package scenes

import (
	_ "image/jpeg"
	_ "image/png"
	"log"

	"github.com/go-gl/mathgl/mgl64"
	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
)

const (
	Gravity     = 0.5
	JumpForce   = -10.0
	MoveSpeed   = 4.0
	FloorHeight = 500.0
)

type Player struct {
	Pos mgl64.Vec3 // 3D Kordinater: X (vänster/höger), Y (upp/ner), Z (djup)
	Vel mgl64.Vec3 // Hastighet

	Width, Height float64 // För (AABB)

	Sprite *ebiten.Image
}

type PlayScene struct {
	player      Player
	groundImg   *ebiten.Image
	isGrounded  bool
}

func NewPlayScene() *PlayScene {
	pImg, _, err := ebitenutil.NewImageFromFile("assets/images/player.jpg")
	if err != nil {
		log.Println("Kunde inte ladda spelar-sprite:", err)
		// Fallback till en tom bild ifall bilden saknas
		pImg = ebiten.NewImage(32, 32) 
	}

	gImg, _, err := ebitenutil.NewImageFromFile("assets/images/ground.jpg")
	if err != nil {
		log.Println("Kunde inte ladda mark-sprite:", err)
		gImg = ebiten.NewImage(800, 100)
	}

	w, h := pImg.Bounds().Dx(), pImg.Bounds().Dy()

	return &PlayScene{
		player: Player{
			Pos:    mgl64.Vec3{400.0, 100.0, 0.0},
			Vel:    mgl64.Vec3{0, 0, 0},
			Width:  float64(w),
			Height: float64(h),
			Sprite: pImg,
		},
		groundImg: gImg,
	}
}

func (s *PlayScene) Update() error {
	// === Input (X axis) ===
	s.player.Vel[0] = 0 // Återställ rörelse varje frame

	if ebiten.IsKeyPressed(ebiten.KeyLeft) || ebiten.IsKeyPressed(ebiten.KeyA) {
		s.player.Vel[0] = -MoveSpeed
	}
	if ebiten.IsKeyPressed(ebiten.KeyRight) || ebiten.IsKeyPressed(ebiten.KeyD) {
		s.player.Vel[0] = MoveSpeed
	}

	// === Hoppa (Y axis) ===
	if (ebiten.IsKeyPressed(ebiten.KeyUp) || ebiten.IsKeyPressed(ebiten.KeySpace)) && s.isGrounded {
		s.player.Vel[1] = JumpForce
		s.isGrounded = false
	}

	// === Fysik / Euler integrering ===
	// 1. Applicera gravitation
	if !s.isGrounded {
		s.player.Vel[1] += Gravity
	}

	// 2. Applicera Velocity till Position
	s.player.Pos = s.player.Pos.Add(s.player.Vel)

	// === "Kollision" med golvet (väldigt simpel 2D-kollision för att simulera ytan på the floor på 2D-skärmen) ===
	if s.player.Pos[1]+s.player.Height >= FloorHeight {
		s.player.Pos[1] = FloorHeight - s.player.Height
		s.player.Vel[1] = 0
		s.isGrounded = true
	} else {
		s.isGrounded = false
	}

	return nil
}

func (s *PlayScene) Draw(screen *ebiten.Image) {
	// === 3D -> 2D Rendering Pipeline (Side View mode) ===
	
	// Rita bakgrund/mark (Väldigt statiskt i det här fallet)
	gOp := &ebiten.DrawImageOptions{}
	gOp.GeoM.Translate(0, FloorHeight)
	screen.DrawImage(s.groundImg, gOp)

	// Rita Spelaren baserat på dess 3D-kordinater översatta till (X, Y) på 2D-skärmen (vi skippar Z i denna view)
	pOp := &ebiten.DrawImageOptions{}
	pOp.GeoM.Translate(s.player.Pos[0], s.player.Pos[1])
	screen.DrawImage(s.player.Sprite, pOp)

	ebitenutil.DebugPrint(screen, "Spelar Scene: SIDOVY. Styr med PILAR och Space.")
}