import uuid
from datetime import date as DateType, datetime
from decimal import Decimal
from typing import Literal

from pydantic import BaseModel, Field

BudgetPeriod = Literal["weekly", "monthly", "quarterly", "yearly"]


class BudgetCreate(BaseModel):
    category_id: uuid.UUID
    name: str = Field(..., min_length=1, max_length=200)
    amount: Decimal = Field(..., gt=0)
    currency: str = Field(default="GBP", min_length=3, max_length=10)
    period: BudgetPeriod = "monthly"
    start_date: DateType
    end_date: DateType | None = None
    rollover: bool = False
    alert_threshold: Decimal = Field(default=Decimal("80"), ge=0, le=100)


class BudgetUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=200)
    amount: Decimal | None = Field(default=None, gt=0)
    period: BudgetPeriod | None = None
    end_date: DateType | None = None
    rollover: bool | None = None
    alert_threshold: Decimal | None = Field(default=None, ge=0, le=100)
    is_active: bool | None = None


class BudgetResponse(BaseModel):
    id: uuid.UUID
    category_id: uuid.UUID
    name: str
    amount: Decimal
    currency: str
    period: str
    start_date: DateType
    end_date: DateType | None
    rollover: bool
    alert_threshold: Decimal
    is_active: bool
    created_at: datetime
    updated_at: datetime

    model_config = {"from_attributes": True}


class BudgetSummaryItem(BaseModel):
    budget_id: uuid.UUID
    budget_name: str
    category_id: uuid.UUID
    category_name: str
    period: str
    budget_amount: Decimal
    spent_amount: Decimal
    remaining_amount: Decimal
    percent_used: Decimal
    is_over_budget: bool
    alert_triggered: bool
    currency: str
    period_start: DateType
    period_end: DateType