// 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.

#include <pthread.h>
#include <fstream>
#include <sstream>

#include "cube/cube_bvar.h"
#include "cube/dict.h"
#include "cube/dict_set.h"
#include "cube/framework.h"
#include "cube/recycle.h"

using BUTIL_RAPIDJSON_NAMESPACE::Document;
using BUTIL_RAPIDJSON_NAMESPACE::Value;
using BUTIL_RAPIDJSON_NAMESPACE::StringRef;

namespace {
static ::rec::mcube::Framework* g_instance = NULL;
}

namespace rec {
namespace mcube {

Framework* Framework::instance() {
  if (g_instance == NULL) {
    g_instance = new Framework();
  }

  return g_instance;
}

Framework::~Framework() {}

int Framework::init(uint32_t dict_split, bool in_mem) {
  Recycle* rec = Recycle::get_instance();
  int ret = rec->init();
  if (ret != 0) {
    LOG(ERROR) << "init recycle failed";
    return ret;
  }

  /*
  _dict[0] = new (std::nothrow) Dict();
  _dict[1] = NULL;
  */
  init_dict(dict_split);
  VirtualDict* cur_dict = _dict[_dict_idx];
  _dict_path = "./data";
  _max_val_size = 1024;
  _in_mem = in_mem;

  std::string version_file = _dict_path + "/VERSION";
  std::string version_path = "";
  std::ifstream input(version_file.c_str());
  if (!std::getline(input, version_path)) {
    version_path = "";
  } else {
    version_path = "/" + version_path;
  }
  input.close();

  LOG(INFO) << "load dict from" << _dict_path << version_path;
  if (_dict_split > 1) {
    _dict_set_path.clear();
    _dict_set_path.resize(_dict_split);
    std::stringstream dict_set_path_buf;
    for (size_t i = 0; i < _dict_split; ++i) {
      dict_set_path_buf.str(std::string());
      dict_set_path_buf.clear();
      dict_set_path_buf << _dict_path << "/" << i;
      _dict_set_path[i] = dict_set_path_buf.str();
    }
    ret = cur_dict->load(_dict_set_path, _in_mem, version_path);
  } else {
    ret = cur_dict->load(_dict_path, _in_mem, version_path);
  }

  if (ret != 0) {
    LOG(WARNING) << "init: load dict data failed err=" << ret
                 << ". starting service with empty data.";
  } else {
    LOG(INFO) << "load dict from " << _dict_path << version_path << " done";
  }

  _status = Status::F_RUNNING;

  return 0;
}

int Framework::destroy() {
  Recycle* recycle = Recycle::get_instance();
  int ret = recycle->destroy();
  if (ret != 0) {
    LOG(WARNING) << "destroy recycle failed";
  }
  return 0;
}

void Framework::init_dict(uint32_t dict_split) {
  _dict_split = dict_split;

  if (_dict_split <= 1) {
    _dict[0] = new (std::nothrow) Dict();
    _dict[1] = NULL;
  } else {
    _dict[0] = new (std::nothrow) DictSet(_dict_split);
    _dict[1] = NULL;
  }
}

VirtualDict* Framework::create_dict() {
  if (_dict_split > 1) {
    return new (std::nothrow) DictSet(_dict_split);
  } else {
    return new (std::nothrow) Dict();
  }
}

void Framework::release(VirtualDict* dict) { dict->atom_dec_seek_num(); }

int Framework::status(Document* res) {
  res->SetObject();
  Document::AllocatorType& allocator = res->GetAllocator();
  Value cur_version;
  Value bg_version;
  cur_version.SetString(StringRef(get_cur_version().c_str()));
  bg_version.SetString(StringRef((get_bg_version().c_str())));
  res->AddMember("cur_version", cur_version, allocator);
  res->AddMember("bg_version", bg_version, allocator);
  res->AddMember("status", _status.load(), allocator);
  return 0;
}

int Framework::seek(const DictRequest* req, DictResponse* res) {
  g_request_num << 1;
  VirtualDict* cur_dict = get_cur_dict();
  char* val_buf = new char[_max_val_size];
  g_keys_num << req->keys_size();
  g_total_key_num << req->keys_size();

  std::vector<DictValue*> values(req->keys_size());
  for (int i = 0; i < req->keys_size(); ++i) {
    values[i] = res->add_values();
  }

  for (int i = 0; i < req->keys_size(); ++i) {
    uint64_t val_size = _max_val_size;
    // DictValue* val = res->add_values();
    DictValue* val = values[i];
    if (cur_dict->seek(req->keys(i), val_buf, &val_size)) {
      val->set_status(0);
      val->set_value(val_buf, val_size);
    } else {
      val->set_status(-1);
      val->set_value("");
    }
  }

