package org.seasar.extension.jta.xa;

import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;

import org.seasar.framework.exception.SXAException;

public abstract class AbstractXAResource
	implements XAResource, XAResourceStatus {

	private Xid currentXid_;
	private int status_ = RS_NONE;
	private int timeout_ = 0;

	public AbstractXAResource() {
	}

	public void start(Xid xid, int flags) throws XAException {
		switch (flags) {
			case TMNOFLAGS :
				begin(xid);
				break;
			case TMRESUME :
				resume(xid);
				break;
			default :
				throw new SXAException(
					"ESSR0032",
					new Object[] { String.valueOf(flags)});
		}
	}

	private void begin(Xid xid) throws XAException {
		assertCurrentXidNull();
		doBegin(xid);
		currentXid_ = xid;
		status_ = RS_ACTIVE;
	}

	private void assertCurrentXidNull() throws XAException {
		if (currentXid_ != null) {
			throw new SXAException("ESSR0316", null);
		}
	}

	protected abstract void doBegin(Xid xid) throws XAException;

	private void resume(Xid xid) throws XAException {
		assertCurrentXidSame(xid);
		assertStatusSuspended();
		doResume(xid);
		status_ = RS_ACTIVE;
	}

	private void assertCurrentXidSame(final Xid xid) throws XAException {
		if (currentXid_ != xid) {
			throw new SXAException(
				"ESSR0319",
				new Object[] { xid, currentXid_ });
		}
	}

	private void assertStatusSuspended() throws XAException {
		if (status_ != RS_SUSPENDED) {
			throw new SXAException("ESSR0323", null);
		}
	}

	protected abstract void doResume(Xid xid) throws XAException;

	public void end(Xid xid, int flags) throws XAException {
		assertCurrentXidSame(xid);
		assertStatusActive();
		switch (flags) {
			case TMSUSPEND :
				suspend(xid);
				break;
			case TMFAIL :
				fail(xid);
				break;
			case TMSUCCESS :
				success(xid);
				break;
			default :
				throw new SXAException(
					"ESSR0032",
					new Object[] { String.valueOf(flags)});
		}
	}

	private void assertStatusActive() throws XAException {
		if (status_ != RS_ACTIVE) {
			throw new SXAException("ESSR0324", null);
		}
	}

	private void suspend(Xid xid) throws XAException {
		doSuspend(xid);
		status_ = RS_SUSPENDED;
	}

	protected abstract void doSuspend(Xid xid) throws XAException;

	private void fail(Xid xid) throws XAException {
		doFail(xid);
		status_ = RS_FAIL;
	}

	protected abstract void doFail(Xid xid) throws XAException;

	private void success(Xid xid) throws XAException {
		doSuccess(xid);
		status_ = RS_SUCCESS;
	}

	protected abstract void doSuccess(Xid xid) throws XAException;

	public int prepare(Xid xid) throws XAException {
		assertCurrentXidSame(xid);
		assertStatusSuccess();
		int ret = doPrepare(xid);
		if (ret == XA_OK) {
			status_ = RS_PREPARED;
		} else {
			status_ = RS_NONE;
		}
		return ret;
	}

	private void assertStatusSuccess() throws XAException {
		if (status_ != RS_SUCCESS) {
			throw new SXAException("ESSR0320", null);
		}
	}

	protected abstract int doPrepare(Xid xid) throws XAException;

	public void commit(Xid xid, boolean onePhase) throws XAException {
		assertCurrentXidSame(xid);
		if (onePhase) {
			assertStatusSuccess();
		} else {
			assertStatusPrepared();
		}
		doCommit(xid, onePhase);
		init();
	}

	private void assertStatusPrepared() throws XAException {
		if (status_ != RS_PREPARED) {
			throw new SXAException("ESSR0321", null);
		}
	}

	protected abstract void doCommit(Xid xid, boolean onePhase)
		throws XAException;

	private void init() {
		currentXid_ = null;
		status_ = RS_NONE;
	}

	public void forget(Xid xid) throws XAException {
		assertCurrentXidSame(xid);
		doForget(xid);
		init();
	}

	protected abstract void doForget(Xid xid) throws XAException;

	public Xid[] recover(final int flag) throws XAException {
		return null;
	}

	public void rollback(final Xid xid) throws XAException {
		assertCurrentXidSame(xid);
		assertStatusFailOrPrepared();
		doRollback(xid);
		init();
	}

	private void assertStatusFailOrPrepared() throws XAException {
		switch (status_) {
			case RS_FAIL :
			case RS_PREPARED :
				break;
			default :
				throw new SXAException("ESSR0322", null);
		}
	}

	protected abstract void doRollback(Xid xid) throws XAException;

	public boolean isSameRM(XAResource xar) throws XAException {
		return false;
	}

	public int getTransactionTimeout() throws XAException {
		return timeout_;
	}

	public boolean setTransactionTimeout(int timeout) throws XAException {
		timeout_ = timeout;
		return true;
	}

	public Xid getCurrentXid() {
		return currentXid_;
	}

	public int getStatus() {
		return status_;
	}
}