/* nautilus-rename-file-popover-controller.c
 *
 * Copyright (C) 2016 the Nautilus developers
 *
 * 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/>.
 *
 */

#include <glib/gi18n.h>

#include <eel/eel-vfs-extensions.h>

#include "nautilus-rename-file-popover-controller.h"

#include "nautilus-directory.h"
#include "nautilus-file-private.h"


#define RENAME_ENTRY_MIN_CHARS 20
#define RENAME_ENTRY_MAX_CHARS 35

struct _NautilusRenameFilePopoverController
{
    NautilusFileNameWidgetController parent_instance;

    NautilusFile *target_file;
    gboolean target_is_folder;

    GtkWidget *rename_file_popover;
    GtkWidget *name_entry;
    GtkWidget *name_label;

    gulong closed_handler_id;
    gulong file_changed_handler_id;
    gulong key_press_event_handler_id;
};

G_DEFINE_TYPE (NautilusRenameFilePopoverController, nautilus_rename_file_popover_controller, NAUTILUS_TYPE_FILE_NAME_WIDGET_CONTROLLER)

static void
disconnect_signal_handlers (NautilusRenameFilePopoverController *self)
{
    g_assert (NAUTILUS_IS_RENAME_FILE_POPOVER_CONTROLLER (self));

    g_clear_signal_handler (&self->closed_handler_id, self->rename_file_popover);
    g_clear_signal_handler (&self->file_changed_handler_id, self->target_file);
    g_clear_signal_handler (&self->key_press_event_handler_id, self->name_entry);
}

static void
reset_state (NautilusRenameFilePopoverController *self)
{
    g_assert (NAUTILUS_IS_RENAME_FILE_POPOVER_CONTROLLER (self));

    disconnect_signal_handlers (self);

    g_clear_object (&self->target_file);

    gtk_popover_popdown (GTK_POPOVER (self->rename_file_popover));
}

static void
rename_file_popover_controller_on_closed (GtkPopover *popover,
                                          gpointer    user_data)
{
    NautilusRenameFilePopoverController *controller;

    controller = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (user_data);

    reset_state (controller);

    g_signal_emit_by_name (controller, "cancelled");
}

static gboolean
nautilus_rename_file_popover_controller_name_is_valid (NautilusFileNameWidgetController  *controller,
                                                       gchar                             *name,
                                                       gchar                            **error_message)
{
    NautilusRenameFilePopoverController *self;
    gboolean is_valid;

    self = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (controller);

    is_valid = TRUE;
    if (strlen (name) == 0)
    {
        is_valid = FALSE;
    }
    else if (strstr (name, "/") != NULL)
    {
        is_valid = FALSE;
        if (self->target_is_folder)
        {
            *error_message = _("Folder names cannot contain “/”.");
        }
        else
        {
            *error_message = _("File names cannot contain “/”.");
        }
    }
    else if (strcmp (name, ".") == 0)
    {
        is_valid = FALSE;
        if (self->target_is_folder)
        {
            *error_message = _("A folder cannot be called “.”.");
        }
        else
        {
            *error_message = _("A file cannot be called “.”.");
        }
    }
    else if (strcmp (name, "..") == 0)
    {
        is_valid = FALSE;
        if (self->target_is_folder)
        {
            *error_message = _("A folder cannot be called “..”.");
        }
        else
        {
            *error_message = _("A file cannot be called “..”.");
        }
    }
    else if (nautilus_file_name_widget_controller_is_name_too_long (controller, name))
    {
        is_valid = FALSE;
        if (self->target_is_folder)
        {
            *error_message = _("Folder name is too long.");
        }
        else
        {
            *error_message = _("File name is too long.");
        }
    }

    if (is_valid && g_str_has_prefix (name, "."))
    {
        /* We must warn about the side effect */
        if (self->target_is_folder)
        {
            *error_message = _("Folders with “.” at the beginning of their name are hidden.");
        }
        else
        {
            *error_message = _("Files with “.” at the beginning of their name are hidden.");
        }
    }

    return is_valid;
}

static gboolean
nautilus_rename_file_popover_controller_ignore_existing_file (NautilusFileNameWidgetController *controller,
                                                              NautilusFile                     *existing_file)
{
    NautilusRenameFilePopoverController *self;
    g_autofree gchar *display_name = NULL;

    self = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (controller);

    display_name = nautilus_file_get_display_name (existing_file);

    return nautilus_file_compare_display_name (self->target_file, display_name) == 0;
}

