// Copyright (C) 2011, 2012, 2013, 2014 PISM Authors
//
// This file is part of PISM.
//
// PISM is free software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the Free Software
// Foundation; either version 3 of the License, or (at your option) any later
// version.
//
// PISM is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
// details.
//
// You should have received a copy of the GNU General Public License
// along with PISM; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

#include "PALapseRates.hh"


PALapseRates::PALapseRates(IceGrid &g, const PISMConfig &conf, PISMAtmosphereModel* in)
  : PLapseRates<PISMAtmosphereModel,PAModifier>(g, conf, in),
    precipitation(g.get_unit_system()),
    air_temp(g.get_unit_system())
{
  precip_lapse_rate = 0;
  option_prefix     = "-atmosphere_lapse_rate";

  PetscErrorCode ierr = allocate_PALapseRates(); CHKERRCONTINUE(ierr);
  if (ierr != 0)
    PISMEnd();

}

PALapseRates::~PALapseRates() {
  // empty
}

PetscErrorCode PALapseRates::allocate_PALapseRates() {
  PetscErrorCode ierr;

  precipitation.init_2d("precipitation", grid);
  precipitation.set_string("pism_intent", "diagnostic");
  precipitation.set_string("long_name",
                           "ice-equivalent precipitation rate with a lapse-rate correction");
  ierr = precipitation.set_units("m s-1"); CHKERRQ(ierr);
  ierr = precipitation.set_glaciological_units("m year-1"); CHKERRQ(ierr);

  air_temp.init_2d("air_temp", grid);
  air_temp.set_string("pism_intent", "diagnostic");
  air_temp.set_string("long_name",
                      "near-surface air temperature with a lapse-rate correction");
  ierr = air_temp.set_units("K"); CHKERRQ(ierr);

  return 0;
}

PetscErrorCode PALapseRates::init(PISMVars &vars) {
  PetscErrorCode ierr;
  bool precip_lapse_rate_set;

  m_t = m_dt = GSL_NAN;  // every re-init restarts the clock

  ierr = input_model->init(vars); CHKERRQ(ierr);

  ierr = verbPrintf(2, grid.com,
                    "  [using air temperature and precipitation lapse corrections]\n"); CHKERRQ(ierr);

  ierr = init_internal(vars); CHKERRQ(ierr);

  ierr = PetscOptionsBegin(grid.com, "", "Lapse rate options", ""); CHKERRQ(ierr);
  {
    ierr = PISMOptionsReal("-precip_lapse_rate",
                           "Elevation lapse rate for the surface mass balance, in m/year per km",
                           precip_lapse_rate, precip_lapse_rate_set); CHKERRQ(ierr);
  }
  ierr = PetscOptionsEnd(); CHKERRQ(ierr);

  ierr = verbPrintf(2, grid.com,
                    "   air temperature lapse rate: %3.3f K per km\n"
                    "   precipitation lapse rate:   %3.3f m/year per km\n",
                    temp_lapse_rate, precip_lapse_rate); CHKERRQ(ierr);

  temp_lapse_rate = grid.convert(temp_lapse_rate, "K/km", "K/m");

  precip_lapse_rate = grid.convert(precip_lapse_rate, "m/year / km", "m/s / m");

  return 0;
}


PetscErrorCode PALapseRates::mean_precipitation(IceModelVec2S &result) {
  PetscErrorCode ierr;
  ierr = input_model->mean_precipitation(result); CHKERRQ(ierr);
  ierr = lapse_rate_correction(result, precip_lapse_rate); CHKERRQ(ierr);
  return 0;
}

PetscErrorCode PALapseRates::mean_annual_temp(IceModelVec2S &result) {
  PetscErrorCode ierr;
  ierr = input_model->mean_annual_temp(result); CHKERRQ(ierr);
  ierr = lapse_rate_correction(result, temp_lapse_rate); CHKERRQ(ierr);
  return 0;
}


PetscErrorCode PALapseRates::begin_pointwise_access() {
  PetscErrorCode ierr;
  ierr = input_model->begin_pointwise_access(); CHKERRQ(ierr);
  ierr = reference_surface.begin_access(); CHKERRQ(ierr);
  ierr = surface->begin_access(); CHKERRQ(ierr);
  return 0;
}

