"""
应用配置管理
使用Pydantic Settings管理环境变量和配置
"""
from typing import List, Optional
from functools import lru_cache

from pydantic import Field
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    """应用设置"""

    # 应用基础配置
    APP_NAME: str = "DeepRisk Backend"
    APP_VERSION: str = "0.1.0"
    DEBUG: bool = Field(default=False, env="DEBUG")
    ENVIRONMENT: str = Field(default="development", env="ENVIRONMENT")
    SECRET_KEY: str = Field(..., env="SECRET_KEY")
    API_V1_STR: str = Field(default="/api/v1", env="API_V1_STR")

    # 数据库配置
    DATABASE_URL: str = Field(..., env="DATABASE_URL")
    DB_ECHO: bool = Field(default=False, env="DB_ECHO")

    # Redis配置
    REDIS_URL: str = Field(default="redis://localhost:6379/0", env="REDIS_URL")
    REDIS_PASSWORD: Optional[str] = Field(default=None, env="REDIS_PASSWORD")
    REDIS_DB: int = Field(default=0, env="REDIS_DB")

    # JWT配置
    JWT_SECRET_KEY: str = Field(..., env="JWT_SECRET_KEY")
    JWT_ALGORITHM: str = Field(default="HS256", env="JWT_ALGORITHM")
    JWT_EXPIRE_MINUTES: int = Field(default=30, env="JWT_EXPIRE_MINUTES")
    JWT_REFRESH_EXPIRE_DAYS: int = Field(default=7, env="JWT_REFRESH_EXPIRE_DAYS")

    # 文件上传配置
    UPLOAD_DIR: str = Field(default="./static/uploads", env="UPLOAD_DIR")
    MAX_FILE_SIZE: int = Field(default=10 * 1024 * 1024, env="MAX_FILE_SIZE")  # 10MB
    ALLOWED_EXTENSIONS: str = Field(
        default="xlsx,xls,csv,pdf,doc,docx",
        env="ALLOWED_EXTENSIONS"
    )

    # Celery配置
    CELERY_BROKER_URL: str = Field(default="redis://localhost:6379/1", env="CELERY_BROKER_URL")
    CELERY_RESULT_BACKEND: str = Field(default="redis://localhost:6379/2", env="CELERY_RESULT_BACKEND")

    # 邮件配置
    MAIL_USERNAME: Optional[str] = Field(default=None, env="MAIL_USERNAME")
    MAIL_PASSWORD: Optional[str] = Field(default=None, env="MAIL_PASSWORD")
    MAIL_FROM: Optional[str] = Field(default=None, env="MAIL_FROM")
    MAIL_PORT: int = Field(default=587, env="MAIL_PORT")
    MAIL_SERVER: Optional[str] = Field(default=None, env="MAIL_SERVER")
    MAIL_FROM_NAME: Optional[str] = Field(default=None, env="MAIL_FROM_NAME")

    # 日志配置
    LOG_LEVEL: str = Field(default="INFO", env="LOG_LEVEL")
    LOG_FILE: str = Field(default="./logs/deeprisk.log", env="LOG_FILE")
    LOG_ROTATION: str = Field(default="100 MB", env="LOG_ROTATION")
    LOG_RETENTION: str = Field(default="30 days", env="LOG_RETENTION")

    # 风险检测配置
    RISK_CHECK_BATCH_SIZE: int = Field(default=1000, env="RISK_CHECK_BATCH_SIZE")
    RISK_DETECTION_THRESHOLD: float = Field(default=0.05, env="RISK_DETECTION_THRESHOLD")
    MAX_CONCURRENT_TASKS: int = Field(default=10, env="MAX_CONCURRENT_TASKS")

    # 报告生成配置
    REPORT_TEMPLATE_DIR: str = Field(default="./templates", env="REPORT_TEMPLATE_DIR")
    REPORT_OUTPUT_DIR: str = Field(default="./static/reports", env="REPORT_OUTPUT_DIR")
    PDF_ENGINE: str = Field(default="reportlab", env="PDF_ENGINE")

    @property
    def allowed_extensions_list(self) -> List[str]:
        """解析ALLOWED_EXTENSIONS为列表"""
        if isinstance(self.ALLOWED_EXTENSIONS, str):
            return [ext.strip() for ext in self.ALLOWED_EXTENSIONS.split(",") if ext.strip()]
        return self.ALLOWED_EXTENSIONS

    class Config:
        env_file = ".env"
        case_sensitive = True


@lru_cache()
def get_settings() -> Settings:
    """获取应用设置实例（单例模式）"""
    return Settings()


# 全局设置实例
settings = get_settings()