/* cc-panel-list.c
 *
 * Copyright (C) 2016 Endless, Inc
 *
 * 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 2 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/>.
 *
 * Author: Georges Basile Stavracas Neto <gbsneto@gnome.org>
 */

#include "cc-panel-list.h"
#include "cc-util.h"

typedef struct
{
  GtkWidget       *row;
  GtkWidget       *description_label;
  CcPanelCategory  category;
  gchar           *id;
  gchar           *name;
  gchar           *description;
} RowData;

struct _CcPanelList
{
  GtkStack            parent;

  GtkWidget          *details_listbox;
  GtkWidget          *devices_listbox;
  GtkWidget          *main_listbox;
  GtkWidget          *search_listbox;

  GtkListBoxRow      *details_row;
  GtkListBoxRow      *devices_row;

  GtkWidget          *empty_search_placeholder;

  gchar              *search_query;

  CcPanelListView     previous_view;
  CcPanelListView     view;
  GHashTable         *id_to_data;
};

G_DEFINE_TYPE (CcPanelList, cc_panel_list, GTK_TYPE_STACK)

enum
{
  PROP_0,
  PROP_SEARCH_MODE,
  PROP_SEARCH_QUERY,
  PROP_VIEW,
  N_PROPS
};

enum
{
  SHOW_PANEL,
  LAST_SIGNAL
};

static GParamSpec *properties [N_PROPS] = { NULL, };
static gint signals [LAST_SIGNAL] = { 0, };

/*
 * Auxiliary methods
 */
static GtkWidget*
get_listbox_from_view (CcPanelList     *self,
                       CcPanelListView  view)
{
  switch (view)
    {
    case CC_PANEL_LIST_MAIN:
      return self->main_listbox;

    case CC_PANEL_LIST_DETAILS:
      return self->details_listbox;

    case CC_PANEL_LIST_DEVICES:
      return self->devices_listbox;

    case CC_PANEL_LIST_SEARCH:
      return self->search_listbox;

    default:
      return NULL;
    }
}

static CcPanelListView
get_view_from_listbox (CcPanelList *self,
                       GtkWidget   *listbox)
{
  if (listbox == self->main_listbox)
    return CC_PANEL_LIST_MAIN;

  if (listbox == self->details_listbox)
    return CC_PANEL_LIST_DETAILS;

  if (listbox == self->devices_listbox)
    return CC_PANEL_LIST_DEVICES;

  return CC_PANEL_LIST_SEARCH;
}

static void
update_search (CcPanelList *self)
{
  /*
   * Only change to the search view is there's a
   * search query available.
   */
  if (self->search_query &&
      g_utf8_strlen (self->search_query, -1) > 0)
    {
      if (self->view == CC_PANEL_LIST_MAIN)
        cc_panel_list_set_view (self, CC_PANEL_LIST_SEARCH);
    }
  else
    {
      if (self->view == CC_PANEL_LIST_SEARCH)
        cc_panel_list_set_view (self, self->previous_view);
    }

  gtk_list_box_invalidate_filter (GTK_LIST_BOX (self->search_listbox));
  gtk_list_box_unselect_all (GTK_LIST_BOX (self->search_listbox));
}

/*
 * RowData functions
 */
static void
row_data_free (RowData *data)
{
  g_free (data->description);
  g_free (data->name);
  g_free (data);
}

static RowData*
row_data_new (CcPanelCategory  category,
              const gchar     *id,
              const gchar     *name,
              const gchar     *description,
              const gchar     *icon)
{
  GtkWidget *label, *grid, *image;
  RowData *data;

  data = g_new0 (RowData, 1);
  data->category = category;
  data->row = gtk_list_box_row_new ();
  data->id = g_strdup (id);
  data->name = g_strdup (name);
  data->description = g_strdup (description);

  /* Setup the row */
  grid = g_object_new (GTK_TYPE_GRID,
                       "visible", TRUE,
                       "hexpand", TRUE,
                       "border-width", 12,
                       "column-spacing", 12,
                       NULL);

  /* Icon */
  image = gtk_image_new_from_icon_name (icon, GTK_ICON_SIZE_BUTTON);
  gtk_style_context_add_class (gtk_widget_get_style_context (image), "dim-label");

  gtk_grid_attach (GTK_GRID (grid), image, 0, 0, 1, 1);

  gtk_widget_show (image);

  /* Name label */
  label = g_object_new (GTK_TYPE_LABEL,
                        "label", name,
                        "visible", TRUE,
                        "xalign", 0.0,
                        "hexpand", TRUE,
                        NULL);
  gtk_grid_attach (GTK_GRID (grid), label, 1, 0, 1, 1);

