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

# Incremental backup of data files to Google Drive using rclone.
# Copies only new/changed files and never deletes remote files.
#
# Usage:
#   scripts/ops/netgescon-data-backup-incremental-gdrive.sh \
#     --source /var/www/netgescon/storage/app/amministratori \
#     --remote gdrive:NetGesconBackups/prod/data-incremental

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
ENV_FILE="${ENV_FILE:-$ROOT_DIR/docker/.env.multisite}"
SOURCE_DIR=""
REMOTE_PATH=""

load_env_file() {
  local env_file="$1"
  local line key value

  while IFS= read -r line || [[ -n "$line" ]]; do
    line="${line%$'\r'}"
    [[ -z "$line" || "$line" =~ ^[[:space:]]*# ]] && continue
    [[ "$line" != *=* ]] && continue

    key="${line%%=*}"
    value="${line#*=}"
    export "$key=$value"
  done < "$env_file"
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --source)
      SOURCE_DIR="$2"
      shift 2
      ;;
    --remote)
      REMOTE_PATH="$2"
      shift 2
      ;;
    --env-file)
      ENV_FILE="$2"
      shift 2
      ;;
    *)
      echo "Unknown option: $1"
      echo "Usage: $0 [--source <dir>] [--remote <rclone-remote:path>] [--env-file <path>]"
      exit 1
      ;;
  esac
done

if [[ -f "$ENV_FILE" ]]; then
  load_env_file "$ENV_FILE"
fi

SOURCE_DIR="${SOURCE_DIR:-${NETGESCON_ARCHIVE_GDRIVE_SOURCE:-${PROD_STORAGE_PATH:-/srv/netgescon/prod/storage}/app/amministratori}}"
REMOTE_PATH="${REMOTE_PATH:-${NETGESCON_ARCHIVE_GDRIVE_REMOTE:-gdrive:NetGesconBackups/prod/documenti-amministratori}}"

if ! command -v rclone >/dev/null 2>&1; then
  echo "Error: rclone not installed."
  exit 1
fi

if [[ ! -d "$SOURCE_DIR" ]]; then
  echo "Error: source directory not found: $SOURCE_DIR"
  exit 1
fi

rclone copy "$SOURCE_DIR" "$REMOTE_PATH" \
  --update \
  --checksum \
  --create-empty-src-dirs \
  --progress

echo "Incremental data backup completed."
echo "SOURCE=$SOURCE_DIR"
echo "REMOTE=$REMOTE_PATH"