apod_daily.sh

#!/bin/bash
WORKDIR=$(dirname "${BASH_SOURCE[0]}")
cd $WORKDIR

screen_num=$(osascript -e "tell application \"System Events\" to return count of desktops")
today_is_video=false
random_apod=false

if [ -z "$1" ]; then
  #echo "No argument supplied"
  TARGETDIR="$PWD/tmp"
else
  TARGETDIR="$1"
fi


if [ ! -d "$TARGETDIR" ]; then
  mkdir $TARGETDIR
fi

apodjson=$(curl -X GET "https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY")
if [ x$apodjson == "x" ]; then
  apodjson=$(curl -x 127.0.0.1:1080 -X GET "https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY")
fi
date=$(echo $apodjson | json_pp | grep "\"date\"" | awk -F '"' '{print $4}')
explanation=$(echo $apodjson | json_pp | grep "\"explanation\"" | awk -F '"' '{print $4}')
title=$(echo $apodjson | json_pp | grep "\"title\"" | awk -F '"' '{print $4}')
media_type=$(echo $apodjson | json_pp | grep "\"media_type\"" | awk -F '"' '{print $4}')
hdurl=$(echo $apodjson | json_pp | grep "\"hdurl\"" | awk -F '"' '{print $4}')
url=$(echo $apodjson | json_pp | grep -w "\"url\"" | awk -F '"' '{print $4}')
apod_date=${date}
epoch=$(date -j -f "%Y-%m-%d" $apod_date +%s)

#remove characters that will cause script failure
#echo $title
#echo $explanation
title=${title//[\\]}
explanation=${explanation//[\\]}  
echo $title
echo $explanation
    
#try to set wallpaper to every screen, if some images are missing, set to the same apod as today.
if [ $media_type == "video" ]; then
  #echo "Today is a video, will try to capture a video snapshot."
  echo "Today is a video, please visit $url for more information."
  osascript -e "display notification \"Astronomy Picture of the Day\" with title \"Today is a video, please visit\" subtitle \"$url\" sound name \"Glass\""
  today_is_video=true
elif [ $media_type == "image" ]; then
  curl -o $TARGETDIR/apod_${date}.jpg ${hdurl}
  echo "Today is an image, change the wallpaper."
  for ((i = 1; i <= ${screen_num}; i++)); do
    date=$(date -r $(($epoch - (i - 1) * 86400)) +"%Y-%m-%d")
    if [ ! -f "$TARGETDIR/apod_${date}.jpg" ]; then
      date=$apod_date
    fi
    echo "apod_${date}"
    osascript -e "tell application \"System Events\"" -e "tell desktop ${i}" -e "set picture rotation to 0" -e "set picture to \"$TARGETDIR/apod_${date}.jpg\"" -e "end tell" -e "end tell"
  done
  osascript -e "display notification \"Astronomy Picture of the Day\" with title \"$title\" subtitle \"$explanation\" sound name \"Glass\""
else
  echo "Error! Today APOD is something weird."
  #do somthing
fi

#clean outdated images
find $TARGETDIR -mtime +$(($screen_num + 3)) -exec rm {} \;