# libs/manage_languages.py

from langdetect import detect
from fastapi import HTTPException
import logging

logger = logging.getLogger(__name__)

def validate_language(language: str) -> None:
    """Validate the language parameter. Throws an HTTPException if the language is invalid."""
    valid_languages = {"french", "italian", "english", "german", "auto"}
    if language not in valid_languages:
        raise HTTPException(
            status_code=400,
            detail="Invalid language. Must be one of: french, italian, english, german, or auto"
        )

def detect_language(current_message: str) -> str:
    """Detect the language of the current message. Defaults to French if detection fails."""
    try:
        detected_lang = detect(current_message)
        if detected_lang == "fr":
            language = "french"
        elif detected_lang == "it":
            language = "italian"
        elif detected_lang == "en":
            language = "english"
        elif detected_lang == "de":
            language = "german"
        else:
            language = "french"
        logger.info(f"Detected language: {language}")
        return language
    except Exception as e:
        logger.error(f"Language detection failed: {str(e)}")
        return "french"