  /* Description label */
  label = g_object_new (GTK_TYPE_LABEL,
                        "label", description,
                        "visible", FALSE,
                        "xalign", 0.0,
                        "hexpand", TRUE,
                        NULL);
  gtk_label_set_max_width_chars (GTK_LABEL (label), 25);
  gtk_label_set_line_wrap (GTK_LABEL (label), TRUE);

  gtk_style_context_add_class (gtk_widget_get_style_context (label), "dim-label");
  gtk_grid_attach (GTK_GRID (grid), label, 1, 1, 1, 1);

  data->description_label = label;

  gtk_container_add (GTK_CONTAINER (data->row), grid);
  gtk_widget_show (data->row);

  g_object_set_data_full (G_OBJECT (data->row), "data", data, (GDestroyNotify) row_data_free);

  return data;
}

/*
 * GtkListBox functions
 */
static gboolean
filter_func (GtkListBoxRow *row,
             gpointer       user_data)
{
  CcPanelList *self;
  RowData *data;
  gchar *search_text, *panel_text, *panel_description;
  gboolean retval;

  self = CC_PANEL_LIST (user_data);
  data = g_object_get_data (G_OBJECT (row), "data");

  if (!self->search_query)
    return TRUE;

  panel_text = cc_util_normalize_casefold_and_unaccent (data->name);
  search_text = cc_util_normalize_casefold_and_unaccent (self->search_query);
  panel_description = cc_util_normalize_casefold_and_unaccent (data->description);

  g_strstrip (panel_text);
  g_strstrip (search_text);
  g_strstrip (panel_description);

  /*
   * The description label is only visible when the search is
   * happening.
   */
  gtk_widget_set_visible (data->description_label, self->view == CC_PANEL_LIST_SEARCH);

  retval = g_strstr_len (panel_text, -1, search_text) != NULL ||
           g_strstr_len (panel_description, -1, search_text) != NULL;

  g_free (panel_text);
  g_free (search_text);
  g_free (panel_description);

  return retval;
}

static gint
sort_function (GtkListBoxRow *a,
               GtkListBoxRow *b,
               gpointer       user_data)
{
  CcPanelList *self;
  RowData *a_data, *b_data;

  self = CC_PANEL_LIST (user_data);

  /* Handle the Devices and the Details rows */
  if (a == self->details_row && b == self->devices_row)
    return 1;
  if (a == self->devices_row && b == self->details_row)
    return -1;
  if (a == self->details_row || a == self->devices_row)
    return 1;
  if (b == self->details_row || b == self->devices_row)
    return -1;

  /*
   * We can only retrieve the data after assuring that none
   * of the rows are Devices and Details.
   */
  a_data = g_object_get_data (G_OBJECT (a), "data");
  b_data = g_object_get_data (G_OBJECT (b), "data");

  if (a_data->category != b_data->category)
    return a_data->category - b_data->category;

  return g_strcmp0 (a_data->name, b_data->name);
}

static gint
search_sort_function (GtkListBoxRow *a,
                      GtkListBoxRow *b,
                      gpointer       user_data)
{
  CcPanelList *self;
  RowData *a_data, *b_data;
  gchar *a_name, *b_name, *search, *a_strstr, *b_strstr;
  gint a_distance, b_distance;
  gint retval;

  self = CC_PANEL_LIST (user_data);
  search = NULL;
  a_data = g_object_get_data (G_OBJECT (a), "data");
  b_data = g_object_get_data (G_OBJECT (b), "data");

  a_distance = b_distance = G_MAXINT;

  a_name = cc_util_normalize_casefold_and_unaccent (a_data->name);
  b_name = cc_util_normalize_casefold_and_unaccent (b_data->name);
  g_strstrip (a_name);
  g_strstrip (b_name);

  if (self->search_query)
    {
      search = cc_util_normalize_casefold_and_unaccent (self->search_query);
      g_strstrip (search);
    }

  /* Default result for empty search */
  if (!search || g_utf8_strlen (search, -1) == 0)
    {
      retval = g_strcmp0 (a_name, b_name);
      goto out;
    }

  a_strstr = g_strstr_len (a_name, -1, search);
  b_strstr = g_strstr_len (b_name, -1, search);

  if (a_strstr)
    a_distance = g_strstr_len (a_name, -1, search) - a_name;

  if (b_strstr)
    b_distance = g_strstr_len (b_name, -1, search) - b_name;

  retval = a_distance - b_distance;

out:
  g_free (a_name);
  g_free (b_name);
  g_free (search);

  return retval;
}

static void
header_func (GtkListBoxRow *row,
             GtkListBoxRow *before,
             gpointer       user_data)
{
  CcPanelList *self = CC_PANEL_LIST (user_data);

  if (!before)
    return;

