package com.nowcoder.enterprise.javademo.utils;

import java.io.IOException;
import java.net.URI;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

import com.alibaba.fastjson.JSON;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.collections4.MultiValuedMap;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 请求牛客API工具类
 *
 * @author guokaijun
 * @date 2021/7/31
 */
public class NowcoderApiRequestUtils {

  /**
   * HTTP调用牛客API并返回字符串，在调用之前根据请求方法设置了通用的请求头和请求参数，并将方法传入的参数置入HTTP请求中。
   *
   * @param path 请求路径，形如"/users/self"的字符串
   * @param params 请求参数，需传递除api_key参数之外的每个接口独有的参数。一个key能对应多个值，值不能为null。
   *               如果接口不需要其他参数，需要传递空Map，不能传null。
   * @param methodName http方法名称。取值范围为 GET、POST、PUT、DELETE 中的一个
   * @return 牛客接口json返回的字符串表示
   */
  public static String request(
      String path, MultiValuedMap<String, Object> params, String methodName) {
    if (HttpGet.METHOD_NAME.equals(methodName)) {
      return getRequest(path, params);
    }

    HttpEntityEnclosingRequestBase uriRequest = getMethod(methodName);
    uriRequest.setURI(URI.create(ConfigUtils.getApiBaseUrl() + path));

    List<NameValuePair> pairList = new ArrayList<>();
    pairList.add(new BasicNameValuePair("api_key", ConfigUtils.getApiKey()));
    params
        .entries()
        .forEach(
            (entry) -> {
              String key = entry.getKey();
              Object val = entry.getValue();
              if (key == null || val == null) return;
              pairList.add(new BasicNameValuePair(key, val.toString()));
            });
    uriRequest.setEntity(new UrlEncodedFormEntity(pairList, StandardCharsets.UTF_8));

    uriRequest.addHeader("Authorization", ConfigUtils.getAuthorization());
    return sendRequest(uriRequest);
  }

  private static HttpEntityEnclosingRequestBase getMethod(String methodName){
    HttpEntityEnclosingRequestBase uriRequest;
    if (HttpPost.METHOD_NAME.equals(methodName)) {
      uriRequest = new HttpPost();
    } else if (HttpPut.METHOD_NAME.equals(methodName)) {
      uriRequest = new HttpPut();
    } else if (HttpDelete.METHOD_NAME.equals(methodName)) {
      uriRequest = new NowcoderHttpDelete();
    } else {
      throw new IllegalArgumentException("Bad methodName.");
    }
    return uriRequest;
  }

  public static String jsonRequest(String path, Object param, String methodName){
    HttpEntityEnclosingRequestBase uriRequest = getMethod(methodName);
    uriRequest.setURI(URI.create(ConfigUtils.getApiBaseUrl() + path + "?api_key=" + ConfigUtils.getApiKey()));
    uriRequest.setEntity(new StringEntity(JSON.toJSONString(param), Charset.defaultCharset()));

    uriRequest.addHeader("Authorization", ConfigUtils.getAuthorization());
    uriRequest.addHeader("Content-Type", "application/json");
    return sendRequest(uriRequest);
  }

  // 执行GET请求
  private static String getRequest(String path, MultiValuedMap<String, Object> params) {

    List<String> pairs = new ArrayList<>();
    pairs.add("api_key=" + ConfigUtils.getApiKey());
    params
        .entries()
        .forEach(
            (entry) -> {
              String key = entry.getKey();
              Object val = entry.getValue();
              if (key == null || val == null) return;
              pairs.add(key + "=" + val);
            });
    String queryParams = StringUtils.join(pairs, "&");

    HttpGet get = new HttpGet(ConfigUtils.getApiBaseUrl() + path + "?" + queryParams);

    get.addHeader("Authorization", ConfigUtils.getAuthorization());

    return sendRequest(get);
  }

  // 发送请求并打印CURL
  private static String sendRequest(HttpRequestBase requestBase) {
    CloseableHttpClient httpClient = HttpClients.createDefault();
    String responseString = null;
    try {
      CloseableHttpResponse response = httpClient.execute(requestBase);
      HttpEntity entity = response.getEntity();
      responseString = EntityUtils.toString(entity, StandardCharsets.UTF_8);
    } catch (IOException e) {
      e.printStackTrace();
    }
    String curlStr = toCurlStr(requestBase);
    System.out.println(curlStr);
    return responseString;
  }

  // 将一次HTTP请求转换成CURL
  private static String toCurlStr(HttpRequestBase requestBase) {
    String httpMethod = requestBase.getMethod();
    String uri = requestBase.getURI().toString();

    List<String> headers = new ArrayList<>();
    for (Header header : requestBase.getAllHeaders()) {
      headers.add(header.getName() + ": " + header.getValue());
    }
    String headersStr = "";
    if (CollectionUtils.isNotEmpty(headers)) {
      for (String header : headers) {
        headersStr += "\\\n --header '" + header + "' ";
      }
    }

    String dataRawStr = "";
    if (requestBase instanceof HttpEntityEnclosingRequestBase) {
      HttpEntity entity = ((HttpEntityEnclosingRequestBase) requestBase).getEntity();
      try {
        dataRawStr = EntityUtils.toString(entity, StandardCharsets.UTF_8);
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
    if (StringUtils.isNotEmpty(dataRawStr)) {
      dataRawStr = String.format("\\\n --data-raw '%s'", dataRawStr);
    }

    String template = "curl --location --request %s '%s' %s %s";
    return String.format(template, httpMethod, uri, headersStr, dataRawStr);
  }

  // 将一次HTTP请求转换成CURL
  private static String toJsonCurlStr(HttpRequestBase requestBase) {
    String httpMethod = requestBase.getMethod();
    String uri = requestBase.getURI().toString();

    List<String> headers = new ArrayList<>();
    for (Header header : requestBase.getAllHeaders()) {
      headers.add(header.getName() + ": " + header.getValue());
    }
    String headersStr = "";
    if (CollectionUtils.isNotEmpty(headers)) {
      for (String header : headers) {
        headersStr += "\\\n --header '" + header + "' ";
      }
    }

    String dataRawStr = "";
    if (requestBase instanceof HttpEntityEnclosingRequestBase) {
      HttpEntity entity = ((HttpEntityEnclosingRequestBase) requestBase).getEntity();
      try {
        dataRawStr = EntityUtils.toString(entity, StandardCharsets.UTF_8);
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
    if (StringUtils.isNotEmpty(dataRawStr)) {
      dataRawStr = String.format("\\\n --data-raw '%s'", dataRawStr);
    }

    String template = "curl --location --request %s '%s' %s %s";
    return String.format(template, httpMethod, uri, headersStr, dataRawStr);
  }
}