/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  
  /*
   * Copyright 2009 Red Hat, Inc.
   *
   * Red Hat 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.waarp.openr66.protocol.http.rest.client;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.handler.codec.http.FullHttpResponse;
  import io.netty.handler.codec.http.HttpContent;
  import io.netty.handler.codec.http.HttpHeaderNames;
  import io.netty.handler.codec.http.HttpObject;
  import io.netty.handler.codec.http.HttpResponse;
  import io.netty.handler.codec.http.HttpResponseStatus;
  import io.netty.handler.codec.http.LastHttpContent;
  import org.waarp.common.crypto.ssl.WaarpSslUtility;
  import org.waarp.common.json.JsonHandler;
  import org.waarp.common.logging.WaarpLogger;
  import org.waarp.common.logging.WaarpLoggerFactory;
  import org.waarp.common.utility.WaarpNettyUtil;
  import org.waarp.common.utility.WaarpStringUtils;
  import org.waarp.gateway.kernel.exception.HttpIncorrectRequestException;
  import org.waarp.gateway.kernel.exception.HttpInvalidAuthenticationException;
  import org.waarp.gateway.kernel.rest.DataModelRestMethodHandler.COMMAND_TYPE;
  import org.waarp.gateway.kernel.rest.RestArgument;
  import org.waarp.gateway.kernel.rest.client.HttpRestClientSimpleResponseHandler;
  import org.waarp.gateway.kernel.rest.client.RestFuture;
  import org.waarp.openr66.protocol.http.rest.handler.HttpRestAbstractR66Handler.ACTIONS_TYPE;
  
  import java.net.ConnectException;
  import java.nio.channels.ClosedChannelException;
  import java.nio.charset.UnsupportedCharsetException;
  
  /**
   * Rest client response handler.
   * <p>
   * Note: by default, no connection are closed except in case of error or if in
   * HTTP 1.0 or explicitly to be
   * closed.
   */
  public abstract class HttpRestR66ClientResponseHandler
      extends SimpleChannelInboundHandler<HttpObject> {
    /**
     * Internal Logger
     */
    private static final WaarpLogger logger =
        WaarpLoggerFactory.getLogger(HttpRestR66ClientResponseHandler.class);
  
    private ByteBuf cumulativeBody;
    protected JsonNode jsonObject;
  
    protected final void addContent(final FullHttpResponse response)
        throws HttpIncorrectRequestException {
      final ByteBuf content = response.content();
      if (content != null && content.isReadable()) {
        WaarpNettyUtil.retain(content);
        if (cumulativeBody != null) {
          cumulativeBody = Unpooled.wrappedBuffer(cumulativeBody, content);
        } else {
          cumulativeBody = content;
        }
        // get the Json equivalent of the Body
        try {
         final String json = cumulativeBody.toString(WaarpStringUtils.UTF8);
         jsonObject = JsonHandler.getFromString(json);
       } catch (final UnsupportedCharsetException e2) {
         logger.warn("Error" + " : {}", e2.getMessage());
         throw new HttpIncorrectRequestException(e2);
       }
       cumulativeBody = null;
     }
   }
 
   /**
    * Setting the RestArgument to the RestFuture and validating RestFuture.
    *
    * @param channel
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected final void actionFromResponse(final Channel channel)
       throws HttpInvalidAuthenticationException {
     boolean includeValidation = false;
     final RestArgument ra = new RestArgument((ObjectNode) jsonObject);
     if (jsonObject == null) {
       logger.debug("Recv: EMPTY");
     }
     final RestFuture restFuture =
         channel.attr(HttpRestClientSimpleResponseHandler.RESTARGUMENT).get();
     restFuture.setRestArgument(ra);
     switch (ra.getMethod()) {
       case DELETE:
         includeValidation = delete(channel, ra);
         break;
       case GET:
         includeValidation = get(channel, ra);
         break;
       case OPTIONS:
         includeValidation = options(channel, ra);
         break;
       case POST:
         includeValidation = post(channel, ra);
         break;
       case PUT:
         includeValidation = put(channel, ra);
         break;
       default:
         break;
     }
     if (!includeValidation) {
       // finalize the future
       restFuture.setSuccess();
     }
   }
 
