from datetime import datetime, date
from decimal import Decimal
from pydantic import BaseModel, Field
from app.schemas.category import CategoryOut
from app.schemas.currency import CurrencyOut


class BudgetCreate(BaseModel):
    category_id: int
    name: str = Field(..., max_length=200)
    amount: Decimal = Field(..., gt=0)
    currency_id: int
    period_type: str = Field(..., pattern="^(monthly|weekly|yearly|custom)$")
    start_date: date
    end_date: date | None = None
    is_active: bool = True


class BudgetUpdate(BaseModel):
    name: str | None = None
    amount: Decimal | None = Field(None, gt=0)
    period_type: str | None = None
    end_date: date | None = None
    is_active: bool | None = None


class BudgetOut(BaseModel):
    id: int
    user_id: int
    category_id: int
    category: CategoryOut
    name: str
    amount: Decimal
    currency_id: int
    currency: CurrencyOut
    period_type: str
    start_date: date
    end_date: date | None = None
    is_active: bool
    created_at: datetime
    spent: Decimal | None = None   # computed field

    model_config = {"from_attributes": True}