"""
Pydantic 数据模型
==================
定义 Flask API 的请求和响应数据结构

用途:
- 类型安全的 API 响应结构
- 调用方数据验证
- IDE 自动补全支持
- 为 Phase 2 (Flask-Pydantic 集成) 做准备

使用示例:
    from datasource.models import OHLCVResponse
    
    # 验证 API 响应
    response = requests.get(url).json()
    validated = OHLCVResponse.model_validate(response)
    
    # 访问字段（有类型提示）
    print(validated.code)
    print(validated.latest_premium)
"""

from pydantic import BaseModel, Field, field_validator
from typing import Optional, List, Dict, Any
from enum import Enum


# ============================================================
# 枚举类型
# ============================================================

class AssetTypeEnum(str, Enum):
    """资产类型枚举"""
    CHINA_INDEX = "china_index"
    CHINA_ETF = "china_etf"
    CHINA_STOCK = "china_stock"
    US_INDEX = "us_index"
    US_STOCK = "us_stock"
    HK_INDEX = "hk_index"
    HK_STOCK = "hk_stock"
    FUTURES = "futures"
    CRYPTO = "crypto"


class AdjTypeEnum(str, Enum):
    """复权类型枚举"""
    RAW = "raw"
    QFQ = "qfq"
    HFQ = "hfq"


class TimeframeEnum(str, Enum):
    """K线周期枚举（加密货币）"""
    D1 = "1d"
    H1 = "1h"
    H4 = "4h"
    M15 = "15m"
    M1 = "1m"


# ============================================================
# 请求模型（Phase 2 使用）
# ============================================================

class OHLCVRequest(BaseModel):
    """
    OHLCV 数据获取请求
    
    使用示例:
        request = OHLCVRequest(
            code="META",
            start="2024-01-01",
            end="2024-03-31",
            adj=AdjTypeEnum.RAW
        )
    """
    code: str = Field(
        ..., 
        min_length=1, 
        max_length=50,
        description="标的代码（如 META, 513100.SH, BTC）"
    )
    start: Optional[str] = Field(
        None,
        pattern=r'^\d{4}-\d{2}-\d{2}$',
        description="开始日期（YYYY-MM-DD），默认90天前"
    )
    end: Optional[str] = Field(
        None,
        pattern=r'^\d{4}-\d{2}-\d{2}$',
        description="结束日期（YYYY-MM-DD），默认今天"
    )
    asset_type: Optional[AssetTypeEnum] = Field(
        None,
        description="资产类型（可选，覆盖自动检测）"
    )
    adj: AdjTypeEnum = Field(
        AdjTypeEnum.RAW,
        description="复权类型（raw/qfq/hfq）"
    )
    timeframe: Optional[TimeframeEnum] = Field(
        TimeframeEnum.D1,
        description="K线周期（仅加密货币需要）"
    )
    nocache: bool = Field(
        False,
        description="是否跳过缓存"
    )

    @field_validator('start', 'end')
    @classmethod
    def validate_date_format(cls, v: Optional[str]) -> Optional[str]:
        """验证日期格式"""
        if v is None:
            return v
        
        # 验证日期合法性
        from datetime import datetime
        try:
            datetime.strptime(v, '%Y-%m-%d')
        except ValueError:
            raise ValueError(f'Invalid date format: {v}. Use YYYY-MM-DD')
        
        return v


class AssetTypeRequest(BaseModel):
    """资产类型检测请求"""
    code: str = Field(
        ...,
        min_length=1,
        max_length=50,
        description="标的代码"
    )


