/*
 * Copyright (c) 2015, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. 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.entgra.device.mgt.plugins.virtualfirealarm.agent.transport.http;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.eclipse.jetty.server.Server;
import io.entgra.device.mgt.plugins.virtualfirealarm.agent.transport.TransportHandler;
import io.entgra.device.mgt.plugins.virtualfirealarm.agent.transport.TransportUtils;

/**
 * This is an abstract class that implements the "TransportHandler" interface. The interface is an abstraction for
 * the core functionality with regards to device-server communication regardless of the Transport protocol. This
 * specific class contains the HTTP-Transport specific implementations. The class implements utility methods for the
 * case of a HTTP communication. However, this "abstract class", even-though it implements the "TransportHandler"
 * interface, does not contain the logic relevant to the interface methods. The specific functionality of the
 * interface methods are intended to be implemented by the concrete class that extends this abstract class and
 * utilizes the HTTP specific functionality (ideally a device API writer who would like to communicate to the device
 * via HTTP Protocol).
 */
public abstract class HTTPTransportHandler implements TransportHandler {
    private static final Log log = LogFactory.getLog(HTTPTransportHandler.class);

    protected Server server;
    protected int port;
    protected int timeoutInterval;

    protected HTTPTransportHandler() {
        this.port = TransportUtils.getAvailablePort(10);
        this.server = new Server(port);
        timeoutInterval = DEFAULT_TIMEOUT_INTERVAL;
    }

    protected HTTPTransportHandler(int port) {
        this.port = port;
        this.server = new Server(this.port);
        timeoutInterval = DEFAULT_TIMEOUT_INTERVAL;
    }

    protected HTTPTransportHandler(int port, int timeoutInterval) {
        this.port = port;
        this.server = new Server(this.port);
        this.timeoutInterval = timeoutInterval;
    }

    public void setTimeoutInterval(int timeoutInterval) {
        this.timeoutInterval = timeoutInterval;
    }

    /**
     * Checks whether the HTTP server is up and listening for incoming requests.
     *
     * @return true if the server is up & listening for requests, else false.
     */
    public boolean isConnected() {
        return server.isStarted();
    }


    protected void incrementPort() {
        this.port = this.port + 1;
        server = new Server(port);
    }

    /**
     * Shuts-down the HTTP Server.
     */
    public void closeConnection() throws Exception {
        if (server != null && isConnected()) {
            server.stop();
        }
    }


}
