/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (C) 2013 Red Hat, Inc.
 */

/**
 * SECTION:nmt-widget-list
 * @short_description: A list of widgets, with Add and Remove buttons
 *
 * #NmtWidgetList presents a homogeneous list of widgets, with "Remove"
 * buttons next to each one, and an "Add" button at the button to add
 * new ones.
 *
 * It is the base class for #NmtAddressList, and is used internally by
 * #NmtRouteTable.
 *
 * FIXME: The way this works is sort of weird.
 */

#include "nm-default.h"

#include "nmt-widget-list.h"

#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdlib.h>

#include "nmt-newt.h"

G_DEFINE_TYPE(NmtWidgetList, nmt_widget_list, NMT_TYPE_NEWT_GRID)

#define NMT_WIDGET_LIST_GET_PRIVATE(o) \
    (G_TYPE_INSTANCE_GET_PRIVATE((o), NMT_TYPE_WIDGET_LIST, NmtWidgetListPrivate))

typedef struct {
    int length;

    NmtWidgetListCallback create_callback;
    gpointer              user_data;
    GDestroyNotify        destroy_notify;

    NmtNewtWidget *empty_widget;

    GPtrArray *widgets;
    GPtrArray *remove_buttons;

    NmtNewtWidget *add_button;
    GBinding *     add_sensitivity;
} NmtWidgetListPrivate;

enum {
    PROP_0,
    PROP_CREATE_CALLBACK,
    PROP_USER_DATA,
    PROP_DESTROY_NOTIFY,
    PROP_EMPTY_WIDGET,
    PROP_LENGTH,

    LAST_PROP
};

enum {
    ADD_CLICKED,
    REMOVE_CLICKED,

    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = {0};

static void add_clicked(NmtNewtButton *button, gpointer user_data);
static void remove_clicked(NmtNewtButton *button, gpointer user_data);

/**
 * NmtWidgetListCallback:
 * @list: the #NmtWidgetList
 * @n: the number of the widget being added
 * @user_data: the callback's user data
 *
 * Called by #NmtWidgetList to ask for a new widget to be created.
 *
 * Note that the widget is not created to go with any particular
 * value, but rather is created to be at a certain spot in the list.
 * When an element is deleted from the list, it is actually always
 * the last widget in the list that is removed, but it is assumed
 * that the widget list is bound to some array-valued property, and
 * so when an element is deleted from that array, the widgets will
 * all update themselves automatically when the array changes.
 *
 * Returns: a new widget for the list
 */

/**
 * nmt_widget_list_new:
 * @create_callback: callback to create new widgets
 * @user_data: user data for @create_callback
 * @destroy_notify: #GDestroyNotify for @user_data
 * @empty_widget: (allow-none): a widget to display when there are
 *   no "real" widgets in the list.
 *
 * Creates a new #NmtWidgetList.
 *
 * Returns: a new #NmtWidgetList.
 */
NmtNewtWidget *
nmt_widget_list_new(NmtWidgetListCallback create_callback,
                    gpointer              user_data,
                    GDestroyNotify        destroy_notify,
                    NmtNewtWidget *       empty_widget)
{
    return g_object_new(NMT_TYPE_WIDGET_LIST,
                        "create-callback",
                        create_callback,
                        "user-data",
                        user_data,
                        "destroy-notify",
                        destroy_notify,
                        "empty-widget",
                        empty_widget,
                        NULL);
}

static void
nmt_widget_list_init(NmtWidgetList *list)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);

    priv->widgets        = g_ptr_array_new();
    priv->remove_buttons = g_ptr_array_new();

    priv->add_button = nmt_newt_button_new(_("Add..."));
    g_signal_connect(priv->add_button, "clicked", G_CALLBACK(add_clicked), list);
    nmt_newt_grid_add(NMT_NEWT_GRID(list), priv->add_button, 0, 0);
}

static void
nmt_widget_list_constructed(GObject *object)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(object);

    if (priv->length == 0 && priv->empty_widget) {
        nmt_newt_widget_set_visible(priv->empty_widget, TRUE);
        nmt_newt_grid_move(NMT_NEWT_GRID(object), priv->add_button, 0, 1);
    }

    G_OBJECT_CLASS(nmt_widget_list_parent_class)->constructed(object);
}

static void
nmt_widget_list_finalize(GObject *object)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(object);

    g_ptr_array_unref(priv->widgets);
    g_ptr_array_unref(priv->remove_buttons);

    if (priv->user_data && priv->destroy_notify)
        priv->destroy_notify(priv->user_data);

    g_clear_object(&priv->empty_widget);

