send_snap_to_prusa_connect_on_octoprint.sh

#!/usr/bin/env bash
# usage; cron entry to run this script every minute.
# the script will take 3 snaps at most, at run, run+20, run+40. Next minute is a new iteration.
# script construction allows changes between snaps, as the script runs itself 3x.

cd "$(dirname "$0")"

# Set default values for environment variables
: "${HTTP_URL:=https://webcam.connect.prusa3d.com/c/snapshot}"
: "${DELAY_SECONDS:=20}"
: "${LONG_DELAY_SECONDS:=60}"

FINGERPRINT="You need a unique string here to identify this camera"
TOKEN="You also need a camera token from the Connect interface"
SNAPSHOTURL="http://127.0.0.1/webcam/?action=snapshot"
LOG="./snap_to_prusa/snaps-"$(date '+%Y-%m-%d')".log"

do_snap() {
    # nigtmode camera experimental.
    nightmode=YES
    [ "day" = "$1" ] && nightmode=NO

    # grab from streamer
    curl -s "$SNAPSHOTURL" -o ./snap_to_prusa/output.jpg 2>/dev/null

    # If no error, upload it.
    if [ $? -eq 0 ]; then
        datestr=$(date +"%a %b %d %H:%M:%S %Z %Y")

        if [ "NO" = "$nightmode" ]; then 
            convert ./snap_to_prusa/output.jpg \
                -quality 85 \
                -filter lanczos \
                -modulate 100,150,100 \
                -channel R -level 20%,80% \
                -channel B -level 30%,100% \
                -channel G -level 0%,90% \
                +channel \
                -pointsize 36 \
                -font 'Helvetica-Neue-Light' \
                -fill white \
                -undercolor '#00000080' \
                -gravity southwest \
                -annotate +10+10 "${datestr}" ./snap_to_prusa/annotated.jpg 2>> "$LOG"
        fi

        if [ "YES" = "$nightmode" ]; then 
            convert ./snap_to_prusa/output.jpg \
                -quality 85 \
                -filter lanczos \
                -pointsize 36 \
                -font 'Helvetica-Neue-Light' \
                -fill white \
                -undercolor '#00000080' \
                -gravity southwest \
                -annotate +10+10 "${datestr}" ./snap_to_prusa/annotated.jpg 2>> "$LOG"
        fi

        # POST the image to the HTTP URL using curl
        curl -X PUT "$HTTP_URL" \
            -H "accept: */*" \
            -H "content-type: image/jpg" \
            -H "fingerprint: $FINGERPRINT" \
            -H "token: $TOKEN" \
            --data-binary "@${PWD}/snap_to_prusa/annotated.jpg" \
            -s \
            --compressed \
            > /dev/null 2>> "$LOG"
    else
        echo "$datestr: Snapshot returned an error. Skipping this cycle." >> "$LOG"
    fi
}

if [ "do_snap" = "$1" ]; then
    do_snap "$@"
else 
    for counter in {1..3}; do

        ./"$(basename "$0")" do_snap "$@"

        if [ $counter -lt 3 ]; then 
            sleep "$DELAY_SECONDS"
        fi
    done
fi