package examples.entity.intro;

import javax.ejb.Interceptors;
import javax.ejb.Remote;
import javax.ejb.Stateful;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.persistence.EntityListener;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceContextType;

/**
 * Stateful session bean facade for account entities, remotely accessible
 */

@Stateful
@Remote(AccountInterface.class)
public class AccountBean implements AccountInterface { 
    
    /** The entity manager, injected by the container */
    @PersistenceContext(type=PersistenceContextType.EXTENDED)    
    private EntityManager manager;
    
    private Account account;
    
    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)    
    public void open(int accountNumber) {
        account = manager.find(Account.class, accountNumber);
        if(account == null)
            account = new Account();
        
        account.ownerName = "anonymous";
        account.accountNumber = accountNumber;
        manager.persist(account);
    }    
    
    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)    
	public int getBalance() {
        if(account==null)
            throw new IllegalStateException();
        return account.balance;
    }
        
    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
    public void deposit(int amount) {
        if(account==null)
            throw new IllegalStateException();
        //manager = emf.createEntityManager(PersistenceContextType.EXTENDED);
        //account = manager.merge(account);
        account.balance += amount;
        //manager.flush();
    }

    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)    
    public int withdraw(int amount) {        
        if(account==null)
            throw new IllegalStateException();
        // manager.lock(account, LockMode.WRITE);
        if (amount > account.balance) {
            return 0;
        } else {
            account.balance -= amount;
            return amount;
        }
    }
   

    
}