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

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"

BACKUP_FILE="${1:-${BACKUP_FILE:-}}"
if [[ -z "${BACKUP_FILE:-}" ]]; then
  echo "Usage: $0 <backup-file.tar.gz>" >&2
  exit 1
fi

if [[ ! -f "$BACKUP_FILE" ]]; then
  echo "[ERR] backup file not found: $BACKUP_FILE" >&2
  exit 1
fi

STORAGE_DIR_HOST="${2:-${STORAGE_DIR_HOST:-}}"
if [[ -z "$STORAGE_DIR_HOST" ]]; then
  echo "[ERR] explicit restore target is required as the second argument or STORAGE_DIR_HOST" >&2
  exit 1
fi

if [[ "${RESTORE_SCOPE:-}" != "shadow" ]]; then
  echo "[ERR] RESTORE_SCOPE=shadow is required; production restore is not available from this command path" >&2
  exit 1
fi

TARGET_PATH="$(realpath -m "$STORAGE_DIR_HOST")"
LIVE_STORAGE_PATH="$(realpath -m "$ROOT_DIR/deploy/trialrun/data/storage")"
if [[ "$TARGET_PATH" == "/" || "$TARGET_PATH" == "$ROOT_DIR" || "$TARGET_PATH" == "$LIVE_STORAGE_PATH" ]]; then
  echo "[ERR] unsafe storage restore target" >&2
  exit 1
fi

if [[ -d "$TARGET_PATH" && -n "$(find "$TARGET_PATH" -mindepth 1 -print -quit)" ]]; then
  echo "[ERR] storage restore target must be empty: $TARGET_PATH" >&2
  exit 1
fi

validate_archive_entries() {
  local entry normalized part listing_line
  tar -tzf "$BACKUP_FILE" >/dev/null
  while IFS= read -r entry; do
    if [[ -z "$entry" || "$entry" == /* ]]; then
      echo "[ERR] unsafe archive path" >&2
      return 1
    fi
    normalized="${entry#./}"
    [[ -z "$normalized" || "$normalized" == "." ]] && continue
    IFS='/' read -r -a path_parts <<<"$normalized"
    for part in "${path_parts[@]}"; do
      if [[ "$part" == ".." ]]; then
        echo "[ERR] unsafe archive path segment" >&2
        return 1
      fi
    done
  done < <(tar -tzf "$BACKUP_FILE")

  tar -tvzf "$BACKUP_FILE" >/dev/null
  while IFS= read -r listing_line; do
    if [[ "${listing_line:0:1}" == "l" || "${listing_line:0:1}" == "h" ]]; then
      echo "[ERR] storage archive links are not allowed" >&2
      return 1
    fi
  done < <(tar -tvzf "$BACKUP_FILE")
}

validate_archive_entries
mkdir -p "$TARGET_PATH"

echo "[INFO] Storage restore start: $BACKUP_FILE"
echo "[INFO] Storage target confirmed: shadow"

tar -xzf "$BACKUP_FILE" --no-same-owner --no-same-permissions -C "$TARGET_PATH"

echo "[OK] Storage restore done: $BACKUP_FILE"