping frame sequence " "$n_loops" "times"
    for i in $(seq 1 "$n_loops") ; do
        for var in "${files[@]}" ; do
            feh --bg-scale "$var"
            sleeptime=$(bc -l <<< "scale=2; 1/"$animate_speed"")
            sleep "$sleeptime"

        done
    done
}

cd "$walldir"
while :
do
    dl_doppler
        cd dark
    loop_frames
        cd -
done
cd -