api/services/portfolio_service.py

from api.models.portfolio import Portfolio
from api.extensions import db
import datetime

class PortfolioService:
    @staticmethod
    def get_recommendation(user_id, risk_level):
        # Generate allocation based on risk level
        allocation = {}
        expected_return = 0.0
        risk_metrics = {}
        
        if risk_level == 'conservative':
            allocation = [
                {'name': '货币基金', 'value': 40, 'color': '#91CC75'},
                {'name': '债券基金', 'value': 40, 'color': '#FAC858'},
                {'name': '股票基金', 'value': 20, 'color': '#EE6666'}
            ]
            expected_return = 4.5
            risk_metrics = {'volatility': 'Low', 'max_drawdown': '5%'}
            
        elif risk_level == 'aggressive':
            allocation = [
                {'name': '货币基金', 'value': 10, 'color': '#91CC75'},
                {'name': '债券基金', 'value': 20, 'color': '#FAC858'},
                {'name': '股票基金', 'value': 70, 'color': '#EE6666'}
            ]
            expected_return = 12.0
            risk_metrics = {'volatility': 'High', 'max_drawdown': '20%'}
            
        else: # balanced or default
            allocation = [
                {'name': '货币基金', 'value': 20, 'color': '#91CC75'},
                {'name': '债券基金', 'value': 40, 'color': '#FAC858'},
                {'name': '股票基金', 'value': 40, 'color': '#EE6666'}
            ]
            expected_return = 8.0
            risk_metrics = {'volatility': 'Medium', 'max_drawdown': '12%'}
            
        # Create or update portfolio record
        portfolio = Portfolio(
            user_id=user_id,
            allocation=allocation,
            expected_return=expected_return,
            risk_metrics=risk_metrics
        )
        
        # In a real app, we might check if one exists and update it, or keep history
        # For simplicity, we just return the object without saving to DB every time if it's just a view
        # But let's save it to simulate persistence
        
        try:
            db.session.add(portfolio)
            db.session.commit()
        except Exception as e:
            print(f"Portfolio DB Save Error: {e}")
            db.session.rollback()
            # Continue even if save fails
            
        return {
            'status': True,
            'portfolio': portfolio.to_dict()
        }

    @staticmethod
    def get_latest_portfolio(user_id):
        portfolio = Portfolio.query.filter_by(user_id=user_id).order_by(Portfolio.generated_at.desc()).first()
        if portfolio:
            return {'status': True, 'portfolio': portfolio.to_dict()}
        return {'status': False, 'message': 'No portfolio found'}