/*
 * 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.juneau.http.response;

import static org.apache.juneau.assertions.Assertions.*;
import static org.apache.juneau.http.HttpEntities.*;

import java.net.*;
import java.util.*;

import org.apache.http.*;
import org.apache.http.impl.*;
import org.apache.http.params.*;
import org.apache.juneau.annotation.*;
import org.apache.juneau.common.utils.*;
import org.apache.juneau.http.*;
import org.apache.juneau.http.header.*;
import org.apache.juneau.internal.*;

/**
 * Basic implementation of the {@link HttpResponse} interface.
 *
 * <p>
 * Although this class implements the various setters defined on the {@link HttpResponse} interface, it's in general
 * going to be more efficient to set the status/headers/content of this bean through the builder.
 *
 * <p>
 * If the <c>unmodifiable</c> flag is set on this bean, calls to the setters will throw {@link UnsupportedOperationException} exceptions.
 *
 * <h5 class='section'>Notes:</h5><ul>
 *    <li class='warn'>Beans are not thread safe unless they're marked as unmodifiable.
 * </ul>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauRestCommonBasics">juneau-rest-common Basics</a>
 * </ul>
 */
@BeanIgnore /* Use toString() to serialize */
public class BasicHttpResponse implements HttpResponse {

   //-----------------------------------------------------------------------------------------------------------------
   // Instance
   //-----------------------------------------------------------------------------------------------------------------

   BasicStatusLine statusLine = new BasicStatusLine();
   HeaderList headers = HeaderList.create();
   HttpEntity content;
   boolean unmodifiable;

   /**
    * Constructor.
    *
    * @param statusLine The HTTP status line.
    */
   public BasicHttpResponse(BasicStatusLine statusLine) {
      setStatusLine(statusLine.copy());
   }

   /**
    * Copy constructor.
    *
    * @param copyFrom The bean to copy from.
    */
   public BasicHttpResponse(BasicHttpResponse copyFrom) {
      statusLine = copyFrom.statusLine.copy();
      headers = copyFrom.headers.copy();
      content = copyFrom.content;
   }

   /**
    * Constructor.
    *
    * <p>
    * This is the constructor used when parsing an HTTP response.
    *
    * @param response The HTTP response to copy from.  Must not be <jk>null</jk>.
    */
   public BasicHttpResponse(HttpResponse response) {
      setHeaders(response.getAllHeaders());
      setContent(response.getEntity());
      setStatusLine(response.getStatusLine());
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Properties
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Specifies whether this bean should be unmodifiable.
    * <p>
    * When enabled, attempting to set any properties on this bean will cause an {@link UnsupportedOperationException}.
    *
    * @return This object.
    */
   public BasicHttpResponse setUnmodifiable() {
      unmodifiable = true;
      return this;
   }

   /**
    * Returns <jk>true</jk> if this bean is unmodifiable.
    *
    * @return <jk>true</jk> if this bean is unmodifiable.
    */
   public boolean isUnmodifiable() {
      return unmodifiable;
   }

   /**
    * Throws an {@link UnsupportedOperationException} if the unmodifiable flag is set on this bean.
    */
   protected final void assertModifiable() {
      if (unmodifiable)
         throw new UnsupportedOperationException("Bean is read-only");
   }

   //-----------------------------------------------------------------------------------------------------------------
   // BasicStatusLine setters.
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Sets the protocol version on the status line.
    *
    * <p>
    * If not specified, <js>"HTTP/1.1"</js> will be used.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setStatusLine(BasicStatusLine value) {
      assertModifiable();
      statusLine = value.copy();
      return this;
   }

   /**
    * Sets the status code on the status line.
    *
    * <p>
    * If not specified, <c>0</c> will be used.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setStatusCode2(int value) {
      statusLine.setStatusCode(value);
      return this;
   }

   /**
    * Sets the protocol version on the status line.
    *
    * <p>
    * If not specified, <js>"HTTP/1.1"</js> will be used.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setProtocolVersion(ProtocolVersion value) {
      statusLine.setProtocolVersion(value);
      return this;
   }

