/*
 * Copyright (C) 2011-2013 Karlsruhe Institute of Technology
 *
 * This file is part of Ufo.
 *
 * This library 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 library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "config.h"

#include <math.h>
#include "ufo-measure-sharpness-task.h"


struct _UfoMeasureSharpnessTaskPrivate {
    gdouble sharpness;
};

static void ufo_task_interface_init (UfoTaskIface *iface);

G_DEFINE_TYPE_WITH_CODE (UfoMeasureSharpnessTask, ufo_measure_sharpness_task, UFO_TYPE_TASK_NODE,
                         G_IMPLEMENT_INTERFACE (UFO_TYPE_TASK,
                                                ufo_task_interface_init))

#define UFO_MEASURE_SHARPNESS_TASK_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE((obj), UFO_TYPE_MEASURE_SHARPNESS_TASK, UfoMeasureSharpnessTaskPrivate))

enum {
    PROP_0,
    PROP_SHARPNESS,
    N_PROPERTIES
};

static GParamSpec *properties[N_PROPERTIES] = { NULL, };

UfoNode *
ufo_measure_sharpness_task_new (void)
{
    return UFO_NODE (g_object_new (UFO_TYPE_MEASURE_SHARPNESS_TASK, NULL));
}

static void
ufo_measure_sharpness_task_setup (UfoTask *task,
                              UfoResources *resources,
                              GError **error)
{
}

static void
ufo_measure_sharpness_task_get_requisition (UfoTask *task,
                                            UfoBuffer **inputs,
                                            UfoRequisition *requisition,
                                            GError **error)
{
    requisition->n_dims = 0;
}

static guint
ufo_measure_sharpness_task_get_num_inputs (UfoTask *task)
{
    return 1;
}

static guint
ufo_measure_sharpness_task_get_num_dimensions (UfoTask *task,
                               guint input)
{
    g_return_val_if_fail (input == 0, 0);
    return 2;
}

static UfoTaskMode
ufo_measure_sharpness_task_get_mode (UfoTask *task)
{
    return UFO_TASK_MODE_PROCESSOR | UFO_TASK_MODE_CPU;
}

static gdouble
measure_sharpness (gfloat *data,
                   guint width,
                   guint height)
{
    gdouble sum = 0.0;

    for (guint y = 1; y < height; y++) {
        for (guint x = 1; x < width; x++) {
            guint index;
            gdouble h_gradient, v_gradient;
            
            index = y * width + x;
            h_gradient = fabs (data[index] - data[index-1]);
            v_gradient = fabs (data[index] - data[index-width]);
            sum += h_gradient + v_gradient;
        }
    }

    return sum / 2.0 / (width * height);
}

static gboolean
ufo_measure_sharpness_task_process (UfoTask *task,
                                    UfoBuffer **inputs,
                                    UfoBuffer *output,
                                    UfoRequisition *requisition)
{
    UfoMeasureSharpnessTaskPrivate *priv;
    UfoRequisition req;
    gfloat *data;

    priv = UFO_MEASURE_SHARPNESS_TASK_GET_PRIVATE (task);
    data = ufo_buffer_get_host_array (inputs[0], NULL);
    ufo_buffer_get_requisition (inputs[0], &req);

    priv->sharpness = measure_sharpness (data, (guint) req.dims[0], (guint) req.dims[1]);
    g_object_notify (G_OBJECT (task), "sharpness");

    return TRUE;
}

static void
ufo_measure_sharpness_task_set_property (GObject *object,
                                         guint property_id,
                                         const GValue *value,
                                         GParamSpec *pspec)
{
    switch (property_id) {
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
            break;
    }
}

static void
ufo_measure_sharpness_task_get_property (GObject *object,
                                         guint property_id,
                                         GValue *value,
                                         GParamSpec *pspec)
{
    UfoMeasureSharpnessTaskPrivate *priv = UFO_MEASURE_SHARPNESS_TASK_GET_PRIVATE (object);

    switch (property_id) {
        case PROP_SHARPNESS:
            g_value_set_double (value, priv->sharpness);
            break;
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
            break;
    }
}

static void
ufo_measure_sharpness_task_finalize (GObject *object)
{
    G_OBJECT_CLASS (ufo_measure_sharpness_task_parent_class)->finalize (object);
}

static void
ufo_task_interface_init (UfoTaskIface *iface)
{
    iface->setup = ufo_measure_sharpness_task_setup;
    iface->get_num_inputs = ufo_measure_sharpness_task_get_num_inputs;
    iface->get_num_dimensions = ufo_measure_sharpness_task_get_num_dimensions;
    iface->get_mode = ufo_measure_sharpness_task_get_mode;
    iface->get_requisition = ufo_measure_sharpness_task_get_requisition;
    iface->process = ufo_measure_sharpness_task_process;
}

static void
ufo_measure_sharpness_task_class_init (UfoMeasureSharpnessTaskClass *klass)
{
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

    gobject_class->set_property = ufo_measure_sharpness_task_set_property;
    gobject_class->get_property = ufo_measure_sharpness_task_get_property;
    gobject_class->finalize = ufo_measure_sharpness_task_finalize;

    properties[PROP_SHARPNESS] =
        g_param_spec_double ("sharpness",
            "Sharpness of the image region",
            "Dimensionless measure describing the sharpness of the image",
            0.0, 1.0, 0.0,
            G_PARAM_READABLE);

    for (guint i = PROP_0 + 1; i < N_PROPERTIES; i++)
        g_object_class_install_property (gobject_class, i, properties[i]);

    g_type_class_add_private (gobject_class, sizeof(UfoMeasureSharpnessTaskPrivate));
}

static void
ufo_measure_sharpness_task_init(UfoMeasureSharpnessTask *self)
{
    self->priv = UFO_MEASURE_SHARPNESS_TASK_GET_PRIVATE(self);
}