/***************************************************************************
 *                  ctmapcube - Map cube generation tool                   *
 * ----------------------------------------------------------------------- *
 *  copyright (C) 2016-2018 by Juergen Knoedlseder                         *
 * ----------------------------------------------------------------------- *
 *                                                                         *
 *  This program 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.                                    *
 *                                                                         *
 *  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 General Public License      *
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  *
 *                                                                         *
 ***************************************************************************/
/**
 * @file ctmapcube.cpp
 * @brief Map cube generation tool implementation
 * @author Juergen Knoedlseder
 */

/* __ Includes ___________________________________________________________ */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <cstdio>
#include "ctmapcube.hpp"
#include "GTools.hpp"

/* __ Method name definitions ____________________________________________ */

/* __ Debug definitions __________________________________________________ */

/* __ Coding definitions _________________________________________________ */

/* __ Constants __________________________________________________________ */


/*==========================================================================
 =                                                                         =
 =                        Constructors/destructors                         =
 =                                                                         =
 ==========================================================================*/

/***********************************************************************//**
 * @brief Void constructor
 ***************************************************************************/
ctmapcube::ctmapcube(void) : ctool(CTMAPCUBE_NAME, VERSION)
{
    // Initialise members
    init_members();

    // Return
    return;
}


/***********************************************************************//**
 * @brief Command line constructor
 *
 * @param[in] argc Number of arguments in command line.
 * @param[in] argv Array of command line arguments.
 ***************************************************************************/
ctmapcube::ctmapcube(int argc, char *argv[]) :
           ctool(CTMAPCUBE_NAME, VERSION, argc, argv)
{
    // Initialise members
    init_members();

    // Return
    return;
}


/***********************************************************************//**
 * @brief Copy constructor
 *
 * @param[in] app Application.
 ***************************************************************************/
ctmapcube::ctmapcube(const ctmapcube& app) : ctool(app)
{
    // Initialise members
    init_members();

    // Copy members
    copy_members(app);

    // Return
    return;
}


/***********************************************************************//**
 * @brief Destructor
 ***************************************************************************/
ctmapcube::~ctmapcube(void)
{
    // Free members
    free_members();

    // Return
    return;
}


/*==========================================================================
 =                                                                         =
 =                               Operators                                 =
 =                                                                         =
 ==========================================================================*/

/***********************************************************************//**
 * @brief Assignment operator
 *
 * @param[in] app Application.
 * @return Application.
 ***************************************************************************/
ctmapcube& ctmapcube::operator=(const ctmapcube& app)
{
    // Execute only if object is not identical
    if (this != &app) {

        // Copy base class members
        this->ctool::operator=(app);

        // Free members
        free_members();

        // Initialise members
        init_members();

        // Copy members
        copy_members(app);

    } // endif: object was not identical

    // Return this object
    return *this;
}


/*==========================================================================
 =                                                                         =
 =                            Public methods                               =
 =                                                                         =
 ==========================================================================*/

/***********************************************************************//**
 * @brief Clear ctmapcube tool
 *
 * Clears ctmapcube tool.
 ***************************************************************************/
void ctmapcube::clear(void)
{
    // Free members
    free_members();
    this->ctool::free_members();

    // Clear base class (needed to conserve tool name and version)
    this->GApplication::clear();

    // Initialise members
    this->ctool::init_members();
    init_members();

    // Write header into logger
    log_header();

    // Return
    return;
}


/***********************************************************************//**
 * @brief Generate map cube.
 *
 * This method reads the task parameters from the parfile and generates the
 * map cube.
 ***************************************************************************/
void ctmapcube::run(void)
{
    // If we're in debug mode then all output is also dumped on the screen
    if (logDebug()) {
        log.cout(true);
    }

    // Get task parameters
    get_parameters();

    // Write input model container into logger
    log_models(NORMAL, m_models, "Input model");

    // Generate map cube
    create_cube();

    // Write result cube into logger
    log_header1(NORMAL, "Map cube");
    log_string(NORMAL, m_cube.print(m_chatter));

    // Optionally publish map cube
    if (m_publish) {
        publish();
    }

    // Return
    return;
}


/***********************************************************************//**
 * @brief Save map cube
 *
 * Saves the map cube into a FITS file.
 ***************************************************************************/
void ctmapcube::save(void)
{
    // Write header
    log_header1(TERSE, "Save map cube");

    // Save map cube if filename is valid and the map cube is not empty
    if ((*this)["outcube"].is_valid() && !m_cube.cube().is_empty()) {

        // Get map cube filename
        m_outcube = (*this)["outcube"].filename();

        // Save map cube
        m_cube.save(m_outcube, clobber());

    }

    // Write into logger what has been done
    std::string fname = (m_outcube.is_empty()) ? "NONE" : m_outcube.url();
    if (m_cube.cube().is_empty()) {
        fname.append(" (cube is empty, no file created)");
    }
    log_value(NORMAL, "Map cube file", fname);

