#!/bin/bash

# for duplicity source build
PATH="$PATH:/usr/local/bin"

# [--retry] interval_name [max_age]
# takes 2 arguments specifying the name of the subfolder,
# and optionally, the max age of the backup

# this script setup by adding a user crontab. see t.org for the script
# it's also setup to email me only when it fails, and only for daily or weekly runs

# uncomment for debugging, prints all commands to stdout
#set -x

set -E
#trap 'echo trapped error from \"$BASH_COMMAND\" returned $? line $LINENO; accumulated_errors=true' ERR
trap 'echo trapped err: $?; accumulated_errors=true' ERR

exec 3>&1 4>&2
exec &>> /tmp/small-backup.log

echo "BEGIN: $(date): args $*"


# only works with a single letter, ie 2D, not 2D12h
half-time() {
    local time_word
    local letter=${1##*[0-9]}
    case $letter in
        s) time_wrod=second ;;
        m) time_word=minute ;;
        h) time_word=hour ;;
        D) time_word=day ;;
        W) time_word=week ;;
        M) time_word=month ;;
        Y) time_word=year ;;
    esac
    echo "${1%%$letter} $time_word"
    local x=$(date +%s -d "${1%%$letter} $time_word")
    local y=$(date +%s)
}


if [[ $1 == --retry ]]; then
    shift
    x=0
    while pid=( $(pidof -o %PPID -x ${0##*/}) ) && (( ${#pid[@]} > 1 )) && (( x < 20 )); do
        x=$(( x + 1 ))
        sleep 30
    done
    if [[ $x == 20 ]]; then
        ps -F ${pid[@]}
        echo timeout error: existing ${0##*/} running for over 5 minutes >&2
        exit 1
    fi
else
    if pid=( $(pidof -o %PPID -x ${0##*/}) ) && (( ${#pid[@]} > 1 )); then
        echo ps -F ${pid[@]}
        ps -F ${pid[@]}
        echo error: existing ${0##*/} running >&2
        exit 1
    fi
fi

interval=$1
max_age=$2
full_backup_arg=""
if [[ $max_age ]]; then
    full_backup_arg="--full-if-older-than $(half-time $max_age)"
fi

rbackup () {

    local d=$1
    shift
    local dest=root@li::/root/rdiff-backups/${d##*/}/${interval}

    c="rdiff-backup $* --create-full-path $d $dest"
    echo "$c"; $c

    if [[ $max_age ]]; then
        c="rdiff-backup --force --remove-older-than $max_age $dest"
        echo "$c"; $c

    fi
}


rbackup /a/bin --exclude /a/bin/fai-basefiles
rbackup /a/c

# this is populated after input_setup.sh is run on login

ssh root@li mkdir -p /root/duplicity-backups/p/$interval
source /p/duplicity/gpg_agent_env
duplicity_dest=rsync://root@li//root/duplicity-backups/p/$interval

x=(/p/*)
if ((${#x[@]} > 1)); then
    set -x
    # archive-dir is sort of a persistent cache
    duplicity --use-agent \
              --encrypt-sign-key E969C67B \
              --include-globbing-filelist /p/duplicity/filelist \
              --archive-dir /p/duplicity/archive \
              --tempdir /p/tmp \
              $full_backup_arg /p $duplicity_dest
    if [[ $max_age ]]; then
        duplicity --use-agent \
                  remove-all-but-n-full 2 --force $duplicity_dest
    fi
    set +x
fi
# example restore command. We only need to make the first argument be a url for it to know it to do restore
# the archive-dir and tempdir args are not needed
# duplicity --use-agent --encrypt-sign-key E969C67B --archive-dir /p/duplicity/archive --tempdir /p/tmp ssh://root@li//root/duplicity-backups/p/weekly /p/duptest


echo END

# to restore duplicity. see man for additional options
# duplicity --use-agent restore ...
if [[ $accumulated_error ]]; then
    eccho "tail -n 50 of /tmp/small-backup.log:"
    tail -n 50 /tmp/small-backup.log
    exit 1
fi