graph_store.py

from flask import Flask, jsonify
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///graph.db'
db = SQLAlchemy(app)

class Node(db.Model):
    __tablename__ = 'node'
    id = db.Column(db.Integer, primary_key=True)
    x = db.Column(db.Integer)
    y = db.Column(db.Integer)
    name = db.Column(db.String(20))
    graph_id = db.Column(db.Integer, db.ForeignKey('graph.id'))


class Edge(db.Model):
    __tablename__ = 'edge'
    id = db.Column(db.Integer, primary_key=True)
    first_node = db.Column(db.Integer)
    second_node = db.Column(db.Integer)
    weight = db.Column(db.Integer)
    graph_id = db.Column(db.Integer, db.ForeignKey('graph.id'))


class Graph(db.Model):
    __tablename__ = 'graph'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50))
    description = db.Column(db.Text)

    nodes = db.relationship('Node', backref='graph', lazy=True)
    edges = db.relationship('Edge', backref='graph', lazy=True)


def add_graph(nodes, edges, graph_name, graph_description):
    session = db.session
    new_graph = Graph(name=graph_name, description=graph_description)
    session.add(new_graph)
    session.commit()
    graph_id = new_graph.id

    try:
        for node in nodes:
            new_node = Node(x=node['x'], y=node['y'], name=node['name'], graph_id=graph_id)
            session.add(new_node)
        session.commit()

        for edge in edges:
            new_edge = Edge(first_node=edge['first_node'], second_node=edge['second_node'], weight=edge['weight'], graph_id=graph_id)
            session.add(new_edge)
        session.commit()

        return jsonify('success')
    except Exception as e:
        session.rollback()
        return jsonify({'error': e}), 500
    finally:
        session.close()


def load_graphs():
    try:
        graphs = Graph.query.all()
        graph_list = []
        for graph in graphs:
            graph_list.append({
                'id': graph.id,
                'name': graph.name
                })
        return jsonify(graph_list)
    except Exception as e:
        return jsonify({'error': str(e)}), 500


def load_graph(graph_id):
    try:
        graph = Graph.query.get(graph_id)
        if graph is None:
            return jsonify({'error': 'Graph not found'}), 404
        graph_data = {
            'id': graph.id,
            'name': graph.name,
            'nodes': [],
            'edges': []
        }

        for node in graph.nodes:
            graph_data['nodes'].append({
                'name': node.name,
                'x': node.x,
                'y': node.y
            })

        for edge in graph.edges:
            graph_data['edges'].append({
                'first_node': edge.first_node,
                'second_node': edge.second_node,
                'weight': edge.weight
            })

        return jsonify(graph_data)

    except Exception as e:
        return jsonify({'error': str(e)}), 500