"""BaseDbHandler - DB Handler 基类。"""

from __future__ import annotations

from typing import Any, Dict, List, Optional, Set, TypeVar, TYPE_CHECKING

from pydantic import BaseModel

from ...common.type_safety import get_pydantic_model_fields
from ..handler import BaseNodeHandler

if TYPE_CHECKING:
    from ...common.sync_node import SyncNode
    from .datasource import DbDataSource

T = TypeVar("T", bound=BaseModel)


class BaseDbHandler(BaseNodeHandler[T]):
    """数据库 Handler 基类。"""

    def __init__(
        self,
        datasource: "DbDataSource",
        node_type: str,
        node_class: type["SyncNode[T]"],
        schema: type[T],
    ):
        super().__init__(node_type, node_class, schema)
        self.datasource = datasource
        self.update_schemas: List[type] = []
        self._target_project_ids: Optional[Set[str]] = None

    def set_target_project_ids(self, target_project_ids: List[str]) -> None:
        if target_project_ids:
            self._target_project_ids = {str(item) for item in target_project_ids if str(item)}
        else:
            self._target_project_ids = None

    def get_update_fields(self, *, exclude: frozenset = frozenset({"id"})) -> List[str]:
        fields: set[str] = set()
        for schema in self.update_schemas:
            for field_name in get_pydantic_model_fields(schema):
                if field_name not in exclude:
                    fields.add(field_name)
        return sorted(fields)

    def _create_basic_node(self, data: Dict[str, Any], depend_ids: Optional[List[str]] = None) -> "SyncNode[T]":
        data_id = self.extract_id(data)
        if self._collection is None:
            raise RuntimeError("Collection not set. Call set_collection() before creating nodes.")

        if data_id:
            existing_node = self._collection.get_by_data_id(self.node_type, data_id)
            if existing_node is not None:
                existing_node.depend_ids = list(depend_ids or [])
                existing_node.set_data(data.copy())
                existing_node.set_origin_data(data.copy())
                return existing_node

        node_id = self._collection.generate_node_id()
        return self.node_class(
            node_id=node_id,
            data_id=data_id,
            data=data.copy(),
            depend_ids=depend_ids or [],
            origin_data=data.copy(),
        )