reverting flask to previous version which should work with new database

backend/app.py

 from flask import Flask, jsonify, request
 from sqlalchemy.orm import sessionmaker
 from sqlalchemy import create_engine
-from backend.models import Node, Edge
+from models import Node, Edge
 from dotenv import load_dotenv
 import os
-from flask_cors import CORS
 
 # Load environment variables from .env file
 load_dotenv()
 
 app = Flask(__name__)
 
-# Enable CORS for all routes and origins
-CORS(app)
-
 # Get the database URL from the environment
 DATABASE_URL = os.getenv('DATABASE_URL')
 if not DATABASE_URL:
     raise ValueError("DATABASE_URL is not set in the environment variables")
 
-# Setup the engine and sessionmaker
 engine = create_engine(DATABASE_URL)
 Session = sessionmaker(bind=engine)
 
-@app.route('/graph', methods=['GET'])
-def get_graph():
+@app.route('/nodes', methods=['GET'])
+def get_nodes():
     try:
         year = request.args.get('year')
-        if year:
-            year = int(year)
-        
         with Session() as session:
-            # Fetch nodes
-            nodes = session.query(Node).filter(Node.year == year).all()
+            query = session.query(Node)
+            if year:
+                query = query.filter(Node.year == year)
+            nodes = query.all()
             node_list = [node.to_dict() for node in nodes]
-
-            # Fetch edges
-            edges = session.query(Edge).filter(Edge.year == year).all()
-            edge_list = []
-            for edge in edges:
-                source_node = session.query(Node).filter(Node.id == edge.source).one_or_none()
-                target_node = session.query(Node).filter(Node.id == edge.target).one_or_none()
-                if source_node and target_node:
-                    edge_list.append({
-                        "id": edge.id,
-                        "label": edge.label,
-                        "source": {
-                            "id": edge.source,
-                            "x": source_node.x,
-                            "y": source_node.y
-                        },
-                        "target": {
-                            "id": edge.target,
-                            "x": target_node.x,
-                            "y": target_node.y
-                        },
-                        "edge_type": edge.edge_type,
-                        "distance": edge.distance,
-                        "year": edge.year
-                    })
-        
-        return jsonify({"nodes": node_list, "edges": edge_list})
+            return jsonify(node_list)
     except Exception as e:
         return jsonify({'error': str(e)}), 500
 
-
+@app.route('/edges', methods=['GET'])
+def get_edges():
+    try:
+        year = request.args.get('year')
+        with Session() as session:
+            query = session.query(Edge)
+            if year:
+                query = query.filter(Edge.year == year)
+            edges = query.all()
+            edge_list = [edge.to_dict() for edge in edges]
+            return jsonify(edge_list)
+    except Exception as e:
+        return jsonify({'error': str(e)}), 500
 
 if __name__ == '__main__':
     app.run(debug=True)