/*
 * Copyright (C) 2008, Red Hat, Inc.
 *
 * 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 2 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, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include "sugar-grid.h"

enum {
  PROP_0,
  PROP_WIDTH,
  PROP_HEIGHT,
};

struct _SugarGrid {
    GObject base_instance;

    SugarGridPrivate *priv;
};

struct _SugarGridClass {
	GObjectClass base_class;
};

struct _SugarGridPrivate {
    guint width;
    guint height;
    guchar *weights;
};

G_DEFINE_TYPE(SugarGrid, sugar_grid, G_TYPE_OBJECT)

void
sugar_grid_setup(SugarGrid *grid, gint width, gint height)
{
    g_free(grid->priv->weights);

    grid->priv->weights = g_new0(guchar, width * height);
    grid->priv->width = width;
    grid->priv->height = height;
}

static gboolean
check_bounds(SugarGrid *grid, GdkRectangle *rect)
{
    return (grid->priv->weights != NULL &&
            grid->priv->width >= rect->x + rect->width &&
            grid->priv->height >= rect->y + rect->height);
}

void
sugar_grid_add_weight(SugarGrid *grid, GdkRectangle *rect)
{
    int i, k;

    if (!check_bounds(grid, rect)) {
        g_warning("Trying to add weight outside the grid bounds.");
        return;
    }

    for (k = rect->y; k < rect->y + rect->height; k++) {
        for (i = rect->x; i < rect->x + rect->width; i++) {
            grid->priv->weights[i + k * grid->priv->width] += 1;
        }
    }
}

void
sugar_grid_remove_weight(SugarGrid *grid, GdkRectangle *rect)
{
    int i, k;

    if (!check_bounds(grid, rect)) {
        g_warning("Trying to remove weight outside the grid bounds.");
        return;
    }

    for (k = rect->y; k < rect->y + rect->height; k++) {
        for (i = rect->x; i < rect->x + rect->width; i++) {
            grid->priv->weights[i + k * grid->priv->width] -= 1;
        }
    }
}

guint
sugar_grid_compute_weight(SugarGrid *grid, GdkRectangle *rect)
{
    int i, k, sum = 0;

    if (!check_bounds(grid, rect)) {
        g_warning("Trying to compute weight outside the grid bounds.");
        return 0;
    }

    for (k = rect->y; k < rect->y + rect->height; k++) {
        for (i = rect->x; i < rect->x + rect->width; i++) {
            sum += grid->priv->weights[i + k * grid->priv->width];
        }
    }

    return sum;
}

static void
sugar_grid_set_property (GObject      *object,
                         guint         property_id,
                         const GValue *value,
                         GParamSpec   *pspec)
{
  SugarGrid *self = SUGAR_GRID (object);

  switch (property_id)
    {
    case PROP_WIDTH:
      g_value_set_uint ((GValue *)value, self->priv->width);
      break;
    case PROP_HEIGHT:
      g_value_set_uint ((GValue *)value, self->priv->height);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
sugar_grid_get_property (GObject    *object,
                         guint       property_id,
                         GValue     *value,
                         GParamSpec *pspec)
{
  SugarGrid *self = SUGAR_GRID (object);

  switch (property_id)
    {
    case PROP_WIDTH:
      g_value_set_uint (value, self->priv->width);
      break;
    case PROP_HEIGHT:
      g_value_set_uint (value, self->priv->height);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
sugar_grid_finalize(GObject *object)
{
    SugarGrid *grid = SUGAR_GRID(object);

    g_free(grid->priv->weights);
}

static void
sugar_grid_class_init(SugarGridClass *grid_class)
{
    GObjectClass *gobject_class;
    GParamSpec *pspec;

    gobject_class = G_OBJECT_CLASS(grid_class);
    gobject_class->finalize = sugar_grid_finalize;
    gobject_class->set_property = sugar_grid_set_property;
    gobject_class->get_property = sugar_grid_get_property;

    g_type_class_add_private (grid_class, sizeof (SugarGridPrivate));

    pspec = g_param_spec_uint ("width", NULL,
                               "Width of the Grid",
                               0, G_MAXUINT, 0,
                               G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
                                     PROP_WIDTH,
                                     pspec);

    pspec = g_param_spec_uint ("height", NULL,
                               "Height of the Grid",
                               0, G_MAXUINT, 0,
                               G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
                                     PROP_HEIGHT,
                                     pspec);
}

static void
sugar_grid_init(SugarGrid *grid)
{
    grid->priv = G_TYPE_INSTANCE_GET_PRIVATE (grid, SUGAR_TYPE_GRID, SugarGridPrivate);
    grid->priv->width = 0;
    grid->priv->height = 0;
    grid->priv->weights = NULL;
}