package top.lvzhiqiang.util;

import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultConnectionKeepAliveStrategy;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.util.*;

/**
 * HTTP工具类
 *
 * @author shiyong
 * 2019-12-17 16:08
 */
public class HttpUtils {

    // 编码格式。发送编码格式统一用UTF-8
    private static final String ENCODING = "UTF-8";

    // 设置连接超时时间，单位毫秒。ConnectTimeoutException
    private static final int CONNECT_TIMEOUT = 60000;

    // 请求获取数据的超时时间(即响应时间)，单位毫秒。如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。SocketTimeoutException
    private static final int SOCKET_TIMEOUT = 30000;

    // 设置从connect Manager获取Connection 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。ConnectionPoolTimeout
    private static final int CONNECTION_REQUEST_TIMEOUT = 60000;

    private static final Logger log = LoggerFactory.getLogger(HttpUtils.class);

    private static CloseableHttpClient httpClient = null;

    /**
     * 自己构建httpclient连接池。通过享元模式来解决该问题来解决HttpClient引起的TCP连接数高问题
     *
     * @return
     */
    public static synchronized CloseableHttpClient getHttpClient() {
        if (httpClient == null) {
            PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
            // 连接池最大连接数，默认为20
            cm.setMaxTotal(2000);
            // 单条链路最大连接数（一个ip+一个端口是一个链路），即每个主机的最大连接数，默认为2
            cm.setDefaultMaxPerRoute(1000);

            ConnectionKeepAliveStrategy kaStrategy = new DefaultConnectionKeepAliveStrategy() {
                @Override
                public long getKeepAliveDuration(HttpResponse response, HttpContext context) {
                    long keepAlive = super.getKeepAliveDuration(response, context);
                    if (keepAlive == -1) {
                        keepAlive = 60000;
                    }
                    return keepAlive;
                }
            };

            httpClient = HttpClients.custom().setConnectionManager(cm).setKeepAliveStrategy(kaStrategy).build();
        }

        return httpClient;
    }

    /**
     * 发送get请求，返回字符串
     *
     * @param url 请求地址
     * @return java.lang.String
     * @author shiyong
     * 2020/4/15 10:54
     */
    public static String doGetToStr(String url) throws IOException, URISyntaxException {
        return doGetToStr(url, new HashMap<>());
    }

    /**
     * 发送get请求，返回字符串
     *
     * @param url    请求地址
     * @param params 请求参数
     * @return java.lang.String
     * @author shiyong
     * 2020/4/15 10:58
     */
    public static String doGetToStr(String url, Map<String, String> params) throws IOException, URISyntaxException {
        return doGetToStr(url, new HashMap<>(), params);
    }

    /**
     * 发送get请求，返回字符串
     *
     * @param url     请求地址
     * @param headers 请求头
     * @param params  请求参数
     * @return java.lang.String
     * @author shiyong
     * 2020/4/15 10:59
     */
    public static String doGetToStr(String url, Map<String, String> headers, Map<String, String> params) throws IOException, URISyntaxException {
        // 创建httpClient对象
        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();

        // 创建httpResponse对象
        CloseableHttpResponse httpResponse = null;
        HttpGet httpGet = null;
        try {
            // 创建访问的地址
            URIBuilder uriBuilder = new URIBuilder(url);

            if (params != null) {
                Set<Map.Entry<String, String>> entrySet = params.entrySet();

                for (Map.Entry<String, String> entry : entrySet) {
                    uriBuilder.setParameter(entry.getKey(), entry.getValue());
                }
            }

            // 创建http对象
            httpGet = new HttpGet(uriBuilder.build());

            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
            httpGet.setConfig(requestConfig);

            // 设置请求头
            packageHeader(headers, httpGet);

            // 执行请求
            httpResponse = httpClient.execute(httpGet);

            if (null == httpResponse || null == httpResponse.getStatusLine() || null == httpResponse.getEntity() || httpResponse.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
                return "";
            }

            return EntityUtils.toString(httpResponse.getEntity(), ENCODING);
        } catch (JSONException e) {
            throw new JSONException(e.getMessage());
        } catch (IOException e) {
            throw new IOException(e);
        } finally {
            // 释放资源
            if (httpGet != null) {
                httpGet.abort();
                httpGet.releaseConnection();
            }
            release(httpResponse, httpClient);
        }
    }


