/*
    * Copyright (C) 2013 Christian Halstrick <christian.halstrick@sap.com>
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
    *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above
   *   copyright notice, this list of conditions and the following
   *   disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   *
   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
   *   products derived from this software without specific prior
   *   written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.eclipse.jgit.transport.http.apache;
  
  import static org.eclipse.jgit.util.HttpSupport.METHOD_GET;
  import static org.eclipse.jgit.util.HttpSupport.METHOD_HEAD;
  import static org.eclipse.jgit.util.HttpSupport.METHOD_POST;
  import static org.eclipse.jgit.util.HttpSupport.METHOD_PUT;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.InetSocketAddress;
  import java.net.MalformedURLException;
  import java.net.ProtocolException;
  import java.net.Proxy;
  import java.net.URL;
  import java.security.KeyManagementException;
  import java.security.NoSuchAlgorithmException;
  import java.security.SecureRandom;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  import javax.net.ssl.HostnameVerifier;
  import javax.net.ssl.KeyManager;
  import javax.net.ssl.SSLContext;
  import javax.net.ssl.TrustManager;
  
  import org.apache.http.Header;
  import org.apache.http.HeaderElement;
  import org.apache.http.HttpEntity;
  import org.apache.http.HttpEntityEnclosingRequest;
  import org.apache.http.HttpHost;
  import org.apache.http.HttpResponse;
  import org.apache.http.client.ClientProtocolException;
  import org.apache.http.client.HttpClient;
  import org.apache.http.client.config.RequestConfig;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpHead;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.client.methods.HttpPut;
  import org.apache.http.client.methods.HttpUriRequest;
  import org.apache.http.config.Registry;
  import org.apache.http.config.RegistryBuilder;
  import org.apache.http.conn.socket.ConnectionSocketFactory;
  import org.apache.http.conn.socket.PlainConnectionSocketFactory;
  import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
  import org.apache.http.impl.client.HttpClientBuilder;
  import org.apache.http.impl.client.HttpClients;
  import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
  import org.eclipse.jgit.annotations.NonNull;
  import org.eclipse.jgit.transport.http.HttpConnection;
  import org.eclipse.jgit.transport.http.apache.internal.HttpApacheText;
  import org.eclipse.jgit.util.TemporaryBuffer;
 import org.eclipse.jgit.util.TemporaryBuffer.LocalFile;
 
 /**
  * A {@link org.eclipse.jgit.transport.http.HttpConnection} which uses
  * {@link org.apache.http.client.HttpClient}
  *
  * @since 3.3
  */
 public class HttpClientConnection implements HttpConnection {
 	HttpClient client;
 
 	URL url;
 
 	HttpUriRequest req;
 
 	HttpResponse resp = null;
 
 	String method = "GET"; //$NON-NLS-1$
 
 	private TemporaryBufferEntity entity;
 
 	private boolean isUsingProxy = false;
 
 	private Proxy proxy;
 
 	private Integer timeout = null;
 
 	private Integer readTimeout;
 
 	private Boolean followRedirects;
 
 	private HostnameVerifier hostnameverifier;
 
 	SSLContext ctx;
 
 	private HttpClient getClient() {
 		if (client == null) {
 			HttpClientBuilder clientBuilder = HttpClients.custom();
 			RequestConfig.Builder configBuilder = RequestConfig.custom();
 			if (proxy != null && !Proxy.NO_PROXY.equals(proxy)) {
 				isUsingProxy = true;
 				InetSocketAddress adr = (InetSocketAddress) proxy.address();
 				clientBuilder.setProxy(
 						new HttpHost(adr.getHostName(), adr.getPort()));
 			}
 			if (timeout != null) {
 				configBuilder.setConnectTimeout(timeout.intValue());
 			}
 			if (readTimeout != null) {
 				configBuilder.setSocketTimeout(readTimeout.intValue());
 			}
 			if (followRedirects != null) {
 				configBuilder
 						.setRedirectsEnabled(followRedirects.booleanValue());
 			}
 			if (hostnameverifier != null) {
 				SSLConnectionSocketFactory sslConnectionFactory = new SSLConnectionSocketFactory(
 						getSSLContext(), hostnameverifier);
 				clientBuilder.setSSLSocketFactory(sslConnectionFactory);
 				Registry<ConnectionSocketFactory> registry = RegistryBuilder
 						.<ConnectionSocketFactory> create()
 						.register("https", sslConnectionFactory)
 						.register("http", PlainConnectionSocketFactory.INSTANCE)
 						.build();
 				clientBuilder.setConnectionManager(
 						new BasicHttpClientConnectionManager(registry));
 			}
 			clientBuilder.setDefaultRequestConfig(configBuilder.build());
 			client = clientBuilder.build();
 		}
 
 		return client;
 	}
 
 	private SSLContext getSSLContext() {
 		if (ctx == null) {
 			try {
 				ctx = SSLContext.getInstance("TLS"); //$NON-NLS-1$
 			} catch (NoSuchAlgorithmException e) {
 				throw new IllegalStateException(
 						HttpApacheText.get().unexpectedSSLContextException, e);
 			}
 		}
 		return ctx;
 	}
 
 	/**
 	 * Sets the buffer from which to take the request body
 	 *
 	 * @param buffer
 	 */
 	public void setBuffer(TemporaryBuffer buffer) {
 		this.entity = new TemporaryBufferEntity(buffer);
 	}
 
 	/**
 	 * Constructor for HttpClientConnection.
 	 *
 	 * @param urlStr
 	 * @throws MalformedURLException
 	 */
 	public HttpClientConnection(String urlStr) throws MalformedURLException {
 		this(urlStr, null);
 	}
 
