"""
Translation via Google Translate, using the ``deep-translator`` library.

This is one of the translation backends selectable from the Controller. It
exposes ``translate(text, target_language)`` and ``translate_batch(...)``.

Target languages use ISO 639-1 codes (e.g. "sw" for Swahili, "fr" for French).

Requires:
    pip install deep-translator

Usage:
    from services.google_translate import GoogleTranslateDriver

    translator = GoogleTranslateDriver()
    translator.translate("Hello world", "sw")
"""

from typing import List
from logging import getLogger

logger = getLogger(__name__)


class GoogleTranslateDriver:
    """Translate text using Google Translate (via deep-translator)."""

    def __init__(self, source: str = "auto"):
        """
        Initialize the Google Translate driver.

        Args:
            source: Source language code, or "auto" to auto-detect.
        """
        self.source = source

    def translate(self, text: str, target_language: str) -> str:
        """
        Translate a single string.

        Args:
            text: Text to translate.
            target_language: ISO 639-1 target language code (e.g. "sw").

        Returns:
            The translated text. Returns the original text on failure.
        """
        from deep_translator import GoogleTranslator

        try:
            return GoogleTranslator(source=self.source, target=target_language).translate(text)
        except Exception:
            logger.exception("Google translation failed; returning original text")
            return text

    def translate_batch(self, texts: List[str], target_language: str) -> List[str]:
        """
        Translate a list of strings into the same target language.

        Args:
            texts: Strings to translate.
            target_language: ISO 639-1 target language code.

        Returns:
            List of translated strings (positionally aligned with ``texts``).
        """
        from deep_translator import GoogleTranslator

        translator = GoogleTranslator(source=self.source, target=target_language)
        results = []
        for text in texts:
            try:
                results.append(translator.translate(text))
            except Exception:
                logger.exception("Google translation failed for an item; keeping original")
                results.append(text)
        return results