PetscErrorCode PALapseRates::end_pointwise_access() {
  PetscErrorCode ierr;
  ierr = input_model->end_pointwise_access(); CHKERRQ(ierr);
  ierr = reference_surface.end_access(); CHKERRQ(ierr);
  ierr = surface->end_access(); CHKERRQ(ierr);
  return 0;
}

PetscErrorCode PALapseRates::init_timeseries(double *ts, unsigned int N) {
  PetscErrorCode ierr;
  ierr = input_model->init_timeseries(ts, N); CHKERRQ(ierr);

  m_ts_times.resize(N);

  ierr = reference_surface.init_interpolation(ts, N); CHKERRQ(ierr);

  return 0;
}

PetscErrorCode PALapseRates::temp_time_series(int i, int j, double *values) {
  PetscErrorCode ierr;
  std::vector<double> usurf(m_ts_times.size());

  ierr = input_model->temp_time_series(i, j, values); CHKERRQ(ierr);

  ierr = reference_surface.interp(i, j, &usurf[0]); CHKERRQ(ierr);

  for (unsigned int m = 0; m < m_ts_times.size(); ++m) {
    values[m] -= temp_lapse_rate * ((*surface)(i, j) - usurf[m]);
  }

  return 0;
}

PetscErrorCode PALapseRates::precip_time_series(int i, int j, double *values) {
  PetscErrorCode ierr;
  std::vector<double> usurf(m_ts_times.size());

  ierr = input_model->precip_time_series(i, j, values); CHKERRQ(ierr);

  ierr = reference_surface.interp(i, j, &usurf[0]); CHKERRQ(ierr);

  for (unsigned int m = 0; m < m_ts_times.size(); ++m) {
    values[m] -= precip_lapse_rate * ((*surface)(i, j) - usurf[m]);
  }

  return 0;
}

PetscErrorCode PALapseRates::temp_snapshot(IceModelVec2S &result) {
  PetscErrorCode ierr;
  ierr = input_model->temp_snapshot(result); CHKERRQ(ierr);
  ierr = lapse_rate_correction(result, temp_lapse_rate); CHKERRQ(ierr);
  return 0;
}

PetscErrorCode PALapseRates::define_variables(std::set<std::string> vars, const PIO &nc, PISM_IO_Type nctype) {
  PetscErrorCode ierr;

  if (set_contains(vars, "air_temp")) {
    ierr = air_temp.define(nc, nctype, true); CHKERRQ(ierr);
  }

  if (set_contains(vars, "precipitation")) {
    ierr = precipitation.define(nc, nctype, true); CHKERRQ(ierr);
  }

  ierr = input_model->define_variables(vars, nc, nctype); CHKERRQ(ierr);

  return 0;
}

PetscErrorCode PALapseRates::write_variables(std::set<std::string> vars, const PIO &nc) {
  PetscErrorCode ierr;

  if (set_contains(vars, "air_temp")) {
    IceModelVec2S tmp;
    ierr = tmp.create(grid, "air_temp", WITHOUT_GHOSTS); CHKERRQ(ierr);
    tmp.metadata() = air_temp;

    ierr = temp_snapshot(tmp); CHKERRQ(ierr);

    ierr = tmp.write(nc); CHKERRQ(ierr);

    vars.erase("air_temp");
  }

  if (set_contains(vars, "precipitation")) {
    IceModelVec2S tmp;
    ierr = tmp.create(grid, "precipitation", WITHOUT_GHOSTS); CHKERRQ(ierr);
    tmp.metadata() = precipitation;

    ierr = mean_precipitation(tmp); CHKERRQ(ierr);
    tmp.write_in_glaciological_units = true;
    ierr = tmp.write(nc); CHKERRQ(ierr);

    vars.erase("precipitation");
  }

  ierr = input_model->write_variables(vars, nc); CHKERRQ(ierr);

  return 0;
}

void PALapseRates::add_vars_to_output(std::string keyword, std::set<std::string> &result) {
  input_model->add_vars_to_output(keyword, result);

  if (keyword == "medium" || keyword == "big") {
    result.insert("air_temp");
    result.insert("precipitation");
  }
}