// Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed 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 <stdint.h>
#include <string>
#include <vector>

#include "brpc/server.h"
#include "cube/cube-api/cube.pb.h"
#include "cube/cube-api/include/meta.h"

namespace rec {
namespace mcube {

struct CubeValue {
  int error;
  std::string buff;
};

class CubeAPI {
 public:
  static CubeAPI* instance();

  static void cleanup();

 public:
  CubeAPI();
  ~CubeAPI();

  /**
   * @brief: init api, not thread safe, should be called before seek.
   * @param [in] conf_file: filepath of config file.
   * @return: error code. 0 for succ.
   */
  int init(const char* conf_file);

  /**
   * @brief: destroy api, should be called before program exit.
   * @return: error code. 0 for succ.
   */
  int destroy();

  /** brief: get data from cube server, thread safe.
   * @param [in] dict_name: dict name.
   * @param [in] key: key to seek.
   * @param [out] val: value of key.
   * @return: error code. 0 for succ.
   */
  int seek(const std::string& dict_name, const uint64_t& key, CubeValue* val);

  /**
   * @brief: get data from cube server, thread safe.
   * @param [in] dict_name: dict name.
   * @param [in] keys: keys to seek.
   * @param [out] vals: value of keys.
   * @return: TODO
   */
  int seek(const std::string& dict_name,
           const std::vector<uint64_t>& keys,
           std::vector<CubeValue>* vals);

  int opt_seek(const std::string& dict_name,
               const std::vector<uint64_t>& keys,
               std::function<void(DictValue*, size_t)> parse);

  /**
   * @brief: get data from cube server, thread safe.
   * @param [in] dict_name: dict name.
   * @param [in] keys: keys to seek.
   * @param [out] vals: value of keys.
   * @param [out] version: data version.
   * @return: TODO
   */
  int seek(const std::string& dict_name,
           const std::vector<uint64_t>& keys,
           std::vector<CubeValue>* vals,
           std::string* version);

  int opt_seek(const std::string& dict_name,
               const std::vector<uint64_t>& keys,
               std::function<void(DictValue*, size_t)> parse,
               std::string* version);

 public:
  static const char* error_msg(int error_code);

 private:
  CubeAPI(const CubeAPI&) {}

 private:
  Meta* _meta;
  bthread_key_t _tls_key;
  // void split(const std::vector<uint64_t>& keys);
};

}  // namespace mcube
}  // namespace rec