/*******************************************************************************
 * This file is part of SWIFT.
 * Copyright (c) 2020 Matthieu Schaller (schaller@strw.leidenuniv.nl)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#ifndef SWIFT_CHEMISTRY_QLA_H
#define SWIFT_CHEMISTRY_QLA_H

/**
 * @file src/chemistry/none/chemistry.h
 * @brief Empty infrastructure for the cases without chemistry function
 */

/* Some standard headers. */
#include <float.h>
#include <math.h>

/* Local includes. */
#include "chemistry_struct.h"
#include "cosmology.h"
#include "error.h"
#include "hydro.h"
#include "parser.h"
#include "part.h"
#include "physical_constants.h"
#include "units.h"

/**
 * @brief Return a string containing the name of a given #chemistry_element.
 */
__attribute__((always_inline)) INLINE static const char *
chemistry_get_element_name(enum chemistry_element elem) {

  static const char *chemistry_element_names[chemistry_element_count] = {};
  error("Attempting to get non-existing element!");
  return chemistry_element_names[elem];
}

/**
 * @brief Initialises the chemistry properties.
 *
 * Nothing to do here.
 *
 * @param parameter_file The parsed parameter file.
 * @param us The current internal system of units.
 * @param phys_const The physical constants in internal units.
 * @param data The global chemistry information (to be filled).
 */
static INLINE void chemistry_init_backend(struct swift_params *parameter_file,
                                          const struct unit_system *us,
                                          const struct phys_const *phys_const,
                                          struct chemistry_global_data *data) {}

/**
 * @brief Prints the properties of the chemistry model to stdout.
 *
 * Nothing to do here.
 *
 * @brief The #chemistry_global_data containing information about the current
 * model.
 */
static INLINE void chemistry_print_backend(
    const struct chemistry_global_data *data) {

  message("Chemistry function is 'Quick Lyman-alpha'.");
}

/**
 * @brief Finishes the density calculation.
 *
 * Nothing to do here.
 *
 * @param p The particle to act upon
 * @param cd The global chemistry information.
 * @param cosmo The current cosmological model.
 */
__attribute__((always_inline)) INLINE static void chemistry_end_density(
    struct part *restrict p, const struct chemistry_global_data *cd,
    const struct cosmology *cosmo) {}

/**
 * @brief Finishes the gradient calculation.
 *
 * Nothing to do here.
 *
 * @param p The particle to act upon.
 * @param cd The global properties of the chemistry scheme.
 */
__attribute__((always_inline)) INLINE static void chemistry_end_gradient(
    struct part *p, const struct chemistry_global_data *cd) {}

/**
 * @brief Updates to the chemistry data after the hydro force loop.
 *
 * @param p The particle to act upon.
 * @param cosmo The current cosmological model.
 * @param with_cosmology Are we running with the cosmology?
 * @param time Current time of the simulation.
 * @param dt Time step (in physical units).
 * @param cd The global properties of the chemistry scheme.
 */
__attribute__((always_inline)) INLINE static void chemistry_end_force(
    struct part *restrict p, const struct cosmology *cosmo,
    const int with_cosmology, const double time, const double dt,
    const struct chemistry_global_data *cd) {}

/**
 * @brief Prepare a particle for the force calculation.
 *
 * Nothing to do here.
 *
 * @param p The particle to act upon
 * @param xp The extended particle data to act upon
 * @param cosmo The current cosmological model.
 * @param dt_alpha The time-step used to evolve non-cosmological quantities such
 *                 as the artificial viscosity.
 * @param dt_therm The time-step used to evolve hydrodynamical quantities.
 * @param cd The global properties of the chemistry scheme.
 */
__attribute__((always_inline)) INLINE static void chemistry_prepare_force(
    struct part *restrict p, struct xpart *restrict xp,
    const struct cosmology *cosmo, const float dt_alpha, const float dt_therm,
    const struct chemistry_global_data *cd) {}

/**
 * @brief Computes the chemistry-related time-step constraint.
 *
 * @param phys_const The physical constants in internal units.
 * @param cosmo The current cosmological model.
 * @param us The internal system of units.
 * @param hydro_props The properties of the hydro scheme.
 * @param cd The global properties of the chemistry scheme.
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float chemistry_timestep(
    const struct phys_const *restrict phys_const,
    const struct cosmology *restrict cosmo,
    const struct unit_system *restrict us,
    const struct hydro_props *hydro_props,
    const struct chemistry_global_data *cd, const struct part *restrict p) {
  return FLT_MAX;
}

