/*
  SuperNotepad (GTK3 + GtkSourceView) - C
  Features:
  - File/Edit/View/Help menus
  - Status bar: Ln/Col + Saved/Modified
  - Word wrap / Status bar / Line numbers toggles
  - .backup file auto-write when modified & unsaved (toggleable)
  - Find, Find Next, Replace, Go To
  - Time/Date insert
  - Print (simple)

  Build:
    meson setup build
    meson compile -C build
    ./build/SuperNotepad
*/

#include <gtk/gtk.h>
#include <gtksourceview/gtksource.h>
#include <time.h>
#include <glib/gstdio.h>

typedef struct {
  GtkApplication *app;
  GtkWidget *win;

  GtkWidget *menubar;

  GtkWidget *scroller;
  GtkSourceView *view;
  GtkSourceBuffer *buffer;

  GtkWidget *status_bar_box;
  GtkWidget *pos_label;
  GtkWidget *state_label;

  gboolean show_status_bar;
  gboolean word_wrap;
  gboolean show_line_numbers;
  gboolean backups_enabled;

  gchar *current_path;     // NULL when untitled
  gchar *backup_path;      // derived or temp
  guint backup_timeout_id; // debounce

  // Find state
  gchar *last_find;
  GtkTextIter last_match_end;
  gboolean has_last_match;
} AppState;

/* ---------- Utility ---------- */

static void free_and_null(gchar **p) {
  if (*p) { g_free(*p); *p = NULL; }
}

static gchar* get_temp_untitled_backup_path(void) {
  // Keep it predictable and easy to find
  return g_build_filename(g_get_tmp_dir(), "SuperNotepad-Untitled.backup", NULL);
}

static gchar* compute_backup_path(AppState *s) {
  if (s->current_path && *s->current_path) {
    return g_strconcat(s->current_path, ".backup", NULL);
  }
  return get_temp_untitled_backup_path();
}

static gchar* buffer_get_all_text(GtkTextBuffer *buf) {
  GtkTextIter start, end;
  gtk_text_buffer_get_start_iter(buf, &start);
  gtk_text_buffer_get_end_iter(buf, &end);
  return gtk_text_buffer_get_text(buf, &start, &end, TRUE);
}

static void update_title(AppState *s) {
  const gchar *name = "SuperNotepad";
  gchar *title = NULL;

  if (s->current_path) {
    gchar *base = g_path_get_basename(s->current_path);
    title = g_strdup_printf("%s - %s", base, name);
    g_free(base);
  } else {
    title = g_strdup_printf("Untitled - %s", name);
  }

  gtk_window_set_title(GTK_WINDOW(s->win), title);
  g_free(title);
}

static void update_status(AppState *s) {
  GtkTextIter iter;
  GtkTextMark *mark = gtk_text_buffer_get_insert(GTK_TEXT_BUFFER(s->buffer));
  gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(s->buffer), &iter, mark);

  int line = gtk_text_iter_get_line(&iter) + 1;
  int col  = gtk_text_iter_get_line_offset(&iter) + 1;

  gchar *pos = g_strdup_printf("Ln %d, Col %d", line, col);
  gtk_label_set_text(GTK_LABEL(s->pos_label), pos);
  g_free(pos);

  gboolean modified = gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer));
  gtk_label_set_text(GTK_LABEL(s->state_label), modified ? "Modified (unsaved)" : "Saved");
}

/* ---------- Backup handling ---------- */

static gboolean write_backup_now(gpointer user_data) {
  AppState *s = (AppState*)user_data;
  s->backup_timeout_id = 0;

  if (!s->backups_enabled) return G_SOURCE_REMOVE;

  if (!gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) return G_SOURCE_REMOVE;

  free_and_null(&s->backup_path);
  s->backup_path = compute_backup_path(s);

  gchar *text = buffer_get_all_text(GTK_TEXT_BUFFER(s->buffer));
  GError *err = NULL;

  if (!g_file_set_contents(s->backup_path, text, -1, &err)) {
    g_warning("Failed writing backup '%s': %s", s->backup_path, err->message);
    g_clear_error(&err);
  }

  g_free(text);
  return G_SOURCE_REMOVE;
}

static void schedule_backup(AppState *s) {
  if (!s->backups_enabled) return;
  if (!gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) return;

  // Debounce: write 1 second after last change
  if (s->backup_timeout_id != 0) return;
  s->backup_timeout_id = g_timeout_add(1000, write_backup_now, s);
}

static void delete_backup_file_if_any(AppState *s) {
  if (!s->backup_path) {
    // compute path once, because we may never have written yet
    s->backup_path = compute_backup_path(s);
  }

  if (s->backup_path) {
    GError *err = NULL;
    if (g_remove(s->backup_path) != 0) {
      // ignore failures (file may not exist)
    }
    if (err) g_clear_error(&err);
  }
}

