fallback_llm.py

"""
Fallback LLM implementation without LlamaIndex dependency.
Direct API clients for maximum compatibility.
"""

import logging
from typing import List, Dict, Optional
import json

# Direct API imports (no LlamaIndex)
try:
    import groq
except ImportError:
    groq = None

try:
    import anthropic
except ImportError:
    anthropic = None

try:
    import google.generativeai as genai
except ImportError:
    genai = None

from .config import config

logger = logging.getLogger(__name__)


class DirectLLMProvider:
    """Direct LLM provider without LlamaIndex dependency"""
    
    def __init__(self):
        self.providers_available = {
            'groq': groq is not None and config.groq_api_key,
            'anthropic': anthropic is not None and config.anthropic_api_key,
            'gemini': genai is not None and config.google_api_key
        }
    
    async def chat(self, messages: List[Dict[str, str]], temperature: float = 0.1) -> str:
        """Chat completion with fallback chain: Groq -> Anthropic -> Gemini -> Mock"""
        
        # Try Groq first
        if self.providers_available['groq']:
            try:
                client = groq.Groq(api_key=config.groq_api_key)
                response = client.chat.completions.create(
                    model="llama-3.1-8b-instant",
                    messages=messages,
                    temperature=temperature,
                    max_tokens=1000
                )
                return response.choices[0].message.content
            except Exception as e:
                logger.warning(f"Groq failed: {e}")
        
        # Fallback to Anthropic
        if self.providers_available['anthropic']:
            try:
                client = anthropic.Anthropic(api_key=config.anthropic_api_key)
                
                # Separate system message
                system_msg = ""
                user_messages = []
                for msg in messages:
                    if msg["role"] == "system":
                        system_msg = msg["content"]
                    else:
                        user_messages.append(msg)
                
                response = client.messages.create(
                    model="claude-3-sonnet-20240229",
                    max_tokens=1000,
                    temperature=temperature,
                    system=system_msg,
                    messages=user_messages
                )
                return response.content[0].text
            except Exception as e:
                logger.warning(f"Anthropic failed: {e}")
        
        # Fallback to Gemini
        if self.providers_available['gemini']:
            try:
                genai.configure(api_key=config.google_api_key)
                model = genai.GenerativeModel('gemini-pro')
                
                # Convert messages to Gemini format
                prompt = ""
                for msg in messages:
                    if msg["role"] == "system":
                        prompt += f"System: {msg['content']}\n\n"
                    elif msg["role"] == "user":
                        prompt += f"User: {msg['content']}\n"
                    elif msg["role"] == "assistant":
                        prompt += f"Assistant: {msg['content']}\n"
                
                response = model.generate_content(prompt)
                return response.text
            except Exception as e:
                logger.warning(f"Gemini failed: {e}")
        
        # Final fallback to mock
        return self._mock_response(messages)
    
    def _mock_response(self, messages: List[Dict[str, str]]) -> str:
        """Mock response for development/fallback"""
        last_msg = messages[-1]["content"].lower() if messages else "hello"
        
        if any(word in last_msg for word in ["book", "schedule", "appointment"]):
            return "I'd be happy to help you book an appointment! Please provide your name, preferred date and time."
        elif any(word in last_msg for word in ["cancel", "delete"]):
            return "I can help you cancel an appointment. Which meeting would you like to cancel?"
        elif any(word in last_msg for word in ["available", "availability"]):
            return "Let me check Peter's availability. What dates are you considering?"
        else:
            return "Hello! I'm ChatCal, your voice-enabled scheduling assistant. How can I help you today?"


# Global instance
direct_llm = DirectLLMProvider()