   /**
    * Method calls when a action REST command is raised as answer
    *
    * @param channel
    * @param ra
    * @param act
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean action(Channel channel, RestArgument ra,
                                     ACTIONS_TYPE act)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST Get command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbGet(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST Post command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbPost(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST Put command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbPut(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST Delete command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbDelete(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST GetMultiple command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbGetMultiple(Channel channel,
                                                 RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST Options command is raised as answer
    *
    * @param channel
    * @param ra
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterDbOptions(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   /**
    * Method calls when a REST command is in error
    *
    * @param channel
    * @param ra (might be null)
    *
    * @return if validation is done (or suppose to be)
    *
    * @throws HttpInvalidAuthenticationException
    */
   protected abstract boolean afterError(Channel channel, RestArgument ra)
       throws HttpInvalidAuthenticationException;
 
   protected final boolean get(final Channel channel, final RestArgument ra)
       throws HttpInvalidAuthenticationException {
     if (logger.isDebugEnabled()) {
       logger.debug(ra.prettyPrint());
     }
     if (ra.getCommand() == COMMAND_TYPE.GET) {
       return afterDbGet(channel, ra);
     } else if (ra.getCommand() == COMMAND_TYPE.MULTIGET) {
       return afterDbGetMultiple(channel, ra);
     } else {
       final String cmd = ra.getCommandField();
       try {
         final ACTIONS_TYPE act = ACTIONS_TYPE.valueOf(cmd);
         return action(channel, ra, act);
       } catch (final Exception e) {
         return false;
       }
     }
   }
 
   protected final boolean put(final Channel channel, final RestArgument ra)
       throws HttpInvalidAuthenticationException {
     if (logger.isDebugEnabled()) {
       logger.debug(ra.prettyPrint());
     }
     if (ra.getCommand() == COMMAND_TYPE.UPDATE) {
       return afterDbPut(channel, ra);
     } else {
       final String cmd = ra.getCommandField();
       try {
         final ACTIONS_TYPE act = ACTIONS_TYPE.valueOf(cmd);
         return action(channel, ra, act);
       } catch (final Exception e) {
         return false;
       }
     }
   }
 
   protected final boolean post(final Channel channel, final RestArgument ra)
       throws HttpInvalidAuthenticationException {
     if (logger.isDebugEnabled()) {
       logger.debug(ra.prettyPrint());
     }
     if (ra.getCommand() == COMMAND_TYPE.CREATE) {
       return afterDbPost(channel, ra);
     } else {
       final String cmd = ra.getCommandField();
       try {
         final ACTIONS_TYPE act = ACTIONS_TYPE.valueOf(cmd);
         return action(channel, ra, act);
       } catch (final Exception e) {
         return false;
       }
     }
   }
 
   protected final boolean delete(final Channel channel, final RestArgument ra)
       throws HttpInvalidAuthenticationException {
     if (logger.isDebugEnabled()) {
       logger.debug(ra.prettyPrint());
     }
     if (ra.getCommand() == COMMAND_TYPE.DELETE) {
       return afterDbDelete(channel, ra);
     } else {
       final String cmd = ra.getCommandField();
       try {
         final ACTIONS_TYPE act = ACTIONS_TYPE.valueOf(cmd);
         return action(channel, ra, act);
       } catch (final Exception e) {
         return false;
       }
     }
   }
 
   protected final boolean options(final Channel channel, final RestArgument ra)
       throws HttpInvalidAuthenticationException {
     if (logger.isDebugEnabled()) {
       logger.debug(ra.prettyPrint());
     }
     if (ra.getCommand() == COMMAND_TYPE.OPTIONS) {
       return afterDbOptions(channel, ra);
     } else {
       final String cmd = ra.getCommandField();
       try {
         final ACTIONS_TYPE act = ACTIONS_TYPE.valueOf(cmd);
         return action(channel, ra, act);
       } catch (final Exception e) {
         return false;
       }
     }
   }
 
