package stone

import "time"
import "image/color"

// Application represents an application.
type Application struct {
	DamageBuffer
	
	title string
	backend Backend
	config Config
}

// SetSize sets the application's buffer size. This may or may not change the
// size of the window, depending on the backend used.
func (application *Application) SetSize (width, height int) {
	application.DamageBuffer.SetSize(width, height)
}

// SetTitle sets the application's title. If in a window, it will appear as the
// window's name.
func (application *Application) SetTitle (title string) {
	application.title = title
	application.backend.SetTitle(title)
}

// Run initializes the application, and then calls callback. Operations inside
// of callback are allowed to interact with the application. Depending on the
// backend used, this function may bind to the main thread.
func (application *Application) Run (
	callback func (application *Application),
) (
	err error,
) {
	// default values for certain parameters
	width, height := application.Size()
	if width  < 1 { width  = 80 }
	if height < 1 { height = 20 }
	application.DamageBuffer.SetSize(width, height)

	// TODO: load these from a file
	application.config.colors = [4]color.Color {
		color.RGBA { R: 0x2B, G: 0x30, B: 0x3C, A: 0xFF },
		color.RGBA { R: 0x4C, G: 0x56, B: 0x6A, A: 0xFF },
		color.RGBA { R: 0x2E, G: 0x34, B: 0x40, A: 0xFF },
		color.RGBA { R: 0xA8, G: 0x55, B: 0x5D, A: 0xFF },
	}
	
	application.config.padding = 4

	application.backend, err = instantiateBackend(application)
	if err != nil { return }
	application.backend.Run(callback)

	return
}

// Await blocks until an event is recieved, or until the specified timeout has
// elapsed. If the timeout is zero, it will wait forever. This function returns
// true if the backend is still active, and false if it has closed.
func (application *Application) Await (timeout time.Duration) (keepRunning bool) {
	keepRunning = application.backend.Await(timeout)
	return
}

// Poll updates the window and checks for new events. This function returns true
// if the backend is still active, and false if it has closed.
func (application *Application) Poll () (keepRunning bool) {
	keepRunning = application.backend.Poll()
	return
}

// Title returns the application's title.
func (application *Application) Title () (title string) {
	title = application.title
	return
}

// Config returns a pointer to the application's configuration.
func (application *Application) Config () (config *Config) {
	config = &application.config
	return
}

// JustPressed returns true if the specified button is pressed, but was not
// pressed the last time events were checked.
func (application *Application) JustPressed (button Button) (pressed  bool) {
	pressed = application.backend.JustPressed(button)
	return
}

// JustReleased returns true if the specified button
func (application *Application) JustReleased (button Button) (released bool) {
	released = application.backend.JustReleased(button)
	return
}

func (application *Application) Pressed (button Button) (pressed  bool) {
	pressed = application.backend.Pressed(button)
	return
}

func (application *Application) Repeated (button Button) (repeated bool) {
	repeated = application.backend.Repeated(button)
	return
}

func (application *Application) Typed () (text string) {
	text = application.backend.Typed()
	return
}

func (application *Application) Resized () (resized bool) {
	resized = application.backend.Resized()
	return
}

func (application *Application) MousePosition () (x, y int) {
	x, y = application.backend.MousePosition()
	return
}