/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * gimpcontainerlistview.c
 * Copyright (C) 2025 Michael Natterer <mitch@gimp.org>
 *
 * 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 <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>

#include <gegl.h>
#include <gtk/gtk.h>

#include "libgimpwidgets/gimpwidgets.h"

#include "widgets-types.h"

#include "core/gimpcontainer.h"
#include "core/gimpcontext.h"
#include "core/gimpviewable.h"

#include "gimpcontainerlistview.h"
#include "gimpcontainerview.h"
#include "gimprow.h"
#include "gimprow-utils.h"
#include "gimpviewrenderer.h"

#include "gimp-intl.h"


typedef struct _GimpContainerListViewPrivate GimpContainerListViewPrivate;

struct _GimpContainerListViewPrivate
{
  GtkListBox *view;

  gboolean    reordering;
  GList      *reordering_selected;
};

#define GET_PRIVATE(obj) \
  ((GimpContainerListViewPrivate *) gimp_container_list_view_get_instance_private ((GimpContainerListView *) obj))


static void     gimp_container_list_view_view_iface_init   (GimpContainerViewInterface *iface);

static void     gimp_container_list_view_constructed       (GObject               *object);
static void     gimp_container_list_view_finalize          (GObject               *object);

static gboolean gimp_container_list_view_popup_menu        (GtkWidget             *widget);

static void     gimp_container_list_view_set_container     (GimpContainerView     *view,
                                                            GimpContainer         *container);
static void     gimp_container_list_view_set_context       (GimpContainerView     *view,
                                                            GimpContext           *context);
static void     gimp_container_list_view_set_selection_mode(GimpContainerView     *view,
                                                            GtkSelectionMode       mode);
static void     gimp_container_list_view_set_view_size     (GimpContainerView     *view);
static gboolean gimp_container_list_view_set_selected      (GimpContainerView     *view,
                                                            GList                 *items);
static gint     gimp_container_list_view_get_selected      (GimpContainerView     *view,
                                                            GList                **items);

static void     gimp_container_list_view_reorder           (GimpContainer         *container,
                                                            GimpObject            *object,
                                                            gint                   old_index,
                                                            gint                   new_index,
                                                            GimpContainerView     *view);
static void     gimp_container_list_view_before_items_changed
                                                           (GimpContainer         *container,
                                                            guint                  position,
                                                            guint                  removed,
                                                            guint                  added,
                                                            GimpContainerView     *view);
static void     gimp_container_list_view_after_items_changed
                                                           (GimpContainer         *container,
                                                            guint                  position,
                                                            guint                  removed,
                                                            guint                  added,
                                                            GimpContainerView     *view);

static void     gimp_container_list_view_selected_rows_changed
                                                            (GtkListBox            *box,
                                                             GimpContainerListView *list_view);
static void     gimp_container_list_view_row_activated      (GtkListBox            *box,
                                                             GimpRow               *row,
                                                             GimpContainerListView *list_view);

static void     gimp_container_list_view_monitor_changed    (GimpContainerListView *view);


G_DEFINE_TYPE_WITH_CODE (GimpContainerListView,
                         gimp_container_list_view,
                         GIMP_TYPE_CONTAINER_BOX,
                         G_ADD_PRIVATE (GimpContainerListView)
                         G_IMPLEMENT_INTERFACE (GIMP_TYPE_CONTAINER_VIEW,
                                                gimp_container_list_view_view_iface_init))

#define parent_class gimp_container_list_view_parent_class

static GimpContainerViewInterface *parent_view_iface = NULL;


static void
gimp_container_list_view_class_init (GimpContainerListViewClass *klass)
{
  GObjectClass   *object_class = G_OBJECT_CLASS (klass);
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);

  object_class->constructed   = gimp_container_list_view_constructed;
  object_class->finalize      = gimp_container_list_view_finalize;

  widget_class->popup_menu    = gimp_container_list_view_popup_menu;
}

static void
gimp_container_list_view_view_iface_init (GimpContainerViewInterface *iface)
{
  parent_view_iface = g_type_interface_peek_parent (iface);

