#!/bin/bash

show_help()
{
cat << end_of_help

 USAGE: $(basename $0) [-h | --help] [--run-schedule] <domain1 domain2...>

 $(basename $0) -- Runs rsync to synchronize previously generated backups of domains from LOCAL_BACKUP_PATH to RSYNC_BACKUP_PATH, from either:
  - A given list of domains passed as arguments, or
  - All domains currently scheduled for backups, if '--run-schedule' is passed as the only argument.
  - Only returns rsync exit code when a single domain is passed. However, failed status is prompted as per domain.

end_of_help
}

# Load common functions:
source /usr/local/bin/vm-functions

case $1 in

    -h|--help)

        # Show help and exit:
        show_help
        exit
    ;;

    --run-schedule)

        rsync_action="Scheduled"

        # Load SCHEDULED_BACKUPS_LIST from external variables list:
        source $external_vars

        # Processes backups from SCHEDULED_BACKUPS_LIST:
        rsync_list=(${SCHEDULED_BACKUPS_LIST[@]})

        # This string is appended to some Unraid messages:
        unraid_logcheck_message=". Check $(basename $SCHEDULE_LOGFILE_PATH) for details."

        # Display initial message to append at logfile:
        screen_header "#"
        echo "$rsync_action Rsync started at: $(date "+%Y-%m-%d %H:%M:%S") ($(cat /etc/timezone))"
        screen_header "#"
    ;;

    *)
        rsync_action="On-demand"

        # Processes backup folders from LOCAL_BACKUP_PATH as main source path, and VMs (passed as arguments) as subfolders:
        rsync_list=($@)
    ;;
esac

if [[ -n ${rsync_list[@]} ]]; then

    # Notify via Unraid about the start of a scheduled process:
    [[ $rsync_action == "Scheduled" && $(os_is_unraid) == true ]] \
        && unraid_notify "normal" "VM-Babysitter" "$rsync_action Rsync" "In progress for domain(s): ${rsync_list[@]}. Avoid to stop/restart this container until further notice"

    for domain in ${rsync_list[@]}; do

        # (Re)Initialize status variable:
        rsync_exit_code=""

        # Build rsync_source directly from variables:
        rsync_source=$LOCAL_BACKUP_PATH/$domain

        # Display screen divider when processing several backup chains:
        [[ ${#rsync_list[@]} -gt 1 ]] \
            && screen_header "-"

        if [[ -d $rsync_source && -n $(ls -A $rsync_source) ]]; then

            # Backup exists. Build rsync_destination directly from variables:
            rsync_destination=$RSYNC_BACKUP_PATH/$domain

            echo "$domain: Syncing backup to $rsync_destination ..."

            if [[ $rsync_destination == *@*:/* ]]; then

                # Remote endpoint. Run rsync with extra options for remote connection when detected:
                rsync $RSYNC_ARGS -e "ssh $SSH_OPTIONS" $rsync_source/ $rsync_destination/

                # Get last status for rsync:
                rsync_exit_code=$?
            else

                # Locally reachable endpoint. Run rsync with user defined arguments only:
                rsync $RSYNC_ARGS $rsync_source/ $rsync_destination/

                # Get last status for rsync:
                rsync_exit_code=$?
            fi

            if [[ $rsync_exit_code -eq 0 ]]; then

                rsync_success_list+=($domain)
                echo "$domain: Backup synced successfully"

            else
                rsync_failed_list+=($domain)
                echo "$domain: Failed to sync backup to $rsync_destination (Rsync exit code: $rsync_exit_code)"
            fi
        else
            rsync_skipped_list+=($domain)
            echo "WARNING: There is no such backup '$rsync_source' to sync"
        fi
    done

    case $rsync_action in

        "On-demand")

            # When multiple backups chains were processed, display that the script has finished:
            [[ ${#rsync_list[@]} -gt 1 ]] \
                && echo -e "\n$(basename $0): Finished\n"

            # Only exits with rsync code when there was only one backup on the list and existed (not skipped):
            [[ ${#rsync_list[@]} -eq 1 && -z ${rsync_skipped_list[@]} ]] \
                && exit $rsync_exit_code
        ;;

        "Scheduled")

            # Displays a brief summary:
            screen_header "-"
            echo -e "$rsync_action Rsync Summary:\n"
            echo "Successful syncs: ${rsync_success_list[@]:-"None"}"
            echo "Failed syncs:     ${rsync_failed_list[@]:-"None"}"
            echo "Missing backups:  ${rsync_skipped_list[@]:-"None"}"

            if [[ $(os_is_unraid) == true ]]; then

                # Notifies via Unraid about the results:
                [[ -z ${rsync_failed_list[@]} ]] \
                    && unraid_notify "normal" "VM-Babysitter" "$rsync_action Rsync" "Success" \
                    || unraid_notify "warning" "VM-Babysitter" "$rsync_action Rsync finished with errors" "Could not sync backup of domain(s): ${rsync_failed_list[@]}$unraid_logcheck_message"
            fi

            echo -e "\n$rsync_action Rsync ended at: $(date "+%Y-%m-%d %H:%M:%S") ($(cat /etc/timezone))\n"
        ;;
    esac

else
    echo -e "No backup path(s) for $rsync_action Rsync to process\n\nUSAGE: $(basename $0) [-h |--help] [--run-schedule] <domain1 domain2...>\n"
fi