node.py

from flask import Flask, jsonify, request, send_from_directory
from flask_cors import CORS

from wallet import Wallet  
from blockchain import Blockchain

app = Flask(__name__)

CORS(app)


@app.route('/', methods=['GET'])
def get_ui():
    return  send_from_directory('ui', 'node.html')

@app.route('/network', methods=['GET'])
def get_nwui():
    return  send_from_directory('ui', 'network.html')


@app.route('/wallet', methods=['POST'])
def create_keys():
    wallet.create_keys()
    if wallet.save_keys():
        
        global blockchain
        blockchain = Blockchain(wallet.public_key,port)
        response = {
            'public_key': wallet.public_key,
            'private_key': wallet.private_key,
            'funds': blockchain.get_balance()
        }
        return jsonify(response), 201
    else:
        response ={
            'message':'Saving Failed!!'
        }
        return jsonify(response), 500



@app.route('/wallet', methods=['GET'])
def load_keys():
    if wallet.load_keys():
        
        global blockchain
        blockchain = Blockchain(wallet.public_key,port)
        response = {
            'public_key': wallet.public_key,
            'private_key': wallet.private_key,
            'funds':blockchain.get_balance()
        }
        return jsonify(response), 201
    else:
        response ={
            'message':'Saving Failed!!'
        }
        return jsonify(response), 500

    
@app.route('/balance',methods=['GET'])
def get_balance():
    balance = blockchain.get_balance()
    if balance != None:
        response ={
            'message': 'Fetching balance succesful',
            'funds':balance
        }
        return jsonify(response),200
    else:
        response = {
            'message': 'Fetching balance failed',
            'wallet_setup': wallet.public_key != None
        }
        return jsonify(response), 500


@app.route('/broadcast-transaction',methods=['POST'])
def broadcast_transaction():
    values=request.get_json()
    if not values:
        response ={
            'message':'no data found'
        }
        return jsonify(response),400
    required = ['sender','recipient','amount','signature']
    if not all(key in values for key in required):
        response ={
            'message':' data missing'
        }
        return jsonify(response),400
    success = blockchain.add_transaction(values['recipient'],values['sender'], values['signature'],values['amount'],is_receiving=True)
    if success:
        response = {
            'message':' Successfully added transaction',
            'transaction': {
                'sender': values['sender'],
                'recipient': values['recipient'],
                'amount': values['amount'],
                'signature': values['signature']
            }
        }
        return jsonify(response),201
    else:
        response ={
            'message':'creating transaction failed'
        }
        return jsonify(response),500



@app.route('/broadcast-block',methods=['POST'])
def broadcast_block():
    values=request.get_json()
    if not values:
        response ={
            'message':'no data found'
        }
        return jsonify(response),400
    if 'block' not in values:
        response ={
            'message':' data missing'
        }
        return jsonify(response),400
    block = values['block']
    if block['index'] == blockchain.chain[-1].index+1:
        if blockchain.add_block(block):
            response={'message':'block added'}
            return jsonify(response),201
        else:
            response ={'message':'block seems invalid'}
            return jsonify(response),409

    elif block['index'] > blockchain.chain[-1].index:
        response={
            'message':'blockchain seems to different from local blockchain'
        }
        blockchain.resolve_conflicts = True
        return jsonify(response), 200
    else:
        response={
            'message':'blockchain seems to be shorter,block not added'
        }
        return jsonify(response), 409






@app.route('/transaction', methods=['POST'])
def add_transaction():
    if wallet.public_key == None:
        response = {
            'message': 'No wallet setup'
        }
        return jsonify(response), 400
    values = request.get_json()
    if not values:
        response = {
            'message': 'No data sent'
        }
        return jsonify(response), 400
    required_fields = ['recipient','amount']
    if not all(field in values for field in required_fields):
        response = {
            'message': 'Required data missing'
        }
        return jsonify(response), 400
    recipient = values['recipient']
    amount = values['amount']
    signature = wallet.sign_transaction(wallet.public_key,recipient,amount)
    success = blockchain.add_transaction(recipient,wallet.public_key,signature,amount)
    if success:
        response ={
            'message':' Successful transaction',
            'transaction': {
                'sender': wallet.public_key,
                'recipient': recipient,
                'amount': amount,
                'signature': signature
            },
            'funds':blockchain.get_balance()
        }
        return jsonify(response), 201
    else:
        response = {
            'message': 'Creating transaction failed'
        }
        return jsonify(response), 500



@app.route('/mine', methods=['POST'])
def mine():
    if blockchain.resolve_conflicts== True:
        response ={'message':'Resolve conflicts first, block not added'}
        return jsonify(response),409
    block = blockchain.mine_block()
   
    if  block != None:
        dict_block = block.__dict__.copy()
        dict_block['transactions'] = [tx.__dict__ for tx in dict_block['transactions']]

        response = {
            'message': 'Adding a block successful',
            'wallet_set_up': dict_block,
            'funds': blockchain.get_balance()
        }
        return jsonify(response),201

    else:
        response = {
            'message': 'Adding a block failed',
            'wallet_set_up':wallet.public_key != None
        }
        return jsonify(response), 500

@app.route('/resolve-conflicts', methods =['POST'])
def resolve_conflicts():
    replaced = blockchain.resolve()
    if replaced:
        response= {'message': 'Chain was replaced!'}
    else:
        response= {'message': 'Chain not  replaced!'}
    return jsonify(response),200






@app.route('/transactions',methods=['GET'])
def get_open_transactions():
    transactions = blockchain.get_open_transactions()
    dict_transactions = [tx.__dict__ for tx in transactions]
    return jsonify(dict_transactions), 200



@app.route('/chain', methods=['GET'])
def get_chain():
    chain_snapshot = blockchain.chain
    dict_chain = [block.__dict__.copy() for block in chain_snapshot]
    for dict_block in dict_chain:
        dict_block['transactions']= [tx.__dict__ for tx in dict_block['transactions']]
    return jsonify(dict_chain), 200


@app.route('/node',methods=['POST'])
def add_node():
    values = request.get_json()
    if not values:
        response = {
            'message': 'No data sent.'
        }
        return jsonify(response),400

    if 'node' not in values:
        response={
            'message': 'No node data sent'
        }
        return jsonify(response),400
    node = values['node']
    blockchain.add_peer_node(node)
    response = {
        'message':'Node added successfully',
        'all_nodes': blockchain.get_peer_nodes()
    }
    return jsonify(response),200

@app.route('/node/<node_url>',methods=['DELETE'])
def remove_node(node_url):
    if node_url == '' or node_url == None:
        response={
            'message':'No node found'
        }
        return jsonify(response),400
    blockchain.remove_peer_node(node_url)
    response ={
        'message':'Node removed',
        'all_nodes': blockchain.get_peer_nodes()
    }
    return jsonify(response),200


@app.route('/nodes',methods=['GET'])
def get_nodes():
    nodes = blockchain.get_peer_nodes()
    response ={
        'all_nodes': nodes
    }
    return jsonify(response),200





if __name__ == '__main__':
    from argparse import ArgumentParser
    parser = ArgumentParser()
    parser.add_argument('-p','--port',type=int,default=8888)
    args = parser.parse_args()
    port = args.port
    wallet = Wallet(port)
    blockchain = Blockchain(wallet.public_key,port)
    app.run(host='0.0.0.0',port=port,debug=True)