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

/**
 * SECTION:nmt-newt-widget
 * @short_description: Base TUI Widget class
 *
 * #NmtNewtWidget is the abstract base class for nmt-newt. All widgets
 * inherit from one of its two subclasses: #NmtNewtComponent, for
 * widgets that wrap a (single) #newtComponent, and #NmtNewtContainer,
 * for widgets consisting of multiple components. See those classes
 * for more details.
 *
 * With the exception of #NmtNewtForm, all widgets start out with a
 * floating reference, which will be sunk by the container they are
 * added to. #NmtNewtForm is the "top-level" widget type, and so does
 * not have a floating reference.
 *
 * FIXME: need RTL support
 */

#include "nm-default.h"

#include "nmt-newt-widget.h"
#include "nmt-newt-form.h"

G_DEFINE_ABSTRACT_TYPE(NmtNewtWidget, nmt_newt_widget, G_TYPE_INITIALLY_UNOWNED)

#define NMT_NEWT_WIDGET_GET_PRIVATE(o) \
    (G_TYPE_INSTANCE_GET_PRIVATE((o), NMT_TYPE_NEWT_WIDGET, NmtNewtWidgetPrivate))

typedef struct {
    NmtNewtWidget *parent;
    gboolean       visible, realized, valid;
    gboolean       exit_on_activate;

    int pad_left, pad_top, pad_right, pad_bottom;
} NmtNewtWidgetPrivate;

enum {
    PROP_0,

    PROP_PARENT,
    PROP_VISIBLE,
    PROP_VALID,
    PROP_EXIT_ON_ACTIVATE,

    LAST_PROP
};

enum {
    NEEDS_REBUILD,
    ACTIVATED,

    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = {0};

static void
nmt_newt_widget_init(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    priv->visible = TRUE;
    priv->valid   = TRUE;
}

static void
nmt_newt_widget_finalize(GObject *object)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(object);

    nmt_newt_widget_unrealize(NMT_NEWT_WIDGET(object));
    g_clear_object(&priv->parent);

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

/**
 * nmt_newt_widget_realize:
 * @widget: an #NmtNewtWidget
 *
 * "Realizes" @widget. That is, creates #newtComponents corresponding
 * to @widget and its children.
 *
 * You should not need to call this yourself; an #NmtNewtForm will
 * cause its children to be realized and unrealized as needed.
 */
void
nmt_newt_widget_realize(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    if (!priv->realized) {
        NMT_NEWT_WIDGET_GET_CLASS(widget)->realize(widget);
        priv->realized = TRUE;
    }
}

/**
 * nmt_newt_widget_unrealize:
 * @widget: an #NmtNewtWidget
 *
 * "Unrealizes" @widget, destroying its #newtComponents.
 *
 * You should not need to call this yourself; an #NmtNewtForm will
 * cause its children to be realized and unrealized as needed.
 */
void
nmt_newt_widget_unrealize(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    if (priv->realized) {
        NMT_NEWT_WIDGET_GET_CLASS(widget)->unrealize(widget);
        priv->realized = FALSE;
    }
}

/**
 * nmt_newt_widget_get_realized:
 * @widget: an #NmtNewtWidget
 *
 * Checks if @widget is realized or not.
 *
 * Returns: whether @widget is realized.
 */
gboolean
nmt_newt_widget_get_realized(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    return priv->realized;
}

/**
 * nmt_newt_widget_get_components:
 * @widget: an #NmtNewtWidget
 *
 * Gets the #newtComponents that make up @widget, if @widget is
 * visible. If @widget has not yet been realized, it will be realized
 * first.
 *
 * If this function is called on a widget, then the widget will assume
 * that someone else is now responsible for destroying the components,
 * and so it will not destroy them itself when the widget is
 * destroyed. Normally, components will end up being destroyed by the
 * #NmtNewtForm they are added to.
 *
 * Returns: a %NULL-terminated array of components, in focus-chain
 *   order. You must free the array with g_free() when you are done
 *   with it.
 */
newtComponent *
nmt_newt_widget_get_components(NmtNewtWidget *widget)
{
    if (nmt_newt_widget_get_visible(widget)) {
        nmt_newt_widget_realize(widget);
        return NMT_NEWT_WIDGET_GET_CLASS(widget)->get_components(widget);
    } else
        return NULL;
}

/**
 * nmt_newt_widget_find_component:
 * @widget: an #NmtNewtWidget
 * @co: a #newtComponent
 *
 * Finds the widget inside @widget that owns @co.
 *
 * Return value: @co's owner, or %NULL if it was not found.
 */
NmtNewtWidget *
nmt_newt_widget_find_component(NmtNewtWidget *widget, newtComponent co)
{
    return NMT_NEWT_WIDGET_GET_CLASS(widget)->find_component(widget, co);
}