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

static void
ensure_widgets(NmtWidgetList *list)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);
    NmtNewtWidget *       widget, *button, *focus;
    gboolean              was_empty;
    NmtNewtForm *         form;
    int                   i;

    was_empty = priv->widgets->len == 0;

    if (priv->length < priv->widgets->len) {
        /* remove excess widgets */
        for (i = priv->length; i < priv->widgets->len; i++) {
            nmt_newt_container_remove(NMT_NEWT_CONTAINER(list), priv->widgets->pdata[i]);
            nmt_newt_container_remove(NMT_NEWT_CONTAINER(list), priv->remove_buttons->pdata[i]);
        }
        g_ptr_array_set_size(priv->widgets, priv->length);
        g_ptr_array_set_size(priv->remove_buttons, priv->length);

    } else if (priv->length > priv->widgets->len) {
        /* add new widgets */
        for (i = priv->widgets->len; i < priv->length; i++) {
            widget = NMT_WIDGET_LIST_GET_CLASS(list)->create_widget(list, i);

            nmt_newt_grid_add(NMT_NEWT_GRID(list), widget, 0, i);
            g_ptr_array_add(priv->widgets, widget);

            button = nmt_newt_button_new(_("Remove"));
            g_signal_connect(button, "clicked", G_CALLBACK(remove_clicked), list);

            nmt_newt_grid_add(NMT_NEWT_GRID(list), button, 1, i);
            nmt_newt_widget_set_padding(button, 1, 0, 0, 0);
            g_ptr_array_add(priv->remove_buttons, button);
        }

    } else
        return;

    if (priv->widgets->len == 0 && priv->empty_widget) {
        nmt_newt_widget_set_visible(priv->empty_widget, TRUE);
        nmt_newt_grid_move(NMT_NEWT_GRID(list), priv->add_button, 0, 1);
    } else {
        if (was_empty && priv->empty_widget)
            nmt_newt_widget_set_visible(priv->empty_widget, FALSE);
        nmt_newt_grid_move(NMT_NEWT_GRID(list), priv->add_button, 0, priv->length);
    }

    form = nmt_newt_widget_get_form(NMT_NEWT_WIDGET(list));
    if (form) {
        if (priv->widgets->len) {
            if (was_empty)
                focus = priv->widgets->pdata[0];
            else
                focus = priv->widgets->pdata[priv->widgets->len - 1];
        } else
            focus = priv->add_button;
        nmt_newt_form_set_focus(form, focus);
    }

    g_clear_object(&priv->add_sensitivity);
    if (priv->widgets->len) {
        widget                = priv->widgets->pdata[priv->widgets->len - 1];
        priv->add_sensitivity = g_object_bind_property(widget,
                                                       "valid",
                                                       priv->add_button,
                                                       "sensitive",
                                                       G_BINDING_SYNC_CREATE);
        g_object_add_weak_pointer(G_OBJECT(priv->add_sensitivity),
                                  (gpointer *) &priv->add_sensitivity);
    } else
        nmt_newt_component_set_sensitive(NMT_NEWT_COMPONENT(priv->add_button), TRUE);
}

static void
add_clicked(NmtNewtButton *button, gpointer list)
{
    g_signal_emit(G_OBJECT(list), signals[ADD_CLICKED], 0, NULL);
}

static void
remove_clicked(NmtNewtButton *button, gpointer list)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);
    int                   i;

    for (i = 0; i < priv->remove_buttons->len; i++) {
        if (priv->remove_buttons->pdata[i] == (gpointer) button)
            break;
    }
    g_return_if_fail(i < priv->remove_buttons->len);

    g_signal_emit(G_OBJECT(list), signals[REMOVE_CLICKED], 0, i, NULL);
}

static NmtNewtWidget *
nmt_widget_list_real_create_widget(NmtWidgetList *list, int n)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);

    g_return_val_if_fail(priv->create_callback != NULL, NULL);

    return priv->create_callback(list, n, priv->user_data);
}

/**
 * nmt_widget_list_get_length:
 * @list: the #NmtNewtWidgetList
 *
 * Gets the number of widgets in the list.
 *
 * Returns: the number of widgets in the list.
 */
int
nmt_widget_list_get_length(NmtWidgetList *list)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);

    return priv->length;
}

/**
 * nmt_widget_list_set_length:
 * @list: the #NmtNewtWidgetList
 * @length: the new length
 *
 * Changes the number of widgets in the list. Widgets will be added or
 * deleted as necessary.
 */
void
nmt_widget_list_set_length(NmtWidgetList *list, int length)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(list);

    if (priv->length != length) {
        priv->length = length;
        g_object_notify(G_OBJECT(list), "length");
    }

    ensure_widgets(list);
}

static void
nmt_widget_list_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(object);

