// Copyright 2019 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package driver

import (
	"errors"
	"image"
)

type UIContext interface {
	Update(afterFrameUpdate func()) error
	Layout(outsideWidth, outsideHeight float64)
	AdjustPosition(x, y float64) (float64, float64)
}

// RegularTermination represents a regular termination.
// Run can return this error, and if this error is received,
// the game loop should be terminated as soon as possible.
var RegularTermination = errors.New("regular termination")

type UI interface {
	Run(width, height int, scale float64, title string, context UIContext, graphics Graphics) error
	RunWithoutMainLoop(width, height int, scale float64, title string, context UIContext, graphics Graphics) <-chan error

	DeviceScaleFactor() float64
	CursorMode() CursorMode
	IsFullscreen() bool
	IsRunnableInBackground() bool
	IsVsyncEnabled() bool
	IsWindowDecorated() bool
	IsWindowResizable() bool
	ScreenSizeInFullscreen() (int, int)
	WindowPosition() (int, int)
	IsScreenTransparent() bool
	MonitorPosition() (int, int)
	CanHaveWindow() bool // TODO: Create a 'Widnow' interface.

	SetCursorMode(mode CursorMode)
	SetFullscreen(fullscreen bool)
	SetRunnableInBackground(runnableInBackground bool)
	SetVsyncEnabled(enabled bool)
	SetWindowDecorated(decorated bool)
	SetWindowIcon(iconImages []image.Image)
	SetWindowResizable(resizable bool)
	SetWindowTitle(title string)
	SetWindowPosition(x, y int)
	SetWindowSize(width, height int)
	SetScreenTransparent(transparent bool)

	Input() Input
}