package tins2020

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

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

	tool         Tool
	toolChanged  *Events
	speedChanged *Events
	simulation   Animation
}

type GameSpeed string

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

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("anemone", FlowerDescriptor{
		Name:         "Anemone",
		Description:  "A very generic flower that thrives in a temperate climate.",
		IconTemplate: "flower-anemone-%s",
		BuyPrice:     10,
		SellPrice:    3,
		Traits:       NewAnemoneTraits(),
		Unlocked:     true,
	})
	herbarium.Add("loosestrife", FlowerDescriptor{
		Name:         "Loosestrife",
		Description:  "A simple flower that will spread in temperate and wet climates.",
		IconTemplate: "flower-loosestrife-%s",
		BuyPrice:     100,
		SellPrice:    20,
		Traits:       NewLoosestrifeTraits(),
		Unlocked:     false,
	})
	herbarium.Add("coneflower", FlowerDescriptor{
		Name:         "Coneflower",
		Description:  "A beautifull flower that can withstand hotter climates.",
		IconTemplate: "flower-coneflower-%s",
		BuyPrice:     500,
		SellPrice:    100,
		Traits:       NewConeflowerTraits(),
		Unlocked:     false,
	})
	herbarium.Add("tulip", FlowerDescriptor{
		Name:         "Tulip",
		Description:  "A lovely flower that prefers a bit humid and colder climates.",
		IconTemplate: "flower-tulip-%s",
		BuyPrice:     20000,
		SellPrice:    5000,
		Traits:       NewTulipTraits(),
		Unlocked:     false,
	})
	herbarium.Add("ajuga", FlowerDescriptor{
		Name:         "Ajuga",
		Description:  "A flower that is resitant to cold climates and spreads very easily.",
		IconTemplate: "flower-ajuga-%s",
		BuyPrice:     100000,
		SellPrice:    10000,
		Traits:       NewAjugaTraits(),
		Unlocked:     false,
	})
	return &Game{
		Speed:     GameSpeedNormal,
		Balance:   100,
		Terrain:   terrain,
		Herbarium: herbarium,

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

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

func (g *Game) setSpeed(speed GameSpeed) {
	if speed == g.Speed {
		return
	}
	if speed == GameSpeedPaused {
		g.SpeedBeforePause = g.Speed
	}
	g.Speed = speed
	g.speedChanged.Notify(speed)

	switch speed {
	case GameSpeedPaused:
		g.simulation.Pause()
	case GameSpeedNormal:
		g.simulation.SetInterval(simulationInterval)
		g.simulation.Run()
	case GameSpeedFast:
		g.simulation.SetInterval(fastSimulationInterval)
		g.simulation.Run()
	}
}

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.ID, flower.Traits)
				}
			}
		}
		if Sqr32(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) {
	id := g.Terrain.DigFlower(tile)
	desc, ok := g.Herbarium.Find(id)
	if !ok {
		return
	}
	g.Balance += desc.SellPrice
}

func (g *Game) Pause() { g.setSpeed(GameSpeedPaused) }

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.BuyPrice > g.Balance {
		// TODO: notify user of insufficient balance?
		return
	}
	g.Balance -= flower.BuyPrice
	g.Terrain.AddFlower(tile, id, flower.Traits)
}

func (g *Game) Resume() { g.setSpeed(g.SpeedBeforePause) }

func (g *Game) Run() { g.setSpeed(GameSpeedNormal) }

func (g *Game) RunFast() { g.setSpeed(GameSpeedFast) }

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

func (g *Game) SelectShovel() {
	g.selectTool(&ShovelTool{})
}

func (g *Game) SelectResearch() {
	g.Pause()
}

func (g *Game) SpeedChanged() EventHandler { return g.speedChanged }

func (g *Game) TogglePause() {
	if g.Speed == GameSpeedPaused {
		g.Resume()
	} else {
		g.Pause()
	}
}

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)
}