package engine

import (
	"encoding/gob"
	"fmt"
	"image"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
)

var (
	_ interface {
		Drawer
		Hider
	} = &PerfDisplay{}

	_ interface {
		Drawer
		Hider
		Updater
	} = &DebugToast{}
)

func init() {
	gob.Register(&DebugToast{})
	gob.Register(&PerfDisplay{})
}

// DebugToast debugprints a string for a while, then disappears.
type DebugToast struct {
	ID
	Hides
	Pos   image.Point
	Timer int // ticks
	Text  string
}

func (d *DebugToast) Draw(screen *ebiten.Image, _ *ebiten.DrawImageOptions) {
	ebitenutil.DebugPrintAt(screen, d.Text, d.Pos.X, d.Pos.Y)
}

// Draw last.
func (DebugToast) DrawAfter(x Drawer) bool {
	switch x.(type) {
	case *DebugToast, PerfDisplay:
		return false
	}
	return true
}

func (DebugToast) DrawBefore(x Drawer) bool {
	return false
}

func (d *DebugToast) String() string {
	return fmt.Sprintf("DebugToast@%v", d.Pos)
}

func (d *DebugToast) Toast(text string) {
	d.Text = text
	d.Timer = 120
	d.Hides = false
}

func (d *DebugToast) Update() error {
	if d.Hides = d.Timer <= 0; !d.Hides {
		d.Timer--
	}
	return nil
}

// PerfDisplay debugprints CurrentTPS and CurrentFPS in the top left.
type PerfDisplay struct {
	Hides
}

func (p PerfDisplay) Draw(screen *ebiten.Image, _ *ebiten.DrawImageOptions) {
	ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f  FPS: %0.2f", ebiten.CurrentTPS(), ebiten.CurrentFPS()))
}

// Draw last.
func (PerfDisplay) DrawAfter(x Drawer) bool {
	switch x.(type) {
	case *DebugToast, PerfDisplay:
		return false
	}
	return true
}

func (PerfDisplay) DrawBefore(Drawer) bool {
	return false
}

func (PerfDisplay) String() string { return "PerfDisplay" }