"""
Application configuration with environment variable support.
"""

import os
from functools import lru_cache
from pydantic_settings import BaseSettings
from typing import Optional


class Settings(BaseSettings):
    """Application settings loaded from environment variables."""
    
    # Hugging Face configuration
    # Available fusion models:
    #   - DeepFakeDetector/fusion-logreg-final (Logistic Regression - default)
    #   - DeepFakeDetector/fusion-meta-final (Meta-classifier)
    HF_FUSION_REPO_ID: str = "DeepFakeDetector/fusion-logreg-final"
    HF_CACHE_DIR: str = ".hf_cache"
    HF_TOKEN: Optional[str] = None
    
    # Google Gemini API configuration
    GOOGLE_API_KEY: Optional[str] = None
    GEMINI_MODEL: str = "gemini-2.5-flash"
    
    @property
    def llm_enabled(self) -> bool:
        """Check if LLM explanations are available."""
        return self.GOOGLE_API_KEY is not None and len(self.GOOGLE_API_KEY) > 0
    
    # Application configuration
    ENABLE_DEBUG: bool = False
    LOG_LEVEL: str = "INFO"
    
    # Server configuration
    HOST: str = "0.0.0.0"
    PORT: int = 8000
    
    # CORS configuration
    CORS_ORIGINS: str = "http://localhost:5173,http://localhost:3000,https://www.deepfake-detector.app,https://deepfake-detector.app"
    
    @property
    def cors_origins_list(self) -> list[str]:
        """Parse CORS origins from comma-separated string."""
        return [origin.strip() for origin in self.CORS_ORIGINS.split(",") if origin.strip()]
    
    # API configuration
    API_V1_PREFIX: str = "/api/v1"
    PROJECT_NAME: str = "DeepFake Detector API"
    VERSION: str = "0.1.0"
    
    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"
        case_sensitive = True


@lru_cache()
def get_settings() -> Settings:
    """Get cached settings instance."""
    return Settings()


settings = get_settings()