  /* The Details row always have the separator */
  if (row == self->details_row)
    {
      GtkWidget *separator;

      separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
      gtk_widget_set_hexpand (separator, TRUE);
      gtk_widget_show (separator);

      gtk_list_box_row_set_header (row, separator);
    }
  else
    {
      RowData *row_data, *before_data;

      if (row == self->devices_row ||
          before == self->details_row ||
          before == self->devices_row)
        {
          return;
        }

      /*
       * We can only retrieve the data after assuring that none
       * of the rows are Devices and Details.
       */
      row_data = g_object_get_data (G_OBJECT (row), "data");
      before_data = g_object_get_data (G_OBJECT (before), "data");

      if (row_data->category != before_data->category)
        {
          GtkWidget *separator;

          separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
          gtk_widget_set_hexpand (separator, TRUE);
          gtk_widget_show (separator);

          gtk_list_box_row_set_header (row, separator);
        }
    }
}

/*
 * Callbacks
 */
static void
row_activated_cb (GtkWidget     *listbox,
                  GtkListBoxRow *row,
                  CcPanelList   *self)
{
  RowData *data;

  /* Details */
  if (row == self->details_row)
    {
      cc_panel_list_set_view (self, CC_PANEL_LIST_DETAILS);
      return;
    }

  /* Devices */
  if (row == self->devices_row)
    {
      cc_panel_list_set_view (self, CC_PANEL_LIST_DEVICES);
      return;
    }

  /*
   * When a panel is selected, the previous one should be
   * unselected, except when it's search.
   */
  if (listbox != self->search_listbox)
    {
      if (listbox != self->main_listbox)
        gtk_list_box_unselect_all (GTK_LIST_BOX (self->main_listbox));

      if (listbox != self->details_listbox)
        gtk_list_box_unselect_all (GTK_LIST_BOX (self->details_listbox));

      if (listbox != self->devices_listbox)
        gtk_list_box_unselect_all (GTK_LIST_BOX (self->devices_listbox));
    }

  /*
   * Since we're not sure that the activated row is in the
   * current view, set the view here.
   */
  cc_panel_list_set_view (self, get_view_from_listbox (self, listbox));

  data = g_object_get_data (G_OBJECT (row), "data");

  g_signal_emit (self, signals[SHOW_PANEL], 0, data->id);
}

static void
search_row_activated_cb (GtkWidget     *listbox,
                         GtkListBoxRow *row,
                         CcPanelList   *self)
{
  GtkWidget *real_listbox;
  RowData *data;
  GList *children, *l;

  data = g_object_get_data (G_OBJECT (row), "data");

  if (data->category == CC_CATEGORY_DETAILS)
    real_listbox = self->details_listbox;
  else if (data->category == CC_CATEGORY_DEVICES)
    real_listbox = self->devices_listbox;
  else
    real_listbox = self->main_listbox;

  /* Select the correct row */
  children = gtk_container_get_children (GTK_CONTAINER (real_listbox));

  for (l = children; l != NULL; l = l->next)
    {
      RowData *real_row_data;

      real_row_data = g_object_get_data (l->data, "data");

      /*
       * The main listbox has the Details & Devices rows, and neither
       * of them contains "data", so we have to ensure we have valid
       * data before going on.
       */
      if (!real_row_data)
        continue;

      if (g_strcmp0 (real_row_data->id, data->id) == 0)
        {
          GtkListBoxRow *real_row;

          real_row = GTK_LIST_BOX_ROW (real_row_data->row);

          gtk_list_box_select_row (GTK_LIST_BOX (real_listbox), real_row);
          gtk_widget_grab_focus (GTK_WIDGET (real_row));

          g_signal_emit_by_name (real_row, "activate");
          break;
        }
    }

  g_list_free (children);
}

static void
cc_panel_list_finalize (GObject *object)
{
  CcPanelList *self = (CcPanelList *)object;

  g_clear_pointer (&self->search_query, g_free);
  g_clear_pointer (&self->id_to_data, g_hash_table_destroy);

