1from __future__ import annotations
 2
 3from typing import TYPE_CHECKING, Any
 4
 5if TYPE_CHECKING:
 6    from plain.models.backends.base.base import BaseDatabaseWrapper
 7    from plain.models.fields import Field
 8
 9
10class BaseDatabaseValidation:
11    """Encapsulate backend-specific validation."""
12
13    def __init__(self, connection: BaseDatabaseWrapper) -> None:
14        self.connection = connection
15
16    def preflight(self) -> list[Any]:
17        return []
18
19    def check_field(self, field: Field, **kwargs: Any) -> list[Any]:
20        errors = []
21        # Backends may implement a check_field_type() method.
22        if (
23            hasattr(self, "check_field_type")
24            and
25            # Ignore any related fields.
26            not getattr(field, "remote_field", None)
27        ):
28            # Ignore fields with unsupported features.
29            db_supports_all_required_features = all(
30                getattr(self.connection.features, feature, False)
31                for feature in field.model.model_options.required_db_features
32            )
33            if db_supports_all_required_features:
34                field_type = field.db_type(self.connection)
35                # Ignore non-concrete fields.
36                if field_type is not None:
37                    errors.extend(self.check_field_type(field, field_type))
38        return errors