/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2015, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.as.cli.embedded;

import org.jboss.logmanager.LogContext;
import org.jboss.logmanager.LogContextSelector;
import org.jboss.stdio.StdioContext;
import org.jboss.stdio.StdioContextSelector;

/**
 * {@link org.jboss.stdio.StdioContextSelector} and {@link org.jboss.logmanager.LogContextSelector}
 * that uses an {@link java.lang.InheritableThreadLocal} as a source of the contexts.
 *
 * @author Brian Stansberry (c) 2015 Red Hat Inc.
 */
class ThreadLocalContextSelector implements LogContextSelector, StdioContextSelector {

    private final InheritableThreadLocal<Contexts> threadLocal = new InheritableThreadLocal<>();

    private final Contexts localContexts;
    private final Contexts defaultContexts;

    ThreadLocalContextSelector(Contexts local, Contexts defaults) {
        assert local != null;
        assert local.getLogContext() != null; // local.stdioContext can be null
        assert defaults != null;
        assert defaults.getStdioContext() != null;
        assert defaults.getLogContext() != null;
        this.localContexts = local;
        this.defaultContexts = defaults;
    }

    Contexts pushLocal() {
        Contexts result = threadLocal.get();
        threadLocal.set(localContexts);
        return result;
    }

    void restore(Contexts toRestore) {
        threadLocal.set(toRestore);
    }

    @Override
    public StdioContext getStdioContext() {
        Contexts threadContext = threadLocal.get();
        StdioContext local = threadContext != null ? threadContext.getStdioContext() : null;
        return local == null ? defaultContexts.getStdioContext() : local;
    }

    @Override
    public LogContext getLogContext() {
        Contexts threadContext = threadLocal.get();
        LogContext local = threadContext != null ? threadContext.getLogContext() : null;
        return local == null ? defaultContexts.getLogContext() : local;
    }

}