/*
 * 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.dubbo.rpc.protocol.tri.transport;

import org.apache.dubbo.common.logger.ErrorTypeAwareLogger;
import org.apache.dubbo.common.logger.LoggerFactory;
import org.apache.dubbo.rpc.HeaderFilter;
import org.apache.dubbo.rpc.PathResolver;
import org.apache.dubbo.rpc.TriRpcStatus;
import org.apache.dubbo.rpc.executor.ExecutorSupport;
import org.apache.dubbo.rpc.model.FrameworkModel;
import org.apache.dubbo.rpc.protocol.tri.compressor.DeCompressor;
import org.apache.dubbo.rpc.protocol.tri.stream.TripleServerStream;

import java.util.List;
import java.util.concurrent.Executor;

import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http2.Http2DataFrame;
import io.netty.handler.codec.http2.Http2HeadersFrame;
import io.netty.handler.codec.http2.Http2ResetFrame;
import io.netty.handler.codec.http2.Http2StreamChannel;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.ReferenceCounted;

import static org.apache.dubbo.common.constants.LoggerCodeConstants.PROTOCOL_FAILED_RESPONSE;

public class TripleHttp2FrameServerHandler extends ChannelDuplexHandler {

    private static final ErrorTypeAwareLogger LOGGER =
            LoggerFactory.getErrorTypeAwareLogger(TripleHttp2FrameServerHandler.class);
    private final PathResolver pathResolver;
    private final ExecutorSupport executorSupport;
    private final String acceptEncoding;
    private final TripleServerStream tripleServerStream;

    public TripleHttp2FrameServerHandler(
            FrameworkModel frameworkModel,
            ExecutorSupport executorSupport,
            List<HeaderFilter> filters,
            Http2StreamChannel channel,
            TripleWriteQueue writeQueue) {
        this.executorSupport = executorSupport;
        this.acceptEncoding = String.join(
                ",", frameworkModel.getExtensionLoader(DeCompressor.class).getSupportedExtensions());
        this.pathResolver =
                frameworkModel.getExtensionLoader(PathResolver.class).getDefaultExtension();
        // The executor will be assigned in onHeadersRead method
        tripleServerStream = new TripleServerStream(
                channel, frameworkModel, null, pathResolver, acceptEncoding, filters, writeQueue);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof Http2HeadersFrame) {
            onHeadersRead(ctx, (Http2HeadersFrame) msg);
        } else if (msg instanceof Http2DataFrame) {
            onDataRead(ctx, (Http2DataFrame) msg);
        } else if (msg instanceof ReferenceCounted) {
            // ignored
            ReferenceCountUtil.release(msg);
        }
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        if (evt instanceof Http2ResetFrame) {
            onResetRead(ctx, (Http2ResetFrame) evt);
        } else {
            super.userEventTriggered(ctx, evt);
        }
    }

    public void onResetRead(ChannelHandlerContext ctx, Http2ResetFrame frame) {
        LOGGER.warn(
                PROTOCOL_FAILED_RESPONSE, "", "", "Triple Server received remote reset errorCode=" + frame.errorCode());
        if (tripleServerStream != null) {
            tripleServerStream.transportObserver.cancelByRemote(frame.errorCode());
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        if (LOGGER.isWarnEnabled()) {
            LOGGER.warn(PROTOCOL_FAILED_RESPONSE, "", "", "Exception in processing triple message", cause);
        }
        TriRpcStatus status = TriRpcStatus.getStatus(cause, "Provider's error:\n" + cause.getMessage());
        tripleServerStream.cancelByLocal(status);
    }

    public void onDataRead(ChannelHandlerContext ctx, Http2DataFrame msg) throws Exception {
        tripleServerStream.transportObserver.onData(msg.content(), msg.isEndStream());
    }

    public void onHeadersRead(ChannelHandlerContext ctx, Http2HeadersFrame msg) throws Exception {
        Executor executor = executorSupport.getExecutor(msg.headers());
        tripleServerStream.setExecutor(executor);
        tripleServerStream.transportObserver.onHeader(msg.headers(), msg.isEndStream());
    }
}
