Create chain.py

blockchain/chain.py

@@ -0,0 +1,61 @@
+from block import Block
+from transaction import Transaction
+from wallet import Wallet
+
+class Chain:
+    def __init__(self):
+        self.chain = [self.create_genesis_block()]
+        self.pending_transactions = []
+        self.mining_reward = 10
+        self.difficulty = 2
+
+    def create_genesis_block(self):
+        return Block(0, '0', [])
+
+    def get_latest_block(self):
+        return self.chain[-1]
+
+    def add_transaction(self, transaction):
+        self.pending_transactions.append(transaction)
+
+    def mine_pending_transactions(self, miner_wallet):
+        if len(self.pending_transactions) < 1:
+            return False
+
+        new_block = Block(len(self.chain), self.get_latest_block().hash, self.pending_transactions)
+        new_block.mine_block(self.difficulty)
+
+        self.chain.append(new_block)
+
+        self.pending_transactions = [Transaction(None, miner_wallet.public_key, self.mining_reward)]
+
+        return True
+
+    def get_balance_of_address(self, address):
+        balance = 0
+        for block in self.chain:
+            for transaction in block.transactions:
+                if transaction.sender == address:
+                    balance -= transaction.amount
+                elif transaction.recipient == address:
+                    balance += transaction.amount
+        return balance
+
+    def is_chain_valid(self):
+        for i in range(1, len(self.chain)):
+            current_block = self.chain[i]
+            previous_block = self.chain[i - 1]
+
+            if current_block.hash != current_block.calculate_hash():
+                return False
+
+            if current_block.previous_hash != previous_block.hash:
+                return False
+
+        return True
+
+    def __str__(self):
+        return '\n'.join([str(block) for block in self.chain])
+
+    def __repr__(self):
+        return self.__str__()