v6 initial commit, maybe more to follow

wallet/CoinTransaction.js

@@ -0,0 +1,67 @@
+const ChainUtil = require('../chain-util');
+const { MINING_REWARD } = require('../config');
+
+class CoinTransaction {
+  constructor() {
+    this.id = ChainUtil.id();
+    this.input = null;
+    this.outputs = [];
+  }
+
+  update(senderWallet, recipient, amount) {
+    const senderOutput = this.outputs.find(output => output.address === senderWallet.publicKey);
+    if (amount > senderOutput.amount) {
+      console.log(`Amount: ${amount} exceeds balance.`);
+      return;
+    }
+   
+    senderOutput.amount = senderOutput.amount - amount;
+    this.outputs.push({ amount, address: recipient });
+    CoinTransaction.signCoinTransaction(this, senderWallet);
+
+    return this; 
+  }
+
+  static CoinTransactionWithOutputs(senderWallet, outputs) {
+    const cointransaction = new this();
+    cointransaction.outputs.push(...outputs);
+    CoinTransaction.signCoinTransaction(cointransaction, senderWallet);
+    return cointransaction;
+  }
+
+  static newCoinTransaction(senderWallet, recipient, amount) {
+    if (amount > senderWallet.balance) {
+      console.log(`Amount: ${amount} exceeds balance.`);
+      return;
+    }
+
+    return CoinTransaction.CoinTransactionWithOutputs(senderWallet, [
+      { amount: senderWallet.balance - amount, address: senderWallet.publicKey},
+      { amount, address: recipient }]);
+  }
+
+  static rewardCoinTransaction(minerWallet, blockchainWallet) {
+    return CoinTransaction.CoinTransactionWithOutputs(blockchainWallet, [{
+      amount: MINING_REWARD, address: minerWallet.publicKey
+    }]);
+  }
+
+  static signCoinTransaction(cointransaction, senderWallet) {
+    cointransaction.input = {
+      timestamp: Date.now(),
+      amount: senderWallet.balance,
+      address: senderWallet.publicKey,
+      signature: senderWallet.sign(ChainUtil.hash(cointransaction.outputs))
+    }
+  }
+
+  static verifyCoinTransaction(cointransaction) {
+    return ChainUtil.verifySignature(
+      cointransaction.input.address,
+      cointransaction.input.signature,
+      ChainUtil.hash(cointransaction.outputs)
+    );
+  }
+}
+
+module.exports = CoinTransaction;