// 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.

#pragma once

#include <gen_cpp/internal_service.pb.h>

#include <atomic>

#include <cstdint>

#include <mutex>

#include <string>

#include "common/status.h"

namespace google::protobuf {

class Closure;

class RpcController;

} // namespace google::protobuf

namespace doris {

class CdcClientMgr {

public:

    CdcClientMgr();

    ~CdcClientMgr();

    void stop();

    // Request CDC client to handle a request

    void request_cdc_client_impl(const PRequestCdcClientRequest* request,

                                 PRequestCdcClientResult* result, google::protobuf::Closure* done);

    Status send_request_to_cdc_client(const std::string& api, const std::string& params_body,

                                      std::string* response);

    Status start_cdc_client(PRequestCdcClientResult* result);

#ifdef BE_TEST

    // For testing only: get current child PID

    pid_t get_child_pid() const { return _get_child_pid(); }

    // For testing only: publish a PID and return its generation-qualified identity.

    uint64_t set_child_pid_for_test(pid_t pid);

    uint64_t get_child_identity_for_test() const { return _get_child_identity(); }

    // For testing only: run the production cleanup gate for an exact identity.

    bool terminate_child_identity_for_test(uint64_t identity);

    // For testing only: inspect the exact identity through the normal WNOHANG path.

    bool inspect_child_identity_for_test(uint64_t identity);

    // For testing only: invoke the installed handler body deterministically.

    static void invoke_sigchld_handler_for_test();

    // For testing only: pause a deterministic handler after it has copied the published identity.

    static void pause_sigchld_handler_for_test(bool pause);

    static bool sigchld_handler_paused_for_test();

    // For testing only: observe a normal thread failing to claim an owned child.

    static void reset_child_claim_failed_for_test();

    static bool child_claim_failed_for_test();

    // For testing only: pause after inspect's WNOHANG=0 observation and before claim release.

    static void pause_child_inspection_after_running_for_test(bool pause);

    static bool child_inspection_paused_for_test();

    // Pause a handler before claiming a copied identity, and after claiming a stale identity.

    static void pause_sigchld_before_claim_for_test(bool pause);

    static bool sigchld_before_claim_paused_for_test();

    static void pause_stale_child_claim_for_test(bool pause);

    static bool stale_child_claim_paused_for_test();

    // For testing only: inspect / drive the adopt-external flag

    bool get_adopted_external_for_test() const { return _adopted_external.load(); }

    void set_adopted_external_for_test(bool v) { _adopted_external.store(v); }

#endif

private:

    uint64_t _get_child_identity() const;

    pid_t _get_child_pid() const;

    uint64_t _publish_child_pid(pid_t pid);

    bool _terminate_child_identity(uint64_t identity);

    std::mutex _start_mutex;

    std::atomic<bool> _adopted_external {false};

};

} // namespace doris