/*
    * Copyright 2015 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.netty.handler.codec.http2;
  
  import io.netty.handler.codec.TooLongFrameException;
  import io.netty.util.internal.UnstableApi;
  
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * A skeletal builder implementation of {@link InboundHttp2ToHttpAdapter} and its subtypes.
   */
  @UnstableApi
  public abstract class AbstractInboundHttp2ToHttpAdapterBuilder<
          T extends InboundHttp2ToHttpAdapter, B extends AbstractInboundHttp2ToHttpAdapterBuilder<T, B>> {
  
      private final Http2Connection connection;
      private int maxContentLength;
      private boolean validateHttpHeaders;
      private boolean propagateSettings;
  
      /**
       * Creates a new {@link InboundHttp2ToHttpAdapter} builder for the specified {@link Http2Connection}.
       *
       * @param connection the object which will provide connection notification events
       *                   for the current connection
       */
      protected AbstractInboundHttp2ToHttpAdapterBuilder(Http2Connection connection) {
          this.connection = checkNotNull(connection, "connection");
      }
  
      @SuppressWarnings("unchecked")
      protected final B self() {
          return (B) this;
      }
  
      /**
       * Returns the {@link Http2Connection}.
       */
      protected Http2Connection connection() {
          return connection;
      }
  
      /**
       * Returns the maximum length of the message content.
       */
      protected int maxContentLength() {
          return maxContentLength;
      }
  
      /**
       * Specifies the maximum length of the message content.
       *
       * @param maxContentLength the maximum length of the message content. If the length of the message content
       *        exceeds this value, a {@link TooLongFrameException} will be raised
       * @return {@link AbstractInboundHttp2ToHttpAdapterBuilder} the builder for the {@link InboundHttp2ToHttpAdapter}
       */
      protected B maxContentLength(int maxContentLength) {
          this.maxContentLength = maxContentLength;
          return self();
      }
  
      /**
       * Return {@code true} if HTTP header validation should be performed.
       */
      protected boolean isValidateHttpHeaders() {
          return validateHttpHeaders;
      }
  
      /**
       * Specifies whether validation of HTTP headers should be performed.
       *
       * @param validate
       * <ul>
       * <li>{@code true} to validate HTTP headers in the http-codec</li>
       * <li>{@code false} not to validate HTTP headers in the http-codec</li>
       * </ul>
       * @return {@link AbstractInboundHttp2ToHttpAdapterBuilder} the builder for the {@link InboundHttp2ToHttpAdapter}
       */
      protected B validateHttpHeaders(boolean validate) {
          validateHttpHeaders = validate;
          return self();
      }
  
      /**
       * Returns {@code true} if a read settings frame should be propagated along the channel pipeline.
       */
     protected boolean isPropagateSettings() {
         return propagateSettings;
     }
 
     /**
      * Specifies whether a read settings frame should be propagated along the channel pipeline.
      *
      * @param propagate if {@code true} read settings will be passed along the pipeline. This can be useful
      *                     to clients that need hold off sending data until they have received the settings.
      * @return {@link AbstractInboundHttp2ToHttpAdapterBuilder} the builder for the {@link InboundHttp2ToHttpAdapter}
      */
     protected B propagateSettings(boolean propagate) {
         propagateSettings = propagate;
         return self();
     }
 
     /**
      * Builds/creates a new {@link InboundHttp2ToHttpAdapter} instance using this builder's current settings.
      */
     protected T build() {
         final T instance;
         try {
             instance = build(connection(), maxContentLength(),
                                      isValidateHttpHeaders(), isPropagateSettings());
         } catch (Throwable t) {
             throw new IllegalStateException("failed to create a new InboundHttp2ToHttpAdapter", t);
         }
         connection.addListener(instance);
         return instance;
     }
 
     /**
      * Creates a new {@link InboundHttp2ToHttpAdapter} with the specified properties.
      */
     protected abstract T build(Http2Connection connection, int maxContentLength,
                                boolean validateHttpHeaders, boolean propagateSettings) throws Exception;
 }