AutonetSellCar/backend/app/services/translation_service.py

"""
Azure Translator Service for dealer descriptions
Supports Korean → English, Mongolian, Russian direct translation
"""
import os
import httpx
from typing import Optional, Dict
import json


class AzureTranslationService:
    """Microsoft Azure Translator API Service"""

    AZURE_ENDPOINT = "https://api.cognitive.microsofttranslator.com"
    API_VERSION = "3.0"

    def __init__(self):
        self.api_key = os.getenv("AZURE_TRANSLATOR_KEY", "")
        self.region = os.getenv("AZURE_TRANSLATOR_REGION", "koreacentral")
        self._is_configured = bool(self.api_key)

    @property
    def is_configured(self) -> bool:
        """Check if Azure Translator API is configured"""
        return self._is_configured

    async def translate(self, text: str, target_lang: str, source_lang: str = "ko") -> Optional[str]:
        """
        Translate text from source language to target language

        Args:
            text: Text to translate (Korean)
            target_lang: Target language code (en, mn, ru)
            source_lang: Source language code (default: ko)

        Returns:
            Translated text or None if failed
        """
        if not self._is_configured:
            print("[Translation] Azure Translator API not configured")
            return None

        if not text or not text.strip():
            return ""

        try:
            url = f"{self.AZURE_ENDPOINT}/translate"
            params = {
                "api-version": self.API_VERSION,
                "from": source_lang,
                "to": target_lang
            }
            headers = {
                "Ocp-Apim-Subscription-Key": self.api_key,
                "Ocp-Apim-Subscription-Region": self.region,
                "Content-Type": "application/json"
            }
            body = [{"text": text}]

            async with httpx.AsyncClient(timeout=30.0) as client:
                response = await client.post(
                    url,
                    params=params,
                    headers=headers,
                    json=body
                )

                if response.status_code == 200:
                    result = response.json()
                    if result and len(result) > 0 and "translations" in result[0]:
                        translated = result[0]["translations"][0]["text"]
                        print(f"[Translation] Success: {source_lang} -> {target_lang}")
                        return translated
                else:
                    error_msg = response.text
                    print(f"[Translation] API Error ({response.status_code}): {error_msg}")
                    return None

        except Exception as e:
            print(f"[Translation] Exception: {e}")
            return None

    async def translate_all_languages(self, text: str) -> Dict[str, Optional[str]]:
        """
        Translate text to all supported languages (en, mn, ru) in a single API call

        Args:
            text: Korean text to translate

        Returns:
            Dictionary with translations: {
                'en': '...',
                'mn': '...',
                'ru': '...'
            }
        """
        if not text or not text.strip():
            return {'en': '', 'mn': '', 'ru': ''}

        if not self._is_configured:
            print("[Translation] Azure Translator API not configured")
            return {'en': None, 'mn': None, 'ru': None}

        try:
            # Azure supports multiple target languages in a single call
            url = f"{self.AZURE_ENDPOINT}/translate"
            params = {
                "api-version": self.API_VERSION,
                "from": "ko",
                "to": ["en", "mn", "ru"]  # All three languages at once
            }
            headers = {
                "Ocp-Apim-Subscription-Key": self.api_key,
                "Ocp-Apim-Subscription-Region": self.region,
                "Content-Type": "application/json"
            }
            body = [{"text": text}]

            async with httpx.AsyncClient(timeout=30.0) as client:
                response = await client.post(
                    url,
                    params=params,
                    headers=headers,
                    json=body
                )

                if response.status_code == 200:
                    result = response.json()
                    if result and len(result) > 0 and "translations" in result[0]:
                        translations = result[0]["translations"]
                        result_dict = {'en': None, 'mn': None, 'ru': None}

                        for trans in translations:
                            lang = trans.get("to")
                            text_translated = trans.get("text")
                            if lang in result_dict:
                                result_dict[lang] = text_translated

                        print(f"[Translation] Success: ko -> en, mn, ru (batch)")
                        return result_dict
                else:
                    error_msg = response.text
                    print(f"[Translation] API Error ({response.status_code}): {error_msg}")
                    return {'en': None, 'mn': None, 'ru': None}

        except Exception as e:
            print(f"[Translation] Exception: {e}")
            return {'en': None, 'mn': None, 'ru': None}


# Singleton instance
_translation_service: Optional[AzureTranslationService] = None


def get_translation_service() -> AzureTranslationService:
    """Get or create the translation service singleton"""
    global _translation_service
    if _translation_service is None:
        _translation_service = AzureTranslationService()
    return _translation_service


async def translate_dealer_description(text: str) -> Dict[str, Optional[str]]:
    """
    Convenience function to translate dealer description to all languages

    Args:
        text: Korean dealer description

    Returns:
        Dictionary with translations for en, mn, ru
    """
    service = get_translation_service()
    return await service.translate_all_languages(text)