/* ---------- File I/O ---------- */

static gboolean maybe_confirm_discard(AppState *s) {
  if (!gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) return TRUE;

  GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
    GTK_DIALOG_MODAL,
    GTK_MESSAGE_WARNING,
    GTK_BUTTONS_NONE,
    "This document has unsaved changes.");
  gtk_dialog_add_buttons(GTK_DIALOG(d),
    "Cancel", GTK_RESPONSE_CANCEL,
    "Discard", GTK_RESPONSE_REJECT,
    "Save", GTK_RESPONSE_ACCEPT,
    NULL);

  int resp = gtk_dialog_run(GTK_DIALOG(d));
  gtk_widget_destroy(d);

  if (resp == GTK_RESPONSE_ACCEPT) {
    // Save
    // If no path, force Save As
    return FALSE; // caller will handle save flow by calling save action
  }
  if (resp == GTK_RESPONSE_REJECT) return TRUE;
  return FALSE;
}

static gboolean save_to_path(AppState *s, const gchar *path) {
  gchar *text = buffer_get_all_text(GTK_TEXT_BUFFER(s->buffer));
  GError *err = NULL;

  gboolean ok = g_file_set_contents(path, text, -1, &err);
  g_free(text);

  if (!ok) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_ERROR, GTK_BUTTONS_OK,
      "Save failed:\n%s", err ? err->message : "Unknown error");
    gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);
    g_clear_error(&err);
    return FALSE;
  }

  free_and_null(&s->current_path);
  s->current_path = g_strdup(path);

  gtk_text_buffer_set_modified(GTK_TEXT_BUFFER(s->buffer), FALSE);
  update_title(s);
  update_status(s);

  // Once saved, remove backup (it’s no longer “unsaved”)
  delete_backup_file_if_any(s);

  return TRUE;
}

static void action_new(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  if (gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_QUESTION, GTK_BUTTONS_NONE,
      "Save changes before creating a new document?");
    gtk_dialog_add_buttons(GTK_DIALOG(d),
      "Cancel", GTK_RESPONSE_CANCEL,
      "Don't Save", GTK_RESPONSE_REJECT,
      "Save", GTK_RESPONSE_ACCEPT,
      NULL);
    int resp = gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);

    if (resp == GTK_RESPONSE_CANCEL) return;
    if (resp == GTK_RESPONSE_ACCEPT) {
      // delegate to save; if no path, do Save As
      // We'll just call the save handler and let it decide.
      // If user cancels save dialog, abort new.
      // The easiest is: do a Save As if no path, else Save.
      // We'll implement inline here.

      if (s->current_path) {
        if (!save_to_path(s, s->current_path)) return;
      } else {
        GtkWidget *dlg = gtk_file_chooser_dialog_new("Save As",
          GTK_WINDOW(s->win),
          GTK_FILE_CHOOSER_ACTION_SAVE,
          "_Cancel", GTK_RESPONSE_CANCEL,
          "_Save", GTK_RESPONSE_ACCEPT,
          NULL);
        gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE);
        int r = gtk_dialog_run(GTK_DIALOG(dlg));
        if (r == GTK_RESPONSE_ACCEPT) {
          char *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg));
          gtk_widget_destroy(dlg);
          if (!filename) return;
          gboolean ok = save_to_path(s, filename);
          g_free(filename);
          if (!ok) return;
        } else {
          gtk_widget_destroy(dlg);
          return;
        }
      }
    }
    // else "Don't Save": continue
  }

  gtk_text_buffer_set_text(GTK_TEXT_BUFFER(s->buffer), "", -1);
  gtk_text_buffer_set_modified(GTK_TEXT_BUFFER(s->buffer), FALSE);
  free_and_null(&s->current_path);
  free_and_null(&s->last_find);
  s->has_last_match = FALSE;

  update_title(s);
  update_status(s);
  delete_backup_file_if_any(s);
}

static void action_open(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  if (gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_QUESTION, GTK_BUTTONS_NONE,
      "Save changes before opening another file?");
    gtk_dialog_add_buttons(GTK_DIALOG(d),
      "Cancel", GTK_RESPONSE_CANCEL,
      "Don't Save", GTK_RESPONSE_REJECT,
      "Save", GTK_RESPONSE_ACCEPT,
      NULL);
    int resp = gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);

    if (resp == GTK_RESPONSE_CANCEL) return;
    if (resp == GTK_RESPONSE_ACCEPT) {
      if (s->current_path) {
        if (!save_to_path(s, s->current_path)) return;
      } else {
        GtkWidget *sd = gtk_file_chooser_dialog_new("Save As",
          GTK_WINDOW(s->win),
          GTK_FILE_CHOOSER_ACTION_SAVE,
          "_Cancel", GTK_RESPONSE_CANCEL,
          "_Save", GTK_RESPONSE_ACCEPT,
          NULL);
        gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(sd), TRUE);
        int r = gtk_dialog_run(GTK_DIALOG(sd));
        if (r == GTK_RESPONSE_ACCEPT) {
          char *fn = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(sd));
          gtk_widget_destroy(sd);
          if (!fn) return;
          gboolean ok = save_to_path(s, fn);
          g_free(fn);
          if (!ok) return;
        } else {
          gtk_widget_destroy(sd);
          return;
        }
      }
    }
  }

