//===-- apps/ews/ews.cpp ----------------------------------------*- C++ -*-===//
//
//                 The RoSA Framework -- Application EWS
//
// Distributed under the terms and conditions of the Boost Software License 1.0.
// See accompanying file LICENSE.
//
// If you did not receive a copy of the license file, see
// http://www.boost.org/LICENSE_1_0.txt.
//
//===----------------------------------------------------------------------===//
///
/// \file apps/ews/ews.cpp
///
/// \author David Juhasz (david.juhasz@tuwien.ac.at)
///
/// \date 2017-2020
///
/// \brief The application EWS implements the conventional Early Warning
/// Score (EWS) system.
//===----------------------------------------------------------------------===//

#include "rosa/agent/Abstraction.hpp"

#include "rosa/config/version.h"

#include "rosa/app/Application.hpp"

#include "rosa/support/csv/CSVReader.hpp"
#include "rosa/support/csv/CSVWriter.hpp"
#include "rosa/support/iterator/split_tuple_iterator.hpp"

#include "cxxopts/cxxopts.hpp"

#include <fstream>
#include <numeric>

using namespace rosa;
using namespace rosa::agent;
using namespace rosa::app;
using namespace rosa::terminal;
using namespace rosa::csv;
using namespace rosa::iterator;

const std::string AppName = "EWS";

/// Representation type of warning levels.
/// \note Make sure it suits all defined enumeration values.
using WarningScoreType = uint8_t;

/// Warning levels for abstraction.
enum WarningScore : WarningScoreType {
  No = 0,
  Low = 1,
  High = 2,
  Emergency = 3
};

/// Helper function creating an application agent for pre-processing sensory
/// values.
///
/// Received values are abstracted into a \c WarningScore value, which is the
/// result of the processing function.
///
/// \note The result, \c WarningScore, is returned as \c WarningScoreType
/// because enumeration types are not integrated into built-in types. Hence, a
/// master to these agents receives its input as \c WarningScoreType values, and
/// may cast them to \c WarningScore explicitly.
///
/// \tparam T type of values to receive from the sensor
///
/// \param App the application to create the agent in
/// \param Name name of the new agent
/// \param A abstraction to use
///
/// \return handle for the new agent
template <typename T>
AgentHandle createLowLevelAgent(std::unique_ptr<Application> &App,
                                const std::string &Name,
                                const Abstraction<T, WarningScore> &A) {
  using result = Optional<WarningScoreType>;
  using handler = std::function<result(std::pair<T, bool>)>;
  return App->createAgent(
      Name, handler([&, Name](std::pair<T, bool> I) -> result {
        LOG_INFO_STREAM << "\n******\n"
                        << Name << " " << (I.second ? "<New>" : "<Old>")
                        << " value: " << PRINTABLE(I.first) << "\n******\n";
        return {A(I.first)};
      }));
}

/// Helper function to print an error message in red color to the terminal and
/// exit from the application.
///
/// \note The function never returns as it calles `exit()`.
///
/// \param Error error message
/// \param ExitCode exit code to return from the application
void logErrorAndExit(const std::string &Error, const int ExitCode) {
  LOG_ERROR_STREAM << Color::Red << Error << Color::Default << std::endl;
  exit(ExitCode);
}

int main(int argc, char *argv[]) {
  LOG_INFO_STREAM << '\n'
                  << library_string() << " -- " << Color::Red << AppName
                  << " app" << Color::Default << '\n';

  /// Paths for the CSV files for simulation.
  ///
  ///@{
  std::string DataCSVPath;
  std::string ScoreCSVPath;
  ///@}

  /// Whether CSV files have header row at the beginning.
  bool CSVHeader = false;

  /// Delimiter character in CSV files.
  char CSVDelimiter = ',';

  /// How many cycles of simulation to perform.
  size_t NumberOfSimulationCycles = 16;

  // Handle command-line arguments.
  try {
    cxxopts::Options Options(argv[0], library_string() + " -- " + AppName);
    Options.add_options()("i,input",
                          "Path for the CSV file providing input data",
                          cxxopts::value(DataCSVPath), "file")
                         ("o,output",
                          "Path for the CSV file to write output scores",
                          cxxopts::value(ScoreCSVPath), "file")
                         ("header", "CSV input file has header row",
                          cxxopts::value(CSVHeader)->default_value("false"))
                         ("delimiter", "CSV delimiter character",
                          cxxopts::value(CSVDelimiter)->default_value(","), "char")
                         ("c,cycles", "Number of simulation cycles to perform",
                          cxxopts::value(NumberOfSimulationCycles)->default_value("16"), "int")
                         ("h,help", "Print usage");

    auto Args = Options.parse(argc, argv);

    if (Args.count("help")) {
      LOG_INFO_STREAM << '\n' << Options.help() << std::endl;
      exit(0);
    }

    if (Args.count("input") == 0) {
      throw std::invalid_argument("Argument --input must be defined.");
    }
    if (Args.count("output") == 0) {
      throw std::invalid_argument("Argument --output must be defined.");
    }
  } catch (const cxxopts::OptionException &e) {
    logErrorAndExit(e.what(), 1);
  } catch (const std::invalid_argument &e) {
    logErrorAndExit(e.what(), 1);
  }

  std::unique_ptr<Application> App = Application::create(AppName);

