package stone

import "image"
import "image/color"

// Application represents an application.
type Application struct {
	DamageBuffer
	
	title string
	icons []image.Image
	backend Backend
	config Config
}

// Run initializes the application, starts it, and then returns a channel that
// broadcasts events. If no suitable backend can be found, an error is returned.
func (application *Application) Run () (
	channel chan(Event),
	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.fontName = ""
	application.config.fontSize = 11
	
	application.config.padding = 2

	application.backend, err = instantiateBackend(application)
	if err != nil { return }
	
	channel = make(chan(Event))
	go application.backend.Run(channel)

	return
}

// Draw "commits" changes made in the buffer to the display.
func (application *Application) Draw () {
	application.backend.Draw()
}

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

	return 
}

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

// SetIcon takes in a list of different sizes of an icon, and sets it as the
// application's icon.
func (application *Application) SetIcon (sizes []image.Image) (err error) {
	application.icons = sizes
	if application.backend != nil {
		err = application.backend.SetIcon(sizes)
	}

	return
}

// Icon returns all available sizes of the application's icon. If there is no
// icon, nil is returned.
func (application *Application) Icon () (sizes []image.Image) {
	sizes = application.icons
	return
}

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