    // Return
    return;
}


/***********************************************************************//**
 * @brief Publish map cube
 *
 * @param[in] name Map cube name.
 *
 * Publishes the map cube on a VO Hub.
 ***************************************************************************/
void ctmapcube::publish(const std::string& name)
{
    // Write header into logger
    log_header1(TERSE, "Publish map cube");

    // Set default name is user name is empty
    std::string user_name(name);
    if (user_name.empty()) {
        user_name = CTMAPCUBE_NAME;
    }

    // Write map cube name into logger
    log_value(NORMAL, "Map cube name", user_name);

    // Publish map cube
    m_cube.cube().publish(user_name);

    // Return
    return;
}


/*==========================================================================
 =                                                                         =
 =                             Private methods                             =
 =                                                                         =
 ==========================================================================*/

/***********************************************************************//**
 * @brief Initialise class members
 ***************************************************************************/
void ctmapcube::init_members(void)
{
    // Initialise members
    m_outcube.clear();
    m_ptsrcsig = 1.0;
    m_publish  = false;
    m_chatter  = static_cast<GChatter>(2);

    // Initialise protected members
    m_models.clear();
    m_cube.clear();

    // Return
    return;
}


/***********************************************************************//**
 * @brief Copy class members
 *
 * @param[in] app Application.
 ***************************************************************************/
void ctmapcube::copy_members(const ctmapcube& app)
{
    // Copy attributes
    m_outcube  = app.m_outcube;
    m_ptsrcsig = app.m_ptsrcsig;
    m_publish  = app.m_publish;
    m_chatter  = app.m_chatter;

    // Copy protected members
    m_models = app.m_models;
    m_cube   = app.m_cube;

    // Return
    return;
}


/***********************************************************************//**
 * @brief Delete class members
 ***************************************************************************/
void ctmapcube::free_members(void)
{
    // Return
    return;
}


/***********************************************************************//**
 * @brief Get application parameters
 *
 * Get all task parameters from parameter file or (if required) by querying
 * the user.
 ***************************************************************************/
void ctmapcube::get_parameters(void)
{
    // Read model definition file if required
    if (m_models.size() == 0) {

        // Get model filename
        GFilename inmodel = (*this)["inmodel"].filename();

        // Load models from file
        m_models.load(inmodel);

    } // endif: there were no models

    // Get energy binning parameters
    GEnergies energies(create_ebounds());

    // Get spatial binning parameters
    double      xref     = (*this)["xref"].real();
    double      yref     = (*this)["yref"].real();
    std::string proj     = (*this)["proj"].string();
    std::string coordsys = (*this)["coordsys"].string();
    double      binsz    = (*this)["binsz"].real();
    int         nxpix    = (*this)["nxpix"].integer();
    int         nypix    = (*this)["nypix"].integer();

    // Get remaining hidden parameters
    m_ptsrcsig = (*this)["ptsrcsig"].real();
    m_publish  = (*this)["publish"].boolean();
    m_chatter  = static_cast<GChatter>((*this)["chatter"].integer());

    // If needed later, query output filename now
    if (read_ahead()) {
        (*this)["outcube"].query();
    }

    // Allocate map cube
    GSkyMap cube(proj, coordsys, xref, yref, -binsz, binsz, nxpix, nypix,
                 energies.size());

    // Allocate map cube
    m_cube = GModelSpatialDiffuseCube(cube, energies);

    // Write parameters into logger
    log_parameters(TERSE);

    // Return
    return;
}


/***********************************************************************//**
 * @brief Generate map cube
 *
 * Generate map cube by looping over all sky models in the container.
 ***************************************************************************/
void ctmapcube::create_cube(void)
{
    // Write header into logger
    log_header1(TERSE, "Generate map cube");

    // Loop over all models
    for (int i = 0; i < m_models.size(); ++i) {

        // Get pointer to sky model
        GModelSky* model = dynamic_cast<GModelSky*>(m_models[i]);

        // Fall through if model is not a sky model
        if (model == NULL) {

            // Signal that model is skipped
            log_value(NORMAL, "Skip model", m_models[i]->name());

            // Continue
            continue;

        }

        // Signal that model is used
        log_value(NORMAL, "Use model", m_models[i]->name());

        // Add sky model
        if (dynamic_cast<GModelSpatialPointSource*>(model->spatial()) != NULL) {
            add_ptsrc_model(model);
        }
        else {
            add_model(model);
        }

    } // endfor: looped over energies

    // Return
    return;
}


/***********************************************************************//**
 * @brief Add one model to map cube
 *
 * @param[in] model Pointer to point source sky model.
 *
 * Adds one model to map cube.
 ***************************************************************************/
void ctmapcube::add_model(GModelSky* model)
{
    // Get cube energies
    GEnergies energies = m_cube.energies();

    // Get pointer to sky map
    GSkyMap* map = const_cast<GSkyMap*>(&m_cube.cube());

    // Get the model's bounding circle
    GSkyDir centre;
    double  radius;
    get_bounding_circle(model, &centre, &radius);

    // Add some margin to circle radius
    radius += 0.1;

