#!/usr/bin/env bash
#
# Záloha všech Docker dat na NAS
# - najde všechny kontejnery s volume mounty v /home/<user>/docker
# - zastaví je (volitelně), zabalí data do tar.gz, pošle na NAS
# - ponechá běžící kontejnery běžet (default)
#
# Použití:
#   sudo bash backup-all.sh                       # zálohuj vše (bez zastavení)
#   sudo bash backup-all.sh --stop                # zastav před zálohou
#   sudo bash backup-all.sh --dry-run             # pouze ukaž co by se dělalo
#   sudo bash backup-all.sh --only portainer      # jen jednu službu
#
set -euo pipefail

DEPLOY_USER="${DEPLOY_USER:-deploy}"
DOCKER_HOME="/home/$DEPLOY_USER/docker"
NAS_MOUNT="${NAS_MOUNT:-/Volumes/Backups}"
BACKUP_ROOT="$NAS_MOUNT/Prace/server-backups/$(hostname)"
TS="$(date +%Y%m%d-%H%M%S)"

STOP=false
DRY_RUN=false
ONLY=""

while [[ $# -gt 0 ]]; do
    case $1 in
        --stop) STOP=true; shift ;;
        --dry-run) DRY_RUN=true; shift ;;
        --only) ONLY="$2"; shift 2 ;;
        *) echo "Neznámý parametr: $1" >&2; exit 1 ;;
    esac
done

[[ $EUID -eq 0 ]] || { echo "Spusť jako root: sudo bash $0" >&2; exit 1; }
[[ -d "$DOCKER_HOME" ]] || { echo "Adresář $DOCKER_HOME neexistuje" >&2; exit 1; }

run() {
    if $DRY_RUN; then
        echo "[DRY-RUN] $*"
    else
        echo "▶ $*"
        "$@"
    fi
}

mkdir -p "$BACKUP_ROOT"

for SERVICE_DIR in "$DOCKER_HOME"/*/; do
    SERVICE=$(basename "$SERVICE_DIR")
    [[ -n "$ONLY" && "$SERVICE" != "$ONLY" ]] && continue
    [[ -f "$SERVICE_DIR/docker-compose.yml" ]] || continue

    BACKUP_DIR="$BACKUP_ROOT/$SERVICE"
    BACKUP_FILE="$BACKUP_DIR/${SERVICE}-$TS.tar.zst"

    if $STOP; then
        run docker compose -f "$SERVICE_DIR/docker-compose.yml" stop
    fi

    if [[ -d "$SERVICE_DIR/data" ]]; then
        run mkdir -p "$BACKUP_DIR"
        run tar --zstd -cf "$BACKUP_FILE" -C "$SERVICE_DIR" data
        echo "✓ $SERVICE: $BACKUP_FILE"
    fi

    if $STOP; then
        run docker compose -f "$SERVICE_DIR/docker-compose.yml" start
    fi
done

echo
echo "🎯 Hotovo. Zálohy v: $BACKUP_ROOT"