  if (! parent_view_iface)
    parent_view_iface = g_type_default_interface_peek (GIMP_TYPE_CONTAINER_VIEW);

  iface->set_container      = gimp_container_list_view_set_container;
  iface->set_context        = gimp_container_list_view_set_context;
  iface->set_selection_mode = gimp_container_list_view_set_selection_mode;
  iface->set_view_size      = gimp_container_list_view_set_view_size;
  iface->set_selected       = gimp_container_list_view_set_selected;
  iface->get_selected       = gimp_container_list_view_get_selected;

  iface->use_list_model     = TRUE;
}

static void
gimp_container_list_view_init (GimpContainerListView *list_view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (list_view);
  GimpContainerBox             *box  = GIMP_CONTAINER_BOX (list_view);

  priv->view = GTK_LIST_BOX (gtk_list_box_new ());
  gtk_list_box_set_activate_on_single_click (priv->view, FALSE);
  gtk_container_add (GTK_CONTAINER (box->scrolled_win),
                     GTK_WIDGET (priv->view));
  gtk_widget_show (GTK_WIDGET (priv->view));

  g_signal_connect (priv->view, "selected-rows-changed",
                    G_CALLBACK (gimp_container_list_view_selected_rows_changed),
                    list_view);
  g_signal_connect (priv->view, "row-activated",
                    G_CALLBACK (gimp_container_list_view_row_activated),
                    list_view);

  gimp_container_view_set_dnd_widget (GIMP_CONTAINER_VIEW (list_view),
                                      GTK_WIDGET (priv->view));

  gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (box->scrolled_win),
                                       GTK_SHADOW_IN);
  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (box->scrolled_win),
                                  GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);

  gimp_widget_track_monitor (GTK_WIDGET (list_view),
                             G_CALLBACK (gimp_container_list_view_monitor_changed),
                             NULL, NULL);
}

static void
gimp_container_list_view_constructed (GObject *object)
{
  G_OBJECT_CLASS (parent_class)->constructed (object);
}

static void
gimp_container_list_view_finalize (GObject *object)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (object);

  g_list_free_full (priv->reordering_selected, g_object_unref);
  priv->reordering_selected = NULL;

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static gboolean
gimp_container_list_view_popup_menu (GtkWidget *widget)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (widget);
  GList                        *rows;
  GtkWidget                    *row;
  GtkAllocation                 allocation;

  rows = gtk_list_box_get_selected_rows (priv->view);

  if (g_list_length (rows) != 1)
    {
      g_list_free (rows);

      return FALSE;
    }

  row = rows->data;

  g_list_free (rows);

  gtk_widget_get_allocation (row, &allocation);

  return gimp_editor_popup_menu_at_rect (GIMP_EDITOR (widget),
                                         gtk_widget_get_window (row),
                                         (GdkRectangle *) &allocation,
                                         GDK_GRAVITY_CENTER,
                                         GDK_GRAVITY_NORTH_WEST,
                                         NULL);
}

GtkWidget *
gimp_container_list_view_new (GimpContainer *container,
                              GimpContext   *context,
                              gint           view_size,
                              gint           view_border_width)
{
  g_return_val_if_fail (container == NULL || GIMP_IS_CONTAINER (container),
                        NULL);
  g_return_val_if_fail (context == NULL || GIMP_IS_CONTEXT (context), NULL);
  g_return_val_if_fail (view_size > 0 &&
                        view_size <= GIMP_VIEWABLE_MAX_PREVIEW_SIZE, NULL);
  g_return_val_if_fail (view_border_width >= 0 &&
                        view_border_width <= GIMP_VIEW_MAX_BORDER_WIDTH,
                        NULL);

  return g_object_new (GIMP_TYPE_CONTAINER_LIST_VIEW,
                       "view-size",         view_size,
                       "view-border-width", view_border_width,
                       "context",           context,
                       "container",         container,
                       NULL);
}

