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

# Dify docker restore script
# 使用 backups/ 中的备份恢复：
#   1) volumes/ 目录
#   2) Postgres 数据库 dify
#
# 用法：
#   ./restore.sh              # 使用最新备份
#   ./restore.sh 20251124_120000  # 使用指定时间戳的一组备份

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

BACKUP_DIR="$SCRIPT_DIR/backups"
TIMESTAMP="${1:-latest}"

if [ ! -d "$BACKUP_DIR" ]; then
  echo "错误：未找到备份目录 $BACKUP_DIR" >&2
  exit 1
fi

# 选择备份文件
if [ "$TIMESTAMP" = "latest" ]; then
  DB_FILE="$(ls -1t "$BACKUP_DIR"/dify_db_*.sql 2>/dev/null | head -n1 || true)"
  VOL_FILE="$(ls -1t "$BACKUP_DIR"/dify_volumes_*.tar.gz 2>/dev/null | head -n1 || true)"
else
  DB_FILE="$BACKUP_DIR/dify_db_${TIMESTAMP}.sql"
  VOL_FILE="$BACKUP_DIR/dify_volumes_${TIMESTAMP}.tar.gz"
fi

if [ -z "${DB_FILE:-}" ] || [ ! -f "$DB_FILE" ]; then
  echo "错误：未找到数据库备份文件 (dify_db_*.sql)，请检查 $BACKUP_DIR" >&2
  exit 1
fi

if [ -z "${VOL_FILE:-}" ] || [ ! -f "$VOL_FILE" ]; then
  echo "错误：未找到卷备份文件 (dify_volumes_*.tar.gz)，请检查 $BACKUP_DIR" >&2
  exit 1
fi

DB_USER="${POSTGRES_USER:-postgres}"
DB_NAME="${POSTGRES_DB:-dify}"

# 自动检测 db_postgres 容器名，匹配形如 "<project>-db_postgres-1"
DB_CONTAINER="${DB_CONTAINER:-}"
if [ -z "$DB_CONTAINER" ]; then
  DB_CONTAINER="$(docker ps --format '{{.Names}}' | grep 'db_postgres-1$' | head -n1 || true)"
fi

if [ -z "$DB_CONTAINER" ]; then
  echo "错误：未找到名称类似 '*-db_postgres-1' 的运行中容器，请先启动 dify 的 db_postgres 服务。" >&2
  exit 1
fi

echo "将使用备份："
echo "  DB:  $DB_FILE"
echo "  Vol: $VOL_FILE"
read -rp "确认恢复这些备份? 这可能覆盖现有数据 [y/N]: " CONFIRM
if [[ ! "$CONFIRM" =~ ^[Yy]$ ]]; then
  echo "已取消恢复。"
  exit 0
fi

echo "[1/2] 恢复 volumes/ 目录 ..."
tar xzf "$VOL_FILE" -C "$SCRIPT_DIR"

echo "[2/2] 恢复 Postgres 数据库 ${DB_NAME} ..."
# 可选：先清空数据库，按需修改
# docker exec -i "$DB_CONTAINER" psql -U "$DB_USER" -d "$DB_NAME" -c 'DROP SCHEMA public CASCADE; CREATE SCHEMA public;'

docker exec -i "$DB_CONTAINER" \
  psql -U "$DB_USER" -d "$DB_NAME" < "$DB_FILE"

echo "恢复完成。"