package core

import (
	"errors"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/container"
)

// ServiceNameMainWindow is a name for main window service.
const ServiceNameMainWindow = "core/mainwindow"

var (
	// ErrMainWindow indicates that error appeared somewhere in main window service.
	ErrMainWindow = errors.New("main window service")
	// ErrMainWindowIsInvalid indicates that main window service implementation is invalid.
	ErrMainWindowIsInvalid = errors.New("main window service implementation is invalid")
)

// MainWindow is an interface for main window service.
type MainWindow interface {
	// AddTab adds tab in main window.
	AddTab(tab *container.TabItem)
	// MainWindow returns main window instance (e.g. for using as parent with dialogs).
	MainWindow() fyne.Window
	// RegisterAboutWindowSysInfoHandler registers handler for System Info tab in About dialog.
	RegisterAboutWindowSysInfoHandler(name string, hndl SysInfoHandler) error
}

// SysInfoHandler is a function signature for registering with additional system information handler for About dialog.
// It should return valid markdown and should end with "\n".
type SysInfoHandler func() string