void
gimp_container_list_view_set_search_entry (GimpContainerListView *list_view,
                                           GtkSearchEntry        *entry)
{
  g_return_if_fail (GIMP_IS_CONTAINER_LIST_VIEW (list_view));
  g_return_if_fail (GTK_IS_SEARCH_ENTRY (entry));

  g_printerr ("implement gimp_container_list_view_set_search_entry()\n");
}


/*  GimpContainerView methods  */

static void
gimp_container_list_view_set_container (GimpContainerView *view,
                                        GimpContainer     *container)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GimpContainer                *old_container;

  old_container = gimp_container_view_get_container (view);

  if (old_container)
    {
      g_signal_handlers_disconnect_by_func (old_container,
                                            gimp_container_list_view_reorder,
                                            view);
      g_signal_handlers_disconnect_by_func (old_container,
                                            gimp_container_list_view_before_items_changed,
                                            view);
      g_signal_handlers_disconnect_by_func (old_container,
                                            gimp_container_list_view_after_items_changed,
                                            view);

#if 0
      if (! container)
        {
          if (gimp_dnd_viewable_list_source_remove (GTK_WIDGET (list_view->view),
                                                    gimp_container_get_child_type (old_container)))
            {
              gtk_drag_source_unset (GTK_WIDGET (list_view->view));
            }
        }
#endif

      gtk_list_box_bind_model (priv->view, NULL, NULL, NULL, NULL);
    }
  else if (container)
    {
#if 0
      if (gimp_dnd_drag_source_set_by_type (GTK_WIDGET (list_view->view),
                                            GDK_BUTTON1_MASK | GDK_BUTTON2_MASK,
                                            gimp_container_get_child_type (container),
                                            GDK_ACTION_COPY))
        {
          gimp_dnd_viewable_list_source_add (GTK_WIDGET (list_view->view),
                                             gimp_container_get_child_type (container),
                                             gimp_container_list_view_drag_viewable_list,
                                             list_view);
        }
#endif
    }

  parent_view_iface->set_container (view, container);

  if (container)
    {
      g_signal_connect (container, "reorder",
                        G_CALLBACK (gimp_container_list_view_reorder),
                        view);
      g_signal_connect (container, "items-changed",
                        G_CALLBACK (gimp_container_list_view_before_items_changed),
                        view);

      gtk_list_box_bind_model (priv->view, G_LIST_MODEL (container),
                               gimp_row_create_for_container_view,
                               view, NULL);

      g_signal_connect (container, "items-changed",
                        G_CALLBACK (gimp_container_list_view_after_items_changed),
                        view);
    }
}

static void
gimp_container_list_view_set_context (GimpContainerView *view,
                                      GimpContext       *context)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GList                        *children;
  GList                        *child;

  parent_view_iface->set_context (view, context);

  children = gtk_container_get_children (GTK_CONTAINER (priv->view));

  for (child = children; child; child = g_list_next (child))
    {
      gimp_row_set_context (child->data, context);
    }

  g_list_free (children);
}

static void
gimp_container_list_view_set_selection_mode (GimpContainerView *view,
                                             GtkSelectionMode   mode)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);

  parent_view_iface->set_selection_mode (view, mode);

  gtk_list_box_set_selection_mode (priv->view, mode);
}

static void
gimp_container_list_view_set_view_size (GimpContainerView *view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GList                        *children;
  GList                        *child;
  gint                          view_size;
  gint                          border_width;

  view_size = gimp_container_view_get_view_size (view, &border_width);

  children = gtk_container_get_children (GTK_CONTAINER (priv->view));

  for (child = children; child; child = g_list_next (child))
    {
      gimp_row_set_view_size (child->data, view_size, border_width);
    }

  g_list_free (children);
}

static gboolean
gimp_container_list_view_set_selected (GimpContainerView *view,
                                       GList             *items)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GtkAdjustment                *adjustment;
  GtkAllocation                 allocation;
  GList                        *children;
  GList                        *child;
  gdouble                       scroll_offset;
  gint                          top_selected    = G_MAXINT;
  gint                          bottom_selected = 0;

  adjustment = gtk_list_box_get_adjustment (priv->view);

