#!/usr/bin/env bash
# Prune old storage growth snapshot files under logs/storage-growth/.
# Keeps history.csv and cron.log; deletes snapshot_*.txt older than KEEP_DAYS.
# Usage: ./scripts/monitoring/prune-storage-snapshots.sh [--days N] [--dry-run]

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
LOG_DIR="${LOG_DIR:-$PROJECT_ROOT/logs/storage-growth}"
KEEP_DAYS="${KEEP_DAYS:-30}"
DRY_RUN=0

while [ $# -gt 0 ]; do
  case "$1" in
    --days)
      KEEP_DAYS="${2:-30}"
      shift 2
      ;;
    --dry-run)
      DRY_RUN=1
      shift
      ;;
    *)
      shift
      ;;
  esac
done

if [ ! -d "$LOG_DIR" ]; then
  echo "Directory $LOG_DIR does not exist; nothing to prune."
  exit 0
fi

# Delete snapshot_YYYYMMDD_HHMMSS.txt older than KEEP_DAYS (by mtime)
count=0
while IFS= read -r -d '' f; do
  [ -z "$f" ] && continue
  if [ "$DRY_RUN" -eq 1 ]; then
    echo "[dry-run] would remove: $f"
  else
    rm -f "$f"
  fi
  ((count++)) || true
done < <(find "$LOG_DIR" -maxdepth 1 -name 'snapshot_*.txt' -mtime "+${KEEP_DAYS}" -print0 2>/dev/null || true)

if [ "$DRY_RUN" -eq 1 ]; then
  echo "Dry run: would remove $count snapshot(s) older than ${KEEP_DAYS} days."
else
  echo "Removed $count snapshot(s) older than ${KEEP_DAYS} days from $LOG_DIR."
fi