// gtk.wren  (GTK3 bindings)

foreign class Gtk {
  foreign static init_()
  foreign static run_()
  foreign static quit_()

  static init() { init_() }
  static run()  { run_() }
  static quit() { quit_() }
}

foreign class Window {
  // Allocated on the C side; init_ configures the GtkWindow
  construct new(title, width, height) {
    init_(title, width, height)
  }

  // --- foreigns ---
  foreign init_(title, width, height)
  foreign setTitle(title)
  foreign setDefaultSize(width, height)
  foreign add(child)
  foreign showAll()

  // DO NOT declare "foreign onDestroy(_)" here; that would collide with the wrapper below.
  foreign onDestroy_(fn)

  // --- wrappers with validation ---
  onDestroy(fn) {
    if (!(fn is Fn) || fn.arity != 0) Fiber.abort("onDestroy expects Fn with arity 0")
    onDestroy_(fn)
  }
}

foreign class Box {
  // Two convenience constructors mapping to distinct foreign inits
  construct vbox(spacing) { vbox_(spacing) }
  construct hbox(spacing) { hbox_(spacing) }

  // --- foreigns ---
  foreign vbox_(spacing)
  foreign hbox_(spacing)
  foreign packStart(child, expand, fill, padding)
}

foreign class Button {
  construct new(label) { init_(label) }

  // --- foreigns ---
  foreign init_(label)
  foreign setLabel(label)

  // Distinct foreign name to avoid colliding with the wrapper
  foreign onClicked_(fn)

  // --- wrapper ---
  onClicked(fn) {
    if (!(fn is Fn) || fn.arity != 0) Fiber.abort("onClicked expects Fn with arity 0")
    onClicked_(fn)
  }
}

foreign class Entry {
  construct new() { init_() }

  // --- foreigns ---
  foreign init_()
  foreign setText(text)
  foreign text
  foreign onActivate_(fn)
  foreign onChanged_(fn)

  // --- wrappers ---
  onActivate(fn) {
    if (!(fn is Fn) || fn.arity != 0) Fiber.abort("onActivate expects Fn with arity 0")
    onActivate_(fn)
  }
  onChanged(fn) {
    if (!(fn is Fn) || fn.arity != 0) Fiber.abort("onChanged expects Fn with arity 0")
    onChanged_(fn)
  }
}

foreign class Label {
  construct new(text) { init_(text) }

  // --- foreigns ---
  foreign init_(text)
  foreign setText(text)
}