/*
 * 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.
 */

#ifndef CPP_PACKAGE_EXAMPLE_UTILS_H_
#define CPP_PACKAGE_EXAMPLE_UTILS_H_

#include <string>
#include <fstream>
#include <vector>
#include "mxnet-cpp/MxNetCpp.h"

using namespace mxnet::cpp;

#define TRY try {
#define CATCH                                 \
  }                                           \
  catch (dmlc::Error & err) {                 \
    LG << "Status: FAIL";                     \
    LG << "With Error: " << MXGetLastError(); \
    return 1;                                 \
  }

bool isFileExists(const std::string& filename) {
  std::ifstream fhandle(filename.c_str());
  return fhandle.good();
}

bool check_datafiles(const std::vector<std::string>& data_files) {
  for (size_t index = 0; index < data_files.size(); index++) {
    if (!(isFileExists(data_files[index]))) {
      LG << "Error: File does not exist: " << data_files[index];
      return false;
    }
  }
  return true;
}

bool setDataIter(MXDataIter* iter,
                 const std::string& useType,
                 const std::vector<std::string>& data_files,
                 int batch_size) {
  if (!check_datafiles(data_files)) {
    return false;
  }

  iter->SetParam("batch_size", batch_size);
  iter->SetParam("shuffle", 1);
  iter->SetParam("flat", 1);

  if (useType == "Train") {
    iter->SetParam("image", data_files[0]);
    iter->SetParam("label", data_files[1]);
  } else if (useType == "Label") {
    iter->SetParam("image", data_files[2]);
    iter->SetParam("label", data_files[3]);
  }

  iter->CreateDataIter();
  return true;
}

#endif  // CPP_PACKAGE_EXAMPLE_UTILS_H_