/**
 * nmt_newt_widget_set_padding:
 * @widget: an #NmtNewtWidget
 * @pad_left: padding on the left of @widget
 * @pad_top: padding on the top of @widget
 * @pad_right: padding on the right of @widget
 * @pad_bottom: padding on the bottom of @widget
 *
 * Sets the padding on @widget.
 */
void
nmt_newt_widget_set_padding(NmtNewtWidget *widget,
                            int            pad_left,
                            int            pad_top,
                            int            pad_right,
                            int            pad_bottom)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    priv->pad_left   = pad_left;
    priv->pad_top    = pad_top;
    priv->pad_right  = pad_right;
    priv->pad_bottom = pad_bottom;
}

/**
 * nmt_newt_widget_size_request:
 * @widget: an #NmtNewtWidget
 * @width: (out): on output, the widget's requested width
 * @height: (out): on output, the widget's requested height
 *
 * Asks @widget for its requested size. If @widget is not visible,
 * this will return 0, 0. If @widget has not yet been realized, it
 * will be realized first.
 */
void
nmt_newt_widget_size_request(NmtNewtWidget *widget, int *width, int *height)
{
    if (nmt_newt_widget_get_visible(widget)) {
        NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

        nmt_newt_widget_realize(widget);
        NMT_NEWT_WIDGET_GET_CLASS(widget)->size_request(widget, width, height);

        *width += priv->pad_left + priv->pad_right;
        *height += priv->pad_top + priv->pad_bottom;
    } else
        *width = *height = 0;
}

/**
 * nmt_newt_widget_size_allocate:
 * @widget: an #NmtNewtWidget
 * @x: the widget's (absolute) X coordinate
 * @y: the widget's (absolute) Y coordinate
 * @width: the widget's allocated width
 * @height: the widget's allocated height
 *
 * Positions @widget at the given coordinates, with the given size. If
 * @widget is not visible, this has no effect. If @widget has not yet
 * been realized, it will be realized first.
 *
 * @x and @y are absolute coordinates (ie, relative to the screen /
 * terminal window, not relative to @widget's parent).
 *
 * In general, the results are undefined if @width or @height is less
 * than the widget's requested size. If @width or @height is larger
 * than the requested size, most #NmtNewtComponents will ignore the
 * extra space, but some components and most containers will expand to
 * fit.
 */
void
nmt_newt_widget_size_allocate(NmtNewtWidget *widget, int x, int y, int width, int height)
{
    if (nmt_newt_widget_get_visible(widget)) {
        NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

        nmt_newt_widget_realize(widget);
        x += priv->pad_left;
        y += priv->pad_top;
        width -= priv->pad_left + priv->pad_right;
        height -= priv->pad_top + priv->pad_bottom;

        NMT_NEWT_WIDGET_GET_CLASS(widget)->size_allocate(widget, x, y, width, height);
    }
}

/**
 * nmt_newt_widget_get_focus_component:
 * @widget: an #NmtNewtWidget
 *
 * Gets the #newtComponent that should be given the keyboard focus when
 * @widget is focused.
 *
 * Returns: the #newtComponent to focus, or %NULL if @widget can't
 *   take the focus.
 */
newtComponent
nmt_newt_widget_get_focus_component(NmtNewtWidget *widget)
{
    if (!NMT_NEWT_WIDGET_GET_CLASS(widget)->get_focus_component)
        return NULL;

    return NMT_NEWT_WIDGET_GET_CLASS(widget)->get_focus_component(widget);
}

static void
nmt_newt_widget_real_activated(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    if (priv->exit_on_activate)
        nmt_newt_form_quit(nmt_newt_widget_get_form(widget));
}

/**
 * nmt_newt_widget_activated:
 * @widget: an #NmtNewtWidget
 *
 * Tells @widget that its #newtComponent has been activated (ie, the
 * user hit "Return" on it) and emits #NmtNewtWidget::activated.
 *
 * If #NmtNewtWidget:exit-on-activate is set on @widget, then this
 * will call nmt_newt_form_quit() on the widget's form.
 */
void
nmt_newt_widget_activated(NmtNewtWidget *widget)
{
    g_signal_emit(widget, signals[ACTIVATED], 0);
}

