package main

import (
	"fmt"
	"image"
	"image/color"
	"math/rand"
	"sync"
	"time"

	"engo.io/ecs"
	"engo.io/engo"
	"engo.io/engo/common"
)

type DemoScene struct{}

func (*DemoScene) Preload() {}

func (*DemoScene) Setup(u engo.Updater) {
	w, _ := u.(*ecs.World)
	common.SetBackground(color.White)
	w.AddSystem(&common.RenderSystem{})
	w.AddSystem(&FPSLogSystem{})
	w.AddSystem(&SpriteSystem{})
}

func (*DemoScene) Type() string {
	return "demo"
}

type FPSLogSystem struct {
	frames, drawCount int
	ticker            <-chan time.Time
	lock              sync.RWMutex
}

func (f *FPSLogSystem) New(*ecs.World) {
	f.ticker = time.Tick(time.Second)
}

func (f *FPSLogSystem) Update(dt float32) {
	f.frames++
	select {
	case <-f.ticker:
		fmt.Printf("FPS is: %v\n", f.frames)
		f.frames = 0
	default:
	}
}

func (*FPSLogSystem) Remove(e ecs.BasicEntity) {}

type SpriteSystem struct {
	w                   *ecs.World
	textures            []common.Drawable
	spritesheet         *common.Spritesheet
	drawCount, curCount int
}

func (s *SpriteSystem) New(w *ecs.World) {
	s.w = w
	rand.Seed(time.Now().UnixNano())
	engo.Input.RegisterButton("spritesheet", engo.KeyS)
	engo.Input.RegisterButton("lone sprite", engo.KeyA)

	for imgs := 0; imgs < 10; imgs++ {
		img := image.NewNRGBA(image.Rect(0, 0, 25, 25))
		for i := 0; i < 25; i++ {
			for j := 0; j < 25; j++ {
				img.Set(i, j, color.NRGBA{R: uint8(rand.Intn(256)), G: uint8(rand.Intn(256)), B: uint8(rand.Intn(256)), A: 255})
			}
		}
		imgobj := common.NewImageObject(img)
		tex := common.NewTextureSingle(imgobj)
		s.textures = append(s.textures, tex)
	}

	img := image.NewNRGBA(image.Rect(0, 0, 100, 100))
	for i := 0; i < 100; i++ {
		for j := 0; j < 100; j++ {
			img.Set(i, j, color.NRGBA{R: uint8(rand.Intn(256)), G: uint8(rand.Intn(256)), B: uint8(rand.Intn(256)), A: 255})
		}
	}
	imgobj := common.NewImageObject(img)
	tex := common.NewTextureResource(imgobj)
	s.spritesheet = common.NewSpritesheetFromTexture(&tex, 10, 10)
}

type sprite struct {
	ecs.BasicEntity
	common.SpaceComponent
	common.RenderComponent
}

func (s *SpriteSystem) Update(float32) {
	if engo.Input.Button("spritesheet").Down() {
		s.drawCount++
		sp := sprite{BasicEntity: ecs.NewBasic()}
		sp.Position = engo.Point{
			X: rand.Float32() * 800,
			Y: rand.Float32() * 800,
		}
		sp.Rotation = rand.Float32() * 180
		sp.Drawable = s.spritesheet.Drawable(rand.Intn(100))
		for _, system := range s.w.Systems() {
			switch sys := system.(type) {
			case *common.RenderSystem:
				sys.Add(&sp.BasicEntity, &sp.RenderComponent, &sp.SpaceComponent)
			}
		}
	}
	if engo.Input.Button("lone sprite").Down() {
		s.drawCount++
		sp := sprite{BasicEntity: ecs.NewBasic()}
		sp.Position = engo.Point{
			X: rand.Float32() * 800,
			Y: rand.Float32() * 800,
		}
		sp.Rotation = rand.Float32() * 180
		sp.Drawable = s.textures[rand.Intn(len(s.textures))]
		for _, system := range s.w.Systems() {
			switch sys := system.(type) {
			case *common.RenderSystem:
				sys.Add(&sp.BasicEntity, &sp.RenderComponent, &sp.SpaceComponent)
			}
		}
	}
	if s.drawCount != s.curCount {
		s.curCount = s.drawCount
		fmt.Printf("Drawable Count: %v\n", s.curCount)
	}
}

func (*SpriteSystem) Remove(e ecs.BasicEntity) {}

func main() {
	engo.Run(
		engo.RunOptions{
			Width:    800,
			Height:   800,
			FPSLimit: 60,
		},
		&DemoScene{},
	)
}