#!/bin/bash
# author: phga
# date: 2020-10-07
# desc: short rudimentary script to create backups for my bachelor thesis
#       and push them onto a webdav share
# required: ripgrep (rg), otherwise change lines 22, 23 to your grep alternative
#           that supports capture groups
#           gpg encrypted password for nextcloud in same dir as script (./backup_ba_pw.gpg)
me=$(dirname "$0")
tmp_path=$(mktemp -d)
today=$(date +%Y-%m-%d)
archive_name_full="${today}_BA_full.tgz"
archive_name_part="${today}_BA_part.tgz"
# exclude .git, etc.
tar_cmd="tar --exclude-vcs -czf"

# CHANGE THESE TO YOUR REQUIRED DIRS/FILES/PATHS/URLS/USERS
part_backup_files="/home/phga/sync/docs/study/BA/proposal /home/phga/sync/docs/study/BA/BA_WIP.org"
full_backup_files="/home/phga/sync/docs/study/BA"

# Add your own paths, users and password-files separated with a space
backup_paths=("https://nx.phga.de/remote.php/dav/files/toerd/external/no_sync/backups/study_backups/BA/" "https://nc.frfe.de/remote.php/dav/files/toerd/backups/BA/")
nxt_users=(toerd toerd)
nxt_passwds=(backup_ba_pw_phga.de.gpg backup_ba_pw_frfe.de.gpg)
# PASSWORD: see desc in header (./backup_ba_pw.gpg)

# get latest backup date (from filename, order in webdav seems to be asc - lucky for us)
i=0
for bp in ${backup_paths[@]}; do
    last_full_backup=$(curl -s -u ${nxt_users[$i]}:$(gpg -d $me/${nxt_passwds[$i]}) -X PROPFIND "$bp" | rg -o -e "(\d{4}-\d{2}-\d{2})_BA_full" -r '$1' | tail -1)
    last_part_backup=$(curl -s -u ${nxt_users[$i]}:$(gpg -d $me/${nxt_passwds[$i]}) -X PROPFIND "$bp" | rg -o -e "(\d{4}-\d{2}-\d{2})_BA_part" -r '$1' | tail -1)
    if [ ! -z $last_full_backup ]; then
        datediff_full_backup=$((($(date +%s) - $(date -d $last_full_backup +%s)) / (3600 * 24)))
    else
        datediff_full_backup=1337
    fi

    # Info output
    echo --------------------------------------
    echo $bp | rg -o -e ".*\.de"
    echo Last full backup was $datediff_full_backup days ago
    echo Date last full backup: $last_full_backup
    echo Date last part backup: $last_part_backup
    echo --------------------------------------

    # If 14 days have passed, create a new full backup
    if [ -z $last_full_backup ] || [ $datediff_full_backup -gt 14 ]; then
        # if no tar for this backup exists create one
        if [ ! -f "$tmp_path$archive_name_full" ]; then
            $tar_cmd "$tmp_path$archive_name_full" $full_backup_files
        fi
        curl -s -u ${nxt_users[$i]}:$(gpg -d $me/${nxt_passwds[$i]}) -T "$tmp_path$archive_name_full" "$bp$archive_name_full"
    else
        echo "---- No full backup required yet! ----"
    fi

    # if there is no important backup from this day, create one
    if [ -z $last_part_backup ] || [ $today != $last_part_backup ]; then
        if [ ! -f "$tmp_path$archive_name_part" ]; then
            $tar_cmd "$tmp_path$archive_name_part" $part_backup_files
        fi
        curl -s -u ${nxt_users[$i]}:$(gpg -d $me/${nxt_passwds[$i]}) -T "$tmp_path$archive_name_part" "$bp$archive_name_part"
    else
        echo "---- No part backup required yet! ----"
    fi
    ((i++))
done
# remove temp path
rm -r $tmp_path