   @Override
   protected void channelRead0(final ChannelHandlerContext ctx,
                               final HttpObject msg) throws Exception {
     if (msg instanceof HttpResponse) {
       final HttpResponse response = (HttpResponse) msg;
       final HttpResponseStatus status = response.status();
       logger.debug("{}: {} STATUS: {}", HttpHeaderNames.REFERER,
                    response.headers().get(HttpHeaderNames.REFERER), status);
       if (response.status().code() != 200) {
         if (response instanceof FullHttpResponse) {
           addContent((FullHttpResponse) response);
         }
         RestArgument ra = null;
         if (jsonObject != null) {
           ra = new RestArgument((ObjectNode) jsonObject);
           final RestFuture restFuture = ctx.channel().attr(
               HttpRestClientSimpleResponseHandler.RESTARGUMENT).get();
           restFuture.setRestArgument(ra);
           logger.error("Error: " + response.status().code() + ' ' +
                        response.status().reasonPhrase() + '\n' +
                        ra.prettyPrint());
         } else {
           logger.error("Error: " + response.status().code() + ' ' +
                        response.status().reasonPhrase());
         }
         if (!afterError(ctx.channel(), ra)) {
           final RestFuture restFuture = ctx.channel().attr(
               HttpRestClientSimpleResponseHandler.RESTARGUMENT).get();
           restFuture.cancel();
         }
         if (ctx.channel().isActive()) {
           logger.debug("Will close");
           WaarpSslUtility.closingSslChannel(ctx.channel());
         }
       } else {
         if (response instanceof FullHttpResponse) {
           addContent((FullHttpResponse) response);
           actionFromResponse(ctx.channel());
         }
       }
     } else {
       final HttpContent chunk = (HttpContent) msg;
       if (chunk instanceof LastHttpContent) {
         final ByteBuf content = chunk.content();
         if (content != null && content.isReadable()) {
           WaarpNettyUtil.retain(content);
           if (cumulativeBody != null) {
             cumulativeBody = Unpooled.wrappedBuffer(cumulativeBody, content);
           } else {
             cumulativeBody = content;
           }
         }
         // get the Json equivalent of the Body
         if (cumulativeBody == null) {
           jsonObject = JsonHandler.createObjectNode();
         } else {
           try {
             final String json = cumulativeBody.toString(WaarpStringUtils.UTF8);
             jsonObject = JsonHandler.getFromString(json);
           } catch (final Throwable e2) {
             logger.warn("Error" + " : {}", e2.getMessage());
             throw new HttpIncorrectRequestException(e2);
           }
           WaarpNettyUtil.release(cumulativeBody);
           cumulativeBody = null;
         }
         actionFromResponse(ctx.channel());
       } else {
         final ByteBuf content = chunk.content();
         if (content != null && content.isReadable()) {
           WaarpNettyUtil.retain(content);
           if (cumulativeBody != null) {
             cumulativeBody = Unpooled.wrappedBuffer(cumulativeBody, content);
           } else {
             cumulativeBody = content;
           }
         }
       }
     }
   }
 
   @Override
   public void exceptionCaught(final ChannelHandlerContext ctx,
                               final Throwable cause) {
     final RestFuture restFuture =
         ctx.channel().attr(HttpRestClientSimpleResponseHandler.RESTARGUMENT)
            .get();
     if (cause instanceof ClosedChannelException) {
       logger.debug("Close before ending");
       restFuture.setFailure(cause);
       return;
     } else if (cause instanceof ConnectException) {
       if (ctx.channel().isActive()) {
         logger.debug("Will close");
         restFuture.setFailure(cause);
         WaarpSslUtility.closingSslChannel(ctx.channel());
       }
       return;
     }
     logger.warn("Error: {}", cause.getMessage());
     if (ctx.channel() != null && restFuture != null) {
       restFuture.setFailure(cause);
     }
     logger.debug("Will close");
     WaarpSslUtility.closingSslChannel(ctx.channel());
   }
 
 }