/**
 * nmt_newt_widget_get_exit_on_activate:
 * @widget: an #NmtNewtWidget
 *
 * Gets @widget's #NmtNewtWidget:exit-on-activate flag, qv.
 *
 * Returns: @widget's #NmtNewtWidget:exit-on-activate flag
 */
gboolean
nmt_newt_widget_get_exit_on_activate(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    return priv->exit_on_activate;
}

/**
 * nmt_newt_widget_set_exit_on_activate:
 * @widget: an #NmtNewtWidget
 * @exit_on_activate: whether @widget should exit on activate.
 *
 * Sets @widget's #NmtNewtWidget:exit-on-activate flag, qv.
 */
void
nmt_newt_widget_set_exit_on_activate(NmtNewtWidget *widget, gboolean exit_on_activate)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    exit_on_activate = !!exit_on_activate;
    if (priv->exit_on_activate != exit_on_activate) {
        priv->exit_on_activate = exit_on_activate;
        g_object_notify(G_OBJECT(widget), "exit-on-activate");
    }
}

/**
 * nmt_newt_widget_get_visible:
 * @widget: an #NmtNewtWidget
 *
 * Gets @widget's #NmtNewtWidget:visible flag, qv.
 *
 * Returns: @widget's #NmtNewtWidget:visible flag
 */
gboolean
nmt_newt_widget_get_visible(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    return priv->visible;
}

/**
 * nmt_newt_widget_set_visible:
 * @widget: an #NmtNewtWidget
 * @visible: whether @widget should be visible
 *
 * Sets @widget's #NmtNewtWidget:visible flag, qv.
 */
void
nmt_newt_widget_set_visible(NmtNewtWidget *widget, gboolean visible)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    visible = !!visible;
    if (priv->visible != visible) {
        priv->visible = visible;
        g_object_notify(G_OBJECT(widget), "visible");
        nmt_newt_widget_needs_rebuild(widget);
    }
}

/**
 * nmt_newt_widget_set_parent:
 * @widget: an #NmtNewtWidget
 * @parent: @widget's parent
 *
 * Sets @widget's parent to @parent. This is used internally by
 * #NmtNewtContainer implementations; you must use an appropriate
 * container-specific method to actually add a widget to a container.
 */
void
nmt_newt_widget_set_parent(NmtNewtWidget *widget, NmtNewtWidget *parent)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    g_clear_object(&priv->parent);
    priv->parent = parent ? g_object_ref(parent) : NULL;
    g_object_notify(G_OBJECT(widget), "parent");
}

/**
 * nmt_newt_widget_get_parent:
 * @widget: an #NmtNewtWidget
 *
 * Gets @widget's parent
 *
 * Returns: @widget's parent
 */
NmtNewtWidget *
nmt_newt_widget_get_parent(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    return priv->parent;
}

/**
 * nmt_newt_widget_get_form:
 * @widget: an #NmtNewtWidget
 *
 * Gets @widget's top-level form.
 *
 * Returns: @widget's #NmtNewtForm
 */
NmtNewtForm *
nmt_newt_widget_get_form(NmtNewtWidget *widget)
{
    while (widget) {
        if (NMT_IS_NEWT_FORM(widget))
            return NMT_NEWT_FORM(widget);
        widget = nmt_newt_widget_get_parent(widget);
    }

    return NULL;
}

/**
 * nmt_newt_widget_get_valid:
 * @widget: an #NmtNewtWidget
 *
 * Gets @widget's #NmtNewtWidget:valid flag, indicating whether its
 * content is valid.
 *
 * Returns: @widget's #NmtNewtWidget:valid flag
 */
gboolean
nmt_newt_widget_get_valid(NmtNewtWidget *widget)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    return priv->valid;
}

/**
 * nmt_newt_widget_set_valid:
 * @widget: an #NmtNewtWidget
 * @valid: whether @widget is valid
 *
 * Sets @widget's #NmtNewtWidget:valid flag, indicating whether its
 * content is valid.
 *
 * This method should be considered "protected"; if you change it, the
 * widget implementation will likely just change it back at some
 * point.
 */
void
nmt_newt_widget_set_valid(NmtNewtWidget *widget, gboolean valid)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(widget);

    valid = !!valid;
    if (priv->valid == valid)
        return;

    priv->valid = valid;
    g_object_notify(G_OBJECT(widget), "valid");
}

/**
 * nmt_newt_widget_needs_rebuilds:
 * @widget: an #NmtNewtWidget
 *
 * Marks @widget as needing to be "rebuilt" (ie, re-realized). This is
 * called automatically in some cases (such as when adding a widget to
 * or removing it from a container). #NmtNewtComponent implementations
 * should also call this if they need to make some change that can
 * only be done by destroying their current #newtComponent and
 * creating a new one.
 */
void
nmt_newt_widget_needs_rebuild(NmtNewtWidget *widget)
{
    g_signal_emit(widget, signals[NEEDS_REBUILD], 0);
}