  GtkWidget *dlg = gtk_file_chooser_dialog_new("Open",
    GTK_WINDOW(s->win),
    GTK_FILE_CHOOSER_ACTION_OPEN,
    "_Cancel", GTK_RESPONSE_CANCEL,
    "_Open", GTK_RESPONSE_ACCEPT,
    NULL);

  int resp = gtk_dialog_run(GTK_DIALOG(dlg));
  if (resp != GTK_RESPONSE_ACCEPT) { gtk_widget_destroy(dlg); return; }

  char *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg));
  gtk_widget_destroy(dlg);
  if (!filename) return;

  gchar *contents = NULL;
  gsize len = 0;
  GError *err = NULL;

  if (!g_file_get_contents(filename, &contents, &len, &err)) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_ERROR, GTK_BUTTONS_OK,
      "Open failed:\n%s", err ? err->message : "Unknown error");
    gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);
    g_clear_error(&err);
    g_free(filename);
    return;
  }

  gtk_text_buffer_set_text(GTK_TEXT_BUFFER(s->buffer), contents, (gint)len);
  gtk_text_buffer_set_modified(GTK_TEXT_BUFFER(s->buffer), FALSE);

  free_and_null(&s->current_path);
  s->current_path = g_strdup(filename);

  free_and_null(&s->last_find);
  s->has_last_match = FALSE;

  update_title(s);
  update_status(s);

  // backup path changes with opened file
  free_and_null(&s->backup_path);

  g_free(contents);
  g_free(filename);
}

static void action_save_as(GtkWidget *w, gpointer user_data);

static void action_save(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  if (!s->current_path) {
    action_save_as(NULL, s);
    return;
  }

  save_to_path(s, s->current_path);
}

static void action_save_as(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkWidget *dlg = gtk_file_chooser_dialog_new("Save As",
    GTK_WINDOW(s->win),
    GTK_FILE_CHOOSER_ACTION_SAVE,
    "_Cancel", GTK_RESPONSE_CANCEL,
    "_Save", GTK_RESPONSE_ACCEPT,
    NULL);

  gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE);

  if (s->current_path) {
    gtk_file_chooser_set_filename(GTK_FILE_CHOOSER(dlg), s->current_path);
  }

  int resp = gtk_dialog_run(GTK_DIALOG(dlg));
  if (resp != GTK_RESPONSE_ACCEPT) { gtk_widget_destroy(dlg); return; }

  char *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg));
  gtk_widget_destroy(dlg);
  if (!filename) return;

  save_to_path(s, filename);

  g_free(filename);
}

static void action_exit(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  if (gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_QUESTION, GTK_BUTTONS_NONE,
      "Save changes before exiting?");
    gtk_dialog_add_buttons(GTK_DIALOG(d),
      "Cancel", GTK_RESPONSE_CANCEL,
      "Don't Save", GTK_RESPONSE_REJECT,
      "Save", GTK_RESPONSE_ACCEPT,
      NULL);
    int resp = gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);

    if (resp == GTK_RESPONSE_CANCEL) return;
    if (resp == GTK_RESPONSE_ACCEPT) {
      if (s->current_path) {
        if (!save_to_path(s, s->current_path)) return;
      } else {
        action_save_as(NULL, s);
        if (gtk_text_buffer_get_modified(GTK_TEXT_BUFFER(s->buffer))) return; // user canceled
      }
    }
  }

  gtk_window_close(GTK_WINDOW(s->win));
}

/* ---------- Print ---------- */

typedef struct {
  gchar *text;
} PrintData;

static void print_data_free(PrintData *pd) {
  if (!pd) return;
  g_free(pd->text);
  g_free(pd);
}

static void on_print_begin(GtkPrintOperation *op, GtkPrintContext *ctx, gpointer user_data) {
  (void)op; (void)ctx; (void)user_data;
  // single page simplistic; could paginate by measuring
}

static void on_print_draw_page(GtkPrintOperation *op, GtkPrintContext *ctx, int page_nr, gpointer user_data) {
  (void)op; (void)page_nr;
  PrintData *pd = (PrintData*)user_data;

  cairo_t *cr = gtk_print_context_get_cairo_context(ctx);
  PangoLayout *layout = gtk_print_context_create_pango_layout(ctx);

  pango_layout_set_text(layout, pd->text ? pd->text : "", -1);

