/**
    * Licensed to jclouds, Inc. (jclouds) under one or more
    * contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  jclouds 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.jclouds.http;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import java.util.Collection;
  
  import org.jclouds.javax.annotation.Nullable;
  
  import org.jclouds.http.internal.PayloadEnclosingImpl;
  import org.jclouds.io.Payload;
  
  import com.google.common.collect.ImmutableMultimap;
  import com.google.common.collect.Multimap;
  
  /**
   * Represents a request that can be executed within {@link HttpCommandExecutorService}
   * 
   * @author Adrian Cole
   */
  public class HttpMessage extends PayloadEnclosingImpl {
     public static Builder<? extends HttpMessage> builder() {
        return new Builder<HttpMessage>();
     }
  
     public static class Builder<T extends HttpMessage> {
        protected Payload payload;
        protected Multimap<String, String> headers = ImmutableMultimap.of();
  
        public Builder<T> payload(Payload payload) {
           this.payload = payload;
           return this;
        }
  
        public Builder<T> headers(Multimap<String, String> headers) {
           this.headers = ImmutableMultimap.copyOf(checkNotNull(headers, "headers"));
           return this;
        }
  
        @SuppressWarnings("unchecked")
        public T build() {
           return (T) new HttpMessage(payload, headers);
        }
  
        public static <X extends HttpMessage> Builder<X> from(X input) {
           return new Builder<X>().payload(input.getPayload()).headers(input.getHeaders());
        }
     }
  
     protected final Multimap<String, String> headers;
  
     public HttpMessage(@Nullable Payload payload, Multimap<String, String> headers) {
        super(payload);
        this.headers = ImmutableMultimap.copyOf(checkNotNull(headers, "headers"));
     }
  
     public Multimap<String, String> getHeaders() {
        return headers;
     }
  
     /**
      * try to get the value, then try as lowercase.
      */
     public String getFirstHeaderOrNull(String string) {
        Collection<String> values = headers.get(string);
        if (values.size() == 0)
           values = headers.get(string.toLowerCase());
        return (values.size() >= 1) ? values.iterator().next() : null;
     }
  
     public Builder<? extends HttpMessage> toBuilder() {
        return Builder.from(this);
     }
  
     @Override
     public int hashCode() {
        final int prime = 31;
        int result = super.hashCode();
        result = prime * result + ((headers == null) ? 0 : headers.hashCode());
        return result;
     }
  
    @Override
    public boolean equals(Object obj) {
       if (this == obj)
          return true;
       if (!super.equals(obj))
          return false;
       if (getClass() != obj.getClass())
          return false;
       HttpMessage other = (HttpMessage) obj;
       if (headers == null) {
          if (other.headers != null)
             return false;
       } else if (!headers.equals(other.headers))
          return false;
       return true;
    }
 
    @Override
    public String toString() {
       return "[headers=" + headers + ", payload=" + payload + "]";
    }
 
 }