/*
 * 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.filter;

import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;
import com.google.gson.reflect.TypeToken;

import org.apache.dubbo.common.beanutil.JavaBeanAccessor;
import org.apache.dubbo.common.beanutil.JavaBeanDescriptor;
import org.apache.dubbo.common.beanutil.JavaBeanSerializeUtil;
import org.apache.dubbo.common.config.Configuration;
import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.common.extension.ExtensionLoader;
import org.apache.dubbo.common.io.UnsafeByteArrayInputStream;
import org.apache.dubbo.common.io.UnsafeByteArrayOutputStream;
import org.apache.dubbo.common.logger.Logger;
import org.apache.dubbo.common.logger.LoggerFactory;
import org.apache.dubbo.common.serialize.Serialization;
import org.apache.dubbo.common.utils.PojoUtils;
import org.apache.dubbo.common.utils.ReflectUtils;
import org.apache.dubbo.common.utils.StringUtils;
import org.apache.dubbo.rpc.Filter;
import org.apache.dubbo.rpc.Invocation;
import org.apache.dubbo.rpc.Invoker;
import org.apache.dubbo.rpc.Result;
import org.apache.dubbo.rpc.RpcContext;
import org.apache.dubbo.rpc.RpcException;
import org.apache.dubbo.rpc.RpcInvocation;
import org.apache.dubbo.rpc.model.ApplicationModel;
import org.apache.dubbo.rpc.service.GenericException;
import org.apache.dubbo.rpc.service.GenericService;
import org.apache.dubbo.rpc.support.ProtocolUtils;

import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.stream.IntStream;

import static org.apache.dubbo.common.constants.CommonConstants.$INVOKE;
import static org.apache.dubbo.common.constants.CommonConstants.$INVOKE_ASYNC;
import static org.apache.dubbo.common.constants.CommonConstants.GENERIC_SERIALIZATION_BEAN;
import static org.apache.dubbo.common.constants.CommonConstants.GENERIC_SERIALIZATION_GSON;
import static org.apache.dubbo.common.constants.CommonConstants.GENERIC_SERIALIZATION_NATIVE_JAVA;
import static org.apache.dubbo.common.constants.CommonConstants.GENERIC_SERIALIZATION_PROTOBUF;
import static org.apache.dubbo.rpc.Constants.GENERIC_KEY;

/**
 * GenericInvokerFilter.
 */
@Activate(group = CommonConstants.PROVIDER, order = -20000)
public class GenericFilter implements Filter, Filter.Listener {

    private static final Logger logger = LoggerFactory.getLogger(GenericFilter.class);

    private static final Gson gson = new Gson();

    @Override
    public Result invoke(Invoker<?> invoker, Invocation inv) throws RpcException {
        if ((inv.getMethodName().equals($INVOKE) || inv.getMethodName().equals($INVOKE_ASYNC))
                && inv.getArguments() != null
                && inv.getArguments().length == 3
                && !GenericService.class.isAssignableFrom(invoker.getInterface())) {
            String name = ((String) inv.getArguments()[0]).trim();
            String[] types = (String[]) inv.getArguments()[1];
            Object[] args = (Object[]) inv.getArguments()[2];
            try {
                Method method = ReflectUtils.findMethodByMethodSignature(invoker.getInterface(), name, types);
                Class<?>[] params = method.getParameterTypes();
                if (args == null) {
                    args = new Object[params.length];
                }

                if (types == null) {
                    types = new String[params.length];
                }

                if (args.length != types.length) {
                    throw new RpcException("GenericFilter#invoke args.length != types.length, please check your "
                            + "params");
                }
                String generic = inv.getAttachment(GENERIC_KEY);

                if (StringUtils.isBlank(generic)) {
                    generic = RpcContext.getContext().getAttachment(GENERIC_KEY);
                }