  scroll_offset = gtk_adjustment_get_value (adjustment);

  g_signal_handlers_block_by_func (priv->view,
                                   gimp_container_list_view_selected_rows_changed,
                                   view);

  gtk_list_box_unselect_all (priv->view);

  adjustment = gtk_list_box_get_adjustment (priv->view);

  children = gtk_container_get_children (GTK_CONTAINER (priv->view));

  for (child = children; child; child = g_list_next (child))
    {
      GimpViewable *viewable = gimp_row_get_viewable (child->data);

      if (g_list_find (items, viewable))
        {

          gtk_list_box_select_row (priv->view, child->data);

          gtk_widget_get_allocation (child->data, &allocation);

          top_selected    = MIN (top_selected, allocation.y);
          bottom_selected = MAX (bottom_selected, allocation.y + allocation.height);
        }
    }

  g_list_free (children);

  g_signal_handlers_unblock_by_func (priv->view,
                                     gimp_container_list_view_selected_rows_changed,
                                     view);

  gtk_widget_get_allocation (gtk_widget_get_parent (GTK_WIDGET (priv->view)),
                             &allocation);

  if (top_selected < scroll_offset)
    {
      gtk_adjustment_set_value (adjustment, top_selected);
    }
  else if (bottom_selected > scroll_offset + allocation.height)
    {
      gtk_adjustment_set_value (adjustment, bottom_selected - allocation.height);
    }

  _gimp_container_view_selection_changed (view);

  return TRUE;
}

static gint
gimp_container_list_view_get_selected (GimpContainerView  *view,
                                       GList             **items)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GList                        *rows;
  gint                          n_selected;

  rows = gtk_list_box_get_selected_rows (priv->view);

  n_selected = g_list_length (rows);

  if (items)
    {
      GList *row;

      for (row = rows; row; row = g_list_next (row))
        {
          *items = g_list_prepend (*items, gimp_row_get_viewable (row->data));
        }

      *items = g_list_reverse (*items);
    }

  g_list_free (rows);

  return n_selected;
}

static void
gimp_container_list_view_reorder (GimpContainer     *container,
                                  GimpObject        *object,
                                  gint               old_index,
                                  gint               new_index,
                                  GimpContainerView *view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);

  priv->reordering = TRUE;
}

static void
gimp_container_list_view_before_items_changed (GimpContainer     *container,
                                               guint              position,
                                               guint              removed,
                                               guint              added,
                                               GimpContainerView *view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);

  if (priv->reordering)
    {
      gimp_container_view_get_selected (view, &priv->reordering_selected);
      g_list_foreach (priv->reordering_selected, (GFunc) g_object_ref, NULL);
    }
}

static void
gimp_container_list_view_after_items_changed (GimpContainer     *container,
                                              guint              position,
                                              guint              removed,
                                              guint              added,
                                              GimpContainerView *view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);

  if (priv->reordering)
    {
      gimp_container_view_set_selected (view, priv->reordering_selected);

      g_list_free_full (priv->reordering_selected, g_object_unref);
      priv->reordering_selected = NULL;

      priv->reordering = FALSE;
    }
}

static void
gimp_container_list_view_selected_rows_changed (GtkListBox            *box,
                                                GimpContainerListView *list_view)
{
  _gimp_container_view_selection_changed (GIMP_CONTAINER_VIEW (list_view));
}

static void
gimp_container_list_view_row_activated (GtkListBox            *box,
                                        GimpRow               *row,
                                        GimpContainerListView *list_view)
{
  _gimp_container_view_item_activated (GIMP_CONTAINER_VIEW (list_view),
                                       gimp_row_get_viewable (row));
}

static void
gimp_container_list_view_monitor_changed (GimpContainerListView *view)
{
  GimpContainerListViewPrivate *priv = GET_PRIVATE (view);
  GList                        *children;
  GList                        *child;

  children = gtk_container_get_children (GTK_CONTAINER (priv->view));

  for (child = children; child; child = g_list_next (child))
    {
      gimp_row_monitor_changed (child->data);
    }

  g_list_free (children);
}