  // Wrap to page width
  double width = gtk_print_context_get_width(ctx);
  pango_layout_set_width(layout, (int)(width * PANGO_SCALE));
  pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);

  cairo_move_to(cr, 0, 0);
  pango_cairo_show_layout(cr, layout);

  g_object_unref(layout);
}

static void action_print(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  PrintData *pd = g_new0(PrintData, 1);
  pd->text = buffer_get_all_text(GTK_TEXT_BUFFER(s->buffer));

  GtkPrintOperation *op = gtk_print_operation_new();
  gtk_print_operation_set_job_name(op, "SuperNotepad Print");
  gtk_print_operation_set_n_pages(op, 1);

  g_signal_connect(op, "begin-print", G_CALLBACK(on_print_begin), pd);
  g_signal_connect(op, "draw-page", G_CALLBACK(on_print_draw_page), pd);

  GError *err = NULL;
  GtkPrintOperationResult res = gtk_print_operation_run(op,
    GTK_PRINT_OPERATION_ACTION_PRINT_DIALOG,
    GTK_WINDOW(s->win),
    &err);

  if (res == GTK_PRINT_OPERATION_RESULT_ERROR) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_ERROR, GTK_BUTTONS_OK,
      "Print failed:\n%s", err ? err->message : "Unknown error");
    gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);
    g_clear_error(&err);
  }

  g_object_unref(op);
  print_data_free(pd);
}

/* ---------- Edit actions ---------- */

static void action_undo(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;
  if (gtk_source_buffer_can_undo(s->buffer)) gtk_source_buffer_undo(s->buffer);
}

static void action_cut(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;
  GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
  gtk_text_buffer_cut_clipboard(GTK_TEXT_BUFFER(s->buffer), cb, TRUE);
}

static void action_copy(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;
  GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
  gtk_text_buffer_copy_clipboard(GTK_TEXT_BUFFER(s->buffer), cb);
}

static void action_paste(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;
  GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
  gtk_text_buffer_paste_clipboard(GTK_TEXT_BUFFER(s->buffer), cb, NULL, TRUE);
}

static void action_delete(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkTextIter start, end;
  if (gtk_text_buffer_get_selection_bounds(GTK_TEXT_BUFFER(s->buffer), &start, &end)) {
    gtk_text_buffer_delete(GTK_TEXT_BUFFER(s->buffer), &start, &end);
  }
}

static void action_select_all(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkTextIter start, end;
  gtk_text_buffer_get_start_iter(GTK_TEXT_BUFFER(s->buffer), &start);
  gtk_text_buffer_get_end_iter(GTK_TEXT_BUFFER(s->buffer), &end);
  gtk_text_buffer_select_range(GTK_TEXT_BUFFER(s->buffer), &start, &end);
}

static void action_time_date(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  time_t t = time(NULL);
  struct tm lt;
#if defined(_WIN32)
  localtime_s(&lt, &t);
#else
  localtime_r(&t, &lt);
#endif
  char buf[128];
  strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M", &lt);

  GtkTextIter iter;
  GtkTextMark *mark = gtk_text_buffer_get_insert(GTK_TEXT_BUFFER(s->buffer));
  gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(s->buffer), &iter, mark);
  gtk_text_buffer_insert(GTK_TEXT_BUFFER(s->buffer), &iter, buf, -1);
}

/* ---------- Find / Replace / Go To ---------- */

static gboolean do_find_from_iter(AppState *s, const gchar *needle, GtkTextIter *from, gboolean wrap) {
  if (!needle || !*needle) return FALSE;

  GtkTextIter start = *from;
  GtkTextIter match_start, match_end;

  gboolean found = gtk_text_iter_forward_search(&start, needle,
    GTK_TEXT_SEARCH_TEXT_ONLY | GTK_TEXT_SEARCH_VISIBLE_ONLY,
    &match_start, &match_end, NULL);

  if (!found && wrap) {
    GtkTextIter begin;
    gtk_text_buffer_get_start_iter(GTK_TEXT_BUFFER(s->buffer), &begin);
    found = gtk_text_iter_forward_search(&begin, needle,
      GTK_TEXT_SEARCH_TEXT_ONLY | GTK_TEXT_SEARCH_VISIBLE_ONLY,
      &match_start, &match_end, NULL);
  }

  if (found) {
    gtk_text_buffer_select_range(GTK_TEXT_BUFFER(s->buffer), &match_start, &match_end);
    gtk_text_view_scroll_to_iter(GTK_TEXT_VIEW(s->view), &match_start, 0.2, FALSE, 0, 0);

    s->last_match_end = match_end;
    s->has_last_match = TRUE;
    return TRUE;
  }

  return FALSE;
}

static void action_find(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkWidget *dlg = gtk_dialog_new_with_buttons("Find",
    GTK_WINDOW(s->win),
    GTK_DIALOG_MODAL,
    "_Cancel", GTK_RESPONSE_CANCEL,
    "_Find", GTK_RESPONSE_ACCEPT,
    NULL);

