#include "MantidAlgorithms/AddLogDerivative.h"
#include "MantidKernel/System.h"
#include "MantidKernel/TimeSeriesProperty.h"
#include "MantidAPI/MatrixWorkspace.h"
#include "MantidKernel/MandatoryValidator.h"
#include "MantidKernel/BoundedValidator.h"
#include "MantidAPI/Run.h"

using namespace Mantid::Kernel;
using namespace Mantid::API;

namespace Mantid {
namespace Algorithms {

// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(AddLogDerivative)

//----------------------------------------------------------------------------------------------

//----------------------------------------------------------------------------------------------
/** Initialize the algorithm's properties.
 */
void AddLogDerivative::init() {
  declareProperty(
      make_unique<WorkspaceProperty<>>("InputWorkspace", "", Direction::InOut),
      "An input/output workspace. The new log will be added to it.");
  declareProperty(
      "LogName", "", boost::make_shared<MandatoryValidator<std::string>>(),
      "The name that will identify the log entry to perform a derivative.\n"
      "This log must be a numerical series (double).");
  declareProperty("Derivative", 1,
                  boost::make_shared<BoundedValidator<int>>(1, 10),
                  "How many derivatives to perform. Default 1.");
  declareProperty("NewLogName", "", "Name of the newly created log. If not "
                                    "specified, the string '_derivativeN' will "
                                    "be appended to the original name");
}

//----------------------------------------------------------------------------------------------
/** Perform the N^th derivative of a log
 *
 * @param progress :: Progress indicator
 * @param input :: input TSP. Must have N+1 log entries
 * @param name :: name of the resulting log
 * @param numDerivatives :: number of times to perform derivative.
 * @return
 */
Mantid::Kernel::TimeSeriesProperty<double> *AddLogDerivative::makeDerivative(
    API::Progress &progress, Mantid::Kernel::TimeSeriesProperty<double> *input,
    const std::string &name, int numDerivatives) {
  if (input->size() < numDerivatives + 1)
    throw std::runtime_error(
        "Log " + input->name() + " only has " +
        Strings::toString(input->size()) + " values. Need at least " +
        Strings::toString(numDerivatives + 1) + " to make this derivative.");

  std::vector<double> values, dVal;
  std::vector<double> times, dTime;
  values = input->valuesAsVector();
  times = input->timesAsVectorSeconds();

  for (int deriv = 0; deriv < numDerivatives; deriv++) {
    dVal.clear();
    dTime.clear();
    double t0 = times[0];
    double y0 = values[0];
    for (size_t i = 0; i < times.size() - 1; i++) {
      double y1 = values[i + 1];
      double t1 = times[i + 1];
      if (t1 != t0) {
        // Avoid repeated time values giving infinite derivatives
        double dy = (y1 - y0) / (t1 - t0);
        double t = (t0 + t1) / 2.0;
        dVal.push_back(dy);
        dTime.push_back(t);
        // For the next time interval
        t0 = t1;
        y0 = y1;
      }
    }
    times = dTime;
    values = dVal;

    progress.report("Add Log Derivative");
  }

  if (times.empty())
    throw std::runtime_error("Log " + input->name() +
                             " did not have enough non-repeated time values to "
                             "make this derivative.");

  // Convert time in sec to DateAndTime
  DateAndTime start = input->nthTime(0);
  std::vector<DateAndTime> timeFull;
  timeFull.reserve(times.size());
  for (double time : times)
    timeFull.push_back(start + time);

  // Create the TSP out of it
  auto out = new TimeSeriesProperty<double>(name);
  out->addValues(timeFull, values);
  return out;
}

//----------------------------------------------------------------------------------------------
/** Execute the algorithm.
 */
void AddLogDerivative::exec() {
  MatrixWorkspace_sptr ws = getProperty("InputWorkspace");
  std::string LogName = getPropertyValue("LogName");
  std::string NewLogName = getPropertyValue("NewLogName");
  int Derivative = getProperty("Derivative");
  if (!ws)
    return;

  if (NewLogName.empty())
    NewLogName = LogName + "_derivative" + Strings::toString(Derivative);

  Run &run = ws->mutableRun();
  if (!run.hasProperty(LogName))
    throw std::invalid_argument("Log " + LogName +
                                " not found in the workspace sample logs.");
  Property *prop = run.getProperty(LogName);
  if (!prop)
    throw std::invalid_argument("Log " + LogName +
                                " not found in the workspace sample logs.");
  TimeSeriesProperty<double> *tsp =
      dynamic_cast<TimeSeriesProperty<double> *>(prop);
  if (!tsp)
    throw std::invalid_argument("Log " + LogName + " is not a numerical series "
                                                   "(TimeSeriesProperty<double>"
                                                   ") so we can't perform its "
                                                   "derivative.");

  Progress progress(this, 0, 1, Derivative);

  // Perform derivative
  TimeSeriesProperty<double> *output =
      makeDerivative(progress, tsp, NewLogName, Derivative);
  // Add the log
  run.addProperty(output, true);

  g_log.notice() << "Added log named " << NewLogName << '\n';
}

} // namespace Mantid
} // namespace Algorithms