package com.example.spring.bank.tx;

import java.math.BigDecimal;

import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallback;
import org.springframework.transaction.support.TransactionCallbackWithoutResult;
import org.springframework.transaction.support.TransactionTemplate;

import com.example.spring.bank.Account;
import com.example.spring.bank.AccountManager;

/**
 * This class decorates a given AccountManager by adding transaction boundaries.
 * 
 * @author kamal
 *
 */
public class TxAccountManager implements AccountManager {

	private AccountManager accountManager;

	public void setAccountManager(AccountManager accountManager) {
		this.accountManager = accountManager;
	}

	private TransactionTemplate txTemplate;

	public void setTxManager(DataSourceTransactionManager txManager) {
		txTemplate = new TransactionTemplate(txManager);
	}

	@Override
	public Account create() {
		return txTemplate.execute(new TransactionCallback<Account>() {
			@Override
			public Account doInTransaction(TransactionStatus arg0) {
				return accountManager.create();
			}
		});
	}
	
	@Override
	public Account find(int accountNumber) {
		return accountManager.find(accountNumber);
	}

	@Override
	public Account deposit(int accountNumber, BigDecimal amount) {
		return txTemplate.execute(new TransactionCallback<Account>() {

			@Override
			public Account doInTransaction(TransactionStatus arg0) {
				return accountManager.deposit(accountNumber, amount);
			}
		});
	}

	@Override
	public Account withdraw(int accountNumber, BigDecimal amount) {
		return txTemplate.execute(new TransactionCallback<Account>() {

			@Override
			public Account doInTransaction(TransactionStatus arg0) {
				return accountManager.withdraw(accountNumber, amount);
			}
		});
	}

	@Override
	public void delete(int accountNumber) {
		txTemplate.execute(new TransactionCallbackWithoutResult() {

			@Override
			protected void doInTransactionWithoutResult(TransactionStatus arg0) {
				accountManager.delete(accountNumber);
			}
		});
	}

	@Override
	public void chargeForLowBalance(BigDecimal minimumBalance, BigDecimal amount) {
		txTemplate.execute(new TransactionCallbackWithoutResult() {

			@Override
			protected void doInTransactionWithoutResult(TransactionStatus arg0) {
				accountManager.chargeForLowBalance(minimumBalance, amount);
			}
		});
	}

	@Override
	public Account transfer(int accountNumber1, int accountNumber2, BigDecimal amount) {
		return txTemplate.execute(new TransactionCallback<Account>() {

			@Override
			public Account doInTransaction(TransactionStatus status) {
				try {
					return accountManager.transfer(accountNumber1, accountNumber2, amount);
				} catch (Exception e) {
					// Some exception occurred.
					status.setRollbackOnly();
					throw e;
				}
			}
		});
	}
}