  GtkWidget *box = gtk_dialog_get_content_area(GTK_DIALOG(dlg));
  GtkWidget *entry = gtk_entry_new();
  gtk_entry_set_activates_default(GTK_ENTRY(entry), TRUE);
  gtk_box_pack_start(GTK_BOX(box), gtk_label_new("Find what:"), FALSE, FALSE, 6);
  gtk_box_pack_start(GTK_BOX(box), entry, FALSE, FALSE, 6);

  if (s->last_find) gtk_entry_set_text(GTK_ENTRY(entry), s->last_find);

  gtk_dialog_set_default_response(GTK_DIALOG(dlg), GTK_RESPONSE_ACCEPT);
  gtk_widget_show_all(dlg);

  int resp = gtk_dialog_run(GTK_DIALOG(dlg));
  if (resp != GTK_RESPONSE_ACCEPT) { gtk_widget_destroy(dlg); return; }

  const gchar *needle = gtk_entry_get_text(GTK_ENTRY(entry));
  free_and_null(&s->last_find);
  s->last_find = g_strdup(needle);

  GtkTextIter from;
  GtkTextMark *mark = gtk_text_buffer_get_insert(GTK_TEXT_BUFFER(s->buffer));
  gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(s->buffer), &from, mark);

  gboolean ok = do_find_from_iter(s, needle, &from, TRUE);
  gtk_widget_destroy(dlg);

  if (!ok) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_INFO, GTK_BUTTONS_OK,
      "Text not found.");
    gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);
  }
}

static void action_find_next(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;
  if (!s->last_find || !*s->last_find) {
    action_find(NULL, s);
    return;
  }

  GtkTextIter from;
  if (s->has_last_match) from = s->last_match_end;
  else {
    GtkTextMark *mark = gtk_text_buffer_get_insert(GTK_TEXT_BUFFER(s->buffer));
    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(s->buffer), &from, mark);
  }

  gboolean ok = do_find_from_iter(s, s->last_find, &from, TRUE);
  if (!ok) {
    GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
      GTK_DIALOG_MODAL, GTK_MESSAGE_INFO, GTK_BUTTONS_OK,
      "No further matches.");
    gtk_dialog_run(GTK_DIALOG(d));
    gtk_widget_destroy(d);
  }
}

static void action_go_to(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkWidget *dlg = gtk_dialog_new_with_buttons("Go To Line",
    GTK_WINDOW(s->win),
    GTK_DIALOG_MODAL,
    "_Cancel", GTK_RESPONSE_CANCEL,
    "_Go", GTK_RESPONSE_ACCEPT,
    NULL);

  GtkWidget *box = gtk_dialog_get_content_area(GTK_DIALOG(dlg));
  GtkWidget *spin = gtk_spin_button_new_with_range(1, 1000000, 1);

  gtk_box_pack_start(GTK_BOX(box), gtk_label_new("Line number:"), FALSE, FALSE, 6);
  gtk_box_pack_start(GTK_BOX(box), spin, FALSE, FALSE, 6);

  gtk_dialog_set_default_response(GTK_DIALOG(dlg), GTK_RESPONSE_ACCEPT);
  gtk_widget_show_all(dlg);

  int resp = gtk_dialog_run(GTK_DIALOG(dlg));
  if (resp != GTK_RESPONSE_ACCEPT) { gtk_widget_destroy(dlg); return; }

  int line = gtk_spin_button_get_value_as_int(GTK_SPIN_BUTTON(spin));
  gtk_widget_destroy(dlg);

  GtkTextIter iter;
  gtk_text_buffer_get_iter_at_line(GTK_TEXT_BUFFER(s->buffer), &iter, line - 1);
  gtk_text_buffer_place_cursor(GTK_TEXT_BUFFER(s->buffer), &iter);
  gtk_text_view_scroll_to_iter(GTK_TEXT_VIEW(s->view), &iter, 0.2, FALSE, 0, 0);
  update_status(s);
}

static void action_replace(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkWidget *dlg = gtk_dialog_new_with_buttons("Replace",
    GTK_WINDOW(s->win),
    GTK_DIALOG_MODAL,
    "_Close", GTK_RESPONSE_CLOSE,
    "_Replace", 1,
    "Replace _All", 2,
    NULL);

