#!/bin/bash

# Variablen
data_dir="/home/{{ system_user_name }}/docker"
nfs_share="{{ nfs_share }}"
backup_target_usage_threshold="{{nfs_threshold}}" # Prozentuale Schwellenwert für die Speicherauslastung
mount_point="{{ mount_point }}"
backup_repository="$mount_point/{{borg_repo}}"
borg_password="{{borg_pass}}"
email_recipient="{{admin_mail}}"
sender_address="{{sender_address}}"

# Mounten des Backup-Ziels
mount_successful=0
mount_output=$(mount -t nfs "$nfs_share" "$mount_point" 2>&1)
mount_status=$?

if [ "$mount_status" -eq 0 ]; then
    mount_successful=1
else
    echo "Mount fehlgeschlagen: $mount_output" >&2
fi

if [ "$mount_successful" -eq 1 ]; then
    # Repository erstellen, falls nicht vorhanden
    mkdir -p "$backup_repository"    

    # Alle laufenden Container stoppen
    running_containers=$(docker ps --format '{{ "{{.Names}}" }}')
    for container in $running_containers; do
      docker stop "$container"
    done
  
    # Prüfen, ob das Repository existiert, und ggf. erstellen
    export BORG_PASSPHRASE="$borg_password"
    if ! borg list "$backup_repository" >/dev/null 2>&1; then
        borg init --encryption=repokey "$backup_repository"
    fi

    # Backup mit BorgBackup erstellen
    backup_result=$(borg create --stats --compression lz4 "$backup_repository"::'{hostname}-{now:%Y-%m-%d_%H:%M:%S}' $data_dir 2>&1)
    backup_status=$?

    # Alle gestoppten Container starten
    for container in $running_containers; do
      docker start "$container"
    done

    # Backup-Integrität überprüfen
    borg_check_result=$(borg check --repository-only --max-duration 43200 "$backup_repository" 2>&1)

    # Backup-Status und Speicherauslastung prüfen
    if [ "$backup_status" -eq 0 ]; then
      backup_result="Backup erfolgreich:\n$backup_result\n\nIntegrität des Backups überprüft:\n$borg_check_result"
    else
      backup_result="Backup fehlgeschlagen (Status: $backup_status):\n$backup_result\n\nIntegrität des Backups konnte nicht überprüft werden."
    fi

    # Retention Policy anwenden
    borg_prune_result=$(borg prune --keep-daily=7 --keep-weekly=4 --keep-monthly=6 "$backup_repository" 2>&1)

    # Unmounten des Backup-Ziels
    umount_output=$(umount "$mount_point" 2>&1)
    umount_status=$?
    if [ "$umount_status" -ne 0 ]; then
        echo "Unmount fehlgeschlagen: $umount_output" >&2
    fi

       # E-Mail senden
    target_usage=$(df -h "$mount_point" | tail -1 | awk '{ print $5 }')
    target_usage_number=${target_usage%%%}

    if [ "$target_usage_number" -gt "$backup_target_usage_threshold" ]; then
      target_usage_warning="\n\nWARNUNG: Die Speicherauslastung des Backup-Ziels beträgt $target_usage und überschreitet den festgelegten Schwellenwert von $backup_target_usage_threshold%."
    else
      target_usage_warning=""
    fi

hostname=$(hostname)
mail_subject="Backup-Bericht: $hostname - $(date +'%Y-%m-%d %H:%M:%S')"
mail_body="$backup_result\n"

    echo -e "$mail_body$target_usage_warning" | mail -s "$mail_subject" -r "$sender_adress" "$email_recipient"
fi