  //
  // Relevant types and definitions.
  //

  using HRType = int32_t;
  using BRType = int32_t;
  using SpO2Type = int32_t;
  using BPSysType = int32_t;
  using BodyTempType = float;

  //
  // Create deluxe sensors.
  //
  LOG_INFO("Creating sensors.");

  // All sensors are created without defining a normal generator function, but
  // with the default value of the second argument. That, however, requires the
  // data type to be explicitly defined. This is good for simulation only.
  AgentHandle HRSensor = App->createSensor<HRType>("HR Sensor");
  AgentHandle BRSensor = App->createSensor<BRType>("BR Sensor");
  AgentHandle SpO2Sensor = App->createSensor<SpO2Type>("SpO2 Sensor");
  AgentHandle BPSysSensor = App->createSensor<BPSysType>("BPSys Sensor");
  AgentHandle BodyTempSensor =
      App->createSensor<BodyTempType>("BodyTemp Sensor");

  //
  // Create functionalities.
  //
  LOG_INFO("Creating Functionalities for Agents.");

  //
  // Define abstractions.
  //

  RangeAbstraction<HRType, WarningScore> HRAbstraction(
      {{{0, 40}, Emergency},
       {{40, 51}, High},
       {{51, 60}, Low},
       {{60, 100}, No},
       {{100, 110}, Low},
       {{110, 129}, High},
       {{129, 200}, Emergency}},
      Emergency);

  RangeAbstraction<BRType, WarningScore> BRAbstraction({{{0, 9}, High},
                                                        {{9, 14}, No},
                                                        {{14, 20}, Low},
                                                        {{20, 29}, High},
                                                        {{29, 50}, Emergency}},
                                                       Emergency);

  RangeAbstraction<SpO2Type, WarningScore> SpO2Abstraction(
      {{{1, 85}, Emergency},
       {{85, 90}, High},
       {{90, 95}, Low},
       {{95, 100}, No}},
      Emergency);

  RangeAbstraction<BPSysType, WarningScore> BPSysAbstraction(
      {{{0, 70}, Emergency},
       {{70, 81}, High},
       {{81, 101}, Low},
       {{101, 149}, No},
       {{149, 169}, Low},
       {{169, 179}, High},
       {{179, 200}, Emergency}},
      Emergency);

  RangeAbstraction<BodyTempType, WarningScore> BodyTempAbstraction(
      {{{0.f, 28.f}, Emergency},
       {{28.f, 32.f}, High},
       {{32.f, 35.f}, Low},
       {{35.f, 38.f}, No},
       {{38.f, 39.5f}, High},
       {{39.5f, 100.f}, Emergency}},
      Emergency);

  //
  // Create low-level deluxe agents with \c createLowLevelAgent.
  //
  LOG_INFO("Creating low-level agents.");

  AgentHandle HRAgent = createLowLevelAgent(App, "HR Agent", HRAbstraction);
  AgentHandle BRAgent = createLowLevelAgent(App, "BR Agent", BRAbstraction);
  AgentHandle SpO2Agent =
      createLowLevelAgent(App, "SpO2 Agent", SpO2Abstraction);
  AgentHandle BPSysAgent =
      createLowLevelAgent(App, "BPSys Agent", BPSysAbstraction);
  AgentHandle BodyTempAgent =
      createLowLevelAgent(App, "BodyTemp Agent", BodyTempAbstraction);

  //
  // Connect sensors to low-level agents.
  //
  LOG_INFO("Connect sensors to their corresponding low-level agents.");

  App->connectSensor(HRAgent, 0, HRSensor, "HR Sensor Channel");
  App->connectSensor(BRAgent, 0, BRSensor, "BR Sensor Channel");
  App->connectSensor(SpO2Agent, 0, SpO2Sensor, "SpO2 Sensor Channel");
  App->connectSensor(BPSysAgent, 0, BPSysSensor, "BPSys Sensor Channel");
  App->connectSensor(BodyTempAgent, 0, BodyTempSensor,
                     "BodyTemp Sensor Channel");

  //
  // Create a high-level deluxe agent.
  //
  LOG_INFO("Create high-level agent.");

