import uuid
from datetime import date, datetime

from pydantic import BaseModel, field_validator

from app.models.transaction import TransactionType
from app.schemas.common import PaginatedResponse


class CategoryBrief(BaseModel):
    id: uuid.UUID
    name: str
    color: str | None

    model_config = {"from_attributes": True}


class TransactionCreate(BaseModel):
    amount_cents: int
    type: TransactionType
    category_id: uuid.UUID
    description: str | None = None
    transaction_date: date

    @field_validator("amount_cents")
    @classmethod
    def amount_must_be_positive(cls, v: int) -> int:
        if v <= 0:
            raise ValueError("amount_cents must be greater than 0")
        return v


class TransactionUpdate(BaseModel):
    amount_cents: int | None = None
    type: TransactionType | None = None
    category_id: uuid.UUID | None = None
    description: str | None = None
    transaction_date: date | None = None

    @field_validator("amount_cents")
    @classmethod
    def amount_must_be_positive(cls, v: int | None) -> int | None:
        if v is not None and v <= 0:
            raise ValueError("amount_cents must be greater than 0")
        return v


class TransactionResponse(BaseModel):
    id: uuid.UUID
    amount_cents: int
    type: TransactionType
    description: str | None
    category: CategoryBrief
    transaction_date: date
    created_at: datetime

    model_config = {"from_attributes": True}


PaginatedTransactions = PaginatedResponse[TransactionResponse]