#!/bin/bash

THISDIR="$( pwd )"

DIRBASENAME="$( basename "$THISDIR" )"

if [[ -e /proc/sys/kernel/random/uuid ]]; then
    UUID=$(cat /proc/sys/kernel/random/uuid)
else
    UUID=$(uuidgen)
fi

HOSTNAME=$(hostname -s)

TS=$(date -u +%Y-%m-%d-%H-%M-%S)

FN="$TS.$HOSTNAME.$UUID.$DIRBASENAME"

BACKUPDEST=notfound
for DIR in /Volumes/* ; do
    if [[ -e "$DIR/berlin.sneak/backup" ]]; then
        BACKUPDEST="$DIR/berlin.sneak/backup"
    fi
done

if [[ "$BACKUPDEST" = "notfound" ]]; then
    echo "Unable to find backup target disk, exiting." > /dev/stderr
    exit 127
fi

echo "Backup disk found at $BACKUPDEST, backing up $THISDIR..."


KEYSERVER="hkps.pool.sks-keyservers.net"
KEYS=""
KEYS+=" 5539AD00DE4C42F3AFE11575052443F4DF2A55C2" #sneak@sneak.berlin
KEYS+=" FF2530A4F3F152E8865FC17CA833B7CE3F2CC6FC" #JP Yubi 6192
KEYS+=" 078BBD04FBE35D665180EF8A476509F749BFD1AD" #JP Yubi 2811
KEYS+=" 7D1123A022FC90DF389EC65F233196C180B1C28F" #JP Yubi 6643
KEYS+=" F5A3A83B9E65EA3E1A2A48E5FDA763BDDCFAB8AC" #Yubikey 4928206 20160927
KEYS+=" B044B27DCB86641AFE3AB274779D07C54EB7CF85" #Yubikey 4953582 20160927
#KEYS+=" 3FF8DE63855070F8B9CB0D9A67B4CD26470681DA" #Yubikey 4CNano 06931602 20171018

KEYS+=" 1CA168D7E842DFD1745815006F291E6D9AA87738"
KEYS+=" 726D577AFB82E64049B62A8DA763B92AD841A706"
KEYS+=" 04630E42D244BC80717D28D51280F730A9AD633C"
KEYS+=" 5D48805E38B8C2E04103C7728CBD64834BC043EA"
KEYS+=" 8904EE6400E7B7409CE00AA92084C4563F360B45"
KEYS+=" FE65DB157D8BF9E4FEDF50DA927353E2C4507A5B"
KEYS+=" 27CF8E00190D7AF340D8AE55A6C1C5C2083CB579"

GARGS=""
GARGS+=" --trust-model always"
GARGS+=" --compress-algo none"

for KEY in $KEYS ; do
    if ! gpg --list-key $KEY 2>&1 > /dev/null ; then
	    gpg --recv-key --keyserver $KEYSERVER $KEY
    fi
    GARGS+=" -r $KEY"
done

gpg $GARGS --encrypt "$*"

echo "Backing up to $FN..."

tar -c "$THISDIR" |
    pbzip2 |
    gpg $GARGS --encrypt --sign - |
    pv > "$BACKUPDEST/.$FN.tmp" && \
    mv "$BACKUPDEST/.$FN.tmp" "$BACKUPDEST/$FN.gpg" && \
    echo "Backup successful."

exit 0