"""
  索引工具函数。
  
  提取公共逻辑，避免代码重复。
  """
  
  import logging
  from typing import Dict, Any, Optional
  from sqlalchemy import Engine, text

  from config import get_app_config

  from config.tenant_config_loader import get_tenant_config_loader
  from indexer.document_transformer import SPUDocumentTransformer

  from translation import create_translation_client

  
  logger = logging.getLogger(__name__)
  
  
  def load_category_mapping(db_engine: Engine) -> Dict[str, str]:
      """
      加载分类ID到名称的映射（全局，所有租户共享）。
      
      Args:
          db_engine: SQLAlchemy database engine
          
      Returns:
          Dictionary mapping category_id to category_name
      """
      query = text("""
          SELECT DISTINCT
              category_id,
              category
          FROM shoplazza_product_spu
          WHERE deleted = 0 AND category_id IS NOT NULL
      """)
      
      mapping = {}
      try:
          with db_engine.connect() as conn:
              result = conn.execute(query)
              for row in result:
                  category_id = str(int(row.category_id))
                  category_name = row.category

                  if not category_name or not category_name.strip():
                      logger.warning(f"Category ID {category_id} has empty name, skipping")
                      continue

                  mapping[category_id] = category_name
      except Exception as e:
          logger.error(f"Failed to load category mapping: {e}", exc_info=True)

          raise RuntimeError("Failed to load category mapping from MySQL") from e

      
      return mapping
  
  
  def create_document_transformer(
      category_id_to_name: Dict[str, str],
      tenant_id: str,
      searchable_option_dimensions: Optional[list] = None,
      translator: Optional[Any] = None,

      encoder: Optional[Any] = None,

      enable_title_embedding: bool = True,

      image_encoder: Optional[Any] = None,
      enable_image_embedding: bool = False,

      config: Optional[Any] = None,

  ) -> SPUDocumentTransformer:
      """
      创建文档转换器（统一初始化逻辑）。

      Args:
          category_id_to_name: 分类ID到名称的映射
          tenant_id: 租户ID
          searchable_option_dimensions: 可搜索的option维度列表（如果为None则从配置加载）
          translator: 翻译器实例（如果为None则根据配置初始化）

          encoder: 文本编码器实例（如果为None且enable_title_embedding为True则根据配置初始化）
          enable_title_embedding: 是否启用标题向量化（默认True）

          image_encoder: 图片编码器（可选，需实现 encode_image_urls(urls)）
          enable_image_embedding: 是否启用 image_embedding 填充（默认False）
  

      Returns:
          SPUDocumentTransformer实例
      """
      # 加载租户配置
      tenant_config_loader = get_tenant_config_loader()
      tenant_config = tenant_config_loader.get_tenant_config(tenant_id)
      
      # 加载搜索配置（如果需要）

      if (
          searchable_option_dimensions is None
          or translator is None

          or (encoder is None and enable_title_embedding)
          or config is None
      ):

          if config is None:

              config = get_app_config().search

  
          if searchable_option_dimensions is None:
              searchable_option_dimensions = config.spu_config.searchable_option_dimensions
  
          index_langs = tenant_config.get("index_languages") or []
          need_translator = len(index_langs) > 1
          if translator is None and need_translator:

              translator = create_translation_client()

          # 初始化encoder（如果启用标题向量化且未提供encoder）
          if encoder is None and enable_title_embedding and config.query_config.enable_text_embedding:
              from embeddings.text_encoder import TextEmbeddingEncoder
  
              encoder = TextEmbeddingEncoder()
              logger.info("TextEmbeddingEncoder initialized for title embedding")

      
      return SPUDocumentTransformer(
          category_id_to_name=category_id_to_name,
          searchable_option_dimensions=searchable_option_dimensions,
          tenant_config=tenant_config,
          translator=translator,

          encoder=encoder,

          enable_title_embedding=enable_title_embedding,
          image_encoder=image_encoder,
          enable_image_embedding=enable_image_embedding,

      )