  GtkWidget *box = gtk_dialog_get_content_area(GTK_DIALOG(dlg));
  GtkWidget *find_entry = gtk_entry_new();
  GtkWidget *rep_entry  = gtk_entry_new();

  gtk_box_pack_start(GTK_BOX(box), gtk_label_new("Find what:"), FALSE, FALSE, 6);
  gtk_box_pack_start(GTK_BOX(box), find_entry, FALSE, FALSE, 6);
  gtk_box_pack_start(GTK_BOX(box), gtk_label_new("Replace with:"), FALSE, FALSE, 6);
  gtk_box_pack_start(GTK_BOX(box), rep_entry, FALSE, FALSE, 6);

  if (s->last_find) gtk_entry_set_text(GTK_ENTRY(find_entry), s->last_find);

  gtk_widget_show_all(dlg);

  for (;;) {
    int resp = gtk_dialog_run(GTK_DIALOG(dlg));
    if (resp == GTK_RESPONSE_CLOSE) break;

    const gchar *needle = gtk_entry_get_text(GTK_ENTRY(find_entry));
    const gchar *repl   = gtk_entry_get_text(GTK_ENTRY(rep_entry));

    if (!needle || !*needle) {
      GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
        GTK_DIALOG_MODAL, GTK_MESSAGE_INFO, GTK_BUTTONS_OK,
        "Enter text to find.");
      gtk_dialog_run(GTK_DIALOG(d));
      gtk_widget_destroy(d);
      continue;
    }

    free_and_null(&s->last_find);
    s->last_find = g_strdup(needle);

    if (resp == 1) {
      // Replace: if selection matches needle, replace it; else find next
      GtkTextIter sel_start, sel_end;
      if (gtk_text_buffer_get_selection_bounds(GTK_TEXT_BUFFER(s->buffer), &sel_start, &sel_end)) {
        gchar *selected = gtk_text_buffer_get_text(GTK_TEXT_BUFFER(s->buffer), &sel_start, &sel_end, TRUE);
        gboolean matches = (g_strcmp0(selected, needle) == 0);
        g_free(selected);

        if (matches) {
          gtk_text_buffer_begin_user_action(GTK_TEXT_BUFFER(s->buffer));
          gtk_text_buffer_delete(GTK_TEXT_BUFFER(s->buffer), &sel_start, &sel_end);
          gtk_text_buffer_insert(GTK_TEXT_BUFFER(s->buffer), &sel_start, repl, -1);
          gtk_text_buffer_end_user_action(GTK_TEXT_BUFFER(s->buffer));
          // After replace, find next occurrence
          GtkTextIter from = sel_start;
          do_find_from_iter(s, needle, &from, TRUE);
          continue;
        }
      }

      action_find_next(NULL, s);
      continue;
    }

    if (resp == 2) {
      // Replace All
      GtkTextIter iter;
      gtk_text_buffer_get_start_iter(GTK_TEXT_BUFFER(s->buffer), &iter);

      int count = 0;
      gtk_text_buffer_begin_user_action(GTK_TEXT_BUFFER(s->buffer));

      while (1) {
        GtkTextIter ms, me;
        gboolean found = gtk_text_iter_forward_search(&iter, needle,
          GTK_TEXT_SEARCH_TEXT_ONLY | GTK_TEXT_SEARCH_VISIBLE_ONLY,
          &ms, &me, NULL);
        if (!found) break;

        gtk_text_buffer_delete(GTK_TEXT_BUFFER(s->buffer), &ms, &me);
        gtk_text_buffer_insert(GTK_TEXT_BUFFER(s->buffer), &ms, repl, -1);

        iter = ms; // continue after inserted text
        count++;
      }

      gtk_text_buffer_end_user_action(GTK_TEXT_BUFFER(s->buffer));

      GtkWidget *d = gtk_message_dialog_new(GTK_WINDOW(s->win),
        GTK_DIALOG_MODAL, GTK_MESSAGE_INFO, GTK_BUTTONS_OK,
        "Replaced %d occurrence(s).", count);
      gtk_dialog_run(GTK_DIALOG(d));
      gtk_widget_destroy(d);

      continue;
    }
  }

  gtk_widget_destroy(dlg);
}

/* ---------- View toggles ---------- */

static void apply_view_settings(AppState *s) {
  gtk_widget_set_visible(s->status_bar_box, s->show_status_bar);

  gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(s->view),
    s->word_wrap ? GTK_WRAP_WORD_CHAR : GTK_WRAP_NONE);

  gtk_source_view_set_show_line_numbers(s->view, s->show_line_numbers);
}

static void toggle_status_bar(GtkCheckMenuItem *mi, gpointer user_data) {
  AppState *s = (AppState*)user_data;
  s->show_status_bar = gtk_check_menu_item_get_active(mi);
  apply_view_settings(s);
}

static void toggle_word_wrap(GtkCheckMenuItem *mi, gpointer user_data) {
  AppState *s = (AppState*)user_data;
  s->word_wrap = gtk_check_menu_item_get_active(mi);
  apply_view_settings(s);
}

static void toggle_line_numbers(GtkCheckMenuItem *mi, gpointer user_data) {
  AppState *s = (AppState*)user_data;
  s->show_line_numbers = gtk_check_menu_item_get_active(mi);
  apply_view_settings(s);
}