/**
 * @brief Sets all particle fields to sensible values when the #part has 0 ngbs.
 *
 * Nothing to do here.
 *
 * @param p The particle to act upon
 * @param xp The extended particle data to act upon
 * @param cd #chemistry_global_data containing chemistry informations.
 * @param cosmo The current cosmological model.
 */
__attribute__((always_inline)) INLINE static void
chemistry_part_has_no_neighbours(struct part *restrict p,
                                 struct xpart *restrict xp,
                                 const struct chemistry_global_data *cd,
                                 const struct cosmology *cosmo) {}

/**
 * @brief Sets the chemistry properties of the (x-)particles to a valid start
 * state.
 *
 * Nothing to do here.
 *
 * @param phys_const The physical constant in internal units.
 * @param us The unit system.
 * @param cosmo The current cosmological model.
 * @param data The global chemistry information used for this run.
 * @param p Pointer to the particle data.
 * @param xp Pointer to the extended particle data.
 */
__attribute__((always_inline)) INLINE static void chemistry_first_init_part(
    const struct phys_const *restrict phys_const,
    const struct unit_system *restrict us,
    const struct cosmology *restrict cosmo,
    const struct chemistry_global_data *data, const struct part *restrict p,
    struct xpart *restrict xp) {}

/**
 * @brief Sets the chemistry properties of the (x-)particles to a valid start
 * state.
 *
 * Nothing to do here.
 *
 * @param p Pointer to the particle data.
 * @param data The global chemistry information.
 */
__attribute__((always_inline)) INLINE static void chemistry_init_part(
    struct part *restrict p, const struct chemistry_global_data *data) {}

/**
 * @brief Sets the chemistry properties of the sparticles to a valid start
 * state.
 *
 * Nothing to do here.
 *
 * @param phys_const The physical constants in internal units.
 * @param us The internal system of units.
 * @param cosmo The current cosmological model.
 * @param data The global chemistry information.
 * @param sp Pointer to the sparticle data.
 * @param xp Pointer to the extended particle data.
 */
__attribute__((always_inline)) INLINE static void chemistry_first_init_spart(
    const struct chemistry_global_data *data, struct spart *restrict sp) {}

/**
 * @brief Sets the chemistry properties of the sink particles to a valid start
 * state.
 *
 * @param data The global chemistry information.
 * @param sink Pointer to the sink particle data.
 */
__attribute__((always_inline)) INLINE static void chemistry_first_init_sink(
    const struct chemistry_global_data *data, struct sink *restrict sink) {}

/**
 * @brief Initialise the chemistry properties of a black hole with
 * the chemistry properties of the gas it is born from.
 *
 * Nothing to do here.
 *
 * @param bp_data The black hole data to initialise.
 * @param p_data The gas data to use.
 * @param gas_mass The mass of the gas particle.
 */
__attribute__((always_inline)) INLINE static void chemistry_bpart_from_part(
    struct chemistry_bpart_data *bp_data,
    const struct chemistry_part_data *p_data, const double gas_mass) {}

/**
 * @brief Add the chemistry data of a gas particle to a black hole.
 *
 * Nothing to do here.
 *
 * @param bp_data The black hole data to add to.
 * @param p_data The gas data to use.
 * @param gas_mass The mass of the gas particle.
 */
__attribute__((always_inline)) INLINE static void chemistry_add_part_to_bpart(
    struct chemistry_bpart_data *bp_data,
    const struct chemistry_part_data *p_data, const double gas_mass) {}

/**
 * @brief Transfer chemistry data of a gas particle to a black hole.
 *
 * Nothing to do here.
 *
 * @param bp_data The black hole data to add to.
 * @param p_data The gas data to use.
 * @param nibble_mass The mass to be removed from the gas particle.
 * @param nibble_fraction The fraction of the (original) mass of the gas
 *        particle that is removed.
 */
__attribute__((always_inline)) INLINE static void
chemistry_transfer_part_to_bpart(struct chemistry_bpart_data *bp_data,
                                 struct chemistry_part_data *p_data,
                                 const double nibble_mass,
                                 const double nibble_fraction) {}