    /**
     * 发送post请求，返回字符串
     *
     * @param url     请求地址
     * @param headers 请求头
     * @param params  请求参数
     * @return java.lang.String
     * @author shiyong
     * 2020/4/15 11:35
     */
    public static String doPostToStr(String url, Map<String, String> headers, Map<String, String> params) throws IOException, JSONException {
        // 创建httpClient对象
        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();

        // 创建httpResponse对象
        CloseableHttpResponse httpResponse = null;
        HttpPost httpPost = null;
        try {
            // 创建http对象
            httpPost = new HttpPost(url);

            RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setConnectionRequestTimeout(CONNECTION_REQUEST_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
            httpPost.setConfig(requestConfig);
            //httpPost.setHeader(HttpHeaders.CONNECTION, "close");

            packageHeader(headers, httpPost);

            // 封装请求参数
            packageParam(params, httpPost);

            // 执行请求
            httpResponse = httpClient.execute(httpPost);

            if (null == httpResponse || null == httpResponse.getStatusLine() || null == httpResponse.getEntity() || httpResponse.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
                return "";
            }

            return EntityUtils.toString(httpResponse.getEntity(), ENCODING);
        } catch (JSONException e) {
            throw new JSONException(e.getMessage());
        } catch (IOException e) {
            throw new IOException(e);
        } finally {
            // 释放资源
            if (httpPost != null) {
                httpPost.abort();
                httpPost.releaseConnection();
            }
            release(httpResponse, httpClient);
        }
    }

    /**
     * 发送post请求，返回JSONObject
     *
     * @param url    请求地址
     * @param params 参数集合
     * @return com.alibaba.fastjson.JSONObject
     * @author shiyong
     * 2019/11/23 18:39
     */
    public static JSONObject doPost(String url, Map<String, String> params) throws IOException {
        return doPost(url, new HashMap<String, String>(), params);
    }

    /**
     * 发送post请求，返回JSONObject
     *
     * @param url     请求地址
     * @param headers 请求头
     * @param params  请求参数
     * @return com.alibaba.fastjson.JSONObject
     * @author shiyong
     * 2019/11/23 18:35
     */
    public static JSONObject doPost(String url, Map<String, String> headers, Map<String, String> params) throws IOException {
        String content = doPostToStr(url, headers, params);

        if (StringUtils.isEmpty(content)) {
            return new JSONObject();
        }

        return JSONObject.parseObject(content);
    }

    /**
     * 封装请求头
     *
     * @param params     请求头
     * @param httpMethod 请求方式
     * @author shiyong
     * 2019/11/23 19:21
     */
    private static void packageHeader(Map<String, String> params, HttpRequestBase httpMethod) {
        if (params != null) {
            Set<Map.Entry<String, String>> entrySet = params.entrySet();

            for (Map.Entry<String, String> entry : entrySet) {
                // 设置到请求头到HttpRequestBase对象中
                httpMethod.setHeader(entry.getKey(), entry.getValue());
            }
        }
    }

    /**
     * 封装请求参数
     *
     * @param params     请求参数
     * @param httpMethod 请求方式
     * @author shiyong
     * 2019/11/23 19:22
     */
    private static void packageParam(Map<String, String> params, HttpEntityEnclosingRequestBase httpMethod) throws UnsupportedEncodingException {
        if (params != null) {
            List<NameValuePair> nvps = new ArrayList<>();

            Set<Map.Entry<String, String>> entrySet = params.entrySet();

            for (Map.Entry<String, String> entry : entrySet) {
                nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }

            UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, ENCODING);
            formEntity.setContentType(URLEncodedUtils.CONTENT_TYPE);

            // 设置到请求的http对象中
            httpMethod.setEntity(formEntity);
        }
    }

    /**
     * 释放资源
     *
     * @param httpResponse HTTP响应
     * @param httpClient   HTTP客户端
     * @author shiyong
     * 2019/11/23 19:28
     */
    private static void release(CloseableHttpResponse httpResponse, CloseableHttpClient httpClient) {
        try {
            if (httpResponse != null) {
                httpResponse.close();
            }

            // 连接池使用的时候不能关闭连接，否则下次使用会抛异常 java.lang.IllegalStateException: Connection pool shut down
            // 选择使用连接池,就是将连接全部交由连接池管理,而我们在程序中使用了httpClient.close()就破坏了这以规则
            /*if (httpClient != null) {
                httpClient.close();
            }*/
        } catch (IOException e) {
            log.error("释放HTTP请求资源失败！", e);
        }

    }

}