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

class DataRange(BaseModel):
    """日期范围"""
    start: Optional[str] = None
    end: Optional[str] = None


class RequestedRange(BaseModel):
    """用户请求的日期范围"""
    start: str
    end: str


class AvailableRange(BaseModel):
    """可用数据范围"""
    start: Optional[str] = None
    end: Optional[str] = None


class TypeOverride(BaseModel):
    """类型覆盖信息"""
    detected: str
    specified: str
    hint: str


class OHLCVRecord(BaseModel):
    """
    OHLCV 数据记录
    
    字段会根据资产类型动态变化：
    - 股票/指数/ETF: date, open, high, low, close, volume
    - 加密货币: date, open, high, low, close, volume
    - 其他可能包含: amount, change, pct_chg 等
    """
    date: str
    # 其他字段使用 Dict 接受，因为不同资产类型字段不同
    
    class Config:
        extra = "allow"  # 允许额外字段


class NavData(BaseModel):
    """ETF 净值数据"""
    data: List[Dict[str, Any]]
    count: int


class PremiumStats(BaseModel):
    """溢价率统计"""
    mean: float
    std: float
    min: float
    max: float
    median: float


class PremiumSeriesItem(BaseModel):
    """溢价率序列项"""
    date: str
    premium: float


class OHLCVResponse(BaseModel):
    """
    OHLCV 数据获取响应
    
    字段说明:
    - code: 标的代码
    - asset_type: 资产类型
    - adj: 复权类型
    - count: 数据条数
    - data: OHLCV 数据列表
    - cached: 是否命中缓存
    - nav: ETF 净值数据（仅 china_etf）
    - latest_premium: 最新溢价率（仅 china_etf）
    - premium_series: 溢价率序列（仅 china_etf）
    - premium_date: 最新溢价率日期（仅 china_etf）
    - premium_stats: 溢价率统计（仅 china_etf）
    - attrs: 完整元数据
    - info: 标的信息（股票/指数）
    - columns: 数据列名
    - date_range: 数据日期范围
    - requested_range: 用户请求范围
    - available_range: 可用数据范围
    - cache_strategy: 缓存策略说明
    - timeframe: K线周期（加密货币）
    - type_override: 类型覆盖信息
    
    使用示例:
        response = requests.get(url).json()
        validated = OHLCVResponse.model_validate(response)
        
        # 有类型提示
        print(validated.code)
        print(validated.latest_premium)
        print(validated.nav.count if validated.nav else 0)
    """
    code: str = Field(..., description="标的代码")
    asset_type: str = Field(..., description="资产类型")
    adj: str = Field(..., description="复权类型")
    count: int = Field(..., description="数据条数")
    data: List[Dict[str, Any]] = Field(..., description="OHLCV 数据列表")
    cached: Optional[bool] = Field(None, description="是否命中缓存")
    
    # ETF 相关（仅 china_etf）
    nav: Optional[NavData] = Field(None, description="ETF 净值数据")
    latest_premium: Optional[float] = Field(None, description="最新溢价率（%）")
    premium_series: Optional[List[PremiumSeriesItem]] = Field(None, description="溢价率序列")
    premium_date: Optional[str] = Field(None, description="最新溢价率日期")
    premium_stats: Optional[PremiumStats] = Field(None, description="溢价率统计")
    
    # 元数据
    attrs: Optional[Dict[str, Any]] = Field(None, description="完整元数据")
    info: Optional[Dict[str, Any]] = Field(None, description="标的信息")
    
    # 辅助信息
    columns: Optional[List[str]] = Field(None, description="数据列名")
    date_range: Optional[DataRange] = Field(None, description="数据日期范围")
    requested_range: Optional[RequestedRange] = Field(None, description="用户请求范围")
    available_range: Optional[AvailableRange] = Field(None, description="可用数据范围")
    cache_strategy: Optional[str] = Field(None, description="缓存策略说明")
    timeframe: Optional[str] = Field(None, description="K线周期（加密货币）")
    type_override: Optional[TypeOverride] = Field(None, description="类型覆盖信息")

    class Config:
        extra = "allow"  # 允许额外字段，保持向后兼容


class AssetTypeResponse(BaseModel):
    """资产类型检测响应"""
    code: str = Field(..., description="标的代码")
    asset_type: str = Field(..., description="资产类型")
    description: str = Field(..., description="资产类型描述")


class CacheStats(BaseModel):
    """缓存统计信息"""
    lru_cache: Dict[str, Any] = Field(..., description="LRU 缓存统计")
    ttl_cache_size: int = Field(..., description="TTL 缓存大小")
    ttl_seconds: int = Field(..., description="TTL 秒数")
    default_start_date: str = Field(..., description="默认数据起点")
    cache_strategy: str = Field(..., description="缓存策略")


