feat: Add add_transaction POST API

cryptocurrency/simple_cryptocurrency.py

@@ -107,6 +107,7 @@ def update_chain(self):
 app.config['JSONIFY_PRETTYPRINT_REGULAR'] = False
 blockchain = Blockchain()
 
+
 @app.route('/mine_block', methods = ['GET'])
 def mine_block():
     previous_block = blockchain.get_previous_block()
@@ -120,7 +121,6 @@ def mine_block():
     }
     return jsonify(responses), 200
 
-
 @app.route('/get_chain', methods = ['GET'])
 def get_chain():
     response = {
@@ -129,5 +129,20 @@ def get_chain():
     }
     return jsonify(response), 200
 
+@app.route('/add_transaction', methods = ['POST'])
+def add_transaction():
+    json = request.get_json()
+    transaction_keys = ['sender', 'receiver', 'amount']
+    if not all (key in json for key in transaction_keys):
+        return 'Some elements of the transaction are missing', 400
+    index = blockchain.add_transaction(
+        sender = json['sender'],
+        receiver = json['receiver'],
+        amount = json['amount']
+    )
+    response = {
+        'message': f'This transaction will be added to Block {index}'
+    }
+    return jsonify(response), 201
 
 app.run(host = '0.0.0.0', port = 5000)