/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.maven.search.api.transport;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URI;
  import java.net.http.HttpClient;
  import java.net.http.HttpRequest;
  import java.net.http.HttpResponse;
  import java.time.Duration;
  import java.util.AbstractMap;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Java 11 {@link HttpClient} backed transport.
   */
  public class Java11HttpClientTransport implements Transport {
      private static class ResponseImpl implements Response {
  
          private final HttpResponse<?> response;
  
          private final InputStream inputStream;
  
          private ResponseImpl(HttpResponse<?> response, InputStream inputStream) {
              this.response = requireNonNull(response);
              this.inputStream = inputStream;
          }
  
          @Override
          public int getCode() {
              return response.statusCode();
          }
  
          @Override
          public Map<String, String> getHeaders() {
              return response.headers().map().entrySet().stream()
                      .map(e -> new AbstractMap.SimpleEntry<>(
                              e.getKey(), e.getValue().get(0)))
                      .collect(Collectors.toMap(AbstractMap.SimpleEntry::getKey, AbstractMap.SimpleEntry::getValue));
          }
  
          @Override
          public InputStream getBody() {
              return inputStream;
          }
  
          @Override
          public void close() throws IOException {
              if (inputStream != null) {
                  inputStream.close();
              }
          }
      }
  
      private final Duration timeout;
  
      private final HttpClient client;
  
      public Java11HttpClientTransport() {
          this(Duration.ofSeconds(10L));
      }
  
      public Java11HttpClientTransport(Duration timeout) {
          this(
                  timeout,
                  HttpClient.newBuilder()
                          .connectTimeout(timeout)
                          .followRedirects(HttpClient.Redirect.NEVER)
                          .build());
      }
  
      public Java11HttpClientTransport(Duration timeout, HttpClient client) {
          this.timeout = requireNonNull(timeout);
          this.client = requireNonNull(client);
      }
  
      @Override
      public Response get(String serviceUri, Map<String, String> headers) throws IOException {
          HttpRequest.Builder builder = HttpRequest.newBuilder()
                 .timeout(timeout)
                 .uri(URI.create(serviceUri))
                 .GET();
         for (Map.Entry<String, String> header : headers.entrySet()) {
             builder.header(header.getKey(), header.getValue());
         }
         HttpRequest request = builder.build();
         try {
             HttpResponse<InputStream> response = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
             return new ResponseImpl(response, response.body());
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
             throw new IOException(e);
         }
     }
 
     @Override
     public Response head(String serviceUri, Map<String, String> headers) throws IOException {
         HttpRequest.Builder builder = HttpRequest.newBuilder()
                 .timeout(timeout)
                 .uri(URI.create(serviceUri))
                 .method("HEAD", HttpRequest.BodyPublishers.noBody());
         for (Map.Entry<String, String> header : headers.entrySet()) {
             builder.header(header.getKey(), header.getValue());
         }
         HttpRequest request = builder.build();
         try {
             HttpResponse<Void> response = client.send(request, HttpResponse.BodyHandlers.discarding());
             return new ResponseImpl(response, null);
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
             throw new IOException(e);
         }
     }
 }