/**
 *  Copyright 2005-2015 Red Hat, Inc.
 *
 *  Red Hat licenses this file to you under the Apache License, version
 *  2.0 (the "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 *  implied.  See the License for the specific language governing
 *  permissions and limitations under the License.
 */
package io.fabric8.camel;

import org.apache.camel.impl.DefaultComponent;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.state.ConnectionState;
import org.apache.curator.framework.state.ConnectionStateListener;
import org.apache.curator.retry.RetryOneTime;
import io.fabric8.groups.Group;
import io.fabric8.groups.internal.ManagedGroupFactory;
import io.fabric8.groups.internal.ManagedGroupFactoryBuilder;

import java.util.concurrent.Callable;

/**
 */
public abstract class ZKComponentSupport extends DefaultComponent implements Callable<CuratorFramework>, ConnectionStateListener {
    private static final transient Log LOG = LogFactory.getLog(MasterComponent.class);
    private static final String ZOOKEEPER_URL = "zookeeper.url";
    private static final String ZOOKEEPER_PASSWORD = "zookeeper.password";
    private static final String ZOOKEEPER_URL_ENV = "ZOOKEEPER_URL";
    private static final String ZOOKEEPER_HOST_ENV = "ZK_CLIENT_SERVICE_HOST";
    private static final String ZOOKEEPER_PORT_ENV = "ZK_CLIENT_SERVICE_PORT";

    private ManagedGroupFactory managedGroupFactory;
    private CuratorFramework curator;
    private boolean shouldCloseZkClient = false;
    private int maximumConnectionTimeout = 10 * 1000;
    private String zooKeeperUrl;
    private String zooKeeperPassword;

    public CuratorFramework getCurator() {
        if (managedGroupFactory == null) {
            throw new IllegalStateException("Component is not started");
        }
        return managedGroupFactory.getCurator();
    }

    public Group<CamelNodeState> createGroup(String path) {
        if (managedGroupFactory == null) {
            throw new IllegalStateException("Component is not started");
        }
        return managedGroupFactory.createGroup(path, CamelNodeState.class);
    }


    public void setCurator(CuratorFramework curator) {
        this.curator = curator;
        registerAsListener();
    }

    public boolean isShouldCloseZkClient() {
        return shouldCloseZkClient;
    }

    public void setShouldCloseZkClient(boolean shouldCloseZkClient) {
        this.shouldCloseZkClient = shouldCloseZkClient;
    }

    public int getMaximumConnectionTimeout() {
        return maximumConnectionTimeout;
    }

    public void setMaximumConnectionTimeout(int maximumConnectionTimeout) {
        this.maximumConnectionTimeout = maximumConnectionTimeout;
    }


    public String getZooKeeperUrl() {
        return zooKeeperUrl;
    }

    public void setZooKeeperUrl(String zooKeeperUrl) {
        this.zooKeeperUrl = zooKeeperUrl;
    }

    public String getZooKeeperPassword() {
        return zooKeeperPassword;
    }

    public void setZooKeeperPassword(String zooKeeperPassword) {
        this.zooKeeperPassword = zooKeeperPassword;
    }

    @Override
    protected void doStart() throws Exception {
        super.doStart();
        if (curator == null) {
            try {
                CuratorFramework _curator = (CuratorFramework) getCamelContext().getRegistry().lookupByName("curator");
                setCurator(_curator);
                if (curator != null) {
                    LOG.debug("Zookeeper client found in camel registry. " + curator);
                }
            } catch (Exception exception) {
                LOG.warn(exception);
            }
        }
        managedGroupFactory = ManagedGroupFactoryBuilder.create(curator, getClass().getClassLoader(), this);
    }

    public CuratorFramework call() throws Exception {
        String connectString = getZooKeeperUrl();
        if (connectString == null) {
            connectString = System.getenv(ZOOKEEPER_URL_ENV);
        }
        if (connectString == null) {
            String zkHost = System.getenv(ZOOKEEPER_HOST_ENV);
            if (zkHost != null) {
                String zkPort = System.getenv(ZOOKEEPER_PORT_ENV);
                connectString = zkHost + ":" + (zkPort == null ? "2181" : zkPort);
            }
        }
        if (connectString == null) {
            connectString = System.getProperty(ZOOKEEPER_URL, "localhost:2181");
        }
        String password = getZooKeeperPassword();
        if (password == null) {
            System.getProperty(ZOOKEEPER_PASSWORD);
        }
        LOG.debug("CuratorFramework not found in camel registry, creating new with connection " + connectString);
        CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
                                                                         .connectString(connectString)
                                                                         .retryPolicy(new RetryOneTime(1000))
                                                                         .connectionTimeoutMs(getMaximumConnectionTimeout());

        if (password != null && !password.isEmpty()) {
            builder.authorization("digest", ("fabric:"+password).getBytes());
        }

        curator = builder.build();
        LOG.debug("Starting curator " + curator);
        curator.start();
        return curator;
    }

    @Override
    protected void doStop() throws Exception {
        super.doStop();
        if (managedGroupFactory != null) {
            managedGroupFactory.close();
            managedGroupFactory = null;
        }
    }

    @Override
    public void stateChanged(CuratorFramework client, ConnectionState newState) {
        LOG.info("Curator Connection new state: " + newState);
    }

    protected void registerAsListener(){
        if(curator != null){
            curator.getConnectionStateListenable().addListener(this);
        }
    }

}
