#!/usr/bin/env bash
set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
LOG_FILE="$SCRIPT_DIR/raspi-backup.log"

usage() {
  echo "Usage:"
  echo "  ./06_logs.sh            # letzte 200 Zeilen"
  echo "  ./06_logs.sh -f         # live folgen (tail -f)"
  echo "  ./06_logs.sh -n 500     # letzte N Zeilen"
  echo "  ./06_logs.sh --all      # komplettes Log (less, falls vorhanden)"
}

if [[ ! -f "$LOG_FILE" ]]; then
  echo "Kein Log gefunden: $LOG_FILE"
  exit 0
fi

mode="tail"
lines=200

case "${1:-}" in
  "" ) ;;
  -f|--follow) mode="follow" ;;
  -n|--lines)
    [[ -n "${2:-}" ]] || { usage; exit 2; }
    lines="$2"
    ;;
  --all) mode="all" ;;
  -h|--help) usage; exit 0 ;;
  *) usage; exit 2 ;;
esac

case "$mode" in
  follow)
    echo "Folge Log live: $LOG_FILE"
    tail -f "$LOG_FILE"
    ;;
  all)
    if command -v less >/dev/null 2>&1; then
      less "$LOG_FILE"
    else
      cat "$LOG_FILE"
    fi
    ;;
  tail)
    tail -n "$lines" "$LOG_FILE"
    ;;
esac