"""
数据模型定义
使用 Pydantic 进行数据验证
"""
from pydantic import BaseModel, Field
from typing import Dict, Optional
from datetime import datetime


# ============== API 响应模型 ==============

class ExchangeRateAPIResponse(BaseModel):
    """外部 API 原始响应模型"""
    result: str
    documentation: Optional[str] = None
    terms_of_use: Optional[str] = None
    time_last_update_unix: int
    time_last_update_utc: str
    time_next_update_unix: int
    time_next_update_utc: str
    base_code: str
    conversion_rates: Dict[str, float]


# ============== 缓存数据模型 ==============

class CachedRates(BaseModel):
    """缓存的汇率数据"""
    base_code: str
    rates: Dict[str, float]
    last_update_unix: int
    last_update_utc: str
    next_update_utc: str
    cached_at: datetime = Field(default_factory=datetime.now)


# ============== API 请求/响应模型 ==============

class RatesResponse(BaseModel):
    """获取所有汇率的响应"""
    success: bool
    base_currency: str
    rates: Dict[str, float]
    last_update: str
    cached_at: str
    currencies_count: int


class CurrencyRateResponse(BaseModel):
    """获取单个货币汇率的响应"""
    success: bool
    base_currency: str
    currency: str
    rate: float


class ConvertRequest(BaseModel):
    """汇率换算请求"""
    from_currency: str = Field(..., min_length=3, max_length=3, description="源货币代码")
    to_currency: str = Field(..., min_length=3, max_length=3, description="目标货币代码")
    amount: float = Field(..., gt=0, description="换算金额")


class ConvertResponse(BaseModel):
    """汇率换算响应"""
    success: bool
    from_currency: str
    to_currency: str
    amount: float
    result: float
    rate: float
    reverse_rate: float


class BatchConvertRequest(BaseModel):
    """批量换算请求"""
    base_currency: str = Field(..., min_length=3, max_length=3, description="基准货币代码")
    amount: float = Field(..., gt=0, description="换算金额")


class BatchConvertResponse(BaseModel):
    """批量换算响应"""
    success: bool
    base_currency: str
    amount: float
    conversions: Dict[str, float]


class CurrencyInfo(BaseModel):
    """货币信息"""
    code: str
    name: str
    name_cn: str
    symbol: Optional[str] = None


class CurrenciesResponse(BaseModel):
    """货币列表响应"""
    success: bool
    currencies: list[CurrencyInfo]


class ServiceStatusResponse(BaseModel):
    """服务状态响应"""
    status: str
    cache_valid: bool
    last_update: Optional[str] = None
    currencies_count: int
    api_keys_count: int
    update_interval_seconds: int


class ErrorResponse(BaseModel):
    """错误响应"""
    success: bool = False
    error: str
    detail: Optional[str] = None