#!/usr/bin/env bash

###################################################################################
##    backup - a script to automate backup and pruning of borg repositories
##    Copyright (C) 2026 wytch 
##
##    This program is free software: you can redistribute it and/or modify
##    it under the terms of the GNU Affero General Public License as published by
##    the Free Software Foundation, either version 3 of the License, or
##    (at your option) any later version.
##
##    This program is distributed in the hope that it will be useful,
##    but WITHOUT ANY WARRANTY; without even the implied warranty of
##    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##    GNU Affero General Public License for more details.
##
##    You should have received a copy of the GNU Affero General Public License
##    along with this program.  If not, see <https://www.gnu.org/licenses/>.
##
#################################################################################

ERRORLOG='/var/log/borg/error.log'
LOGGING=error
# Check if running as root
if [ "$EUID" -ne 0 ]; then
	printf "Error: This script must be run as root (or via sudo).\n" | tee -a $ERRORLOG 
    exit 1
fi

# Load the environment variables directly
if [ -f /opt/borg/etc/borg_environment ]; then
    # shellcheck source=/dev/null
    source /opt/borg/etc/borg_environment
    
    # Ensure the variables sourced from the file are exported to child processes
    export BORG_REPO BORG_PASSPHRASE
else
    printf "Error: /opt/borg/etc/borg_environment not found.\n" | tee -a $ERRORLOG
    exit 1
fi

# Helpers and error handling
info() { printf "\n%s %s\n\n" "$(date)" "$*" >&2; }
trap 'info "Backup interrupted"; exit 2' INT TERM

info "Starting backup for repository: $BORG_REPO"

# 1. Create Archive
borg create                         \
    --verbose                       \
    --filter AME                    \
    --list                          \
    --stats                         \
    --show-rc                       \
    --compression lz4               \
    --exclude-caches                \
    --exclude 'home/*/.cache/*'     \
    --exclude 'var/log/journal'     \
    --exclude 'var/log/borg'        \
    --exclude 'var/tmp/*'           \
    --exclude 'var/games'           \
    --exclude 'home/*/.var/app'     \
    --exclude 'home/*/Media'        \
    ::'{hostname}-{now}'            \
    /etc                            \
    /home                           \
    /root                           \
    /var                            \
    /opt			    \
    2> >(tee -a $ERRORLOG >&2)

backup_exit=$?

# 2. Prune old backups
info "Pruning repository"
borg prune                          \
    --verbose			    \
    --list                          \
    --glob-archives '{hostname}-*'  \
    --show-rc                       \
    --keep-daily    7               \
    --keep-weekly   4               \
    --keep-monthly  6		    \
    2> >(tee -a $ERRORLOG)

prune_exit=$?

# 3. Compact repository
info "Compacting repository"
borg compact --$LOGGING 2> >(tee -a $ERRORLOG >&2)

compact_exit=$?

# Determine final status code
global_exit=$(( backup_exit > prune_exit ? backup_exit : prune_exit ))
global_exit=$(( compact_exit > global_exit ? compact_exit : global_exit ))

if [ "${global_exit}" -eq 0 ]; then
    info "Backup, Prune, and Compact finished successfully" | tee -a $ERRORLOG 
elif [ "${global_exit}" -eq 1 ]; then
    info "Backup, Prune, and/or Compact finished with warnings" | tee -a $ERRORLOG 
else
    info "Backup, Prune, and/or Compact finished with errors" | tee -a $ERRORLOG 
fi

exit "${global_exit}"