   /**
    * Sets the reason phrase on the status line.
    *
    * <p>
    * If not specified, the reason phrase will be retrieved from the reason phrase catalog
    * using the locale on this builder.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setReasonPhrase2(String value) {
      statusLine.setReasonPhrase(value);
      return this;
   }

   /**
    * Sets the reason phrase catalog used to retrieve reason phrases.
    *
    * <p>
    * If not specified, uses {@link EnglishReasonPhraseCatalog}.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setReasonPhraseCatalog(ReasonPhraseCatalog value) {
      statusLine.setReasonPhraseCatalog(value);
      return this;
   }

   /**
    * Sets the locale used to retrieve reason phrases.
    *
    * <p>
    * If not specified, uses {@link Locale#getDefault()}.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setLocale2(Locale value) {
      statusLine.setLocale(value);
      return this;
   }

   //-----------------------------------------------------------------------------------------------------------------
   // BasicHeaderGroup setters.
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Returns access to the underlying builder for the headers.
    *
    * @return The underlying builder for the headers.
    */
   public HeaderList getHeaders() {
      return headers;
   }

   /**
    * Sets the specified headers on this response.
    *
    * @param value The new value.
    * @return This object.
    */
   public BasicHttpResponse setHeaders(HeaderList value) {
      assertModifiable();
      headers = value.copy();
      return this;
   }

   /**
    * Sets the specified header to the end of the headers in this builder.
    *
    * @param value The header to add.  <jk>null</jk> values are ignored.
    * @return This object.
    */
   public BasicHttpResponse setHeader2(Header value) {
      headers.set(value);
      return this;
   }

   /**
    * Sets the specified header to the end of the headers in this builder.
    *
    * @param name The header name.
    * @param value The header value.
    * @return This object.
    */
   public BasicHttpResponse setHeader2(String name, String value) {
      headers.set(name, value);
      return this;
   }

   /**
    * Sets the specified headers to the end of the headers in this builder.
    *
    * @param values The headers to add.  <jk>null</jk> values are ignored.
    * @return This object.
    */
   public BasicHttpResponse setHeaders2(Header...values) {
      headers.set(values);
      return this;
   }

   /**
    * Sets the specified headers to the end of the headers in this builder.
    *
    * @param values The headers to add.  <jk>null</jk> values are ignored.
    * @return This object.
    */
   public BasicHttpResponse setHeaders(List<Header> values) {
      headers.set(values);
      return this;
   }

   /**
    * Specifies the value for the <c>Location</c> header.
    *
    * @param value The new header location.
    * @return This object.
    */
   public BasicHttpResponse setLocation(URI value) {
      headers.set(Location.of(value));
      return this;
   }

   /**
    * Specifies the value for the <c>Location</c> header.
    *
    * @param value The new header location.
    * @return This object.
    */
   public BasicHttpResponse setLocation(String value) {
      headers.set(Location.of(value));
      return this;
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Body setters.
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Sets the body on this response.
    *
    * @param value The body on this response.
    * @return This object.
    */
   public BasicHttpResponse setContent(String value) {
      return setContent(stringEntity(value));
   }

   /**
    * Sets the body on this response.
    *
    * @param value The body on this response.
    * @return This object.
    */
   public BasicHttpResponse setContent(HttpEntity value) {
      assertModifiable();
      this.content = value;
      return this;
   }

   /**
    * Asserts that the specified HTTP response has the same status code as the one on the status line of this bean.
    *
    * @param response The HTTP response to check.  Must not be <jk>null</jk>.
    * @throws AssertionError If status code is not what was expected.
    */
   protected void assertStatusCode(HttpResponse response) throws AssertionError {
      Utils.assertArgNotNull("response", response);
      int expected = getStatusLine().getStatusCode();
      int actual = response.getStatusLine().getStatusCode();
      assertInteger(actual).setMsg("Unexpected status code.  Expected:[{0}], Actual:[{1}]", expected, actual).is(expected);
   }

