#!/bin/bash

# Use gitea dump to make a backup of Gitea
# https://docs.gitea.io/en-us/backup-and-restore/

set -eu
set -o pipefail
IFS="$(printf '\n\t')"

PROGRAM="${0##*/}"
INSTALL_DIR=/usr/local/bin
TMP_DIR=/home/git/tmp
WORK_DIR=/var/lib/gitea/
DATA_DIR=/var/lib/gitea/data/
LOG_DIR=/var/lib/gitea/log/
REPO_DIR=/home/git/gitea-repositories/
CONFIG_FILE=/etc/gitea/app.ini
DUMP_DIR=/home/git/gitea-dumps
MYSQL_USER={{ user_gitea_db }}
MYSQL_DB={{ name_gitea_db }}
MYSQL_PW={{ pass_gitea_db }}
SCRIPT_LOGFILE=/home/git/gitea_backup.log
SCRIPT_ERRLOGFILE=/home/git/gitea_backup.err

{% raw %}
if [ "$USER" != git ]; then
  echo "You must run this as user 'git'" && exit 1
fi

print_help() {
cat <<-_EOF

$PROGRAM

Usage:
  $PROGRAM {backup|restore <gitea_dump_file>|prune <int>}

Commands:
  backup    Create a backup. Will save to $DUMP_DIR.
  restore   Restore a previously created backup, given on the command line:
            <gitea_dump_file>, absolute path or relative to $PWD.
  prune     Remove previously dumped backups and keep <int> backups.

Options:
  -h        Print this help message and quit.
_EOF
}

do_backup() {
  echo "Backing up Gitea..."
  stop_service
  output_dump_file="$DUMP_DIR/gitea-dump-$(date +'%Y%m%d').zip"
  cd "$INSTALL_DIR" || exit 1
  ./gitea dump -V -f "$output_dump_file" -c "$CONFIG_FILE" -t "$TMP_DIR" --skip-attachment-data --skip-lfs-data -w "$WORK_DIR"
  chmod 640 "$output_dump_file" # Make the file readable by group for scp to different host by different user
  restart_service
  echo "Done."
}

do_restore() {
  echo "Restoring Gitea backup..."
  zip_file="$1"
  zip_dir="${zip_file%.*}" # Remove file extension
  chmod 600 "$zip_file" # Backup has changed permissions, restore them here
  echo "Unzipping $zip_file..." && unzip "$zip_file" -d "$zip_dir" && echo "  OK."
  cd "$zip_dir" || exit 1
  echo -n "Restoring $CONFIG_FILE..." && mv -f app.ini "$CONFIG_FILE" && echo "  OK."
  echo -n "Restoring $DATA_DIR..." && mv -f data/* "$DATA_DIR" && rmdir data && echo "  OK."
  echo -n "Restoring $LOG_DIR..." && mv -f log/* "$LOG_DIR" && rmdir log && echo "  OK."
  echo -n "Restoring $REPO_DIR..." && mkdir -p "$REPO_DIR" && mv -f repos/* "$REPO_DIR" && rmdir repos && echo "  OK."
  echo -n "Changing ownership..." && chown -R git:git "$CONFIG_FILE" /var/lib/gitea && echo "  OK."
  echo -n "Restoring MySQL database..." && mysql --default-character-set=utf8mb4 -u"$MYSQL_USER" -p"$MYSQL_PW" "$MYSQL_DB" < gitea-db.sql && rm gitea-db.sql && echo "  OK."
  rmdir "$zip_dir"
  restart_service
  regenerate_hooks
  echo "Done."
}

do_prune() {
  echo "Pruning Gitea backups and keeping $1 of them..."
  dumps=("$DUMP_DIR"/gitea-dump-*.zip)
  nb_of_dumps="${#dumps[@]}"
  nb_to_keep="$1"
  nb_to_prune=$((nb_of_dumps - nb_to_keep))
  if [ "$nb_to_prune" -gt "$nb_of_dumps" ]; then
    echo "There are only $nb_of_dumps backups, quitting." && exit 1
  fi
  if [ "$nb_to_prune" -le 0 ]; then
    echo "Nothing to do" && exit 1
  else
    for ((i=0; i < nb_to_prune; i++)); do
      echo -n "Removing ${dumps[$i]}..." && rm "${dumps[$i]}" && echo "  OK."
    done
  fi
}

regenerate_hooks() {
  echo "Regenerating hooks..."
  cd "$INSTALL_DIR" || exit 1
  ./gitea admin regenerate hooks --config "$CONFIG_FILE" && echo "Done."
}

stop_service() {
  echo -n "Stopping service..." && sudo systemctl stop gitea.service && echo "  OK."
}

restart_service() {
  echo -n "Restarting service..." && sudo systemctl restart gitea.service && echo "  OK."
}

[ "$#" = 0 ] || [ "$1" = '-h' ] && print_help && exit 1

if [ "$#" = 2 ]; then
  if [ "$1" = restore ]; then
    echo "STARTING restore" >> "$SCRIPT_LOGFILE"
    do_restore "$2" >> "$SCRIPT_LOGFILE" 2>> "$SCRIPT_ERRLOGFILE"
    echo "DONE restore" >> "$SCRIPT_LOGFILE"
  elif [ "$1" = prune ]; then
    echo "STARTING prune" >> "$SCRIPT_LOGFILE"
    do_prune "$2" >> "$SCRIPT_LOGFILE" 2>> "$SCRIPT_ERRLOGFILE"
    echo "DONE prune" >> "$SCRIPT_LOGFILE"
  else
    print_help && exit 1
  fi
elif [ "$#" = 1 ]; then
  if [ "$1" != backup ]; then
    print_help && exit 1
  fi
  echo "STARTING backup" >> "$SCRIPT_LOGFILE"
  do_backup >> "$SCRIPT_LOGFILE" 2>> "$SCRIPT_ERRLOGFILE"
  echo "DONE backup" >> "$SCRIPT_LOGFILE"
else
  print_help && exit 1
fi

exit 0
{% endraw %}