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

static void
cc_panel_list_get_property (GObject    *object,
                            guint       prop_id,
                            GValue     *value,
                            GParamSpec *pspec)
{
  CcPanelList *self = CC_PANEL_LIST (object);

  switch (prop_id)
    {
    case PROP_SEARCH_MODE:
      g_value_set_boolean (value, self->view == CC_PANEL_LIST_SEARCH);
      break;

    case PROP_SEARCH_QUERY:
      g_value_set_string (value, self->search_query);
      break;

    case PROP_VIEW:
      g_value_set_int (value, self->view);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
cc_panel_list_set_property (GObject      *object,
                            guint         prop_id,
                            const GValue *value,
                            GParamSpec   *pspec)
{
  CcPanelList *self = CC_PANEL_LIST (object);

  switch (prop_id)
    {
    case PROP_SEARCH_MODE:
      update_search (self);
      break;

    case PROP_SEARCH_QUERY:
      cc_panel_list_set_search_query (self, g_value_get_string (value));
      break;

    case PROP_VIEW:
      cc_panel_list_set_view (self, g_value_get_int (value));
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
cc_panel_list_class_init (CcPanelListClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);

  object_class->finalize = cc_panel_list_finalize;
  object_class->get_property = cc_panel_list_get_property;
  object_class->set_property = cc_panel_list_set_property;

  /**
   * CcPanelList:show-panel:
   *
   * Emited when a panel is selected.
   */
  signals[SHOW_PANEL] = g_signal_new ("show-panel",
                                      CC_TYPE_PANEL_LIST,
                                      G_SIGNAL_RUN_LAST,
                                      0, NULL, NULL, NULL,
                                      G_TYPE_NONE,
                                      1,
                                      G_TYPE_STRING);

  /**
   * CcPanelList:search-mode:
   *
   * Whether the search is visible or not.
   */
  properties[PROP_SEARCH_MODE] = g_param_spec_boolean ("search-mode",
                                                       "Search mode",
                                                       "Whether it's in search mode or not",
                                                       FALSE,
                                                       G_PARAM_READWRITE);

  /**
   * CcPanelList:search-query:
   *
   * The search that is being applied to sidelist.
   */
  properties[PROP_SEARCH_QUERY] = g_param_spec_string ("search-query",
                                                       "Search query",
                                                       "The current search query",
                                                       NULL,
                                                       G_PARAM_READWRITE);

  /**
   * CcPanelList:view:
   *
   * The current view of the sidelist.
   */
  properties[PROP_VIEW] = g_param_spec_int ("view",
                                            "View",
                                            "The current view of the sidelist",
                                            CC_PANEL_LIST_MAIN,
                                            CC_PANEL_LIST_SEARCH,
                                            CC_PANEL_LIST_MAIN,
                                            G_PARAM_READWRITE);

  g_object_class_install_properties (object_class, N_PROPS, properties);

  gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/ControlCenter/gtk/panel-list.ui");

  gtk_widget_class_bind_template_child (widget_class, CcPanelList, details_listbox);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, details_row);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, devices_listbox);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, devices_row);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, empty_search_placeholder);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, main_listbox);
  gtk_widget_class_bind_template_child (widget_class, CcPanelList, search_listbox);

  gtk_widget_class_bind_template_callback (widget_class, row_activated_cb);
  gtk_widget_class_bind_template_callback (widget_class, search_row_activated_cb);
}

static void
cc_panel_list_init (CcPanelList *self)
{
  gtk_widget_init_template (GTK_WIDGET (self));

  self->id_to_data = g_hash_table_new (g_str_hash, g_str_equal);
  self->view = CC_PANEL_LIST_MAIN;

  gtk_list_box_set_sort_func (GTK_LIST_BOX (self->main_listbox),
                              sort_function,
                              self,
                              NULL);

  gtk_list_box_set_header_func (GTK_LIST_BOX (self->main_listbox),
                                header_func,
                                self,
                                NULL);

  /* Search listbox */
  gtk_list_box_set_sort_func (GTK_LIST_BOX (self->search_listbox),
                              search_sort_function,
                              self,
                              NULL);

  gtk_list_box_set_filter_func (GTK_LIST_BOX (self->search_listbox),
                                filter_func,
                                self,
                                NULL);

  gtk_list_box_set_placeholder (GTK_LIST_BOX (self->search_listbox), self->empty_search_placeholder);
}

