/*-
 * ============LICENSE_START=======================================================
 * sdc-distribution-client
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed 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.
 * ============LICENSE_END=========================================================
 */

package org.openecomp.sdc.http;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.ConnectException;
import java.net.UnknownHostException;
import java.security.KeyStore;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

import org.apache.commons.codec.binary.Base64;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicHeader;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.ssl.TrustStrategy;
import org.openecomp.sdc.api.consumer.IConfiguration;
import org.openecomp.sdc.utils.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HttpAsdcClient implements IHttpAsdcClient {

	private static final String TLS = "TLSv1.2";
	private static final String AUTHORIZATION_HEADER = "Authorization";
	private static final String HTTPS = "https://";
	private static Logger log = LoggerFactory.getLogger(HttpAsdcClient.class.getName());
	private CloseableHttpClient httpClient = null;
	private String serverFqdn = null;
	private String authHeaderValue = "";

	public HttpAsdcClient(IConfiguration configuraion) {
		this.serverFqdn = configuraion.getAsdcAddress();

		String username = configuraion.getUser();
		String password = configuraion.getPassword();
		initSSL(username, password, configuraion.getKeyStorePath(), configuraion.getKeyStorePassword(), configuraion.activateServerTLSAuth());

		String userNameAndPassword = username + ":" + password;
		this.authHeaderValue = "Basic " + Base64.encodeBase64String(userNameAndPassword.getBytes());
	}

	// @SuppressWarnings("deprecation")
	private void initSSL(String username, String password, String keyStorePath, String keyStoePass, boolean isSupportSSLVerification) {

		try {
			HostnameVerifier hostnameVerifier = new HostnameVerifier() {

				@Override
				public boolean verify(String hostname, SSLSession session) {
					return true;
				}
			};

			// SSLContextBuilder is not thread safe
			// @SuppressWarnings("deprecation")
			CredentialsProvider credsProvider = new BasicCredentialsProvider();
			credsProvider.setCredentials(new AuthScope("localhost", 443), new UsernamePasswordCredentials(username, password));
			SSLContext sslContext;
			sslContext = SSLContext.getInstance(TLS);
			TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
			KeyStore trustStore = null;
			tmf.init(trustStore);
			TrustManager[] tms = tmf.getTrustManagers();
			if (isSupportSSLVerification) {

				if (keyStorePath != null && !keyStorePath.isEmpty()) {
					// trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
					// trustStore.load(new FileInputStream(keyStorePath), keyStoePass.toCharArray());

					// Using null here initialises the TMF with the default trust store.

					// Get hold of the default trust manager
					X509TrustManager defaultTm = null;
					for (TrustManager tm : tmf.getTrustManagers()) {
						if (tm instanceof X509TrustManager) {
							defaultTm = (X509TrustManager) tm;
							break;
						}
					}

					// Do the same with your trust store this time
					// Adapt how you load the keystore to your needs
					trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
					trustStore.load(new FileInputStream(keyStorePath), keyStoePass.toCharArray());

					tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
					tmf.init(trustStore);

					// Get hold of the default trust manager
					X509TrustManager myTm = null;
					for (TrustManager tm : tmf.getTrustManagers()) {
						if (tm instanceof X509TrustManager) {
							myTm = (X509TrustManager) tm;
							break;
						}
					}

					// Wrap it in your own class.
					final X509TrustManager finalDefaultTm = defaultTm;
					final X509TrustManager finalMyTm = myTm;
					X509TrustManager customTm = new X509TrustManager() {
						@Override
						public X509Certificate[] getAcceptedIssuers() {
							// If you're planning to use client-cert auth,
							// merge results from "defaultTm" and "myTm".
							return finalDefaultTm.getAcceptedIssuers();
						}

						@Override
						public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
							try {
								finalMyTm.checkServerTrusted(chain, authType);
							} catch (CertificateException e) {
								// This will throw another CertificateException if this fails too.
								finalDefaultTm.checkServerTrusted(chain, authType);
							}
						}

						@Override
						public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
							// If you're planning to use client-cert auth,
							// do the same as checking the server.
							finalDefaultTm.checkClientTrusted(chain, authType);
						}
					};

					tms = new TrustManager[] { customTm };

				}

				sslContext.init(null, tms, null);
				SSLContext.setDefault(sslContext);

				

			} else {

				SSLContextBuilder builder = new SSLContextBuilder();

				builder.loadTrustMaterial(null, new TrustStrategy() {
					public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
						return true;
					}
				});

				sslContext = builder.build();
			}
			
			SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, new String[] { "TLSv1.2" }, null, hostnameVerifier);
			httpClient = HttpClientBuilder.create().setDefaultCredentialsProvider(credsProvider).setSSLSocketFactory(sslsf).build();

		} catch (Exception e) {
			log.error("Failed to create https client", e);