    switch (prop_id) {
    case PROP_CREATE_CALLBACK:
        priv->create_callback = g_value_get_pointer(value);
        break;
    case PROP_USER_DATA:
        priv->user_data = g_value_get_pointer(value);
        break;
    case PROP_DESTROY_NOTIFY:
        priv->destroy_notify = g_value_get_pointer(value);
        break;
    case PROP_LENGTH:
        priv->length = g_value_get_int(value);
        ensure_widgets(NMT_WIDGET_LIST(object));
        break;
    case PROP_EMPTY_WIDGET:
        priv->empty_widget = g_value_get_object(value);
        if (priv->empty_widget) {
            g_object_ref_sink(priv->empty_widget);
            nmt_newt_grid_add(NMT_NEWT_GRID(object), priv->empty_widget, 0, 0);
        }
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
nmt_widget_list_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
    NmtWidgetListPrivate *priv = NMT_WIDGET_LIST_GET_PRIVATE(object);

    switch (prop_id) {
    case PROP_CREATE_CALLBACK:
        g_value_set_pointer(value, priv->create_callback);
        break;
    case PROP_USER_DATA:
        g_value_set_pointer(value, priv->user_data);
        break;
    case PROP_DESTROY_NOTIFY:
        g_value_set_pointer(value, priv->destroy_notify);
        break;
    case PROP_LENGTH:
        g_value_set_int(value, priv->length);
        break;
    case PROP_EMPTY_WIDGET:
        g_value_set_object(value, priv->empty_widget);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
nmt_widget_list_class_init(NmtWidgetListClass *list_class)
{
    GObjectClass *object_class = G_OBJECT_CLASS(list_class);

    g_type_class_add_private(list_class, sizeof(NmtWidgetListPrivate));

    /* virtual methods */
    object_class->constructed  = nmt_widget_list_constructed;
    object_class->set_property = nmt_widget_list_set_property;
    object_class->get_property = nmt_widget_list_get_property;
    object_class->finalize     = nmt_widget_list_finalize;

    list_class->create_widget = nmt_widget_list_real_create_widget;

    /* signals */

    /**
     * NmtNewtWidget::add-clicked:
     * @list: the #NmtNewtWidgetList
     *
     * Emitted when the user clicks the "Add" button. The caller can
     * decide whether or not to add a new widget, and call
     * nmt_widget_list_set_length() with the new length if so.
     *
     * FIXME: the "Add" button should be insensitive if it's
     * not going to work.
     */
    signals[ADD_CLICKED] = g_signal_new("add-clicked",
                                        G_OBJECT_CLASS_TYPE(object_class),
                                        G_SIGNAL_RUN_FIRST,
                                        G_STRUCT_OFFSET(NmtWidgetListClass, add_clicked),
                                        NULL,
                                        NULL,
                                        NULL,
                                        G_TYPE_NONE,
                                        0);
    /**
     * NmtNewtWidget::remove-clicked:
     * @list: the #NmtNewtWidgetList
     * @n: the widget being removed
     *
     * Emitted when the user clicks one of the "Remove" buttons. The
     * caller can decide whether or not to remove the widget, and
     * call nmt_widget_list_set_length() with the new length if so.
     *
     * FIXME: the "Remove" button should be insensitive if it's not
     * going to work.
     */
    signals[REMOVE_CLICKED] = g_signal_new("remove-clicked",
                                           G_OBJECT_CLASS_TYPE(object_class),
                                           G_SIGNAL_RUN_FIRST,
                                           G_STRUCT_OFFSET(NmtWidgetListClass, remove_clicked),
                                           NULL,
                                           NULL,
                                           NULL,
                                           G_TYPE_NONE,
                                           1,
                                           G_TYPE_INT);

    /* properties */

    /**
     * NmtWidgetList:create-callback:
     *
     * Callback called to create a new widget.
     */
    g_object_class_install_property(
        object_class,
        PROP_CREATE_CALLBACK,
        g_param_spec_pointer("create-callback",
                             "",
                             "",
                             G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtWidgetList:user-data:
     *
     * User data for #NmtWidgetList:create-callback
     */
    g_object_class_install_property(
        object_class,
        PROP_USER_DATA,
        g_param_spec_pointer("user-data", "", "", G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtWidgetList:destroy-notify:
     *
     * #GDestroyNotify for #NmtWidgetList:user-data
     */
    g_object_class_install_property(
        object_class,
        PROP_DESTROY_NOTIFY,
        g_param_spec_pointer("destroy-notify", "", "", G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtWidgetList:length:
     *
     * The length of the widget list; changing this value will add or
     * remove widgets from the list.
     */
    g_object_class_install_property(object_class,
                                    PROP_LENGTH,
                                    g_param_spec_int("length",
                                                     "",
                                                     "",
                                                     0,
                                                     G_MAXINT,
                                                     0,
                                                     G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtWidgetList:empty-widget:
     *
     * If non-%NULL, this widget will be displayed when there are
     * no "real" widgets in the list.
     */
    g_object_class_install_property(
        object_class,
        PROP_EMPTY_WIDGET,
        g_param_spec_object("empty-widget",
                            "",
                            "",
                            NMT_TYPE_NEWT_WIDGET,
                            G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
}