/* ---------- Backup toggle (Edit menu) ---------- */

static void toggle_backups(GtkCheckMenuItem *mi, gpointer user_data) {
  AppState *s = (AppState*)user_data;
  s->backups_enabled = gtk_check_menu_item_get_active(mi);

  if (!s->backups_enabled) {
    // Stop pending backup and remove any backup file
    if (s->backup_timeout_id) {
      g_source_remove(s->backup_timeout_id);
      s->backup_timeout_id = 0;
    }
    delete_backup_file_if_any(s);
  } else {
    // If currently modified, schedule one
    schedule_backup(s);
  }
}

/* ---------- Help / About ---------- */

static void action_about(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  GtkWidget *dlg = gtk_message_dialog_new(GTK_WINDOW(s->win),
    GTK_DIALOG_MODAL,
    GTK_MESSAGE_INFO,
    GTK_BUTTONS_OK,
    "SuperNotepage 0.1 by John Paul Wohlscheid and ChatGPT");
  gtk_window_set_title(GTK_WINDOW(dlg), "About");
  gtk_dialog_run(GTK_DIALOG(dlg));
  gtk_widget_destroy(dlg);
}

/* ---------- Buffer signals ---------- */

static void on_mark_set(GtkTextBuffer *buf, GtkTextIter *new_loc, GtkTextMark *mark, gpointer user_data) {
  (void)buf; (void)new_loc; (void)mark;
  AppState *s = (AppState*)user_data;
  update_status(s);
}

static void on_modified_changed(GtkTextBuffer *buf, gpointer user_data) {
  (void)buf;
  AppState *s = (AppState*)user_data;
  update_status(s);
}

static void on_buffer_changed(GtkTextBuffer *buf, gpointer user_data) {
  (void)buf;
  AppState *s = (AppState*)user_data;
  update_status(s);
  schedule_backup(s);
}

/* ---------- Menu building helpers ---------- */

static GtkWidget* menu_item(const gchar *label, GCallback cb, AppState *s) {
  GtkWidget *mi = gtk_menu_item_new_with_label(label);
  if (cb) g_signal_connect(mi, "activate", cb, s);
  return mi;
}

static GtkWidget* check_menu_item(const gchar *label, gboolean active, GCallback toggled_cb, AppState *s) {
  GtkWidget *mi = gtk_check_menu_item_new_with_label(label);
  gtk_check_menu_item_set_active(GTK_CHECK_MENU_ITEM(mi), active);
  if (toggled_cb) g_signal_connect(mi, "toggled", toggled_cb, s);
  return mi;
}

static GtkWidget* build_menubar(AppState *s) {
  GtkWidget *menubar = gtk_menu_bar_new();

  /* File */
  GtkWidget *file_menu = gtk_menu_new();
  GtkWidget *file_root = gtk_menu_item_new_with_label("File");
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(file_root), file_menu);

  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("New",      G_CALLBACK(action_new), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("Open",     G_CALLBACK(action_open), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("Save",     G_CALLBACK(action_save), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("Save As",  G_CALLBACK(action_save_as), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("Print",    G_CALLBACK(action_print), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), gtk_separator_menu_item_new());
  gtk_menu_shell_append(GTK_MENU_SHELL(file_menu), menu_item("Exit",     G_CALLBACK(action_exit), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(menubar), file_root);

  /* Edit */
  GtkWidget *edit_menu = gtk_menu_new();
  GtkWidget *edit_root = gtk_menu_item_new_with_label("Edit");
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(edit_root), edit_menu);

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Undo",     G_CALLBACK(action_undo), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), gtk_separator_menu_item_new());

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Cut",      G_CALLBACK(action_cut), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Copy",     G_CALLBACK(action_copy), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Paste",    G_CALLBACK(action_paste), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Delete",   G_CALLBACK(action_delete), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), gtk_separator_menu_item_new());

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Find",      G_CALLBACK(action_find), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Find Next", G_CALLBACK(action_find_next), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Replace",   G_CALLBACK(action_replace), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Go To",     G_CALLBACK(action_go_to), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), gtk_separator_menu_item_new());

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Select All", G_CALLBACK(action_select_all), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), menu_item("Time/Date",  G_CALLBACK(action_time_date), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu), gtk_separator_menu_item_new());

