"""
Configuration settings loaded from environment variables.
Never hardcode credentials or secrets.
"""

import os
from typing import Optional


class Settings:
    """
    Application settings with sensible defaults.
    Override via environment variables.
    """
    
    # Storage settings
    SUPABASE_URL: str = os.getenv("SUPABASE_URL", "")
    SUPABASE_KEY: str = os.getenv("SUPABASE_KEY", "")
    SUPABASE_TABLE: str = os.getenv("SUPABASE_TABLE", "proofs")
    
    # Hashing settings
    HASH_ALGORITHM: str = os.getenv("HASH_ALGORITHM", "sha256")
    
    # Validation settings
    MAX_FILE_SIZE_MB: int = int(os.getenv("MAX_FILE_SIZE_MB", "10"))
    ALLOWED_CONTENT_TYPES: list = [
        "text/plain",
        "application/pdf",
        "image/png",
        "image/jpeg",
        "application/json",
    ]
    
    # OCR settings
    OCR_ENABLED: bool = os.getenv("OCR_ENABLED", "true").lower() == "true"
    OCR_LANGUAGE: str = os.getenv("OCR_LANGUAGE", "eng")  # Tesseract language code
    
    # AI Sidecar settings (non-authoritative)
    AI_ENABLED: bool = os.getenv("AI_ENABLED", "false").lower() == "true"
    GEMINI_API_KEY: str = os.getenv("GEMINI_API_KEY", "")
    GEMINI_MODEL: str = os.getenv("GEMINI_MODEL", "gemini-1.5-flash")
    GEMINI_TIMEOUT: int = int(os.getenv("GEMINI_TIMEOUT", "10"))  # seconds
    
    @classmethod
    def validate(cls) -> bool:
        """
        Check if required settings are present.
        Returns True if valid, False otherwise.
        """
        if not cls.SUPABASE_URL or not cls.SUPABASE_KEY:
            return False
        return True
    
    @classmethod
    def validate_ai(cls) -> bool:
        """
        Check if AI sidecar is properly configured.
        Returns True if AI can be enabled, False otherwise.
        """
        if not cls.AI_ENABLED:
            return False
        if not cls.GEMINI_API_KEY:
            return False
        return True
    
    @classmethod
    def get_max_file_size_bytes(cls) -> int:
        """Get max file size in bytes."""
        return cls.MAX_FILE_SIZE_MB * 1024 * 1024


# Global settings instance
settings = Settings()