#!/usr/bin/env bash
# SQLite 维护窗口工具：先可恢复备份，再 checkpoint、VACUUM 与完整性校验。 # Logan.Li
set -euo pipefail

db_path=""
backup_dir=""
pid_file=""
maintenance_window="false"

usage() {
  echo "用法: $0 --maintenance-window --db /absolute/sqlite3.db --backup-dir /absolute/backups [--pid-file /absolute/.aiops.pid]" >&2
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --maintenance-window) maintenance_window="true"; shift ;;
    --db) db_path="$2"; shift 2 ;;
    --backup-dir) backup_dir="$2"; shift 2 ;;
    --pid-file) pid_file="$2"; shift 2 ;;
    *) usage; exit 2 ;;
  esac
done

if [[ "$maintenance_window" != "true" || "$db_path" != /* || "$backup_dir" != /* || "$db_path" == "/" || "$backup_dir" == "/" ]]; then
  usage
  exit 2
fi
if [[ ! -f "$db_path" ]]; then
  echo "数据库文件不存在: $db_path" >&2
  exit 2
fi
if ! command -v sqlite3 >/dev/null; then
  echo "未找到 sqlite3 命令" >&2
  exit 2
fi
if [[ -n "$pid_file" && -f "$pid_file" ]]; then
  service_pid=$(tr -d '[:space:]' < "$pid_file")
  if [[ -n "$service_pid" && -d "/proc/$service_pid" ]]; then
    echo "应用仍在运行（PID $service_pid），请先停止写入后重试" >&2
    exit 3
  fi
fi

timestamp=$(date +%Y%m%d%H%M%S)
backup_path="$backup_dir/aiops-sqlite-$timestamp.db"
mkdir -p "$backup_dir"

echo "开始可恢复备份: $backup_path"
sqlite3 "$db_path" ".backup '$backup_path'"
sqlite3 "$backup_path" "PRAGMA integrity_check;" | grep -qx "ok"

echo "执行 WAL checkpoint 与 VACUUM"
sqlite3 "$db_path" "PRAGMA wal_checkpoint(TRUNCATE); VACUUM; PRAGMA integrity_check;" | tail -1 | grep -qx "ok"

echo "维护完成"
du -h "$db_path" "$backup_path"