import json
from pydantic import BaseModel, field_validator
from typing import Optional, Dict, Any, Literal, List
from datetime import datetime


class VasPaymentBase(BaseModel):
    status: Optional[Literal['pending', 'succeeded', 'failed', 'expired', 'late_paid']] = None

    qr_id: Optional[int] = None
    payment_url: Optional[str] = None
    expire_at: Optional[datetime] = None

    provider_payload: Optional[Dict[str, Any]] = None
    
    @field_validator("provider_payload", mode="before")
    def normalize_json_field(cls, v):
        if v is None:
            return None
        if isinstance(v, str):
            try:
                return json.loads(v)
            except Exception:
                return {}
        return v
    
class VasPaymentCreate(BaseModel):
    order_id: str
    provider: Literal['stripe', 'wechat', 'alipay']

class VasPaymentUpdate(VasPaymentBase):
    pass

class VasPaymentOut(VasPaymentBase):
    id: int
    order_id: str

    provider: str
    channel: str

    payment_intent_id: Optional[str]
    external_trade_no: Optional[str]
    
    base_amount: int
    base_currency: str

    amount: int
    currency: str
    random_offset: int
    
    exchange_rate: float  # 注意：仅用于展示，DB 里是 DECIMAL

    created_at: datetime
    updated_at: datetime

    class Config:
        orm_mode = True