/*
 * 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.
 */

/*!
 *  Copyright (c) 2016 by Contributors
 * \file c_api_error.h
 * \brief Common fields of all C APIs
 */
#ifndef NNVM_C_API_C_API_COMMON_H_
#define NNVM_C_API_C_API_COMMON_H_

#include <dmlc/base.h>
#include <dmlc/logging.h>
#include <dmlc/thread_local.h>
#include <nnvm/c_api.h>
#include <nnvm/symbolic.h>
#include <vector>
#include <string>
#include <utility>
#include <unordered_map>

/*! \brief  macro to guard beginning and end section of all functions */
#define API_BEGIN() try {
/*! \brief every function starts with API_BEGIN();
     and finishes with API_END() or API_END_HANDLE_ERROR */
#define API_END() } catch(dmlc::Error &_except_) { return NNAPIHandleException(_except_); } return 0;  // NOLINT(*)
/*!
 * \brief every function starts with API_BEGIN();
 *   and finishes with API_END() or API_END_HANDLE_ERROR
 *   The finally clause contains procedure to cleanup states when an error happens.
 */
#define API_END_HANDLE_ERROR(Finalize) } catch(dmlc::Error &_except_) { Finalize; return NNAPIHandleException(_except_); } return 0; // NOLINT(*)


/*! \brief entry to to easily hold returning information */
struct NNAPIThreadLocalEntry {
  /*! \brief result holder for returning string */
  std::string ret_str;
  /*! \brief result holder for returning strings */
  std::vector<std::string> ret_vec_str;
  /*! \brief result holder for returning string pointers */
  std::vector<const char *> ret_vec_charp;
  /*! \brief result holder for returning handles */
  std::vector<void *> ret_handles;
  /*! \brief argument holder to hold symbol */
  std::unordered_map<std::string, const nnvm::Symbol*> kwarg_symbol;
};

/*! \brief Thread local store that can be used to hold return values. */
typedef dmlc::ThreadLocalStore<NNAPIThreadLocalEntry> NNAPIThreadLocalStore;

/*!
 * \brief handle exception throwed out
 * \param e the exception
 * \return the return value of API after exception is handled
 */
inline int NNAPIHandleException(const dmlc::Error &e) {
  NNAPISetLastError(e.what());
  return -1;
}

#endif  // NNVM_C_API_C_API_COMMON_H_