package com.sdyc.jise.fetch.crawler.requester;

import cn.edu.hfut.dmic.webcollector.model.CrawlDatum;
import cn.edu.hfut.dmic.webcollector.net.HttpResponse;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.apache.http.Header;
import org.apache.http.client.methods.HttpGet;
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.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.util.Map;
import java.util.Objects;

/**
 * <pre>
 *
 * Created by zhenqin.
 * User: zhenqin
 * Date: 17/4/25
 * Time: 16:26
 * Vendor: NowledgeData
 * To change this template use File | Settings | File Templates.
 *
 * </pre>
 *
 * @author zhenqin
 */
@Slf4j
public class HttpClientRequester extends JavaNativeRequester implements Closeable {


    protected final CloseableHttpClient httpClient;


    final PoolingHttpClientConnectionManager cm;

    public HttpClientRequester() {
        try {
            //设置协议http和https对应的处理socket链接工厂的对象
            Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
                    .register("http", PlainConnectionSocketFactory.INSTANCE)
                    .register("https", new SSLConnectionSocketFactory(createIgnoreVerifySSL()))
                    .build();

            cm = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
            httpClient = HttpClients.custom()
                    .setConnectionManager(cm)
                    .setRetryHandler(new DefaultHttpRequestRetryHandler(3, false))
                    .build();
        } catch (Exception e) {
            throw new IllegalStateException(e);
        }
    }


    /**
     * 绕过验证
     *
     * @return
     * @throws NoSuchAlgorithmException
     * @throws KeyManagementException
     */
    public static SSLContext createIgnoreVerifySSL() throws NoSuchAlgorithmException, KeyManagementException {
        SSLContext sc = SSLContext.getInstance("SSLv3");

        // 实现一个X509TrustManager接口，用于绕过验证，不用修改里面的方法
        X509TrustManager trustManager = new X509TrustManager() {
            @Override
            public void checkClientTrusted(
                    java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
                    String paramString) throws CertificateException {
            }

            @Override
            public void checkServerTrusted(
                    java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
                    String paramString) throws CertificateException {
            }

            @Override
            public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };

        sc.init(null, new TrustManager[] { trustManager }, null);
        return sc;
    }

    /**
     * 覆盖父类的方法，使用 HttpClient 实现
     * @param crawlDatum
     * @return
     * @throws Exception
     */
    @Override
    public HttpResponse getResponse(CrawlDatum crawlDatum) throws Exception {
        HttpGet get = new HttpGet(crawlDatum.url());
        if(StringUtils.isNotBlank(cookie)) {
            header.put("Cookie", cookie);
        }

        if(StringUtils.isNotBlank(userAgent)) {
            header.put("User-Agent", userAgent);
        }

        if(!header.isEmpty()) {
            for (Map.Entry<String, String> entry : header.entrySet()) {
                get.addHeader(entry.getKey(), entry.getValue());
            }
        }

        URI url = new URI(crawlDatum.url());
        org.apache.http.HttpResponse resp = httpClient.execute(new HttpGet(url));
        HttpResponse response = new HttpResponse(url.toURL());
        log.debug("fetch url {} return code {}", crawlDatum.url(), resp.getStatusLine().getStatusCode());
        Header[] allHeaders = resp.getAllHeaders();
        if(allHeaders != null) {
            for (Header header : allHeaders) {
                response.addHeader(header.getName(), header.getValue());
            }
        }
        response.setNotFound(Objects.equals(404, resp.getStatusLine().getStatusCode()));
        response.setRedirect(Objects.equals(302, resp.getStatusLine().getStatusCode()));
        response.code(resp.getStatusLine().getStatusCode());
        response.setHtml(EntityUtils.toString(resp.getEntity()));
        EntityUtils.consumeQuietly(resp.getEntity());
        return response;
    }


    @Override
    public void close() throws IOException {
        httpClient.close();
        log.info("closed http client.");
    }
}