#!/bin/sh
set -eu
cd $HOME
LOG=.cache/duplicity/log

# do backup every day
if [ -e "$LOG" ] && [ $(( `date +%s` - `stat -c %Y $LOG` )) -lt 86300 ]; then
    exit 0
fi

# figure out $DISPLAY when running from cron
if [ -z "${DISPLAY:-}" ]; then
    socket="/run/user/`id -u`/X11-display"
    if [ -L "$socket" ]; then
        socket=$(readlink "$socket")
        export DISPLAY=:${socket##*/X}
    fi
fi

if ! ip route | grep -q '^default.*wlan'; then
    notify-send "Backup skipped, not on WLAN"
    exit 0
fi

notify-send "Backup started"
mkdir -p $(dirname $LOG)
env PASSPHRASE="$(cat ~/.backup-passphrase)" duplicity --full-if-older-than 1M --exclude-globbing-filelist .duplicity-ignore . rsync://piware.de/backup/donald >> $LOG || { notify-send "BACKUP FAILED!"; exit 1; }
notify-send "Backup finished successfully"