  // The new agent logs its input values and results in the the sum of them.
  AgentHandle BodyAgent = App->createAgent(
      "Body Agent",
      std::function<Optional<WarningScoreType>(
          std::pair<WarningScoreType, bool>, std::pair<WarningScoreType, bool>,
          std::pair<WarningScoreType, bool>, std::pair<WarningScoreType, bool>,
          std::pair<WarningScoreType, bool>)>(
          [](std::pair<WarningScoreType, bool> HR,
             std::pair<WarningScoreType, bool> BR,
             std::pair<WarningScoreType, bool> SpO2,
             std::pair<WarningScoreType, bool> BPSys,
             std::pair<WarningScoreType, bool> BodyTemp)
              -> Optional<WarningScoreType> {
            LOG_INFO_STREAM
                << "\n*******\nBody Agent trigged with values:\n"
                << (HR.second ? "<New>" : "<Old>")
                << " HR warning score: " << PRINTABLE(HR.first) << "\n"
                << (BR.second ? "<New>" : "<Old>")
                << " BR warning score: " << PRINTABLE(BR.first) << "\n"
                << (SpO2.second ? "<New>" : "<Old>")
                << " SpO2 warning score: " << PRINTABLE(SpO2.first) << "\n"
                << (BPSys.second ? "<New>" : "<Old>")
                << " BPSys warning score: " << PRINTABLE(BPSys.first) << "\n"
                << (BodyTemp.second ? "<New>" : "<Old>")
                << " BodyTemp warning score: " << PRINTABLE(BodyTemp.first)
                << "\n******\n";
            const std::array<WarningScoreType, 5> Values{
                HR.first, BR.first, SpO2.first, BPSys.first, BodyTemp.first};
            const WarningScoreType ews =
                std::reduce(Values.begin(), Values.end(), (WarningScoreType)0);
            return {ews};
          }));

  //
  // Connect low-level agents to the high-level agent.
  //
  LOG_INFO("Connect low-level agents to the high-level agent.");

  App->connectAgents(BodyAgent, 0, HRAgent, "HR Agent Channel");
  App->connectAgents(BodyAgent, 1, BRAgent, "BR Agent Channel");
  App->connectAgents(BodyAgent, 2, SpO2Agent, "SpO2 Agent Channel");
  App->connectAgents(BodyAgent, 3, BPSysAgent, "BPSys Agent Channel");
  App->connectAgents(BodyAgent, 4, BodyTempAgent, "BodyTemp Agent Channel");

  //
  // For simulation output, create a logger agent writing the output of the
  // high-level agent into a CSV file.
  //
  LOG_INFO("Create a logger agent.");

  // Create CSV writer.
  std::ofstream ScoreCSV(ScoreCSVPath);
  csv::CSVWriter<WarningScoreType> ScoreWriter(ScoreCSV, CSVDelimiter);

  // The agent writes each new input value into a CSV file and produces nothing.
  AgentHandle LoggerAgent = App->createAgent(
      "Logger Agent",
      std::function<Optional<unit_t>(std::pair<WarningScoreType, bool>)>(
          [&ScoreWriter](
              std::pair<WarningScoreType, bool> Score) -> Optional<unit_t> {
            if (Score.second) {
              // The state of \p ScoreWriter is not checked, expecting good.
              ScoreWriter << Score.first;
            }
            return {};
          }));

  //
  // Connect the high-level agent to the logger agent.
  //
  LOG_INFO("Connect the high-level agent to the logger agent.");

  App->connectAgents(LoggerAgent, 0, BodyAgent, "Body Agent Channel");

  //
  // Do simulation.
  //
  LOG_INFO("Setting up and performing simulation.");

  //
  // Initialize deluxe context for simulation.
  //

  App->initializeSimulation();

  //
  // Open CSV files and register them for their corresponding sensors.
  //

  // Type aliases for iterators.
  // Type aliases for iterators.
  using CSVDataIterator =
      CSVIterator<HRType, BRType, SpO2Type, BPSysType, BodyTempType>;
  const auto CSVHeaderInfo =
      CSVHeader ? HeaderInformation::HasHeader : HeaderInformation::HasNoHeader;
  std::ifstream DataCSV(DataCSVPath);
  auto [HRRange, BRRange, SpO2Range, BPSysRange, BodyTempRange] =
      splitTupleIterator(
          CSVDataIterator(DataCSV, 0, CSVHeaderInfo, CSVDelimiter),
          CSVDataIterator());

  App->registerSensorValues(HRSensor, std::move(begin(HRRange)), end(HRRange));
  App->registerSensorValues(BRSensor, std::move(begin(BRRange)), end(BRRange));
  App->registerSensorValues(SpO2Sensor, std::move(begin(SpO2Range)),
                            end(SpO2Range));
  App->registerSensorValues(BPSysSensor, std::move(begin(BPSysRange)),
                            end(BPSysRange));
  App->registerSensorValues(BodyTempSensor, std::move(begin(BodyTempRange)),
                            end(BodyTempRange));

  //
  // Simulate.
  //

  App->simulate(NumberOfSimulationCycles);

  return 0;
}