from pydantic import BaseModel, Field
from typing import Optional, List, Union
from decimal import Decimal
from datetime import datetime
from uuid import UUID

from uuid import UUID, uuid4  # Ensure you have this import at the top


class BaseResponse(BaseModel):
    code: int
    message: str
    payload: Optional[dict] = None


### Constants
class PaymentMethod:
    CASH = "cash"
    MPESA = "mpesa"
    LIPA_NUMBER = "lipa_number"
    CREDIT_CARD = "credit_card"

    CHOICES = [CASH, MPESA, LIPA_NUMBER, CREDIT_CARD]


class PaymentStatus:
    ADDED_TO_BALANCE = "Added to balance"
    PURCHASED_PLAN = "Purchased plan"
    PENDING = "PENDING"


class CreatePaymentRequest(BaseModel):
    user_id: Optional[str] = Field(
        None, description="ID of the user making the payment"
    )
    plan_id: Optional[str] = Field(
        None, description="ID of the plan associated with the payment"
    )
    amount: Decimal = Field(..., description="Payment amount")
    payment_method: str = Field(
        ..., description="Method of payment", example=PaymentMethod.CASH
    )
    transaction_id: Optional[str] = Field(
        default_factory=lambda: str(uuid4()),  # Generate a UUID and convert to string
        description="Unique transaction ID (for methods like Lipa Number)",
    )


class UpdatePaymentStatusRequest(BaseModel):
    status: str = Field(
        ..., description="Status of the payment (e.g., pending, completed, failed)"
    )


class PaymentResponse(BaseModel):
    id: Union[UUID, str]
    user_id: Optional[Union[UUID, str]]
    plan_id: Optional[Union[UUID, str]]
    amount: Decimal
    payment_method: str
    status: str
    transaction_id: Optional[Union[UUID, str]]
    created_time: datetime
    updated_time: datetime

    class Config:
        from_attributes = True


class PaymentListResponse(BaseModel):
    payments: List[PaymentResponse]
    total_count: int

    class Config:
        from_attributes = True


class UpdatePaymentUserRequest(BaseModel):
    user_id: str = Field(
        ..., description="ID of the user to link or update for this payment"
    )