/*
    * 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.syncope.core.rest.cxf.batch;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Optional;
  import java.util.Set;
  import java.util.stream.Collectors;
  import javax.servlet.ReadListener;
  import javax.servlet.ServletInputStream;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletRequestWrapper;
  import javax.ws.rs.core.HttpHeaders;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.math.NumberUtils;
  import org.apache.syncope.common.rest.api.batch.BatchRequestItem;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.http.MediaType;
  
  public class BatchItemRequest extends HttpServletRequestWrapper {
  
      private static final Logger LOG = LoggerFactory.getLogger(BatchItemRequest.class);
  
      private final String basePath;
  
      private final BatchRequestItem batchItem;
  
      private final ServletInputStream inputStream;
  
      public BatchItemRequest(
              final String basePath,
              final HttpServletRequest request,
              final BatchRequestItem batchItem) {
  
          super(request);
          this.basePath = basePath;
          this.batchItem = batchItem;
          this.inputStream = new ServletInputStream() {
  
              private final ByteArrayInputStream bais = new ByteArrayInputStream(batchItem.getContent().getBytes());
  
              private boolean isFinished = false;
  
              private boolean isReady = true;
  
              @Override
              public boolean isFinished() {
                  return isFinished;
              }
  
              @Override
              public boolean isReady() {
                  return isReady;
              }
  
              @Override
              public void setReadListener(final ReadListener readListener) {
                  // nope
              }
  
              @Override
              public int read() {
                  isFinished = true;
                  isReady = false;
                  return bais.read();
              }
          };
      }
  
      @Override
      public String getMethod() {
          return batchItem.getMethod();
      }
  
      @Override
      public String getServerName() {
         try {
             return super.getServerName();
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return Optional.ofNullable(getHeader(HttpHeaders.HOST)).
                     map(host -> StringUtils.substringBefore(host, ":")).orElse(null);
         }
     }
 
     @Override
     public int getServerPort() {
         try {
             return super.getServerPort();
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return Optional.ofNullable(getHeader(HttpHeaders.HOST)).
                     map(host -> NumberUtils.toInt(StringUtils.substringAfter(host, ":"))).orElse(0);
         }
     }
 
     @Override
     public StringBuffer getRequestURL() {
         return new StringBuffer(basePath).append(getRequestURI());
     }
 
     @Override
     public String getRequestURI() {
         return batchItem.getRequestURI();
     }
 
     @Override
     public String getQueryString() {
         return batchItem.getQueryString();
     }
 
     @Override
     public String getContentType() {
         return batchItem.getHeaders().containsKey(HttpHeaders.CONTENT_TYPE)
                 ? batchItem.getHeaders().get(HttpHeaders.CONTENT_TYPE).get(0).toString()
                 : MediaType.ALL_VALUE;
     }
 
     @Override
     public int getContentLength() {
         int contentLength = 0;
         if (batchItem.getHeaders().containsKey(HttpHeaders.CONTENT_LENGTH)) {
             try {
                 contentLength = Integer.valueOf(
                         batchItem.getHeaders().get(HttpHeaders.CONTENT_LENGTH).get(0).toString());
             } catch (NumberFormatException e) {
                 LOG.error("Invalid value found for {}: {}",
                         HttpHeaders.CONTENT_LENGTH, batchItem.getHeaders().get(HttpHeaders.CONTENT_LENGTH), e);
             }
         }
         return contentLength;
     }
 
     @Override
     public long getContentLengthLong() {
         return getContentLength();
     }
 
     @Override
     public String getHeader(final String name) {
         try {
             return batchItem.getHeaders().containsKey(name)
                     ? batchItem.getHeaders().get(name).get(0).toString()
                     : HttpHeaders.CONTENT_TYPE.equals(name) || HttpHeaders.ACCEPT.equals(name)
                     ? MediaType.ALL_VALUE
                     : super.getHeader(name);
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return null;
         }
     }
 
     @Override
     public Enumeration<String> getHeaders(final String name) {
         try {
             return batchItem.getHeaders().containsKey(name)
                     ? Collections.enumeration(batchItem.getHeaders().get(name).stream().
                             map(Object::toString).collect(Collectors.toList()))
                     : HttpHeaders.CONTENT_TYPE.equals(name) || HttpHeaders.ACCEPT.equals(name)
                     ? Collections.enumeration(List.of(MediaType.ALL_VALUE))
                     : super.getHeaders(name);
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return Collections.emptyEnumeration();
         }
     }
 
     @Override
     public Enumeration<String> getHeaderNames() {
         try {
             return super.getHeaderNames();
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
 
             Set<String> names = new HashSet<>(batchItem.getHeaders().keySet());
             names.add(HttpHeaders.CONTENT_TYPE);
             names.add(HttpHeaders.ACCEPT);
             return Collections.enumeration(names);
         }
     }
 
     @Override
     public Object getAttribute(final String name) {
         try {
             return super.getAttribute(name);
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return null;
         }
     }
 
     @Override
     public void setAttribute(final String name, final Object o) {
         try {
             super.setAttribute(name, o);
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
         }
     }
 
     @Override
     public String getCharacterEncoding() {
         try {
             return super.getCharacterEncoding();
         } catch (Exception e) {
             LOG.debug("While delegating to wrapped request", e);
             return StandardCharsets.UTF_8.name();
         }
     }
 
     @Override
     public ServletInputStream getInputStream() throws IOException {
         return inputStream;
     }
 }