/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.hc.core5.http2.frame;
  
  import java.nio.ByteBuffer;
  import java.nio.charset.StandardCharsets;
  
  import org.apache.hc.core5.http2.H2Error;
  import org.apache.hc.core5.http2.config.H2Setting;
  import org.apache.hc.core5.util.Args;
  
  /**
   * Abstract {@link RawFrame} factory that supports standard
   * HTTP/2 {@link FrameType}s.
   *
   * @since 5.0
   */
  public abstract class FrameFactory {
  
      public RawFrame createSettings(final H2Setting... settings) {
          final ByteBuffer payload = ByteBuffer.allocate(settings.length * 12);
          for (final H2Setting setting: settings) {
              payload.putShort((short) setting.getCode());
              payload.putInt(setting.getValue());
          }
          payload.flip();
          return new RawFrame(FrameType.SETTINGS.getValue(), 0, 0, payload);
      }
  
      public RawFrame createSettingsAck() {
          return new RawFrame(FrameType.SETTINGS.getValue(), FrameFlag.ACK.getValue(), 0, null);
      }
  
      public RawFrame createResetStream(final int streamId, final H2Error error) {
          Args.notNull(error, "Error");
          return createResetStream(streamId, error.getCode());
      }
  
      public RawFrame createResetStream(final int streamId, final int code) {
          Args.positive(streamId, "Stream id");
          final ByteBuffer payload = ByteBuffer.allocate(4);
          payload.putInt(code);
          payload.flip();
          return new RawFrame(FrameType.RST_STREAM.getValue(), 0, streamId, payload);
      }
  
      public RawFrame createPing(final ByteBuffer opaqueData) {
          Args.notNull(opaqueData, "Opaque data");
          Args.check(opaqueData.remaining() == 8, "Opaque data length must be equal 8");
          return new RawFrame(FrameType.PING.getValue(), 0, 0, opaqueData);
      }
  
      public RawFrame createPingAck(final ByteBuffer opaqueData) {
          Args.notNull(opaqueData, "Opaque data");
          Args.check(opaqueData.remaining() == 8, "Opaque data length must be equal 8");
          return new RawFrame(FrameType.PING.getValue(), FrameFlag.ACK.value, 0, opaqueData);
      }
  
      public RawFrame createGoAway(final int lastStream, final H2Error error, final String message) {
          Args.notNegative(lastStream, "Last stream id");
          final byte[] debugData = message != null ? message.getBytes(StandardCharsets.US_ASCII) : null;
          final ByteBuffer payload = ByteBuffer.allocate(8 + (debugData != null ? debugData.length : 0));
          payload.putInt(lastStream);
          payload.putInt(error.getCode());
          if (debugData != null) {
              payload.put(debugData);
          }
          payload.flip();
          return new RawFrame(FrameType.GOAWAY.getValue(), 0, 0, payload);
      }
  
      public abstract RawFrame createHeaders(int streamId, ByteBuffer payload, boolean endHeaders, boolean endStream);
  
      public abstract RawFrame createContinuation(int streamId, ByteBuffer payload, boolean endHeaders);
 
     public abstract RawFrame createPushPromise(int streamId, ByteBuffer payload, boolean endHeaders);
 
     public abstract RawFrame createData(int streamId, ByteBuffer payload, boolean endStream);
 
     public RawFrame createWindowUpdate(final int streamId, final int increment) {
         Args.notNegative(streamId, "Stream id");
         Args.positive(increment, "Increment");
         final ByteBuffer payload = ByteBuffer.allocate(4);
         payload.putInt(increment);
         payload.flip();
         return new RawFrame(FrameType.WINDOW_UPDATE.getValue(), 0, streamId, payload);
     }
 
 }