import java.util.Vector;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

public class UsingExecutors {

    public static void main(String[] args) {
      int[] initialBalance = {500, 800};                               // The initial account balances
      int[] totalCredits = new int[initialBalance.length];             // Two different cr totals
      int[] totalDebits = new int[initialBalance.length];              // Two different db totals
      int transactionCount = 20;                                       // Number of debits and of credits
      int clerkCount = 2;

      // Create the account, the bank, and the clerks...
      Bank theBank = new Bank();                                       // Create a bank
      Vector<Clerk> clerks = new Vector<Clerk>();                      // Stores the clerk
      Vector<Account> accounts = new Vector<Account>();                // Stores the accounts

      for(int i = 0 ; i < clerkCount ; ++i) {
        clerks.add(new Clerk(i+1, theBank));                           // Create the clerks
      }

      for(int i = 0 ; i < initialBalance.length; ++i) {
        accounts.add(new Account(i+1, initialBalance[i]));             // Create accounts
        totalCredits[i] = totalDebits[i] = 0;
      }

      ExecutorService threadPool = Executors.newCachedThreadPool();

      // Create and start the transaction source threads
      Future<int[]> credits = threadPool.submit(new TransactionSource(TransactionType.CREDIT, transactionCount, accounts, clerks));
      Future<int[]> debits = threadPool.submit(new TransactionSource(TransactionType.DEBIT, transactionCount, accounts, clerks));

      // Create and start the clerk threads
      for(Clerk clerk : clerks) {
        threadPool.submit(clerk);
      }
      try {
        totalCredits = credits.get();
        totalDebits = debits.get();
      } catch(ExecutionException e) {
        System.out.println(e.getCause());
      } catch(InterruptedException e) {
        System.out.println(e);
      }

    // Orderly shutdown when all threads have ended
    threadPool.shutdown();
    try {
      threadPool.awaitTermination(10L, TimeUnit.SECONDS);
    } catch(InterruptedException e) {
      System.out.println(e);
    }

    if(threadPool.isTerminated()) {
      System.out.println("\nAll clerks have completed their tasks.\n");
    } else {
      System.out.println("\nClerks still running - shutting down anyway.\n");
      threadPool.shutdownNow();
    }

    // Now output the results
    for(int i = 0 ; i < accounts.size() ; ++i) {
      System.out.println("Account Number:"+accounts.get(i).getAccountNumber()+"\n"+
         "Original balance    : $" + initialBalance[i] + "\n" +
         "Total credits       : $" + totalCredits[i] + "\n" +
         "Total debits        : $" + totalDebits[i] + "\n" +
         "Final balance       : $" + accounts.get(i).getBalance() + "\n" +
         "Should be           : $" + (initialBalance[i]
                                   + totalCredits[i]
                                   - totalDebits[i]) + "\n");
    }
  }
}