utils/gemini_explainer.py

import google.generativeai as genai
from typing import Dict, List, Optional
import config

class GeminiExplainer:
    """Alternative LLM explainer using Google Gemini"""
    
    def __init__(self):
        if config.GEMINI_API_KEY:
            genai.configure(api_key=config.GEMINI_API_KEY)
            self.model = genai.GenerativeModel(config.GEMINI_MODEL)
            self.enabled = True
        else:
            self.enabled = False
    
    def explain_recommendation(
        self,
        card: str,
        rewards: float,
        rewards_rate: str,
        merchant: str,
        category: str,
        amount: float,
        warnings: Optional[List[str]] = None,
        annual_potential: float = 0,
        alternatives: Optional[List[Dict]] = None
    ) -> str:
        """Generate explanation using Gemini"""
        
        if not self.enabled:
            return "Gemini explainer not configured"
        
        prompt = f"""You are a friendly financial advisor explaining credit card rewards to everyday consumers.

Transaction Details:
- Merchant: {merchant}
- Category: {category}
- Amount: ${amount:.2f}

Recommended Card: {card}
Rewards Earned: ${rewards:.2f} ({rewards_rate})
Annual Potential: ${annual_potential:.2f}/year

Task: Explain in 2-3 simple sentences why this card is the best choice. Use friendly, conversational language.
Focus on the tangible benefit (e.g., "That's like getting a free coffee every week!").

{"Warnings to mention: " + ", ".join(warnings) if warnings else ""}
"""
        
        try:
            response = self.model.generate_content(prompt)
            return response.text
        except Exception as e:
            return f"Gemini explanation unavailable: {str(e)}"
    
    def generate_spending_insights(
        self,
        user_id: str,
        total_spending: float,
        total_rewards: float,
        optimization_score: int,
        top_categories: List[Dict],
        recommendations_count: int
    ) -> str:
        """Generate personalized insights using Gemini"""
        
        if not self.enabled:
            return "Gemini insights not configured"
        
        prompt = f"""You are a financial coach reviewing a user's credit card rewards performance.

User Stats:
- Total Spending: ${total_spending:.2f}
- Total Rewards: ${total_rewards:.2f}
- Optimization Score: {optimization_score}/100
- Optimized Transactions: {recommendations_count}
- Top Categories: {', '.join([c.get('category', 'Unknown') for c in top_categories[:3]])}

Task: Provide 3 actionable insights in a friendly, motivating tone. Each insight should be 1 sentence.
Focus on what they're doing well and one improvement opportunity.
"""
        
        try:
            response = self.model.generate_content(prompt)
            return response.text
        except Exception as e:
            return f"Gemini insights unavailable: {str(e)}"

def get_gemini_explainer():
    """Factory function to get Gemini explainer"""
    return GeminiExplainer()