class ErrorResponse(BaseModel):
    """错误响应"""
    error: str = Field(..., description="错误信息")
    code: Optional[str] = Field(None, description="标的代码")
    asset_type: Optional[str] = Field(None, description="资产类型")
    adj: Optional[str] = Field(None, description="复权类型")
    detected_type: Optional[str] = Field(None, description="自动检测的类型")
    example: Optional[str] = Field(None, description="示例请求")
    hint: Optional[str] = Field(None, description="提示信息")
    valid_adj: Optional[List[str]] = Field(None, description="有效的 adj 值")
    valid_types: Optional[List[str]] = Field(None, description="有效的资产类型")
    valid_timeframes: Optional[List[str]] = Field(None, description="有效的 timeframe 值")

    class Config:
        extra = "allow"  # 允许额外字段


# ============================================================
# 模型工具函数
# ============================================================

def validate_ohlcv_response(data: Dict[str, Any]) -> OHLCVResponse:
    """
    验证 OHLCV API 响应
    
    Args:
        data: API 返回的 JSON 数据
    
    Returns:
        验证后的响应对象
    
    Raises:
        ValidationError: 数据不符合模型定义
    
    使用示例:
        response = requests.get(url).json()
        validated = validate_ohlcv_response(response)
        
        # 安全访问字段
        if validated.nav:
            print(f"净值数据条数: {validated.nav.count}")
    """
    return OHLCVResponse.model_validate(data)


def dataframe_to_records(df, date_format: str = '%Y-%m-%d') -> List[Dict[str, Any]]:
    """
    将 DataFrame 转换为 OHLCVRecord 兼容的字典列表
    
    Args:
        df: pandas DataFrame
        date_format: 日期格式字符串
    
    Returns:
        字典列表（可直接用于 OHLCVResponse.data）
    """
    if df is None or len(df) == 0:
        return []
    
    df_reset = df.reset_index()
    
    # 处理日期列
    date_columns = ['date', 'Date', 'index', 'trade_date', 'datetime']
    for col in date_columns:
        if col in df_reset.columns:
            try:
                import pandas as pd
                df_reset[col] = pd.to_datetime(df_reset[col]).dt.strftime(date_format)
                if col != 'date':
                    df_reset = df_reset.rename(columns={col: 'date'})
                break
            except Exception:
                pass
    
    return df_reset.to_dict(orient='records')


# ============================================================
# DataFrame → Pydantic Model 转换函数
# ============================================================

def dataframe_to_ohlcv_response(
    df: Any,  # pd.DataFrame
    code: str,
    asset_type: str,
    adj: str = 'raw',
    cached: bool = False,
    nav_df: Optional[Any] = None,  # Optional[pd.DataFrame]
    premium_series: Optional[Any] = None,  # Optional[pd.Series]
    info: Optional[Dict[str, Any]] = None,
    attrs: Optional[Dict[str, Any]] = None,
    date_format: Optional[str] = None,
    **kwargs
) -> 'OHLCVResponse':
    """
    将 DataFrame 转换为 OHLCVResponse 模型
    
    用途:
    - Flask API: 统一响应结构
    - 本地调用: 获得类型安全的响应对象
    
    Args:
        df: 主数据 DataFrame（OHLCV）
        code: 标的代码
        asset_type: 资产类型
        adj: 复权类型
        cached: 是否命中缓存
        nav_df: ETF 净值 DataFrame（可选）
        premium_series: 溢价率 Series（可选）
        info: 标的信息（可选）
        attrs: 完整元数据（可选）
        date_format: 日期格式（可选，默认根据 asset_type 自动选择）
        **kwargs: 其他字段（columns, date_range, timeframe 等）
    
    Returns:
        OHLCVResponse 模型实例
    
    使用示例:
        # Flask API
        df = fetcher.fetch("META", start, end)
        response = dataframe_to_ohlcv_response(
            df, code="META", asset_type="us_stock", adj="raw"
        )
        return response.model_dump(mode='json')
        