static void
nmt_newt_widget_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
    NmtNewtWidget *widget = NMT_NEWT_WIDGET(object);

    switch (prop_id) {
    case PROP_PARENT:
        nmt_newt_widget_set_parent(widget, g_value_get_object(value));
        break;
    case PROP_VISIBLE:
        nmt_newt_widget_set_visible(widget, g_value_get_boolean(value));
        break;
    case PROP_EXIT_ON_ACTIVATE:
        nmt_newt_widget_set_exit_on_activate(widget, g_value_get_boolean(value));
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
nmt_newt_widget_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
    NmtNewtWidgetPrivate *priv = NMT_NEWT_WIDGET_GET_PRIVATE(object);

    switch (prop_id) {
    case PROP_PARENT:
        g_value_set_object(value, priv->parent);
        break;
    case PROP_VISIBLE:
        g_value_set_boolean(value, priv->visible);
        break;
    case PROP_VALID:
        g_value_set_boolean(value, priv->valid);
        break;
    case PROP_EXIT_ON_ACTIVATE:
        g_value_set_boolean(value, priv->exit_on_activate);
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}

static void
nmt_newt_widget_class_init(NmtNewtWidgetClass *widget_class)
{
    GObjectClass *object_class = G_OBJECT_CLASS(widget_class);

    g_type_class_add_private(widget_class, sizeof(NmtNewtWidgetPrivate));

    /* virtual methods */
    object_class->set_property = nmt_newt_widget_set_property;
    object_class->get_property = nmt_newt_widget_get_property;
    object_class->finalize     = nmt_newt_widget_finalize;

    widget_class->activated = nmt_newt_widget_real_activated;

    /* signals */

    /**
     * NmtNewtWidget::needs-rebuild:
     * @widget: the #NmtNewtWidget
     *
     * Emitted when nmt_newt_widget_need_rebuild() is called on @widget
     * or any of its children. This signal propagates up the container
     * hierarchy, eventually reaching the top-level #NmtNewtForm.
     */
    signals[NEEDS_REBUILD] = g_signal_new("needs-rebuild",
                                          G_OBJECT_CLASS_TYPE(object_class),
                                          G_SIGNAL_RUN_FIRST,
                                          G_STRUCT_OFFSET(NmtNewtWidgetClass, needs_rebuild),
                                          NULL,
                                          NULL,
                                          NULL,
                                          G_TYPE_NONE,
                                          0);

    /**
     * NmtNewtWidget::activated:
     * @widget: the #NmtNewtWidget
     *
     * Emitted when the widget's #newtComponent is activated.
     */
    signals[ACTIVATED] = g_signal_new("activated",
                                      G_OBJECT_CLASS_TYPE(object_class),
                                      G_SIGNAL_RUN_FIRST,
                                      G_STRUCT_OFFSET(NmtNewtWidgetClass, activated),
                                      NULL,
                                      NULL,
                                      NULL,
                                      G_TYPE_NONE,
                                      0);

    /* properties */

    /**
     * NmtNewtWidget:parent:
     *
     * The widget's parent widget, or %NULL if it has no parent.
     */
    g_object_class_install_property(object_class,
                                    PROP_PARENT,
                                    g_param_spec_object("parent",
                                                        "",
                                                        "",
                                                        NMT_TYPE_NEWT_WIDGET,
                                                        G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtNewtWidget:visible:
     *
     * Whether the widget is visible. Invisible widgets do not get
     * realized or sized.
     */
    g_object_class_install_property(
        object_class,
        PROP_VISIBLE,
        g_param_spec_boolean("visible", "", "", TRUE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtNewtWidget:valid:
     *
     * Whether the widget's content is considered valid. Components
     * determine their own validity. A container, by default, is
     * considered valid if all of its children are valid.
     */
    g_object_class_install_property(
        object_class,
        PROP_VALID,
        g_param_spec_boolean("valid", "", "", TRUE, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
    /**
     * NmtNewtWidget:exit-on-activate:
     *
     * If %TRUE, the widget will call nmt_newt_form_quit() on its form
     * when it is activated.
     */
    g_object_class_install_property(
        object_class,
        PROP_EXIT_ON_ACTIVATE,
        g_param_spec_boolean("exit-on-activate",
                             "",
                             "",
                             FALSE,
                             G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}