static gboolean
name_entry_on_f2_pressed (GtkWidget                           *widget,
                          NautilusRenameFilePopoverController *self)
{
    guint text_length;
    gint start_pos;
    gint end_pos;
    gboolean all_selected;

    text_length = (guint) gtk_entry_get_text_length (GTK_ENTRY (widget));
    if (text_length == 0)
    {
        return GDK_EVENT_STOP;
    }

    gtk_editable_get_selection_bounds (GTK_EDITABLE (widget),
                                       &start_pos, &end_pos);

    all_selected = (start_pos == 0) && ((guint) end_pos == text_length);
    if (!all_selected || !nautilus_file_is_regular_file (self->target_file))
    {
        gtk_editable_select_region (GTK_EDITABLE (widget), 0, -1);
    }
    else
    {
        gint start_offset;
        gint end_offset;

        /* Select the name part without the file extension */
        eel_filename_get_rename_region (gtk_entry_get_text (GTK_ENTRY (widget)),
                                        &start_offset, &end_offset);
        gtk_editable_select_region (GTK_EDITABLE (widget),
                                    start_offset, end_offset);
    }

    return GDK_EVENT_STOP;
}

static gboolean
name_entry_on_undo (GtkWidget                           *widget,
                    NautilusRenameFilePopoverController *self)
{
    g_autofree gchar *display_name = NULL;

    display_name = nautilus_file_get_display_name (self->target_file);

    gtk_entry_set_text (GTK_ENTRY (widget), display_name);

    gtk_editable_select_region (GTK_EDITABLE (widget), 0, -1);

    return GDK_EVENT_STOP;
}

static gboolean
name_entry_on_event (GtkWidget *widget,
                     GdkEvent  *event,
                     gpointer   user_data)
{
    NautilusRenameFilePopoverController *self;
    guint keyval;
    GdkModifierType state;

    if (gdk_event_get_event_type (event) != GDK_KEY_PRESS)
    {
        return GDK_EVENT_PROPAGATE;
    }

    self = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (user_data);

    if (G_UNLIKELY (!gdk_event_get_keyval (event, &keyval)))
    {
        g_return_val_if_reached (GDK_EVENT_PROPAGATE);
    }
    if (G_UNLIKELY (!gdk_event_get_state (event, &state)))
    {
        g_return_val_if_reached (GDK_EVENT_PROPAGATE);
    }

    if (keyval == GDK_KEY_F2)
    {
        return name_entry_on_f2_pressed (widget, self);
    }
    else if (keyval == GDK_KEY_z && (state & GDK_CONTROL_MASK) != 0)
    {
        return name_entry_on_undo (widget, self);
    }

    return GDK_EVENT_PROPAGATE;
}

static void
target_file_on_changed (NautilusFile *file,
                        gpointer      user_data)
{
    NautilusRenameFilePopoverController *controller;

    controller = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (user_data);

    if (nautilus_file_is_gone (file))
    {
        reset_state (controller);

        g_signal_emit_by_name (controller, "cancelled");
    }
}

NautilusRenameFilePopoverController *
nautilus_rename_file_popover_controller_new (void)
{
    NautilusRenameFilePopoverController *self;
    g_autoptr (GtkBuilder) builder = NULL;
    GtkWidget *rename_file_popover;
    GtkWidget *error_revealer;
    GtkWidget *error_label;
    GtkWidget *name_entry;
    GtkWidget *activate_button;
    GtkWidget *name_label;

    builder = gtk_builder_new_from_resource ("/org/gnome/nautilus/ui/nautilus-rename-file-popover.ui");
    rename_file_popover = GTK_WIDGET (gtk_builder_get_object (builder, "rename_file_popover"));
    error_revealer = GTK_WIDGET (gtk_builder_get_object (builder, "error_revealer"));
    error_label = GTK_WIDGET (gtk_builder_get_object (builder, "error_label"));
    name_entry = GTK_WIDGET (gtk_builder_get_object (builder, "name_entry"));
    activate_button = GTK_WIDGET (gtk_builder_get_object (builder, "rename_button"));
    name_label = GTK_WIDGET (gtk_builder_get_object (builder, "name_label"));

    self = g_object_new (NAUTILUS_TYPE_RENAME_FILE_POPOVER_CONTROLLER,
                         "error-revealer", error_revealer,
                         "error-label", error_label,
                         "name-entry", name_entry,
                         "activate-button", activate_button,
                         NULL);

    self->rename_file_popover = g_object_ref_sink (rename_file_popover);
    self->name_entry = name_entry;
    self->name_label = name_label;

    gtk_popover_set_default_widget (GTK_POPOVER (rename_file_popover), name_entry);

