package internal

import (
	"fmt"
	"image"
	"image/color"

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

const (
	BaseWidth  = 640
	BaseHeight = 360
)

type Game struct {
	width       int
	height      int
	ball        *ball
	leftPaddle  *paddle
	rightPaddle *paddle
	debug       bool
	img         *ebiten.Image
}

var _ ebiten.Game = (*Game)(nil)

func NewGame(width, height int, debug bool) *Game {
	return &Game{
		width:       width,
		height:      height,
		ball:        newBall(width, height),
		leftPaddle:  newLeftPaddle(width, height, true),
		rightPaddle: newRightPaddle(width, height, false),
		debug:       debug,
	}
}

func (g *Game) Update() error {
	bounds := image.Rect(0, 0, g.width, g.height)

	if err := g.ball.update(bounds); err != nil {
		return fmt.Errorf("couldn't update ball: %w", err)
	}

	if err := g.leftPaddle.update(bounds, g.ball); err != nil {
		return fmt.Errorf("couldn't update left paddle: %w", err)
	}

	if err := g.rightPaddle.update(bounds, g.ball); err != nil {
		return fmt.Errorf("couldn't update right paddle: %w", err)
	}

	return nil
}

var backgroundColor = color.Black

func (g *Game) Draw(screen *ebiten.Image) {
	if g.img == nil {
		g.img = ebiten.NewImage(g.width, g.height)
	}

	g.img.Fill(backgroundColor)

	g.ball.draw(g.img)
	g.leftPaddle.draw(g.img)
	g.rightPaddle.draw(g.img)

	if g.debug {
		g.drawDebug()
	}

	screen.DrawImage(g.img, nil)
}

func (g *Game) drawDebug() {
	ebitenutil.DebugPrint(
		g.img,
		fmt.Sprintf(
			"FPS: %0.2f"+
				"\nBall: x=%v, y=%v, speedX=%v, speedY=%v, radius=%v"+
				"\nLeft paddle: x=%v, y=%v, speed=%v, width=%v, height=%v, isControlledByPlayer=%v"+
				"\nRight paddle: x=%v, y=%v, speed=%v, width=%v, height=%v, isControlledByPlayer=%v",
			ebiten.ActualFPS(),
			g.ball.x,
			g.ball.y,
			g.ball.speedX,
			g.ball.speedY,
			g.ball.r,
			g.leftPaddle.x,
			g.leftPaddle.y,
			g.leftPaddle.speed,
			g.leftPaddle.width,
			g.leftPaddle.height,
			g.leftPaddle.isControlledByPlayer,
			g.rightPaddle.x,
			g.rightPaddle.y,
			g.rightPaddle.speed,
			g.rightPaddle.width,
			g.rightPaddle.height,
			g.rightPaddle.isControlledByPlayer,
		),
	)
}

//nolint:nonamedreturns
func (g *Game) Layout(outsideWidth, outsideHeight int) (_screenWidth, _screenHeight int) {
	if g.width != outsideWidth || g.height != outsideHeight {
		ratioWidth := float32(outsideWidth) / float32(g.width)
		ratioHeight := float32(outsideHeight) / float32(g.height)

		g.ball.resize(ratioWidth, ratioHeight)
		g.leftPaddle.resize(ratioWidth, ratioHeight)
		g.rightPaddle.resize(ratioWidth, ratioHeight)

		if g.img != nil {
			g.img.Dispose()
			g.img = nil
		}

		g.width = outsideWidth
		g.height = outsideHeight
	}

	return outsideWidth, outsideHeight
}