		}

		return;
	}

	public HttpAsdcResponse postRequest(String requestUrl, HttpEntity entity, Map<String, String> headersMap) {
		return postRequest(requestUrl, entity, headersMap, true).getFirst();
	}

	public Pair<HttpAsdcResponse, CloseableHttpResponse> postRequest(String requestUrl, HttpEntity entity, Map<String, String> headersMap, boolean closeTheRequest) {
		Pair<HttpAsdcResponse, CloseableHttpResponse> ret;
		CloseableHttpResponse httpResponse = null;
		HttpAsdcResponse response = null;
		HttpPost httpPost = new HttpPost(HTTPS + serverFqdn + requestUrl);
		List<Header> headers = addHeadersToHttpRequest(headersMap);
		for (Header header : headers) {
			httpPost.addHeader(header);
		}

		httpPost.setHeader(AUTHORIZATION_HEADER, this.authHeaderValue);

		httpPost.setEntity(entity);
		try {
			httpResponse = httpClient.execute(httpPost);
			response = new HttpAsdcResponse(httpResponse.getStatusLine().getStatusCode(), httpResponse.getEntity());

		} catch (IOException e) {
			log.error("failed to send request to url: " + requestUrl);
			StringEntity errorEntity = null;
			try {
				errorEntity = new StringEntity("failed to send request");
			} catch (UnsupportedEncodingException e1) {
			}

			response = new HttpAsdcResponse(500, errorEntity);

		} finally {
			if (closeTheRequest) {
				if (httpResponse != null) {
					try {
						httpResponse.close();

					} catch (IOException e) {
						log.error("failed to close http response");
					}
				}
				ret = new Pair<>(response, null);
			} else {
				ret = new Pair<>(response, httpResponse);
			}
		}

		return ret;
	}

	public HttpAsdcResponse getRequest(String requestUrl, Map<String, String> headersMap) {

		return getRequest(requestUrl, headersMap, true).getFirst();

	}

	public Pair<HttpAsdcResponse, CloseableHttpResponse> getRequest(String requestUrl, Map<String, String> headersMap, boolean closeTheRequest) {
		Pair<HttpAsdcResponse, CloseableHttpResponse> ret;
		CloseableHttpResponse httpResponse = null;
		String url = HTTPS + serverFqdn + requestUrl;
		log.debug("url to send {}", url);
		HttpGet httpGet = new HttpGet(url);
		List<Header> headers = addHeadersToHttpRequest(headersMap);
		for (Header header : headers) {
			httpGet.addHeader(header);
		}

		httpGet.setHeader(AUTHORIZATION_HEADER, this.authHeaderValue);

		HttpAsdcResponse response = null;
		try {
			httpResponse = httpClient.execute(httpGet);

			log.debug("GET Response Status {}", httpResponse.getStatusLine().getStatusCode());
			Header[] headersRes = httpResponse.getAllHeaders();
			Map<String, String> headersResMap = new HashMap<>();
			for (Header header : headersRes) {
				headersResMap.put(header.getName(), header.getValue());
			}
			response = new HttpAsdcResponse(httpResponse.getStatusLine().getStatusCode(), httpResponse.getEntity(), headersResMap);

		} catch (UnknownHostException | ConnectException e) {
			log.error("failed to connect to url: {}", requestUrl, e);
			StringEntity errorEntity = null;
			try {
				errorEntity = new StringEntity("failed to connect");
			} catch (UnsupportedEncodingException e1) {
			}

			response = new HttpAsdcResponse(HttpStatus.SC_BAD_GATEWAY, errorEntity);

		} catch (IOException e) {
			log.error("failed to send request to url: " + requestUrl + " error " + e.getMessage());
			StringEntity errorEntity = null;
			try {
				errorEntity = new StringEntity("failed to send request " + e.getMessage());
			} catch (UnsupportedEncodingException e1) {
			}

			response = new HttpAsdcResponse(HttpStatus.SC_BAD_GATEWAY, errorEntity);

		} finally {

			if (closeTheRequest) {
				if (httpResponse != null) {
					try {
						httpResponse.close();

					} catch (IOException e) {
						log.error("failed to close http response");
					}
				}
				ret = new Pair<HttpAsdcResponse, CloseableHttpResponse>(response, null);
			} else {
				ret = new Pair<HttpAsdcResponse, CloseableHttpResponse>(response, httpResponse);
			}
		}

		return ret;

	}

	public void closeHttpClient() {
		try {
			httpClient.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			log.error("failed to close http client");
		}

	}

	private List<Header> addHeadersToHttpRequest(Map<String, String> headersMap) {

		List<Header> requestHeaders = new ArrayList<Header>();

		Set<String> headersKyes = headersMap.keySet();
		for (String key : headersKyes) {
			Header requestHeader = new BasicHeader(key, headersMap.get(key));
			requestHeaders.add(requestHeader);
		}

		return requestHeaders;
	}

}