/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2014 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.caravan.io.http.impl;
  
  import java.util.Arrays;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.http.Header;
  import org.apache.http.HttpEntityEnclosingRequest;
  import org.apache.http.client.methods.HttpDelete;
  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.HttpUriRequest;
  import org.apache.http.entity.ByteArrayEntity;
  import org.apache.http.entity.StringEntity;
  
  import com.google.common.collect.ImmutableListMultimap;
  import com.google.common.collect.LinkedHashMultimap;
  import com.google.common.collect.Multimap;
  import com.netflix.loadbalancer.Server;
  
  import io.wcm.caravan.io.http.request.CaravanHttpRequest;
  
  /**
   * Utility methods for preparing a request for execution.
   */
  public final class RequestUtil {
  
    /**
     * Choose protocol automatically.
     */
    public static final String PROTOCOL_AUTO = "auto";
    /**
     * Non secure protocol.
     */
    public static final String PROTOCOL_HTTP = "http";
    /**
     * Secure protocol.
     */
    public static final String PROTOCOL_HTTPS = "https";
  
    private RequestUtil() {
      // static methods only
    }
  
    /**
     * @param server Server
     * @return URL prefix with scheme, hostname and port
     */
    public static String buildUrlPrefix(Server server, String protocol) {
      StringBuilder urlPrefix = new StringBuilder();
      if (StringUtils.equals(protocol, PROTOCOL_HTTP)) {
        urlPrefix.append("http://");
        if (server.getPort() == 80) {
          urlPrefix.append(server.getHost());
        }
        else {
          urlPrefix.append(server.getHost()).append(":").append(server.getPort());
        }
      }
      else if (StringUtils.equals(protocol, PROTOCOL_HTTPS)) {
        urlPrefix.append("https://");
        if (server.getPort() == 443 || server.getPort() == 80) {
          urlPrefix.append(server.getHost());
        }
        else {
          urlPrefix.append(server.getHost()).append(":").append(server.getPort());
        }
      }
      else {
        if (server.getPort() == 443 || server.getPort() == 8443) {
          urlPrefix.append("https");
        }
        else {
          urlPrefix.append("http");
        }
        urlPrefix.append("://").append(server.getHost());
        if (server.getPort() != 80 && server.getPort() != 443) {
          urlPrefix.append(':').append(server.getPort());
        }
      }
     return urlPrefix.toString();
   }
 
   /**
    * @param request Requset
    * @return HTTP client request object
    */
   public static HttpUriRequest buildHttpRequest(CaravanHttpRequest request) {
 
     // http method
     HttpUriRequest httpRequest;
     String method = StringUtils.upperCase(request.getMethod());
     switch (method) {
       case HttpGet.METHOD_NAME:
         httpRequest = new HttpGet(request.getUrl());
         break;
       case HttpPost.METHOD_NAME:
         httpRequest = new HttpPost(request.getUrl());
         break;
       case HttpPut.METHOD_NAME:
         httpRequest = new HttpPut(request.getUrl());
         break;
       case HttpDelete.METHOD_NAME:
         httpRequest = new HttpDelete(request.getUrl());
         break;
       default:
         throw new IllegalArgumentException("Unsupported HTTP method type: " + request.getMethod());
     }
 
     // headers
     request.getHeaders().entries().forEach(e -> httpRequest.addHeader(e.getKey(), e.getValue()));
 
     // body
     if ((httpRequest instanceof HttpEntityEnclosingRequest) && request.getBody() != null) {
       HttpEntityEnclosingRequest entityHttpRequest = (HttpEntityEnclosingRequest)httpRequest;
       if (request.getCharset() != null) {
         entityHttpRequest.setEntity(new StringEntity(new String(request.getBody(), request.getCharset()), request.getCharset()));
       }
       else {
         entityHttpRequest.setEntity(new ByteArrayEntity(request.getBody()));
       }
     }
 
     return httpRequest;
   }
 
   /**
    * @param headerArray Http-client header array
    * @return Map with header values
    */
   public static Multimap<String, String> toHeadersMap(Header... headerArray) {
     LinkedHashMultimap<String, String> headerMap = LinkedHashMultimap.create();
     Arrays.stream(headerArray).forEach(h -> headerMap.put(h.getName(), h.getValue()));
     return ImmutableListMultimap.copyOf(headerMap);
   }
 
 }