package tins2020

import (
	"log"
	"math/rand"
	"time"
)

type Game struct {
	Balance          int
	Speed            GameSpeed
	SpeedBeforePause GameSpeed
	Herbarium        Herbarium
	Terrain          *Map

	tool        Tool
	toolChanged *Events
	simulation  Animation
}

type GameSpeed string

const (
	GameSpeedNormal GameSpeed = "normal"
	GameSpeedFast             = "fast"
	GameSpeedPaused           = "paused"
)

type Map struct {
	Temp    NoiseMap
	Humid   NoiseMap
	Variant NoiseMap
	PlaceX  NoiseMap // displacement map of props
	PlaceY  NoiseMap

	Flowers map[Point]Flower
}

func (m *Map) AddFlower(pos Point, traits FlowerTraits) {
	m.Flowers[pos] = m.NewFlower(pos, traits)
}

func (m *Map) NewFlower(pos Point, traits FlowerTraits) Flower {
	flower := Flower{
		Traits: traits,
	}
	temp, humid := float32(m.Temp.Value(pos.X, pos.Y)), float32(m.Humid.Value(pos.X, pos.Y))
	flower.Traits.UpdateModifier(temp, humid)
	return flower
}

const simulationInterval = 120 * time.Millisecond
const fastSimulationInterval = 40 * time.Millisecond

func NewGame() *Game {
	terrain := &Map{
		Temp:    NewNoiseMap(rand.Int63()),
		Humid:   NewNoiseMap(rand.Int63()),
		Variant: NewRandomNoiseMap(rand.Int63()),
		PlaceX:  NewRandomNoiseMap(rand.Int63()),
		PlaceY:  NewRandomNoiseMap(rand.Int63()),
		Flowers: map[Point]Flower{},
	}
	herbarium := NewHerbarium()
	herbarium.Add("poppy", FlowerDescriptor{
		Name:         "Poppy",
		Description:  "A very generic flower that thrives in a moderate climate.",
		IconTemplate: "flower-poppy-%s",
		Price:        10,
		Traits:       NewPoppyTraits(),
		Unlocked:     true,
	})
	return &Game{
		Speed:     GameSpeedNormal,
		Balance:   100,
		Terrain:   terrain,
		Herbarium: herbarium,

		toolChanged: NewEvents(),
		simulation:  NewAnimation(time.Millisecond * 10),
	}
}

func (g *Game) selectTool(t Tool) {
	g.tool = t
	g.toolChanged.Notify(t)
}

func (g *Game) tick() {
	randomNeighbor := func(pos Point) Point {
		switch rand.Intn(4) {
		case 0:
			return Pt(pos.X-1, pos.Y)
		case 1:
			return Pt(pos.X, pos.Y-1)
		case 2:
			return Pt(pos.X+1, pos.Y)
		case 3:
			return Pt(pos.X, pos.Y+1)
		}
		return pos
	}
	flowers := map[Point]Flower{}
	for pos, flower := range g.Terrain.Flowers {
		if rand.Float32() < flower.Traits.Spread {
			dst := randomNeighbor(pos)
			if _, ok := g.Terrain.Flowers[dst]; !ok {
				if _, ok := flowers[dst]; !ok {
					flowers[dst] = g.Terrain.NewFlower(dst, flower.Traits)
				}
			}
		}
		if rand.Float32() < flower.Traits.Life*flower.Traits.LifeModifier {
			flowers[pos] = flower
		}
	}
	g.Terrain.Flowers = flowers
}

func (g *Game) CancelTool() {
	g.selectTool(nil)
}

func (g *Game) Dig(tile Point) {
	// TODO: implement
}

func (g *Game) Pause() {
	if g.Speed == GameSpeedPaused {
		return
	}
	g.SpeedBeforePause = g.Speed
	g.Speed = GameSpeedPaused
	g.simulation.Pause()
}

func (g *Game) PlantFlower(id string, tile Point) {
	flower, ok := g.Herbarium.Find(id)
	if !ok {
		log.Println("user was able to plant a flower that doesn't exist")
		return
	}
	if flower.Price > g.Balance {
		// TODO: notify user of insufficient balance?
		return
	}
	g.Balance -= flower.Price
	g.Terrain.AddFlower(tile, flower.Traits)
}

func (g *Game) Resume() {
	switch g.SpeedBeforePause {
	case GameSpeedNormal:
		g.Run()
	case GameSpeedFast:
		g.RunFast()
	}
}

func (g *Game) Run() {
	g.Speed = GameSpeedNormal
	g.simulation.SetInterval(simulationInterval)
	g.simulation.Run()
}

func (g *Game) RunFast() {
	g.Speed = GameSpeedFast
	g.simulation.SetInterval(fastSimulationInterval)
	g.simulation.Run()
}

func (g *Game) SelectPlantFlowerTool(id string) {
	g.selectTool(&PlantFlowerTool{FlowerID: id})
}

func (g *Game) Tool() Tool { return g.tool }

func (g *Game) ToolChanged() EventHandler { return g.toolChanged }

func (g *Game) Update() {
	for g.simulation.Animate() {
		g.tick()
	}
}

func (g *Game) UserClickedTile(pos Point) {
	if g.tool == nil {
		return
	}
	g.tool.ClickedTile(g, pos)
}