package zombie

import (
	"bytes"
	"fmt"
	"github.com/hajimehoshi/ebiten/v2"
	"gitlab.com/kbr4/9heroja/collision"
	"gitlab.com/kbr4/9heroja/configuration"
	"gitlab.com/kbr4/9heroja/resources"
	"image"
	"log"
	"math"
	"time"
)

const WalkSpeedMs = 50

var (
	zombieImage *ebiten.Image
	walkTicker  *time.Ticker
)

type Zombie struct {
	step      int
	direction configuration.Direction
	IsWalking bool
	X         float64
	Y         float64
	OffsetX   float64
	OffsetY   float64
	IsDead    bool
	TargetX   float64
	TargetY   float64
}

type spritePosition struct {
	x int
	y int
}

func (z *Zombie) DrawZombie(screen *ebiten.Image) {

	// set movement positions to be hashmap of sprite positions for each direction

	movementPositions := map[configuration.Direction][]spritePosition{}
	movementPositions[configuration.North] = []spritePosition{
		{0, 0},
		{32, 0},
		{64, 0},
		{96, 0},
	}
	movementPositions[configuration.NorthEast] = movementPositions[configuration.North]
	movementPositions[configuration.East] = movementPositions[configuration.North]
	movementPositions[configuration.SouthEast] = movementPositions[configuration.North]
	movementPositions[configuration.South] = movementPositions[configuration.North]
	movementPositions[configuration.SouthWest] = movementPositions[configuration.North]
	movementPositions[configuration.West] = movementPositions[configuration.North]
	movementPositions[configuration.NorthWest] = movementPositions[configuration.North]

	p := movementPositions[z.direction][z.step%4]

	op := &ebiten.DrawImageOptions{}
	op.GeoM.Reset()
	op.GeoM.Translate(z.X+z.OffsetX, z.Y+z.OffsetY)
	op.GeoM.Scale(1, 1)
	// Apply red tint if the zombie is dead
	if z.IsDead {
		op.ColorScale.Scale(1, 0, 0, 1) // Scale the red channel up, green and blue down.
	}
	screen.DrawImage(zombieImage.SubImage(image.Rect(p.x+1, p.y, p.x+resources.ZombieTileSize, p.y+resources.HeroTileSize)).(*ebiten.Image), op)
}

func init() {
	img, _, err := image.Decode(bytes.NewReader(resources.Zombie_png))
	if err != nil {
		log.Fatal(err)
	}
	zombieImage = ebiten.NewImageFromImage(img)
	walkTicker = time.NewTicker(WalkSpeedMs * time.Millisecond)
	// go routine that runs on every tick and increases step

}

func NewZombie() *Zombie {
	zombie := &Zombie{
		step:      0,
		IsWalking: false,
		IsDead:    false,
	}

	go func() {
		for {
			select {
			case <-walkTicker.C:
				if zombie.IsWalking {
					zombie.step++
					if zombie.step > 3 {
						zombie.step = 0
					}

					zombie.Move()
				}
			}
		}
	}()
	return zombie
}

func (z *Zombie) Walk() {

	if !z.IsWalking {
		walkTicker.Reset(WalkSpeedMs * time.Millisecond)
		z.IsWalking = true

	}

}

func (z *Zombie) ChangeDirection(d configuration.Direction) {
	if d != configuration.PreviouslyHeld {
		z.direction = d
	}
}

func (z *Zombie) Stop() {
	z.step = 2
	z.IsWalking = false
}

func (z *Zombie) CollisionShape() collision.Polygon {
	if !z.IsDead {
		return collision.Polygon{
			Points: []collision.Point{
				{X: z.X + z.OffsetX, Y: z.Y + z.OffsetY},
				{X: z.X + z.OffsetX + 32, Y: z.Y + z.OffsetY},
				{X: z.X + z.OffsetX + 32, Y: z.Y + z.OffsetY + 32},
				{X: z.X + z.OffsetX, Y: z.Y + z.OffsetY + 32},
			},
		}
	} else {
		return collision.Polygon{
			Points: []collision.Point{},
		}
	}
}

func (z *Zombie) CollisionObjectType() collision.ObjectType {
	return collision.Zombie
}

func (z *Zombie) HandleCollisionEvent(other collision.Collidable) {
	coll := other.CollisionObjectType()
	switch coll {
	case collision.Hero:
		z.Stop()
		z.IsDead = true
	case collision.Bullet:
		fmt.Println("Zombie hit by bullet")
		z.Stop()
		z.IsDead = true
	}
}

func (z *Zombie) Move() {
	fmt.Printf("Zombie target: %f, %f\n", z.TargetX, z.TargetY)
	directionX := (z.TargetX - z.X) / math.Abs(z.TargetX+z.X)
	directionY := (z.TargetY - z.Y) / math.Abs(z.TargetY+z.Y)
	z.X += directionX
	z.Y += directionY
}