/*
    * Copyright 2013 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty5.handler.codec.http.websocketx;
  
  import io.netty5.channel.ChannelHandler;
  import io.netty5.channel.ChannelHandlerContext;
  import io.netty5.handler.codec.http.FullHttpResponse;
  import io.netty5.util.concurrent.Future;
  import io.netty5.util.concurrent.Promise;
  
  import java.util.concurrent.TimeUnit;
  
  import static io.netty5.util.internal.ObjectUtil.checkPositive;
  
  class WebSocketClientProtocolHandshakeHandler implements ChannelHandler {
  
      private static final long DEFAULT_HANDSHAKE_TIMEOUT_MS = 10000L;
  
      private final WebSocketClientHandshaker handshaker;
      private final long handshakeTimeoutMillis;
      private ChannelHandlerContext ctx;
      private Promise<Void> handshakePromise;
  
      WebSocketClientProtocolHandshakeHandler(WebSocketClientHandshaker handshaker) {
          this(handshaker, DEFAULT_HANDSHAKE_TIMEOUT_MS);
      }
  
      WebSocketClientProtocolHandshakeHandler(WebSocketClientHandshaker handshaker, long handshakeTimeoutMillis) {
          this.handshaker = handshaker;
          this.handshakeTimeoutMillis = checkPositive(handshakeTimeoutMillis, "handshakeTimeoutMillis");
      }
  
      @Override
      public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
          this.ctx = ctx;
          handshakePromise = ctx.newPromise();
      }
  
      @Override
      public void channelActive(final ChannelHandlerContext ctx) throws Exception {
          ctx.fireChannelActive();
          handshaker.handshake(ctx.channel()).addListener(future -> {
              if (future.isFailed()) {
                  handshakePromise.tryFailure(future.cause());
                  ctx.fireChannelExceptionCaught(future.cause());
              }
          });
          applyHandshakeTimeout();
      }
  
      @Override
      public void channelInactive(ChannelHandlerContext ctx) throws Exception {
          if (!handshakePromise.isDone()) {
              handshakePromise.tryFailure(new WebSocketClientHandshakeException("channel closed with handshake " +
                                                                                "in progress"));
          }
  
          ctx.fireChannelInactive();
      }
  
      @Override
      public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
          if (!(msg instanceof FullHttpResponse)) {
              ctx.fireChannelRead(msg);
              return;
          }
  
          try (FullHttpResponse response = (FullHttpResponse) msg) {
              if (!handshaker.isHandshakeComplete()) {
                  handshaker.finishHandshake(ctx.channel(), response);
                  handshakePromise.trySuccess(null);
                  ctx.fireChannelInboundEvent(new WebSocketClientHandshakeCompletionEvent(handshaker.version()));
                  ctx.pipeline().remove(this);
                  return;
              }
              throw new IllegalStateException("WebSocketClientHandshaker should have been non finished yet");
          }
      }
  
      private void applyHandshakeTimeout() {
          final Promise<Void> localHandshakePromise = handshakePromise;
          if (handshakeTimeoutMillis <= 0 || localHandshakePromise.isDone()) {
              return;
          }
  
          final Future<?> timeoutFuture = ctx.executor().schedule(() -> {
             if (localHandshakePromise.isDone()) {
                 return;
             }
 
             WebSocketHandshakeException exception = new WebSocketHandshakeTimeoutException(
                     "handshake timed out after " + handshakeTimeoutMillis + "ms");
             if (localHandshakePromise.tryFailure(exception)) {
                 ctx.flush()
                    .fireChannelInboundEvent(new WebSocketClientHandshakeCompletionEvent(exception))
                    .close();
             }
         }, handshakeTimeoutMillis, TimeUnit.MILLISECONDS);
 
         // Cancel the handshake timeout when handshake is finished.
         localHandshakePromise.asFuture().addListener(f -> timeoutFuture.cancel());
     }
 
     /**
      * This method is visible for testing.
      *
      * @return current handshake future
      */
     Future<Void> getHandshakeFuture() {
         return handshakePromise.asFuture();
     }
 }