   @Override /* Object */
   public String toString() {
      StringBuilder sb = new StringBuilder().append(statusLine).append(' ').append(headers);
      if (content != null)
         sb.append(' ').append(content);
      return sb.toString();
   }

   @Override /* HttpMessage */
   public ProtocolVersion getProtocolVersion() {
      return statusLine.getProtocolVersion();
   }

   @Override /* HttpMessage */
   public boolean containsHeader(String name) {
      return headers.contains(name);
   }

   @Override /* HttpMessage */
   public Header[] getHeaders(String name) {
      return headers.getAll(name);
   }

   @Override /* HttpMessage */
   public Header getFirstHeader(String name) {
      return headers.getFirst(name).orElse(null);
   }

   @Override /* HttpMessage */
   public Header getLastHeader(String name) {
      return headers.getLast(name).orElse(null);
   }

   @Override /* HttpMessage */
   public Header[] getAllHeaders() {
      return headers.getAll();
   }

   @Override /* HttpMessage */
   public void addHeader(Header value) {
      headers.append(value);
   }

   @Override /* HttpMessage */
   public void addHeader(String name, String value) {
      headers.append(name, value);
   }

   @Override /* HttpMessage */
   public void setHeader(Header value) {
      headers.set(value);
   }

   @Override /* HttpMessage */
   public void setHeader(String name, String value) {
      headers.set(name, value);
   }

   @Override /* HttpMessage */
   public void setHeaders(Header[] values) {
      headers.removeAll().append(values);
   }

   @Override /* HttpMessage */
   public void removeHeader(Header value) {
      headers.remove(value);
   }

   @Override /* HttpMessage */
   public void removeHeaders(String name) {
      headers.remove(name);
   }

   @Override /* HttpMessage */
   public HeaderIterator headerIterator() {
      return headers.headerIterator();
   }

   @Override /* HttpMessage */
   public HeaderIterator headerIterator(String name) {
      return headers.headerIterator(name);
   }

   @SuppressWarnings("deprecation")
   @Override /* HttpMessage */
   public HttpParams getParams() {
      return null;
   }

   @SuppressWarnings("deprecation")
   @Override /* HttpMessage */
   public void setParams(HttpParams params) {
   }

   @Override /* HttpMessage */
   public StatusLine getStatusLine() {
      return statusLine;
   }

   @Override /* HttpMessage */
   public void setStatusLine(StatusLine value) {
      setStatusLine(value.getProtocolVersion(), value.getStatusCode(), value.getReasonPhrase());
   }

   @Override /* HttpMessage */
   public void setStatusLine(ProtocolVersion ver, int code) {
      statusLine.setProtocolVersion(ver).setStatusCode(code);
   }

   @Override /* HttpMessage */
   public void setStatusLine(ProtocolVersion ver, int code, String reason) {
      statusLine.setProtocolVersion(ver).setReasonPhrase(reason).setStatusCode(code);
   }

   @Override /* HttpMessage */
   public void setStatusCode(int code) throws IllegalStateException {
      statusLine.setStatusCode(code);
   }

   @Override /* HttpMessage */
   public void setReasonPhrase(String reason) throws IllegalStateException {
      statusLine.setReasonPhrase(reason);
   }

   @Override /* HttpMessage */
   public HttpEntity getEntity() {
      // Constructing a StringEntity is somewhat expensive, so don't create it unless it's needed.
      if (content == null)
         content = stringEntity(getStatusLine().getReasonPhrase());
      return content;
   }

   @Override /* HttpMessage */
   public void setEntity(HttpEntity entity) {
      assertModifiable();
      this.content = entity;
   }

   @Override /* HttpMessage */
   public Locale getLocale() {
      return statusLine.getLocale();
   }

   @Override /* HttpMessage */
   public void setLocale(Locale loc) {
      statusLine.setLocale(loc);
   }
}