package blockchain;

import java.security.Security;
import java.util.ArrayList;

public class NoobChainV2 {
    public static ArrayList<Block> blockchain = new ArrayList<Block>();
    public static int difficulty = 5;

    public static Wallet walletA;
    public static Wallet walletB;

    /**
     * @return Boolean
     */
    public static Boolean isChainValid() {
        Block currentBlock;
        Block previousBlock;
        String hashTarget = new String(new char[difficulty]).replace('\0', '0');

        // loop through blockchain to check hashes:
        for (int i = 1; i < blockchain.size(); i++) {
            currentBlock = blockchain.get(i);
            previousBlock = blockchain.get(i - 1);
            // compare registered hash and calculated hash:
            if (!currentBlock.hash.equals(currentBlock.calculateHash())) {
                System.out.println("Current Hashes not equal");
                return false;
            }
            // compare previous hash and registered previous hash
            if (!previousBlock.hash.equals(currentBlock.previousHash)) {
                System.out.println("Previous Hashes not equal");
                return false;
            }
            // check if hash is solved
            if (!currentBlock.hash.substring(0, difficulty).equals(hashTarget)) {
                System.out.println("This block hasn't been mined");
                return false;
            }
        }
        return true;
    }

    /**
     * Noob blockchain.
     *
     * @param args no arguments
     */

    public static void main(String[] args) {
        // Setup Bouncey castle as a Security Provider
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        // Create the new wallets
        walletA = new Wallet();
        walletB = new Wallet();
        // Test public and private keys
        System.out.println("Private key: " + StringUtil.getStringFromKey(walletA.privateKey));
        System.out.println("Public key: " + StringUtil.getStringFromKey(walletA.publicKey));
        // Create a test transaction from WalletA to walletB
        Transaction transaction = new Transaction(walletA.publicKey, walletB.publicKey, 5, null);
        transaction.generateSignature(walletA.privateKey);
        // Verify the signature works and verify it from the public key
        System.out.println("Is signature verified: " + transaction.verifiySignature());
    }
}