                if (StringUtils.isEmpty(generic)
                        || ProtocolUtils.isDefaultGenericSerialization(generic)
                        || ProtocolUtils.isGenericReturnRawResult(generic)) {
                    try {
                        args = PojoUtils.realize(args, params, method.getGenericParameterTypes());
                    } catch (IllegalArgumentException e) {
                        throw new RpcException(e);
                    }
                } else if (ProtocolUtils.isGsonGenericSerialization(generic)) {
                    args = getGsonGenericArgs(args, method.getGenericParameterTypes());
                } else if (ProtocolUtils.isJavaGenericSerialization(generic)) {
                    Configuration configuration = ApplicationModel.getEnvironment().getConfiguration();
                    if (!configuration.getBoolean(CommonConstants.ENABLE_NATIVE_JAVA_GENERIC_SERIALIZE, false)) {
                        String notice = "Trigger the safety barrier! " +
                                "Native Java Serializer is not allowed by default." +
                                "This means currently maybe being attacking by others. " +
                                "If you are sure this is a mistake, " +
                                "please set `" + CommonConstants.ENABLE_NATIVE_JAVA_GENERIC_SERIALIZE + "` enable in configuration! " +
                                "Before doing so, please make sure you have configure JEP290 to prevent serialization attack.";
                        logger.error(notice);
                        throw new RpcException(new IllegalStateException(notice));
                    }

                    for (int i = 0; i < args.length; i++) {
                        if (byte[].class == args[i].getClass()) {
                            try (UnsafeByteArrayInputStream is = new UnsafeByteArrayInputStream((byte[]) args[i])) {
                                args[i] = ExtensionLoader.getExtensionLoader(Serialization.class)
                                        .getExtension(GENERIC_SERIALIZATION_NATIVE_JAVA)
                                        .deserialize(null, is).readObject();
                            } catch (Exception e) {
                                throw new RpcException("Deserialize argument [" + (i + 1) + "] failed.", e);
                            }
                        } else {
                            throw new RpcException(
                                    "Generic serialization [" +
                                            GENERIC_SERIALIZATION_NATIVE_JAVA +
                                            "] only support message type " +
                                            byte[].class +
                                            " and your message type is " +
                                            args[i].getClass());
                        }
                    }
                } else if (ProtocolUtils.isBeanGenericSerialization(generic)) {
                    for (int i = 0; i < args.length; i++) {
                        if (args[i] instanceof JavaBeanDescriptor) {
                            args[i] = JavaBeanSerializeUtil.deserialize((JavaBeanDescriptor) args[i]);
                        } else {
                            throw new RpcException(
                                    "Generic serialization [" +
                                            GENERIC_SERIALIZATION_BEAN +
                                            "] only support message type " +
                                            JavaBeanDescriptor.class.getName() +
                                            " and your message type is " +
                                            args[i].getClass().getName());
                        }
                    }
                } else if (ProtocolUtils.isProtobufGenericSerialization(generic)) {
                    // as proto3 only accept one protobuf parameter
                    if (args.length == 1 && args[0] instanceof String) {
                        try (UnsafeByteArrayInputStream is =
                                     new UnsafeByteArrayInputStream(((String) args[0]).getBytes())) {
                            args[0] = ExtensionLoader.getExtensionLoader(Serialization.class)
                                    .getExtension(GENERIC_SERIALIZATION_PROTOBUF)
                                    .deserialize(null, is).readObject(method.getParameterTypes()[0]);
                        } catch (Exception e) {
                            throw new RpcException("Deserialize argument failed.", e);
                        }
                    } else {
                        throw new RpcException(
                                "Generic serialization [" +
                                        GENERIC_SERIALIZATION_PROTOBUF +
                                        "] only support one " + String.class.getName() +
                                        " argument and your message size is " +
                                        args.length + " and type is" +
                                        args[0].getClass().getName());
                    }
                }

