package system

import (
	"image/color"
	_ "image/png"

	"code.rocketnine.space/tslocum/doctorlectro/asset"

	"code.rocketnine.space/tslocum/doctorlectro/component"
	"code.rocketnine.space/tslocum/doctorlectro/world"
	"code.rocketnine.space/tslocum/gohan"
	"github.com/hajimehoshi/ebiten/v2"
)

type WinSystem struct {
	Position *component.Position
	Velocity *component.Velocity
	Player   *component.Player

	op  *ebiten.DrawImageOptions
	img *ebiten.Image
}

func NewWinSystem() *WinSystem {
	s := &WinSystem{
		op:  &ebiten.DrawImageOptions{},
		img: ebiten.NewImage(world.ScreenWidth, world.ScreenHeight),
	}
	s.img.Fill(color.RGBA{0, 0, 0, 255})

	return s
}

func (s *WinSystem) Update(_ gohan.Entity) error {
	if world.GameOverTicks == 0 {
		return nil
	}
	world.GameOverTicks++
	return nil
}

func (s *WinSystem) Draw(e gohan.Entity, screen *ebiten.Image) error {
	if world.GameOverTicks == 0 {
		return nil
	}

	const fadeOutTime = 144 * 3
	var alpha float64
	if world.GameOverTicks < fadeOutTime {
		alpha = float64(world.GameOverTicks) / fadeOutTime
	} else if world.GameOverTicks == fadeOutTime {
		// Draw newspaper
		s.img = asset.ImgNewspaper
		alpha = 0
	} else if world.GameOverTicks >= fadeOutTime*2 {
		alpha = 1
	} else {
		// Fade in newspaper
		alpha = float64(world.GameOverTicks-fadeOutTime) / fadeOutTime
	}

	if world.GameOverTicks >= fadeOutTime {
		screen.Fill(color.RGBA{0, 0, 0, 255})
	}

	s.op.ColorM.Reset()
	s.op.ColorM.Scale(1, 1, 1, alpha)
	screen.DrawImage(s.img, s.op)
	return nil
}