/*
 * 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.common.utils.Utils.*;
import static org.apache.juneau.http.HttpEntities.*;
import static org.apache.juneau.http.HttpHeaders.*;

import java.lang.reflect.*;
import java.text.*;
import java.util.*;

import org.apache.http.*;
import org.apache.http.impl.*;
import org.apache.http.params.*;
import org.apache.juneau.*;
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 for error responses.
 *
 * <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>
 *
 * @serial exclude
 */
@BeanIgnore /* Use toString() to serialize */
public class BasicHttpException extends BasicRuntimeException implements HttpResponse {

   private static final long serialVersionUID = 1L;

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

   /**
    * Constructor.
    *
    * @param statusCode The HTTP status code.
    * @param cause The caused-by exception.  Can be <jk>null</jk>.
    * @param msg The message.  Can be <jk>null</jk>.
    * @param args The message arguments.
    */
   public BasicHttpException(int statusCode, Throwable cause, String msg, Object...args) {
      super(cause, msg, args);
      setStatusCode(statusCode);
      setContent(f(msg, args));
   }

   /**
    * Constructor.
    *
    * @param statusCode The HTTP status code.
    */
   public BasicHttpException(int statusCode) {
      super((Throwable)null);
      setStatusCode(statusCode);
   }

   /**
    * Constructor.
    *
    * @param statusCode The HTTP status code.
    * @param msg The message.  Can be <jk>null</jk>.
    * @param args Optional {@link MessageFormat}-style arguments in the message.
    */
   public BasicHttpException(int statusCode, String msg, Object...args) {
      super(msg, args);
      setStatusCode(statusCode);
   }

   /**
    * Constructor.
    *
    * @param statusCode The HTTP status code.
    * @param causedBy The cause.  Can be <jk>null</jk>.
    */
   public BasicHttpException(int statusCode, Throwable causedBy) {
      super(causedBy);
      setStatusCode(statusCode);
   }

   /**
    * Constructor.
    */
   public BasicHttpException() {
      super((Throwable)null);
   }

   /**
    * Constructor.
    *
    * <p>
    * This is the constructor used when parsing an HTTP response.
    *
    * @param response The HTTP response being parsed.
    */
   public BasicHttpException(HttpResponse response) {
      super((Throwable)null);
      Header h = response.getLastHeader("Thrown");
      if (h != null)
         setMessage(thrown(h.getValue()).asParts().get().get(0).getMessage());
      setHeaders(response.getAllHeaders());
      setContent(response.getEntity());
      setStatusCode(response.getStatusLine().getStatusCode());
   }

   /**
    * Copy constructor.
    *
    * @param copyFrom The bean to copy.
    */
   protected BasicHttpException(BasicHttpException copyFrom) {
      this(0, copyFrom.getCause(), copyFrom.getMessage());
      setStatusLine(copyFrom.statusLine.copy());
   }

   //-----------------------------------------------------------------------------------------------------------------
   // 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.
    */
   @Override
   public BasicHttpException setUnmodifiable() {
      super.setUnmodifiable();
      statusLine.setUnmodifiable();
      return this;
   }

   //-----------------------------------------------------------------------------------------------------------------
   // 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 BasicHttpException setStatusLine(BasicStatusLine value) {
      assertModifiable();
      statusLine = value.copy();
      return this;
   }

   /**
    * Same as {@link #setStatusCode(int)} but returns this object.
    *
    * @param code The new status code.
    * @return This object.
    * @throws IllegalStateException If status code could not be set.
    */
   public BasicHttpException setStatusCode2(int code) throws IllegalStateException {
      setStatusCode(code);
      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 BasicHttpException 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 BasicHttpException 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 BasicHttpException 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 BasicHttpException 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() {
      assertModifiable();
      return headers;
   }

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

   /**
    * Sets a header on this response.
    *
    * @param name The header name.
    * @param value The header value.
    * @return This object.
    */
   public BasicHttpException setHeader2(String name, Object value) {
      headers.set(name, value);
      return this;
   }

   /**
    * Sets multiple headers on this response.
    *
    * @param values The headers to add.
    * @return This object.
    */
   public BasicHttpException setHeaders2(Header...values) {
      headers.set(values);
      return this;
   }

   /**
    * Sets the specified headers on this response.
    *
    * @param values The headers to set.  <jk>null</jk> values are ignored.
    * @return This object.
    */
   public BasicHttpException setHeaders(List<Header> values) {
      headers.set(values);
      return this;
   }

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

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

   /**
    * Sets the body on this response.
    *
    * @param value The body on this response.
    * @return This object.
    */
   public BasicHttpException 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);
   }

   /**
    * Returns the root cause of this exception.
    *
    * <p>
    * The root cause is the first exception in the init-cause parent chain that's not one of the following:
    * <ul>
    *    <li>{@link BasicHttpException}
    *    <li>{@link InvocationTargetException}
    * </ul>
    *
    * @return The root cause of this exception, or <jk>null</jk> if no root cause was found.
    */
   public Throwable getRootCause() {
      Throwable t = this;
      while(t != null) {
         if (! (t instanceof BasicHttpException || t instanceof InvocationTargetException))
            return t;
         t = t.getCause();
      }
      return null;
   }

   /**
    * Returns all error messages from all errors in this stack.
    *
    * <p>
    * Typically useful if you want to render all the error messages in the stack, but don't want to render all the
    * stack traces too.
    *
    * @param scrubForXssVulnerabilities
    *    If <jk>true</jk>, replaces <js>'&lt;'</js>, <js>'&gt;'</js>, and <js>'&amp;'</js> characters with spaces.
    * @return All error messages from all errors in this stack.
    */
   public String getFullStackMessage(boolean scrubForXssVulnerabilities) {
      String msg = getMessage();
      StringBuilder sb = new StringBuilder();
      if (msg != null) {
         if (scrubForXssVulnerabilities)
            msg = msg.replace('<', ' ').replace('>', ' ').replace('&', ' ');
         sb.append(msg);
      }
      Throwable e = getCause();
      while (e != null) {
         msg = e.getMessage();
         if (msg != null && scrubForXssVulnerabilities)
            msg = msg.replace('<', ' ').replace('>', ' ').replace('&', ' ');
         String cls = e.getClass().getSimpleName();
         if (msg == null)
            sb.append(f("\nCaused by ({0})", cls));
         else
            sb.append(f("\nCaused by ({0}): {1}", cls, msg));
         e = e.getCause();
      }
      return sb.toString();
   }

   @Override /* Throwable */
   public String getMessage() {
      String m = super.getMessage();
      if (m == null && getCause() != null)
         m = getCause().getMessage();
      if (m == null)
         m = statusLine.getReasonPhrase();
      return m;
   }

   @Override /* Object */
   public int hashCode() {
      int i = 0;
      Throwable t = this;
      while (t != null) {
         for (StackTraceElement e : t.getStackTrace())
         i ^= e.hashCode();
         t = t.getCause();
      }
      return i;
   }

   @Override /* Object */
   public String toString() {
      return emptyIfNull(getLocalizedMessage());
   }

   @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(getMessage());
      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);
   }
   @Override /* Overridden from BasicRuntimeException */
   public BasicHttpException setMessage(String message, Object...args) {
      super.setMessage(message, args);
      return this;
   }
}