  // Backup toggle (you requested: option in Edit menu to turn off backup)
  gtk_menu_shell_append(GTK_MENU_SHELL(edit_menu),
    check_menu_item("Create .backup when unsaved", TRUE, G_CALLBACK(toggle_backups), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(menubar), edit_root);

  /* View */
  GtkWidget *view_menu = gtk_menu_new();
  GtkWidget *view_root = gtk_menu_item_new_with_label("View");
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(view_root), view_menu);

  gtk_menu_shell_append(GTK_MENU_SHELL(view_menu),
    check_menu_item("Status Bar", TRUE, G_CALLBACK(toggle_status_bar), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(view_menu),
    check_menu_item("Word Wrap", FALSE, G_CALLBACK(toggle_word_wrap), s));
  gtk_menu_shell_append(GTK_MENU_SHELL(view_menu),
    check_menu_item("Line Numbering", TRUE, G_CALLBACK(toggle_line_numbers), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(menubar), view_root);

  /* Help */
  GtkWidget *help_menu = gtk_menu_new();
  GtkWidget *help_root = gtk_menu_item_new_with_label("Help");
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(help_root), help_menu);

  gtk_menu_shell_append(GTK_MENU_SHELL(help_menu), menu_item("About", G_CALLBACK(action_about), s));

  gtk_menu_shell_append(GTK_MENU_SHELL(menubar), help_root);

  return menubar;
}

/* ---------- App init ---------- */

static void on_window_destroy(GtkWidget *w, gpointer user_data) {
  (void)w;
  AppState *s = (AppState*)user_data;

  if (s->backup_timeout_id) {
    g_source_remove(s->backup_timeout_id);
    s->backup_timeout_id = 0;
  }

  free_and_null(&s->current_path);
  free_and_null(&s->backup_path);
  free_and_null(&s->last_find);

  g_free(s);
}

static void app_activate(GtkApplication *app, gpointer user_data) {
  (void)user_data;

  AppState *s = g_new0(AppState, 1);
  s->app = app;

  s->show_status_bar = TRUE;
  s->word_wrap = FALSE;
  s->show_line_numbers = TRUE;
  s->backups_enabled = TRUE;

  s->win = gtk_application_window_new(app);
  gtk_window_set_default_size(GTK_WINDOW(s->win), 900, 600);

  // Main layout
  GtkWidget *root = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
  gtk_container_add(GTK_CONTAINER(s->win), root);

  // Menubar
  s->menubar = build_menubar(s);
  gtk_box_pack_start(GTK_BOX(root), s->menubar, FALSE, FALSE, 0);

  // Text editor
  s->buffer = GTK_SOURCE_BUFFER(gtk_source_buffer_new(NULL));
  s->view = GTK_SOURCE_VIEW(gtk_source_view_new_with_buffer(s->buffer));
  gtk_source_view_set_show_line_numbers(s->view, TRUE);

  s->scroller = gtk_scrolled_window_new(NULL, NULL);
  gtk_container_add(GTK_CONTAINER(s->scroller), GTK_WIDGET(s->view));
  gtk_box_pack_start(GTK_BOX(root), s->scroller, TRUE, TRUE, 0);

  // Status bar box
  s->status_bar_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 8);
  gtk_widget_set_margin_start(s->status_bar_box, 8);
  gtk_widget_set_margin_end(s->status_bar_box, 8);
  gtk_widget_set_margin_top(s->status_bar_box, 4);
  gtk_widget_set_margin_bottom(s->status_bar_box, 4);

  s->pos_label = gtk_label_new("Ln 1, Col 1");
  s->state_label = gtk_label_new("Saved");

  gtk_box_pack_start(GTK_BOX(s->status_bar_box), s->pos_label, FALSE, FALSE, 0);
  gtk_box_pack_end(GTK_BOX(s->status_bar_box), s->state_label, FALSE, FALSE, 0);

  gtk_box_pack_end(GTK_BOX(root), s->status_bar_box, FALSE, FALSE, 0);

  apply_view_settings(s);
  update_title(s);
  update_status(s);

  // Buffer signals
  g_signal_connect(s->buffer, "mark-set", G_CALLBACK(on_mark_set), s);
  g_signal_connect(s->buffer, "modified-changed", G_CALLBACK(on_modified_changed), s);
  g_signal_connect(s->buffer, "changed", G_CALLBACK(on_buffer_changed), s);

  // Cleanup
  g_signal_connect(s->win, "destroy", G_CALLBACK(on_window_destroy), s);

  gtk_widget_show_all(s->win);
}

int main(int argc, char **argv) {
  GtkApplication *app = gtk_application_new("com.example.SuperNotepad", G_APPLICATION_DEFAULT_FLAGS);
  g_signal_connect(app, "activate", G_CALLBACK(app_activate), NULL);

  int status = g_application_run(G_APPLICATION(app), argc, argv);
  g_object_unref(app);
  return status;
}