  if (req->version_required()) {
    res->set_version(cur_dict->version());
  }

  // delete [] keys;
  delete[] val_buf;
  release(cur_dict);
  return 0;
}

int Framework::reload(const std::string& v_path) {
  int ret = bg_load_base(v_path);
  if (ret != 0) {
    LOG(WARNING) << "background load dict base failed";
  } else {
    LOG(INFO) << "background load dict base succ";
  }

  ret = bg_switch();
  if (ret != 0) {
    LOG(WARNING) << "switch background dict failed";
  } else {
    LOG(INFO) << "switch background dict succ";
  }

  ret = bg_unload();
  if (ret != 0) {
    LOG(WARNING) << "unload background dict failed";
  } else {
    LOG(INFO) << "unload background dict succ";
  }

  return ret;
}

int Framework::patch(const std::string& v_path) {
  int ret = bg_load_patch(v_path);
  if (ret != 0) {
    LOG(WARNING) << "background load dict patch failed";
  } else {
    LOG(INFO) << "background load dict patch succ";
  }

  ret = bg_switch();
  if (ret != 0) {
    LOG(WARNING) << "switch background dict failed";
  } else {
    LOG(INFO) << "switch background dict succ";
  }

  ret = bg_unload();
  if (ret != 0) {
    LOG(WARNING) << "unload background dict failed";
  } else {
    LOG(INFO) << "unload background dict succ";
  }

  return ret;
}

int Framework::bg_load_base(const std::string& v_path) {
  int ret = bg_unload();
  if (ret != 0) {
    LOG(WARNING) << "unload background dict failed";
  }

  VirtualDict* bg_dict = create_dict();

  if (!bg_dict) {
    LOG(ERROR) << "create Dict failed";
    return -1;
  }

  _status = Status::F_LOADING;
  if (_dict_split > 1) {
    ret = bg_dict->load(_dict_set_path, _in_mem, v_path);
  } else {
    ret = bg_dict->load(_dict_path, _in_mem, v_path);
  }
  _status = Status::F_RUNNING;
  if (ret != 0) {
    LOG(WARNING) << "load background dict failed";
    delete bg_dict;
    bg_dict = NULL;
    return ret;
  } else {
    LOG(INFO) << "load background dict succ";
    set_bg_dict(bg_dict);
  }

  return ret;
}

int Framework::bg_load_patch(const std::string& v_path) {
  int ret = bg_unload();
  if (ret != 0) {
    LOG(WARNING) << "unload background dict failed";
  }

  VirtualDict* bg_dict = create_dict();

  if (!bg_dict) {
    LOG(ERROR) << "create Dict failed";
    return -1;
  }

  _status = Status::F_LOADING;
  if (_dict[_dict_idx]) {
    bg_dict->set_base_dict(_dict[_dict_idx]);
    LOG(INFO) << "set base dict from current dict " << _dict_idx;
  }

  if (_dict_split > 1) {
    ret = bg_dict->load(_dict_set_path, _in_mem, v_path);
  } else {
    ret = bg_dict->load(_dict_path, _in_mem, v_path);
  }
  _status = Status::F_RUNNING;
  if (ret != 0) {
    LOG(WARNING) << "load background dict failed";
    delete bg_dict;
    bg_dict = NULL;
    return ret;
  } else {
    LOG(INFO) << "load background dict succ";
    set_bg_dict(bg_dict);
  }
  return ret;
}

int Framework::bg_unload() {
  VirtualDict* bg_dict = get_bg_dict();
  if (bg_dict != NULL) {
    set_bg_dict(NULL);
    Recycle* recycle = Recycle::get_instance();
    recycle->recycle(bg_dict);
  }
  LOG(INFO) << "unload background dict succ";
  return 0;
}

int Framework::bg_switch() {
  _rw_lock.w_lock();
  int bg_idx = 1 - _dict_idx;
  if (!_dict[bg_idx]) {
    LOG(WARNING) << "switch dict failed because NULL";
    _rw_lock.unlock();
    return -1;
  }
  _dict_idx = bg_idx;
  _rw_lock.unlock();
  return 0;
}

int Framework::enable(const std::string& version) {
  int ret = 0;
  if (version != "" && version == get_cur_version()) {
    ret = 0;
  } else if (version == get_bg_version()) {
    ret = bg_switch();
  } else {
    LOG(WARNING) << "bg dict version not matched";
    ret = -1;
  }
  return ret;
}

}  // namespace mcube
}  // namespace rec