    // Loop over all map cube pixels
    for (int ipixel = 0; ipixel < map->npix(); ++ipixel) {

        // Get pixel sky direction
        GSkyDir dir = map->inx2dir(ipixel);

        // Skip pixel if it's outside the bounding circle
        if (centre.dist_deg(dir) > radius) {
            continue;
        }

        // Loop over all energy bins
        for (int iebin = 0; iebin < energies.size(); ++iebin) {

            // Set photon
            GPhoton photon(dir, energies[iebin], GTime());

            // Add model value
            map->operator()(ipixel, iebin) += model->value(photon);

        } // endfor: looped over all energies

    } // endfor: looped over all pixels

    // Return
    return;
}


/***********************************************************************//**
 * @brief Add one point source model to map cube
 *
 * @param[in] model Pointer to point source sky model.
 *
 * Adds one point source model to map cube.
 ***************************************************************************/
void ctmapcube::add_ptsrc_model(GModelSky* model)
{
    // Get pointer to sky map
    GSkyMap* map = const_cast<GSkyMap*>(&m_cube.cube());

    // If Gaussian sigma is positive then replace the point sources by a
    // Gaussian with the user defined width
    if (m_ptsrcsig > 0.0) {

        // Get the point source centre (radius is ignored)
        GSkyDir centre;
        double  radius;
        get_bounding_circle(model, &centre, &radius);

        // Set the Gaussian sigma in degrees (m_ptsrcsig is in arcmin)
        double sigma = m_ptsrcsig/60.0;

        // Create a Gaussian spatial model
        GModelSpatialRadialGauss spatial(centre, sigma);

        // Create a new model reusing the spectral and temporal components
        // of the original model
        GModelSky skymodel(spatial, *(model->spectral()), *(model->temporal()));

        // Add model
        add_model(&skymodel);

    } // endif: Gaussian sigma was positive

    // ... otherwise set a single map pixel
    else {

        // Get point source spatial component
        GModelSpatialPointSource* ptsrc =
                    static_cast<GModelSpatialPointSource*>(model->spatial());

        // Get point source direction
        GSkyDir dir = ptsrc->dir();

        // Get cube energies
        GEnergies energies = m_cube.energies();

        // Get test sky map for flux computation
        GSkyMap test_map(*map);

        // Continue only if map contains point source sky direction
        if (map->contains(dir)) {

            // Get map pixel
            int ipixel = map->dir2inx(dir);

            // Loop over all energy bins
            for (int iebin = 0; iebin < energies.size(); ++iebin) {

                // Set photon using the point source sky direction
                GPhoton photon(dir, energies[iebin], GTime());

                // Compute model value
                double value = model->value(photon);

                // Compute flux normalization
                test_map(ipixel, iebin) = value;
                double flux = test_map.flux(ipixel, iebin);
                double norm = (flux > 0.0) ? value / flux : 0.0;

                // Add model to sky map
                map->operator()(ipixel, iebin) += norm * value;

            } // endfor: looped over all energies

        } // endif: map contained sky direction

    } // endelse: Gaussian sigma was non positive

    // Return
    return;
}


/***********************************************************************//**
 * @brief Get bounding circle for a sky model
 *
 * @param[in] model Pointer to sky model.
 * @param[out] dir Centre of bounding circle.
 * @param[out] radius Radius of bounding circle (degrees).
 *
 * Determine for any spatial model the bounding circle. The bounding circle
 * is a circular region that fully enclosed the model.
 *
 * The method does not verify the validity of the pointer arguments.
 ***************************************************************************/
void ctmapcube::get_bounding_circle(GModelSky* model,
                                    GSkyDir*   dir,
                                    double*    radius) const
{
    // Interpret the spatial model component as point source, radial source
    // or elliptical source
    GModelSpatialPointSource* ptsrc =
                 dynamic_cast<GModelSpatialPointSource*>(model->spatial());
    GModelSpatialRadial* radial =
                 dynamic_cast<GModelSpatialRadial*>(model->spatial());
    GModelSpatialElliptical* elliptical =
                 dynamic_cast<GModelSpatialElliptical*>(model->spatial());

    // If the spatial component as a point source then extract the source
    // position and set the radius of the bounding box to 0.1 degrees
    if (ptsrc != NULL) {
        *dir    = ptsrc->dir();
        *radius = 0.1;
    }

    // ... otherwise, if the spatial component is a radial source then extract
    // the source position and set the radius of the bounding box from the
    // value returned by theta_max() in radians
    else if (radial != NULL) {
        *dir    = radial->dir();
        *radius = radial->theta_max() * gammalib::rad2deg;
    }

    // ... otherwise, if the spatial component is an elliptical source then
    // extract the source position and set the radius of the bounding box from
    // the value returned by theta_max() in radians
    else if (elliptical != NULL) {
        *dir    = elliptical->dir();
        *radius = elliptical->theta_max() * gammalib::rad2deg;
    }

    // ... otherwise use the entire sky
    else {
        *radius = 180.0;
    }

    // Return
    return;
}