"""
Multi-language Prompt Loader

Loads system prompts for different agents in different languages.
"""
import yaml
from pathlib import Path
from typing import Optional
from utils.logger import get_logger

logger = get_logger(__name__)

# Base directory for prompt templates
PROMPTS_DIR = Path(__file__).parent

# Supported locales
SUPPORTED_LOCALES = ["en", "nl", "de", "es", "fr", "it", "tr"]

# Default locale
DEFAULT_LOCALE = "en"


class PromptLoader:
    """Load and cache prompt templates for different languages"""

    def __init__(self):
        self._cache = {}

    def get_prompt(self, agent_type: str, locale: str) -> str:
        """Get system prompt for agent type and locale

        Args:
            agent_type: Type of agent (customer_service, aftersale, order, product, router)
            locale: Language locale (en, nl, de, etc.)

        Returns:
            System prompt string
        """
        # Validate locale
        if locale not in SUPPORTED_LOCALES:
            logger.warning(
                "Unsupported locale, using default",
                requested_locale=locale,
                default_locale=DEFAULT_LOCALE
            )
            locale = DEFAULT_LOCALE

        # Check cache
        cache_key = f"{agent_type}:{locale}"
        if cache_key in self._cache:
            return self._cache[cache_key]

        # Load prompt file
        prompt_file = PROMPTS_DIR / agent_type / f"{locale}.yaml"

        if not prompt_file.exists():
            logger.warning(
                "Prompt file not found, using default",
                agent_type=agent_type,
                locale=locale,
                file=str(prompt_file)
            )
            # Fallback to English
            prompt_file = PROMPTS_DIR / agent_type / f"{DEFAULT_LOCALE}.yaml"

        if not prompt_file.exists():
            # Fallback to hardcoded English prompt
            logger.error("No prompt file found, using fallback", agent_type=agent_type)
            return self._get_fallback_prompt(agent_type)

        # Load and parse YAML
        try:
            with open(prompt_file, 'r', encoding='utf-8') as f:
                data = yaml.safe_load(f)

            prompt = data.get('system_prompt', '')
            self._cache[cache_key] = prompt
            return prompt

        except Exception as e:
            logger.error("Failed to load prompt file", file=str(prompt_file), error=str(e))
            return self._get_fallback_prompt(agent_type)

    def _get_fallback_prompt(self, agent_type: str) -> str:
        """Get fallback prompt if file loading fails"""
        fallbacks = {
            "customer_service": """You are a professional B2B customer service assistant. Help users with their questions.""",
            "aftersale": """You are a professional B2B aftersale service assistant. Help users with returns and exchanges.""",
            "order": """You are a professional B2B order assistant. Help users with order inquiries.""",
            "product": """You are a professional B2B product assistant. Help users find products.""",
            "router": """You are an AI assistant that routes user messages to appropriate agents."""
        }
        return fallbacks.get(agent_type, "You are a helpful AI assistant.")


# Global loader instance
_loader = PromptLoader()


def get_prompt(agent_type: str, locale: str) -> str:
    """Get system prompt for agent type and locale

    Args:
        agent_type: Type of agent (customer_service, aftersale, order, product, router)
        locale: Language locale (en, nl, de, etc.)

    Returns:
        System prompt string
    """
    return _loader.get_prompt(agent_type, locale)