GtkWidget*
cc_panel_list_new (void)
{
  return g_object_new (CC_TYPE_PANEL_LIST, NULL);
}

gboolean
cc_panel_list_activate (CcPanelList *self)
{
  GtkListBoxRow *row;
  GtkWidget *listbox;

  g_return_val_if_fail (CC_IS_PANEL_LIST (self), FALSE);

  listbox = get_listbox_from_view (self, self->view);

  if (self->view == CC_PANEL_LIST_SEARCH)
    row = gtk_list_box_get_row_at_y (GTK_LIST_BOX (listbox), 0);
  else
    row = gtk_list_box_get_row_at_index (GTK_LIST_BOX (listbox), 0);

  /* If the row is valid, activate it */
  if (row)
    {
      gtk_list_box_select_row (GTK_LIST_BOX (listbox), row);
      gtk_widget_grab_focus (GTK_WIDGET (row));

      g_signal_emit_by_name (row, "activate");
    }

  return row != NULL;
}

const gchar*
cc_panel_list_get_search_query (CcPanelList *self)
{
  g_return_val_if_fail (CC_IS_PANEL_LIST (self), NULL);

  return self->search_query;
}

void
cc_panel_list_set_search_query (CcPanelList *self,
                                const gchar *search)
{
  g_return_if_fail (CC_IS_PANEL_LIST (self));

  if (g_strcmp0 (self->search_query, search) != 0)
    {
      g_clear_pointer (&self->search_query, g_free);
      self->search_query = g_strdup (search);

      update_search (self);

      g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SEARCH_QUERY]);

      gtk_list_box_invalidate_filter (GTK_LIST_BOX (self->search_listbox));
      gtk_list_box_invalidate_sort (GTK_LIST_BOX (self->search_listbox));
    }
}

CcPanelListView
cc_panel_list_get_view (CcPanelList *self)
{
  g_return_val_if_fail (CC_IS_PANEL_LIST (self), -1);

  return self->view;
}

void
cc_panel_list_set_view (CcPanelList     *self,
                        CcPanelListView  view)
{
  g_return_if_fail (CC_IS_PANEL_LIST (self));

  if (self->view != view)
    {
      GtkWidget *visible_child;
      gboolean should_crossfade;

      self->previous_view = self->view;
      self->view = view;

      /*
       * When changing to or from the search view, the animation should
       * be crossfade. Otherwise, it's the previous-forward movement.
       */
      should_crossfade = view == CC_PANEL_LIST_SEARCH ||
                         self->previous_view == CC_PANEL_LIST_SEARCH;

      gtk_stack_set_transition_type (GTK_STACK (self),
                                     should_crossfade ? GTK_STACK_TRANSITION_TYPE_CROSSFADE :
                                                        GTK_STACK_TRANSITION_TYPE_SLIDE_LEFT_RIGHT);

      visible_child = get_listbox_from_view (self, view);

      gtk_stack_set_visible_child (GTK_STACK (self), visible_child);

      g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_VIEW]);
      g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SEARCH_MODE]);
    }
}

void
cc_panel_list_add_panel (CcPanelList     *self,
                         CcPanelCategory  category,
                         const gchar     *id,
                         const gchar     *title,
                         const gchar     *description,
                         const gchar     *icon)
{
  GtkWidget *listbox;
  RowData *data, *search_data;

  g_return_if_fail (CC_IS_PANEL_LIST (self));

  /* Add the panel to the proper listbox */
  data = row_data_new (category, id, title, description, icon);

  switch (category)
    {
    case CC_CATEGORY_DEVICES:
      listbox = self->devices_listbox;
      break;

    case CC_CATEGORY_DETAILS:
      listbox = self->details_listbox;
      break;

    default:
      listbox = self->main_listbox;
      break;
    }

  gtk_container_add (GTK_CONTAINER (listbox), data->row);

  /* And add to the search listbox too */
  search_data = row_data_new (category, id, title, description, icon);
  gtk_container_add (GTK_CONTAINER (self->search_listbox), search_data->row);

  g_hash_table_insert (self->id_to_data, data->id, data);
}

/**
 * cc_panel_list_set_active_panel:
 * @self: a #CcPanelList
 * @id: the id of the panel to be activated
 *
 * Sets the current active panel.
 */
void
cc_panel_list_set_active_panel (CcPanelList *self,
                                const gchar *id)
{
  GtkWidget *listbox;
  RowData *data;

  g_return_if_fail (CC_IS_PANEL_LIST (self));

  data = g_hash_table_lookup (self->id_to_data, id);

  g_assert (data != NULL);

  listbox = gtk_widget_get_parent (data->row);

  gtk_list_box_select_row (GTK_LIST_BOX (listbox), GTK_LIST_BOX_ROW (data->row));
  gtk_widget_grab_focus (data->row);

  g_signal_emit_by_name (data->row, "activate");
}