 	/**
 	 * Constructor for HttpClientConnection.
 	 *
 	 * @param urlStr
 	 * @param proxy
 	 * @throws MalformedURLException
 	 */
 	public HttpClientConnection(String urlStr, Proxy proxy)
 			throws MalformedURLException {
 		this(urlStr, proxy, null);
 	}
 
 	/**
 	 * Constructor for HttpClientConnection.
 	 *
 	 * @param urlStr
 	 * @param proxy
 	 * @param cl
 	 * @throws MalformedURLException
 	 */
 	public HttpClientConnection(String urlStr, Proxy proxy, HttpClient cl)
 			throws MalformedURLException {
 		this.client = cl;
 		this.url = new URL(urlStr);
 		this.proxy = proxy;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public int getResponseCode() throws IOException {
 		execute();
 		return resp.getStatusLine().getStatusCode();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public URL getURL() {
 		return url;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String getResponseMessage() throws IOException {
 		execute();
 		return resp.getStatusLine().getReasonPhrase();
 	}
 
 	private void execute() throws IOException, ClientProtocolException {
 		if (resp != null) {
 			return;
 		}
 
 		if (entity == null) {
 			resp = getClient().execute(req);
 			return;
 		}
 
 		try {
 			if (req instanceof HttpEntityEnclosingRequest) {
 				HttpEntityEnclosingRequest eReq = (HttpEntityEnclosingRequest) req;
 				eReq.setEntity(entity);
 			}
 			resp = getClient().execute(req);
 		} finally {
 			entity.close();
 			entity = null;
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public Map<String, List<String>> getHeaderFields() {
 		Map<String, List<String>> ret = new HashMap<>();
 		for (Header hdr : resp.getAllHeaders()) {
 			List<String> list = ret.get(hdr.getName());
 			if (list == null) {
 				list = new LinkedList<>();
 				ret.put(hdr.getName(), list);
 			}
 			for (HeaderElement hdrElem : hdr.getElements()) {
 				list.add(hdrElem.toString());
 			}
 		}
 		return ret;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setRequestProperty(String name, String value) {
 		req.addHeader(name, value);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setRequestMethod(String method) throws ProtocolException {
 		this.method = method;
 		if (METHOD_GET.equalsIgnoreCase(method)) {
 			req = new HttpGet(url.toString());
 		} else if (METHOD_HEAD.equalsIgnoreCase(method)) {
 			req = new HttpHead(url.toString());
 		} else if (METHOD_PUT.equalsIgnoreCase(method)) {
 			req = new HttpPut(url.toString());
 		} else if (METHOD_POST.equalsIgnoreCase(method)) {
 			req = new HttpPost(url.toString());
 		} else {
 			this.method = null;
 			throw new UnsupportedOperationException();
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setUseCaches(boolean usecaches) {
 		// not needed
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setConnectTimeout(int timeout) {
 		this.timeout = Integer.valueOf(timeout);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setReadTimeout(int readTimeout) {
 		this.readTimeout = Integer.valueOf(readTimeout);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String getContentType() {
 		HttpEntity responseEntity = resp.getEntity();
 		if (responseEntity != null) {
 			Header contentType = responseEntity.getContentType();
 			if (contentType != null)
 				return contentType.getValue();
 		}
 		return null;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public InputStream getInputStream() throws IOException {
 		return resp.getEntity().getContent();
 	}
 
 	// will return only the first field
 	/** {@inheritDoc} */
 	@Override
 	public String getHeaderField(@NonNull String name) {
 		Header header = resp.getFirstHeader(name);
 		return (header == null) ? null : header.getValue();
 	}
 
 	@Override
 	public List<String> getHeaderFields(@NonNull String name) {
 		return Collections.unmodifiableList(Arrays.asList(resp.getHeaders(name))
 				.stream().map(Header::getValue).collect(Collectors.toList()));
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public int getContentLength() {
 		Header contentLength = resp.getFirstHeader("content-length"); //$NON-NLS-1$
 		if (contentLength == null) {
 			return -1;
 		}
 
 		try {
 			int l = Integer.parseInt(contentLength.getValue());
 			return l < 0 ? -1 : l;
 		} catch (NumberFormatException e) {
 			return -1;
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setInstanceFollowRedirects(boolean followRedirects) {
 		this.followRedirects = Boolean.valueOf(followRedirects);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setDoOutput(boolean dooutput) {
 		// TODO: check whether we can really ignore this.
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setFixedLengthStreamingMode(int contentLength) {
 		if (entity != null)
 			throw new IllegalArgumentException();
 		entity = new TemporaryBufferEntity(new LocalFile(null));
 		entity.setContentLength(contentLength);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public OutputStream getOutputStream() throws IOException {
 		if (entity == null)
 			entity = new TemporaryBufferEntity(new LocalFile(null));
 		return entity.getBuffer();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setChunkedStreamingMode(int chunklen) {
 		if (entity == null)
 			entity = new TemporaryBufferEntity(new LocalFile(null));
 		entity.setChunked(true);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public String getRequestMethod() {
 		return method;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public boolean usingProxy() {
 		return isUsingProxy;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void connect() throws IOException {
 		execute();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void setHostnameVerifier(HostnameVerifier hostnameverifier) {
 		this.hostnameverifier = hostnameverifier;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void configure(KeyManager[] km, TrustManager[] tm,
 			SecureRandom random) throws KeyManagementException {
 		getSSLContext().init(km, tm, random);
 	}
 }