/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.tuscany.sca.host.http.client;

import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.apache.http.ConnectionReuseStrategy;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLInitializationException;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.NoConnectionReuseStrategy;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.PoolingClientConnectionManager;
import org.apache.http.impl.conn.SchemeRegistryFactory;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.protocol.HttpContext;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.LifeCycleListener;
import org.apache.tuscany.sca.core.UtilityExtensionPoint;

/**
 * @version $Rev$ $Date$
 */
public class HttpClientFactory implements LifeCycleListener {
    private int soTimeout = 30000;
    private int connectionTimeout = 60000;
    private boolean staleCheckingEnabled = false;
    private long timeToLive = 60; // seconds
    private int maxPerRoute = 256;
    private int maxTotal = 1024;
    private boolean sslHostVerificationEnabled = false;

    private HttpClient httpClient;

    public static HttpClientFactory getInstance(ExtensionPointRegistry registry) {
        UtilityExtensionPoint utilities = registry.getExtensionPoint(UtilityExtensionPoint.class);
        return utilities.getUtility(HttpClientFactory.class);
    }

    public HttpClientFactory() {

    }

    public HttpClientFactory(ExtensionPointRegistry registry, Map<String, String> attributes) {
        if (attributes != null) {
            String val = attributes.get("soTimeout");
            if (val != null) {
                this.soTimeout = Integer.parseInt(val);
            }
            val = attributes.get("connectionTimeout");
            if (val != null) {
                this.connectionTimeout = Integer.parseInt(val);
            }
            val = attributes.get("staleCheckingEnabled");
            if (val != null) {
                this.staleCheckingEnabled = Boolean.parseBoolean(val);
            }
            val = attributes.get("timeToLive");
            if (val != null) {
                this.timeToLive = Long.parseLong(val);
            }
            val = attributes.get("sslHostVerificationEnabled");
            if (val != null) {
                this.sslHostVerificationEnabled = Boolean.parseBoolean(val);
            }
            val = attributes.get("maxTotal");
            if (val != null) {
                this.maxTotal = Integer.parseInt(val);
            }
            val = attributes.get("maxPerRoute");
            if (val != null) {
                this.maxPerRoute = Integer.parseInt(val);
            }
        }
    }

    public HttpClient createHttpClient() {
        HttpParams defaultParameters = new BasicHttpParams();

        HttpProtocolParams.setContentCharset(defaultParameters, "UTF-8");
        HttpConnectionParams.setConnectionTimeout(defaultParameters, connectionTimeout);
        HttpConnectionParams.setSoTimeout(defaultParameters, soTimeout);
        HttpConnectionParams.setStaleCheckingEnabled(defaultParameters, staleCheckingEnabled);

        // See https://issues.apache.org/jira/browse/HTTPCLIENT-1138
        SchemeRegistry supportedSchemes = null;
        try {
            supportedSchemes = SchemeRegistryFactory.createSystemDefault();
        } catch (SSLInitializationException e) {
            // Fall back to the default as some systems don't have all properties configured correctly, such as the keyStorePassword
            supportedSchemes = SchemeRegistryFactory.createDefault();
        }

        if (!sslHostVerificationEnabled) {
            // FIXME: By pass host name verification
            SSLSocketFactory socketFactory =
                (SSLSocketFactory)supportedSchemes.getScheme("https").getSchemeSocketFactory();
            socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
        }

        PoolingClientConnectionManager connectionManager =
            new PoolingClientConnectionManager(supportedSchemes, timeToLive, TimeUnit.SECONDS);

        connectionManager.setDefaultMaxPerRoute(maxPerRoute);
        connectionManager.setMaxTotal(maxTotal);

        DefaultHttpClient client = new DefaultHttpClient(connectionManager, defaultParameters);
        if (timeToLive <= 0) {
            client.setReuseStrategy(new NoConnectionReuseStrategy());
        }
        return client;
    }

    @Override
    public void start() {
        if (httpClient == null) {
            httpClient = createHttpClient();
        }
    }

    @Override
    public void stop() {
        if (httpClient != null) {
            httpClient.getConnectionManager().shutdown();
            httpClient = null;
        }
    }

    public HttpClient getHttpClient() {
        return httpClient;
    }
}