/**
 * @brief Add the chemistry data of a black hole to another one.
 *
 * Nothing to do here.
 *
 * @param bp_data The black hole data to add to.
 * @param swallowed_data The black hole data to use.
 */
__attribute__((always_inline)) INLINE static void chemistry_add_bpart_to_bpart(
    struct chemistry_bpart_data *bp_data,
    const struct chemistry_bpart_data *swallowed_data) {}

/**
 * @brief Split the metal content of a particle into n pieces
 *
 * Nothing to do here.
 *
 * @param p The #part.
 * @param n The number of pieces to split into.
 */
__attribute__((always_inline)) INLINE static void chemistry_split_part(
    struct part *p, const double n) {}

/**
 * @brief Returns the total metallicity (metal mass fraction) of the
 * gas particle to be used in feedback/enrichment related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_total_metal_mass_fraction_for_feedback(
    const struct part *restrict p) {

  return 0.f;
}

/**
 * @brief Returns the abundance array (metal mass fractions) of the
 * gas particle to be used in feedback/enrichment related routines.
 *
 * No metallicity treatment here -> return NULL array.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float const *
chemistry_get_metal_mass_fraction_for_feedback(const struct part *restrict p) {

  return NULL;
}

/**
 * @brief Returns the total metallicity (metal mass fraction) of the
 * star particle to be used in feedback/enrichment related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param sp Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_star_total_metal_mass_fraction_for_feedback(
    const struct spart *sp) {

  return 0.f;
}

/**
 * @brief Returns the abundance array (metal mass fractions) of the
 * star particle to be used in feedback/enrichment related routines.
 *
 * No metallicity treatment here -> return NULL array.
 *
 * @param sp Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float const *
chemistry_get_star_metal_mass_fraction_for_feedback(const struct spart *sp) {

  return NULL;
}

/**
 * @brief Returns the total metallicity (metal mass fraction) of the
 * gas particle to be used in cooling related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_total_metal_mass_fraction_for_cooling(const struct part *p) {

  return 0.f;
}

/**
 * @brief Returns the abundance array (metal mass fractions) of the
 * gas particle to be used in cooling related routines.
 *
 * No metallicity treatment here -> return NULL array.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float const *
chemistry_get_metal_mass_fraction_for_cooling(const struct part *p) {

  return NULL;
}

/**
 * @brief Returns the total metallicity (metal mass fraction) of the
 * gas particle to be used in star formation related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_total_metal_mass_fraction_for_star_formation(
    const struct part *p) {

  return 0.f;
}

/**
 * @brief Returns the abundance array (metal mass fractions) of the
 * gas particle to be used in star formation related routines.
 *
 * No metallicity treatment here -> return NULL array.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float const *
chemistry_get_metal_mass_fraction_for_star_formation(const struct part *p) {

  return NULL;
}

/**
 * @brief Returns the total metal mass of the
 * gas particle to be used in the stats related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_total_metal_mass_for_stats(const struct part *restrict p) {

  return 0.f;
}

/**
 * @brief Returns the total metal mass of the
 * star particle to be used in the stats related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_star_total_metal_mass_for_stats(const struct spart *restrict sp) {

  return 0.f;
}

/**
 * @brief Returns the total metal mass of the
 * black hole particle to be used in the stats related routines.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param p Pointer to the particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_bh_total_metal_mass_for_stats(const struct bpart *restrict bp) {

  return 0.f;
}

/**
 * @brief Returns the total metallicity (metal mass fraction) of the
 * star particle to be used in the luminosity calculations.
 *
 * No metallicity treatment here -> return 0.
 *
 * @param sp Pointer to the star particle data.
 */
__attribute__((always_inline)) INLINE static float
chemistry_get_star_total_metal_mass_fraction_for_luminosity(
    const struct spart *restrict sp) {

  return 0.f;
}

/**
 * @brief Extra chemistry operations to be done during the drift.
 *
 * @param p Particle to act upon.
 * @param xp The extended particle data to act upon.
 * @param dt_drift The drift time-step for positions.
 * @param dt_therm The drift time-step for thermal quantities.
 * @param cosmo The current cosmological model.
 * @param chem_data The global properties of the chemistry scheme.
 */
__attribute__((always_inline)) INLINE static void chemistry_predict_extra(
    struct part *p, struct xpart *xp, float dt_drift, float dt_therm,
    const struct cosmology *cosmo,
    const struct chemistry_global_data *chem_data) {}

#endif /* SWIFT_CHEMISTRY_QLA_H */