#!/bin/bash

show_help()
{
cat << end_of_help

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

 $(basename $0) -- Runs virtnbdbackup to create/update backup chains of domains to LOCAL_BACKUP_PATH, from either:
  - A given list of domains passed as arguments,
  - All domains currently scheduled for backups, if '--run-schedule' is passed as the only argument, or
  - Creates new backup chains if '--create-new ' is passed as first argument, and then all domains as further arguments (forcing retention policy appliance in the process)

end_of_help
}

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

case $1 in

    -h|--help)

        # Show help and exit:
        show_help
        exit
    ;;
    --create-new)

        # Creates new backup chains of VMs in need of it (passed as arguments),
        # during container start or when a new VM is detected, appending/exporting VMs to their correspondent lists,
        # depending on the result:
        backup_action="Initial"

        # Forces to read from the 2nd argument, where the (first) VM is expected to be declared:
        shift

        # Virtnbdbackup mode is set to 'full':
        backup_mode="full"

        # Populates the backups list from VMs passed as (remaining) arguments:
        backups_list=($@)

        # This string is appended to some Unraid messages:
        unraid_logcheck_message=". Check container logs, or $(basename $LOGFILE_PATH) for details."
    ;;

    --run-schedule)

        # Performs backups from SCHEDULED_BACKUPS_LIST when called via cron,
        # updating/exporting correspondent lists, depending on the results (included deleted VMs):
        backup_action="Scheduled"

        # Processes initial backups list from SCHEDULED_BACKUPS_LIST in external variables file:
        source $external_vars
        backups_list=($SCHEDULED_BACKUPS_LIST)

        # Virtnbdbackup mode is set to 'auto':
        backup_mode="auto"

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

        # On Scheduled mode, force '--no-color' for more clarity in log files:
        [[ -z $(grep -o -e "--nocolor" <<< "$VIRTNBDBACKUP_ARGS") ]] \
            && VIRTNBDBACKUP_ARGS="$VIRTNBDBACKUP_ARGS --nocolor"

        # Display initial message to be appended into log file:
        screen_header "#"
        echo "$backup_action Backup started at: $(date "+%Y-%m-%d %H:%M:%S") ($(cat /etc/timezone))"
        screen_header "#"
    ;;

    *)
        # Without flags, the script performs 'on-demand' backups of the VMs passed as arguments. No lists are updated or exported.
        # Is mostly for test/debugging purposes, so use with care:

        # TODO: Add user confirmation action.
        backup_action="On-demand"

        # Virtnbdbackup mode is set to 'auto':
        backup_mode="auto"

        # Processes initial backups list from VMs (as arguments):
        backups_list=($@)
    ;;
esac

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

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

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

        screen_header "-"

        if [[ $(domain_exists $domain) == yes ]]; then

            # When backup action is to create a new backup chain, force the application of retention policy, prior to perform the backup operation:
            [[ $backup_action == "Initial" ]] && force_retention_policy="--force"

            vm-retention-policy $force_retention_policy $domain

            if [[ ! -d $LOCAL_BACKUP_PATH/$domain || -z $(ls -A $LOCAL_BACKUP_PATH/$domain) ]] \
            && [[ $(domain_state $domain) == "shut off" && -z $(grep -o -e "-S" -e "--start-domain" <<< "$VIRTNBDBACKUP_ARGS") ]]; then

                # Under specific scenario of new backup chain and powered off VMs,
                # force --start-server to turn on the VM in paused mode:
                start_domain="--start-domain"

            elif [[ $(domain_state $domain) == running ]]; then

                echo "$domain: Checking QEMU guest agent..."
                agent_is_connected=$(domain_agent_connected $domain $VM_WAIT_TIME)

                [[ $agent_is_connected ==  true ]] \
                    && echo "$domain: Success" \
                    || echo "WARNING: Timed out awaiting for domain '$domain' QEMU guest agent. Backup may not be concurrent (not installed onto guest OS?)"
            fi

            # Perform the backup operation:
            echo ""
            virtnbdbackup $start_domain -d $domain -l $backup_mode -o $LOCAL_BACKUP_PATH/$domain $VIRTNBDBACKUP_ARGS

            # Get last status for virtnbdbackup:
            virtnbdbackup_exit_code=$?

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

                # Backup chain creation was successful!
                backup_success_list+=($domain)

            else
                # Failed to create a new backup chain:
                backup_failed_list+=($domain)
                echo "WARNING: $backup_action Backup of $domain finished with errors (Virtnbdbackup exit code: $virtnbdbackup_exit_code)"
            fi

        else
            # Create a separated list of 'lost' VMs, and prompt about the unexpected error
            backup_skipped_list+=($domain)
            echo "WARNING: There is no such domain '$domain' to backup"
        fi
    done

    if [[ -n $RSYNC_BACKUP_PATH && -z $RSYNC_SCHEDULE  && -n ${backup_success_list[@]} ]]; then