        # 本地调用
        df = fetcher.fetch("513100.SH", start, end)
        nav_df = df.attrs.get('nav')
        premium = df.attrs.get('premium')
        
        response = dataframe_to_ohlcv_response(
            df,
            code="513100.SH",
            asset_type="china_etf",
            nav_df=nav_df,
            premium_series=premium
        )
        print(response.nav.count)  # IDE 有自动补全
    """
    import pandas as pd
    
    # 自动选择日期格式
    if date_format is None:
        date_format = '%Y-%m-%d %H:%M:%S' if asset_type == 'crypto' else '%Y-%m-%d'
    
    # 转换主数据
    data = dataframe_to_records(df, date_format) if df is not None else []
    
    # 构建响应数据
    response_data = {
        "code": code,
        "asset_type": asset_type,
        "adj": adj,
        "count": len(data),
        "data": data,
        "cached": cached,
    }
    
    # 添加 info（优先使用传入的，其次从 df.attrs 获取）
    if info is not None:
        response_data['info'] = info
    elif hasattr(df, 'attrs') and df.attrs and 'info' in df.attrs:
        response_data['info'] = df.attrs['info']
    
    # 添加 nav（如果有）
    if nav_df is not None and isinstance(nav_df, pd.DataFrame):
        nav_records = dataframe_to_records(nav_df, date_format)
        response_data['nav'] = {
            "data": nav_records,
            "count": len(nav_records)
        }
    
    # 添加 premium（如果有）
    if premium_series is not None and isinstance(premium_series, pd.Series) and len(premium_series) > 0:
        # 最新溢价率
        latest_premium = float(premium_series.iloc[-1])
        response_data['latest_premium'] = round(latest_premium, 6)
        response_data['premium_date'] = premium_series.index[-1].strftime(date_format)
        
        # 溢价率序列
        premium_list = [
            {"date": date.strftime(date_format), "premium": round(float(premium), 6)}
            for date, premium in premium_series.items()
        ]
        response_data['premium_series'] = premium_list
        
        # 溢价率统计
        response_data['premium_stats'] = {
            "mean": round(float(premium_series.mean()), 6),
            "std": round(float(premium_series.std()), 6),
            "min": round(float(premium_series.min()), 6),
            "max": round(float(premium_series.max()), 6),
            "median": round(float(premium_series.median()), 6),
        }
    
    # 添加 attrs（如果有）
    if attrs is not None:
        # 过滤内部缓存元数据
        public_attrs = {k: v for k, v in attrs.items() if not k.startswith('_cache_')}
        
        # 转换 DataFrame/Series 为可序列化格式
        attrs_serializable = {}
        for key, value in public_attrs.items():
            if isinstance(value, pd.DataFrame):
                attrs_serializable[key] = {
                    'data': dataframe_to_records(value, date_format),
                    'count': len(value)
                }
            elif isinstance(value, pd.Series):
                series_copy = value.copy()
                series_copy.index = series_copy.index.strftime(date_format)
                attrs_serializable[key] = {
                    'type': 'series',
                    'data': series_copy.to_dict(),
                    'name': value.name
                }
            else:
                attrs_serializable[key] = value
        
        if attrs_serializable:
            response_data['attrs'] = attrs_serializable
    elif hasattr(df, 'attrs') and df.attrs:
        # 从 df.attrs 提取
        public_attrs = {k: v for k, v in df.attrs.items() if not k.startswith('_cache_')}
        if public_attrs:
            attrs_serializable = {}
            for key, value in public_attrs.items():
                if isinstance(value, pd.DataFrame):
                    attrs_serializable[key] = {
                        'data': dataframe_to_records(value, date_format),
                        'count': len(value)
                    }
                elif isinstance(value, pd.Series):
                    series_copy = value.copy()
                    series_copy.index = series_copy.index.strftime(date_format)
                    attrs_serializable[key] = {
                        'type': 'series',
                        'data': series_copy.to_dict(),
                        'name': value.name
                    }
                else:
                    attrs_serializable[key] = value
            
            if attrs_serializable:
                response_data['attrs'] = attrs_serializable
    
    # 添加其他辅助信息
    response_data.update(kwargs)
    
    # 验证并返回模型
    return OHLCVResponse.model_validate(response_data)