/* Copyright 2015 The TensorFlow 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 "tensorflow/core/public/session.h"

#include <string>

#include "tensorflow/core/common_runtime/session_factory.h"
#include "tensorflow/core/lib/core/errors.h"
#include "tensorflow/core/lib/monitoring/gauge.h"
#include "tensorflow/core/platform/logging.h"
#include "tensorflow/core/platform/monitoring.h"

namespace tensorflow {
namespace {

auto* session_created = monitoring::Gauge<bool, 0>::New(
    "/tensorflow/core/session_created", "True if a session was created.");

}  // namespace

Session::Session() {}

Session::~Session() {}

Status Session::Run(const RunOptions& run_options,
                    const std::vector<std::pair<string, Tensor> >& inputs,
                    const std::vector<string>& output_tensor_names,
                    const std::vector<string>& target_node_names,
                    std::vector<Tensor>* outputs, RunMetadata* run_metadata) {
  return errors::Unimplemented(
      "Run with options is not supported for this session.");
}

Status Session::PRunSetup(const std::vector<string>& input_names,
                          const std::vector<string>& output_names,
                          const std::vector<string>& target_nodes,
                          string* handle) {
  return errors::Unimplemented(
      "Partial run is not supported for this session.");
}

Status Session::PRun(const string& handle,
                     const std::vector<std::pair<string, Tensor> >& inputs,
                     const std::vector<string>& output_names,
                     std::vector<Tensor>* outputs) {
  return errors::Unimplemented(
      "Partial run is not supported for this session.");
}

Session* NewSession(const SessionOptions& options) {
  SessionFactory* factory;
  Status s = SessionFactory::GetFactory(options, &factory);
  if (!s.ok()) {
    LOG(ERROR) << s;
    return nullptr;
  }
  // Starts exporting metrics through a platform-specific monitoring API (if
  // provided). For builds using "tensorflow/core/platform/default", this is
  // currently a no-op.
  session_created->GetCell()->Set(true);
  monitoring::StartExporter();
  Session* out_session;
  s = NewSession(options, &out_session);
  if (!s.ok()) {
    LOG(ERROR) << "Failed to create session: " << s;
    return nullptr;
  }
  return out_session;
}

Status NewSession(const SessionOptions& options, Session** out_session) {
  SessionFactory* factory;
  Status s = SessionFactory::GetFactory(options, &factory);
  if (!s.ok()) {
    *out_session = nullptr;
    LOG(ERROR) << s;
    return s;
  }
  // Starts exporting metrics through a platform-specific monitoring API (if
  // provided). For builds using "tensorflow/core/platform/default", this is
  // currently a no-op.
  session_created->GetCell()->Set(true);
  monitoring::StartExporter();
  s = factory->NewSession(options, out_session);
  if (!s.ok()) {
    *out_session = nullptr;
  }
  return s;
}

Status Reset(const SessionOptions& options,
             const std::vector<string>& containers) {
  SessionFactory* factory;
  TF_RETURN_IF_ERROR(SessionFactory::GetFactory(options, &factory));
  return factory->Reset(options, containers);
}

}  // namespace tensorflow
