"""API schemas (Pydantic) for PreschoolPlanningDays.

Schemas are the API boundary — they validate request bodies and shape
responses, kept separate from the domain entity so the wire format can
evolve independently.

`PreschoolPlanningDaysResponse.default_for` builds a response for a (child,
year) with no persisted row, using `Child.preschool_planning_days_per_year`
as the planned figure and `taken_days=None` ("not recorded"). `is_default`
tells the caller (frontend, or later the allocation engine) whether the
figures are a real record or just the child's fallback default.
"""

from datetime import datetime
from uuid import UUID

from pydantic import BaseModel, Field

from app.entities.child import Child
from app.entities.preschool_planning_days import PreschoolPlanningDays


class PreschoolPlanningDaysPlannedUpdate(BaseModel):
    planned_days: int = Field(ge=0, le=30)


class PreschoolPlanningDaysTakenUpdate(BaseModel):
    taken_days: int = Field(ge=0, le=30)


class PreschoolPlanningDaysResponse(BaseModel):
    id: UUID | None
    child_id: UUID
    year: int
    planned_days: int
    taken_days: int | None
    is_default: bool
    created_at: datetime | None
    updated_at: datetime | None

    @classmethod
    def from_entity(cls, entity: PreschoolPlanningDays) -> "PreschoolPlanningDaysResponse":
        return cls(
            id=entity.id,
            child_id=entity.child_id,
            year=entity.year,
            planned_days=entity.planned_days,
            taken_days=entity.taken_days,
            is_default=False,
            created_at=entity.created_at,
            updated_at=entity.updated_at,
        )

    @classmethod
    def default_for(cls, child: Child, year: int) -> "PreschoolPlanningDaysResponse":
        """A (child, year) with no persisted row: fall back to the child's default."""
        return cls(
            id=None,
            child_id=child.id,
            year=year,
            planned_days=child.preschool_planning_days_per_year,
            taken_days=None,
            is_default=True,
            created_at=None,
            updated_at=None,
        )