#include "nautilus-view-model.h"
#include "nautilus-view-item.h"
#include "nautilus-global-preferences.h"

struct _NautilusViewModel
{
    GObject parent_instance;

    GHashTable *map_files_to_model;
    GListStore *internal_model;
    GtkMultiSelection *selection_model;
    GtkSorter *sorter;
    gulong sorter_changed_id;
};

static GType
nautilus_view_model_get_item_type (GListModel *list)
{
    return NAUTILUS_TYPE_VIEW_ITEM;
}

static guint
nautilus_view_model_get_n_items (GListModel *list)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (list);

    if (self->internal_model == NULL)
    {
        return 0;
    }

    return g_list_model_get_n_items (G_LIST_MODEL (self->internal_model));
}

static gpointer
nautilus_view_model_get_item (GListModel *list,
                              guint       position)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (list);

    if (self->internal_model == NULL)
    {
        return NULL;
    }

    return g_list_model_get_item (G_LIST_MODEL (self->internal_model), position);
}

static void
nautilus_view_model_list_model_init (GListModelInterface *iface)
{
    iface->get_item_type = nautilus_view_model_get_item_type;
    iface->get_n_items = nautilus_view_model_get_n_items;
    iface->get_item = nautilus_view_model_get_item;
}


static gboolean
nautilus_view_model_is_selected (GtkSelectionModel *model,
                                 guint              position)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (model);
    GtkSelectionModel *selection_model = GTK_SELECTION_MODEL (self->selection_model);

    return gtk_selection_model_is_selected (selection_model, position);
}

static GtkBitset *
nautilus_view_model_get_selection_in_range (GtkSelectionModel *model,
                                            guint              pos,
                                            guint              n_items)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (model);
    GtkSelectionModel *selection_model = GTK_SELECTION_MODEL (self->selection_model);

    return gtk_selection_model_get_selection_in_range (selection_model, pos, n_items);
}

static gboolean
nautilus_view_model_set_selection (GtkSelectionModel *model,
                                   GtkBitset         *selected,
                                   GtkBitset         *mask)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (model);
    GtkSelectionModel *selection_model = GTK_SELECTION_MODEL (self->selection_model);
    gboolean res;

    res = gtk_selection_model_set_selection (selection_model, selected, mask);

    return res;
}


static void
nautilus_view_model_selection_model_init (GtkSelectionModelInterface *iface)
{
    iface->is_selected = nautilus_view_model_is_selected;
    iface->get_selection_in_range = nautilus_view_model_get_selection_in_range;
    iface->set_selection = nautilus_view_model_set_selection;
}

G_DEFINE_TYPE_WITH_CODE (NautilusViewModel, nautilus_view_model, G_TYPE_OBJECT,
                         G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL,
                                                nautilus_view_model_list_model_init)
                         G_IMPLEMENT_INTERFACE (GTK_TYPE_SELECTION_MODEL,
                                                nautilus_view_model_selection_model_init))

enum
{
    PROP_0,
    PROP_SORTER,
    N_PROPS
};

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

static void
dispose (GObject *object)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (object);

    if (self->selection_model != NULL)
    {
        g_signal_handlers_disconnect_by_func (self->selection_model,
                                              gtk_selection_model_selection_changed,
                                              self);
        g_object_unref (self->selection_model);
        self->selection_model = NULL;
    }

    if (self->internal_model != NULL)
    {
        g_signal_handlers_disconnect_by_func (self->internal_model,
                                              g_list_model_items_changed,
                                              self);
        g_object_unref (self->internal_model);
        self->internal_model = NULL;
    }

    g_clear_signal_handler (&self->sorter_changed_id, self->sorter);

    G_OBJECT_CLASS (nautilus_view_model_parent_class)->dispose (object);
}

static void
finalize (GObject *object)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (object);

    G_OBJECT_CLASS (nautilus_view_model_parent_class)->finalize (object);

    g_hash_table_destroy (self->map_files_to_model);
    g_clear_object (&self->sorter);
}

static void
get_property (GObject    *object,
              guint       prop_id,
              GValue     *value,
              GParamSpec *pspec)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (object);

    switch (prop_id)
    {
        case PROP_SORTER:
        {
            g_value_set_object (value, nautilus_view_model_get_sorter (self));
        }
        break;

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

static void
set_property (GObject      *object,
              guint         prop_id,
              const GValue *value,
              GParamSpec   *pspec)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (object);

    switch (prop_id)
    {
        case PROP_SORTER:
        {
            nautilus_view_model_set_sorter (self, g_value_get_object (value));
        }
        break;

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

static void
constructed (GObject *object)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (object);