                RpcInvocation rpcInvocation =
                        new RpcInvocation(method, invoker.getInterface().getName(), invoker.getUrl().getProtocolServiceKey(), args,
                                inv.getObjectAttachments(), inv.getAttributes());
                rpcInvocation.setInvoker(inv.getInvoker());
                rpcInvocation.setTargetServiceUniqueName(inv.getTargetServiceUniqueName());

                return invoker.invoke(rpcInvocation);
            } catch (NoSuchMethodException | ClassNotFoundException e) {
                throw new RpcException(e.getMessage(), e);
            }
        }
        return invoker.invoke(inv);
    }

    private Object[] getGsonGenericArgs(final Object[] args, Type[] types) {
        return IntStream.range(0, args.length).mapToObj(i -> {
            if (!(args[i] instanceof String)) {
                throw new RpcException("When using GSON to deserialize generic dubbo request arguments, the arguments must be of type String");
            }
            String str = args[i].toString();
            Type type = TypeToken.get(types[i]).getType();
            try {
                return gson.fromJson(str, type);
            } catch (JsonSyntaxException ex) {
                throw new RpcException(String.format("Generic serialization [%s] Json syntax exception thrown when parsing (message:%s type:%s) error:%s", GENERIC_SERIALIZATION_GSON, str, type.toString(), ex.getMessage()));
            }
        }).toArray();
    }

    @Override
    public void onResponse(Result appResponse, Invoker<?> invoker, Invocation inv) {
        if ((inv.getMethodName().equals($INVOKE) || inv.getMethodName().equals($INVOKE_ASYNC))
                && inv.getArguments() != null
                && inv.getArguments().length == 3
                && !GenericService.class.isAssignableFrom(invoker.getInterface())) {

            String generic = inv.getAttachment(GENERIC_KEY);
            if (StringUtils.isBlank(generic)) {
                generic = RpcContext.getContext().getAttachment(GENERIC_KEY);
            }

            if (appResponse.hasException()) {
                Throwable appException = appResponse.getException();
                if (appException instanceof GenericException) {
                    GenericException tmp = (GenericException) appException;
                    appException = new com.alibaba.dubbo.rpc.service.GenericException(tmp.getExceptionClass(), tmp.getExceptionMessage());
                }
                if (!(appException instanceof com.alibaba.dubbo.rpc.service.GenericException)) {
                    appException = new com.alibaba.dubbo.rpc.service.GenericException(appException);
                }
                appResponse.setException(appException);
            }
            if (ProtocolUtils.isJavaGenericSerialization(generic)) {
                try {
                    UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream(512);
                    ExtensionLoader.getExtensionLoader(Serialization.class).getExtension(GENERIC_SERIALIZATION_NATIVE_JAVA)
                            .serialize(null, os).writeObject(appResponse.getValue());
                    appResponse.setValue(os.toByteArray());
                } catch (IOException e) {
                    throw new RpcException(
                            "Generic serialization [" +
                                    GENERIC_SERIALIZATION_NATIVE_JAVA +
                                    "] serialize result failed.", e);
                }
            } else if (ProtocolUtils.isBeanGenericSerialization(generic)) {
                appResponse.setValue(JavaBeanSerializeUtil.serialize(appResponse.getValue(), JavaBeanAccessor.METHOD));
            } else if (ProtocolUtils.isProtobufGenericSerialization(generic)) {
                try {
                    UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream(512);
                    ExtensionLoader.getExtensionLoader(Serialization.class)
                            .getExtension(GENERIC_SERIALIZATION_PROTOBUF)
                            .serialize(null, os).writeObject(appResponse.getValue());
                    appResponse.setValue(os.toString());
                } catch (IOException e) {
                    throw new RpcException("Generic serialization [" +
                            GENERIC_SERIALIZATION_PROTOBUF +
                            "] serialize result failed.", e);
                }
            } else if (ProtocolUtils.isGenericReturnRawResult(generic)) {
                return;
            } else {
                appResponse.setValue(PojoUtils.generalize(appResponse.getValue()));
            }
        }
    }

    @Override
    public void onError(Throwable t, Invoker<?> invoker, Invocation invocation) {

    }
}
