/*
 * Copyright (c) 2008-2016 Computer Network Information Center (CNIC), Chinese Academy of Sciences.
 * 
 * This file is part of Duckling project.
 *
 * 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. 
 *
 */
package cn.vlabs.umt.oauth.client;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.Map;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import cn.vlabs.umt.oauth.client.request.OAuthClientRequest;
import cn.vlabs.umt.oauth.client.response.OAuthClientResponse;
import cn.vlabs.umt.oauth.client.response.OAuthClientResponseFactory;
import cn.vlabs.umt.oauth.common.OAuth;
import cn.vlabs.umt.oauth.common.exception.OAuthProblemException;
import cn.vlabs.umt.oauth.common.exception.OAuthSystemException;
import cn.vlabs.umt.oauth.common.utils.OAuthUtils;

public class HttpsConnectionClient implements HttpClient {

	@Override
	public <T extends OAuthClientResponse> T execute(OAuthClientRequest request, Map<String, String> headers,
			String requestMethod, Class<T> responseClass) throws OAuthSystemException, OAuthProblemException {
		 String responseBody = null;
	        URLConnection c = null;
	        int responseCode = 0;
	        try {
	        	TrustManager easyTrustManager = new X509TrustManager() {
				    public void checkClientTrusted(X509Certificate[] chain,
				      String authType) throws CertificateException {
				     // 哦，这很简单！
				    }
				    public void checkServerTrusted(X509Certificate[] chain,
				      String authType) throws CertificateException {
				      //哦，这很简单！
				    }
				    public X509Certificate[] getAcceptedIssuers() {
				     return null;
				    }
			   };
			   TrustManager[] tm = { easyTrustManager };
		        SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
		        sslContext.init(null, tm, new java.security.SecureRandom());
		        // 从上述SSLContext对象中得到SSLSocketFactory对象
		        SSLSocketFactory ssf = sslContext.getSocketFactory();
		        
	            URL url = new URL(request.getLocationUri());

	            c = url.openConnection();
	            responseCode = -1;
	            if (c instanceof HttpsURLConnection) {
	            	HttpsURLConnection httpURLConnection = (HttpsURLConnection)c;
	            	httpURLConnection.setSSLSocketFactory(ssf);
	            	httpURLConnection.setHostnameVerifier(new javax.net.ssl.HostnameVerifier() {
						public boolean verify(String hostname, javax.net.ssl.SSLSession sslSession) {
							return true;
						}
					});
	                if (headers != null && !headers.isEmpty()) {
	                    for (Map.Entry<String, String> header : headers.entrySet()) {
	                        httpURLConnection.addRequestProperty(header.getKey(), header.getValue());
	                    }
	                }
	                
	                if (request.getHeaders() != null) {
	                    for (Map.Entry<String, String> header : request.getHeaders().entrySet()) {
	                    	httpURLConnection.addRequestProperty(header.getKey(), header.getValue());
	                    }
	                }

	                if (!OAuthUtils.isEmpty(requestMethod)) {
	                    httpURLConnection.setRequestMethod(requestMethod);
	                    if (requestMethod.equals(OAuth.HttpMethod.POST)) {
	                        httpURLConnection.setDoOutput(true);
	                        OutputStream ost = httpURLConnection.getOutputStream();
	                        PrintWriter pw = new PrintWriter(ost);
	                        pw.print(request.getBody());
	                        pw.flush();
	                        pw.close();
	                    }
	                } else {
	                    httpURLConnection.setRequestMethod(OAuth.HttpMethod.GET);
	                }

	                httpURLConnection.connect();

	                InputStream inputStream;
	                responseCode = httpURLConnection.getResponseCode();
	                if (responseCode == 400) {
	                    inputStream = httpURLConnection.getErrorStream();
	                } else {
	                    inputStream = httpURLConnection.getInputStream();
	                }

	                responseBody = OAuthUtils.saveStreamAsString(inputStream);
	            }
	        } catch (IOException e) {
	            throw new OAuthSystemException(e);
	        } catch (NoSuchAlgorithmException e) {
	        	 throw new OAuthSystemException(e);
			} catch (NoSuchProviderException e) {
				 throw new OAuthSystemException(e);
			} catch (KeyManagementException e) {
				throw new OAuthSystemException(e);
			}

	        return OAuthClientResponseFactory
	            .createCustomResponse(responseBody, c.getContentType(), responseCode, responseClass);
	}

	@Override
	public void shutdown() {
		// TODO Auto-generated method stub
		
	}

}