    G_OBJECT_CLASS (nautilus_view_model_parent_class)->constructed (object);

    self->internal_model = g_list_store_new (NAUTILUS_TYPE_VIEW_ITEM);
    self->selection_model = gtk_multi_selection_new (g_object_ref (G_LIST_MODEL (self->internal_model)));
    self->map_files_to_model = g_hash_table_new (NULL, NULL);

    g_signal_connect_swapped (self->internal_model, "items-changed",
                              G_CALLBACK (g_list_model_items_changed), self);
    g_signal_connect_swapped (self->selection_model, "selection-changed",
                              G_CALLBACK (gtk_selection_model_selection_changed), self);
}

static void
nautilus_view_model_class_init (NautilusViewModelClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    object_class->dispose = dispose;
    object_class->finalize = finalize;
    object_class->get_property = get_property;
    object_class->set_property = set_property;
    object_class->constructed = constructed;

    properties[PROP_SORTER] =
        g_param_spec_object ("sorter",
                             "", "",
                             GTK_TYPE_SORTER,
                             G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);

    g_object_class_install_properties (object_class, N_PROPS, properties);
}

static void
nautilus_view_model_init (NautilusViewModel *self)
{
}

static gint
compare_data_func (gconstpointer a,
                   gconstpointer b,
                   gpointer      user_data)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (user_data);

    if (self->sorter == NULL)
    {
        return GTK_ORDERING_EQUAL;
    }

    return gtk_sorter_compare (self->sorter, (gpointer) a, (gpointer) b);
}

static void
on_sorter_changed (GtkSorter       *sorter,
                   GtkSorterChange  change,
                   gpointer         user_data)
{
    NautilusViewModel *self = NAUTILUS_VIEW_MODEL (user_data);

    g_list_store_sort (self->internal_model, compare_data_func, self);
}

NautilusViewModel *
nautilus_view_model_new (void)
{
    return g_object_new (NAUTILUS_TYPE_VIEW_MODEL, NULL);
}

GtkSorter *
nautilus_view_model_get_sorter (NautilusViewModel *self)
{
    return self->sorter;
}

void
nautilus_view_model_set_sorter (NautilusViewModel *self,
                                GtkSorter         *sorter)
{
    if (self->sorter != NULL)
    {
        g_clear_signal_handler (&self->sorter_changed_id, self->sorter);
    }

    if (g_set_object (&self->sorter, sorter))
    {
        g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SORTER]);
    }

    if (self->sorter != NULL)
    {
        self->sorter_changed_id = g_signal_connect (self->sorter, "changed",
                                                    G_CALLBACK (on_sorter_changed), self);
        g_list_store_sort (self->internal_model, compare_data_func, self);
    }
}

GQueue *
nautilus_view_model_get_items_from_files (NautilusViewModel *self,
                                          GQueue            *files)
{
    GList *l;
    guint n_items;
    GQueue *items;

    n_items = g_list_model_get_n_items (G_LIST_MODEL (self->internal_model));
    items = g_queue_new ();
    for (l = g_queue_peek_head_link (files); l != NULL; l = l->next)
    {
        NautilusFile *file1;

        file1 = NAUTILUS_FILE (l->data);
        for (guint i = 0; i < n_items; i++)
        {
            g_autoptr (NautilusViewItem) item = NULL;
            NautilusFile *file2;
            g_autofree gchar *file1_uri = NULL;
            g_autofree gchar *file2_uri = NULL;

            item = g_list_model_get_item (G_LIST_MODEL (self->internal_model), i);
            file2 = nautilus_view_item_get_file (item);
            file1_uri = nautilus_file_get_uri (file1);
            file2_uri = nautilus_file_get_uri (file2);
            if (g_strcmp0 (file1_uri, file2_uri) == 0)
            {
                g_queue_push_tail (items, item);
                break;
            }
        }
    }

    return items;
}

NautilusViewItem *
nautilus_view_model_get_item_from_file (NautilusViewModel *self,
                                        NautilusFile      *file)
{
    return g_hash_table_lookup (self->map_files_to_model, file);
}

void
nautilus_view_model_remove_item (NautilusViewModel *self,
                                 NautilusViewItem  *item)
{
    guint i;

    if (g_list_store_find (self->internal_model, item, &i))
    {
        NautilusFile *file;

        file = nautilus_view_item_get_file (item);
        g_list_store_remove (self->internal_model, i);
        g_hash_table_remove (self->map_files_to_model, file);
    }
}

void
nautilus_view_model_remove_all_items (NautilusViewModel *self)
{
    g_list_store_remove_all (self->internal_model);
    g_hash_table_remove_all (self->map_files_to_model);
}

void
nautilus_view_model_add_item (NautilusViewModel *self,
                              NautilusViewItem  *item)
{
    g_hash_table_insert (self->map_files_to_model,
                         nautilus_view_item_get_file (item),
                         item);
    g_list_store_insert_sorted (self->internal_model, item, compare_data_func, self);
}

void
nautilus_view_model_add_items (NautilusViewModel *self,
                               GQueue            *items)
{
    g_autofree gpointer *array = NULL;
    GList *l;
    int i = 0;

    /* Sort items before adding them to the internal model. This ensures that
     * the first sorted item is become the initial focus and scroll anchor. */
    g_queue_sort (items, compare_data_func, self);

    array = g_malloc_n (g_queue_get_length (items),
                        sizeof (NautilusViewItem *));

    for (l = g_queue_peek_head_link (items); l != NULL; l = l->next)
    {
        array[i] = l->data;
        g_hash_table_insert (self->map_files_to_model,
                             nautilus_view_item_get_file (l->data),
                             l->data);
        i++;
    }

    g_list_store_splice (self->internal_model,
                         g_list_model_get_n_items (G_LIST_MODEL (self->internal_model)),
                         0, array, g_queue_get_length (items));

    g_list_store_sort (self->internal_model, compare_data_func, self);
}

guint
nautilus_view_model_get_index (NautilusViewModel *self,
                               NautilusViewItem  *item)
{
    guint i = G_MAXUINT;
    gboolean found;

    found = g_list_store_find (self->internal_model, item, &i);
    g_warn_if_fail (found);

    return i;
}