    return self;
}

NautilusFile *
nautilus_rename_file_popover_controller_get_target_file (NautilusRenameFilePopoverController *self)
{
    g_return_val_if_fail (NAUTILUS_IS_RENAME_FILE_POPOVER_CONTROLLER (self), NULL);

    return self->target_file;
}

void
nautilus_rename_file_popover_controller_show_for_file   (NautilusRenameFilePopoverController *self,
                                                         NautilusFile                        *target_file,
                                                         GdkRectangle                        *pointing_to,
                                                         GtkWidget                           *relative_to)
{
    g_autoptr (NautilusDirectory) containing_directory = NULL;
    g_autofree gchar *display_name = NULL;
    gint n_chars;

    g_assert (NAUTILUS_IS_RENAME_FILE_POPOVER_CONTROLLER (self));
    g_assert (NAUTILUS_IS_FILE (target_file));

    reset_state (self);

    self->target_file = g_object_ref (target_file);

    if (!nautilus_file_is_self_owned (self->target_file))
    {
        g_autoptr (NautilusFile) parent = NULL;

        parent = nautilus_file_get_parent (self->target_file);
        containing_directory = nautilus_directory_get_for_file (parent);
    }
    else
    {
        containing_directory = nautilus_directory_get_for_file (self->target_file);
    }

    nautilus_file_name_widget_controller_set_containing_directory (NAUTILUS_FILE_NAME_WIDGET_CONTROLLER (self),
                                                                   containing_directory);

    self->target_is_folder = nautilus_file_is_directory (self->target_file);

    self->closed_handler_id = g_signal_connect (self->rename_file_popover,
                                                "closed",
                                                G_CALLBACK (rename_file_popover_controller_on_closed),
                                                self);

    self->file_changed_handler_id = g_signal_connect (self->target_file,
                                                      "changed",
                                                      G_CALLBACK (target_file_on_changed),
                                                      self);

    self->key_press_event_handler_id = g_signal_connect (self->name_entry,
                                                         "event",
                                                         G_CALLBACK (name_entry_on_event),
                                                         self);

    gtk_label_set_text (GTK_LABEL (self->name_label),
                        self->target_is_folder ? _("Folder name") :
                        _("File name"));

    display_name = nautilus_file_get_display_name (self->target_file);

    gtk_entry_set_text (GTK_ENTRY (self->name_entry), display_name);

    gtk_popover_set_pointing_to (GTK_POPOVER (self->rename_file_popover), pointing_to);
    gtk_popover_set_relative_to (GTK_POPOVER (self->rename_file_popover), relative_to);

    gtk_popover_popup (GTK_POPOVER (self->rename_file_popover));

    if (nautilus_file_is_regular_file (self->target_file))
    {
        gint start_offset;
        gint end_offset;

        /* Select the name part without the file extension */
        eel_filename_get_rename_region (display_name,
                                        &start_offset, &end_offset);
        gtk_editable_select_region (GTK_EDITABLE (self->name_entry),
                                    start_offset, end_offset);
    }

    n_chars = g_utf8_strlen (display_name, -1);
    gtk_entry_set_width_chars (GTK_ENTRY (self->name_entry),
                               MIN (MAX (n_chars, RENAME_ENTRY_MIN_CHARS),
                                    RENAME_ENTRY_MAX_CHARS));
}

static void
on_name_accepted (NautilusFileNameWidgetController *controller)
{
    NautilusRenameFilePopoverController *self;

    self = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (controller);

    reset_state (self);
}

static void
nautilus_rename_file_popover_controller_init (NautilusRenameFilePopoverController *self)
{
    g_signal_connect_after (self, "name-accepted", G_CALLBACK (on_name_accepted), self);
}

static void
nautilus_rename_file_popover_controller_finalize (GObject *object)
{
    NautilusRenameFilePopoverController *self;

    self = NAUTILUS_RENAME_FILE_POPOVER_CONTROLLER (object);

    reset_state (self);

    gtk_widget_destroy (self->rename_file_popover);
    g_clear_object (&self->rename_file_popover);

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

static void
nautilus_rename_file_popover_controller_class_init (NautilusRenameFilePopoverControllerClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);
    NautilusFileNameWidgetControllerClass *parent_class = NAUTILUS_FILE_NAME_WIDGET_CONTROLLER_CLASS (klass);

    object_class->finalize = nautilus_rename_file_popover_controller_finalize;

    parent_class->name_is_valid = nautilus_rename_file_popover_controller_name_is_valid;
    parent_class->ignore_existing_file = nautilus_rename_file_popover_controller_ignore_existing_file;
}