import os
import secrets
from pathlib import Path
from typing import List, Union, Optional

from pydantic import EmailStr, validator
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    # Project settings
    PROJECT_NAME: str = "Deft Trade"
    PROJECT_DESCRIPTION: str = "DeFi Trading Simulation Platform"
    VERSION: str = "0.1.0"
    API_V1_STR: str = "/api/v1"
    
    # Security settings
    SECRET_KEY: str = os.environ.get("SECRET_KEY") or secrets.token_urlsafe(32)
    JWT_SECRET_KEY: str = os.environ.get("JWT_SECRET_KEY") or secrets.token_urlsafe(32)
    ACCESS_TOKEN_EXPIRE_MINUTES: int = int(os.environ.get("ACCESS_TOKEN_EXPIRE_MINUTES", 30))
    REFRESH_TOKEN_EXPIRE_DAYS: int = int(os.environ.get("REFRESH_TOKEN_EXPIRE_DAYS", 7))
    ALGORITHM: str = "HS256"
    
    # CORS settings
    BACKEND_CORS_ORIGINS: List[str] = ["*"]
    
    @validator("BACKEND_CORS_ORIGINS", pre=True)
    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], str]:
        if isinstance(v, str) and not v.startswith("["):
            return [i.strip() for i in v.split(",")]
        elif isinstance(v, (list, str)):
            return v
        raise ValueError(v)
    
    # Database
    DB_DIR: Path = Path("/app") / "storage" / "db"
    
    # Email settings
    EMAILS_ENABLED: bool = os.environ.get("EMAILS_ENABLED", "False").lower() == "true"
    SMTP_TLS: bool = os.environ.get("SMTP_TLS", "True").lower() == "true"
    SMTP_PORT: Optional[int] = int(os.environ.get("SMTP_PORT", 587)) if os.environ.get("SMTP_PORT") else None
    SMTP_HOST: Optional[str] = os.environ.get("SMTP_HOST")
    SMTP_USER: Optional[str] = os.environ.get("SMTP_USER")
    SMTP_PASSWORD: Optional[str] = os.environ.get("SMTP_PASSWORD")
    EMAILS_FROM_EMAIL: Optional[EmailStr] = os.environ.get("EMAILS_FROM_EMAIL")
    EMAILS_FROM_NAME: Optional[str] = os.environ.get("EMAILS_FROM_NAME")
    
    # File upload
    UPLOAD_DIR: Path = Path("/app") / "storage" / "uploads"
    KYC_UPLOAD_DIR: Path = Path("/app") / "storage" / "kyc"
    DEPOSIT_PROOFS_DIR: Path = Path("/app") / "storage" / "deposit_proofs"
    MAX_UPLOAD_SIZE: int = int(os.environ.get("MAX_UPLOAD_SIZE", 5 * 1024 * 1024))  # 5 MB default
    
    # Admin default settings
    ADMIN_EMAIL: EmailStr = os.environ.get("ADMIN_EMAIL", "admin@defttrade.com")
    ADMIN_PASSWORD: str = os.environ.get("ADMIN_PASSWORD", "change-me-please")
    
    # 2FA settings
    TWO_FACTOR_REQUIRED: bool = os.environ.get("TWO_FACTOR_REQUIRED", "False").lower() == "true"
    
    # Bot simulation settings
    BOT_SIMULATION_INTERVAL: int = int(os.environ.get("BOT_SIMULATION_INTERVAL", 60))  # Seconds
    
    # Transaction settings
    MIN_DEPOSIT_AMOUNT: float = float(os.environ.get("MIN_DEPOSIT_AMOUNT", 10.0))
    MIN_WITHDRAWAL_AMOUNT: float = float(os.environ.get("MIN_WITHDRAWAL_AMOUNT", 10.0))
    WITHDRAWAL_FEE_PERCENTAGE: float = float(os.environ.get("WITHDRAWAL_FEE_PERCENTAGE", 1.0))
    
    class Config:
        case_sensitive = True
        env_file = ".env"


settings = Settings()