        # When Rsync is enabled and a schedule was not set, activate rsync mode:
        on_demand_rsync=true

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

            screen_header "-"

            # Attempts to transfer changes via rsync:
            vm-rsync $domain

            # Get last status for rsync:
            rsync_exit_code=$?

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

                # Rsync exited normally:
                rsync_success_list+=($domain)
            else
                # Rsync failed:
                rsync_failed_list+=($domain)
            fi
        done
    fi

    case $backup_action in

        "On-demand") # Display that the script has finished:

            echo -e "\n$(basename $0): Finished\n"
        ;;

        *) # All other backup scenarios:

            # Reload SCHEDULED_BACKUPS_LIST and FAILED_VMS_LIST again, since other VMs could have been processed during this run:
            source $external_vars

            # Grab current SCHEDULED_BACKUPS_LIST as array:
            new_schedule_backups_list=($SCHEDULED_BACKUPS_LIST)

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

                # Add any successfully backed up VM into SCHEDULED_BACKUPS_LIST that is not currently present into this list:
                [[ -z $(item_position $domain "new_schedule_backups_list") ]] && new_schedule_backups_list+=($domain)
            done

            for domain in ${backup_failed_list[@]} ${backup_skipped_list[@]}; do

                failed_domain_index=$(item_position $domain "new_schedule_backups_list")

                if [[ -n $failed_domain_index ]]; then

                    # Delete each failed or skipped domain found into new_schedule_backups_list:
                    unset new_schedule_backups_list[$failed_domain_index]

                    # Rebuild the array upon each iteration:
                    new_schedule_backups_list=(${new_schedule_backups_list[@]})
                fi
            done

            # Append failed failed to its correspondent list to be exported:
            FAILED_VMS_LIST+=" ${backup_failed_list[@]}"

            # And update SCHEDULED_BACKUPS_LIST with changes, if any:
            SCHEDULED_BACKUPS_LIST=" ${new_schedule_backups_list[@]}"

            # Export the variables:
            sed -i \
            -e "s/FAILED_VMS_LIST=.*/FAILED_VMS_LIST=\"$FAILED_VMS_LIST\"/" \
            -e "s/SCHEDULED_BACKUPS_LIST=.*/SCHEDULED_BACKUPS_LIST=\"$SCHEDULED_BACKUPS_LIST\"/" \
            $external_vars

            # Show a final summary:
            screen_header "-"
            echo -e "$backup_action Backup Summary:\n"
            echo "Successful backups: ${backup_success_list[@]:-"None"}"
            echo "Failed backups:     ${backup_failed_list[@]:-"None"}"
            echo "Missing VMs:        ${backup_skipped_list[@]:-"None"}"

            if [[ $on_demand_rsync == true ]]; then

                # Only show remote stats when remote endppoint is set:
                screen_header "-"
                echo -e "$backup_action Rsync Summary:\n"
                echo "Successful syncs: ${rsync_success_list[@]:-"None"}"
                echo "Failed syncs:     ${rsync_failed_list[@]:-"None"}"
            fi

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

                # Notifies via Unraid about the results:
                if [[ -z ${backup_failed_list[@]} && -z ${rsync_failed_list[@]} && -z ${backup_skipped_list[@]} ]]; then

                    unraid_notify "normal" "VM-Babysitter" "$backup_action Backup" "Finished Successfully"

                else
                    [[ -n ${backup_skipped_list[@]} ]] \
                        && unraid_notify "warning" "VM-Babysitter" "$backup_action Backup" "Unable to find domain(s): ${backup_skipped_list[@]} and therefore removed from schedule (maybe deleted by the user?)"

                    [[ -n ${backup_failed_list[@]} ]] \
                        && unraid_notify "warning" "VM-Babysitter" "$backup_action Backup finished with errors" "Could not backup domain(s): ${backup_failed_list[@]}$unraid_logcheck_message"

                    [[ -n ${rsync_failed_list[@]} ]] \
                        && unraid_notify "warning" "VM-Babysitter" "$backup_action Rsync finished with errors" "Could not sync backup of domain(s): ${rsync_failed_list[@]}$unraid_logcheck_message"
                fi
            fi

            # Append the ending date and time into log file:
            echo -e "\n$backup_action Backup ended at: $(date "+%Y-%m-%d %H:%M:%S") ($(cat /etc/timezone))\n"
        ;;
    esac

else
    echo -e "No domain(s) for $backup_action Backup to process\n\nUSAGE: $(basename $0) [--run-schedule] [--create-new] [domain1 domain2...]\n"
fi