package core

type Environment struct {
	width, height int
	state         map[string][][]float32
	value         [][]bool
	col           [][]bool
}

func (e *Environment) Width() int {
	return e.width
}

func (e *Environment) Height() int {
	return e.height
}

func (e *Environment) InitPheromone(name string) {
	state := make([][]float32, e.width)
	for x := range state {
		state[x] = make([]float32, e.height)
	}
	e.state[name] = state
}

func NewEnvironment(width int, height int) *Environment {
	env := new(Environment)
	env.width = width
	env.height = height
	env.state = make(map[string][][]float32)

	env.col = make([][]bool, width)
	for x := range env.col {
		env.col[x] = make([]bool, height)
	}

	env.value = make([][]bool, width)
	for x := range env.value {
		env.value[x] = make([]bool, height)
	}
	return env
}

func (e *Environment) Mark(pheromone string, x, y int, amount float32) {

	_, exists := e.state[pheromone]
	if !exists {
		e.InitPheromone(pheromone)
	}

	e.state[pheromone][x][y] = e.state[pheromone][x][y] + amount
	if e.state[pheromone][x][y] > 255 {
		e.state[pheromone][x][y] = 255
	}
}

func (e Environment) Occupy(x, y int) {
	e.col[x][y] = true
}

func (e Environment) Check(x, y int) bool {
	return e.col[x][y]
}

func (e Environment) Leave(x, y int) {
	e.col[x][y] = false
}

func (e Environment) HasValue(x, y int) bool {
	return e.value[x][y]
}

func (e Environment) PutValue(x, y int) {
	e.value[x][y] = true
}

func (e Environment) TakeValue(x, y int) {
	e.value[x][y] = false
}

func (e Environment) Sniff(pheromone string, x, y int) float32 {
	return e.state[pheromone][x][y]
}

func (e *Environment) normXY(x int, y int) (int, int) {
	if x < 0 {
		x = (e.width - 1)
	} else if x >= e.width {
		x = x % (e.width)
	}

	if y < 0 {
		y = (e.height - 1)
	} else if y >= e.height {
		y = y % (e.height)
	}

	return x, y
}

func (e *Environment) Evaporate(rate float32, pheromone string) {
	//log.Debugf("Evap")

	_, exists := e.state[pheromone]
	if !exists {
		e.InitPheromone(pheromone)
	}

	pheromoneprev := pheromone + "prev"

	e.state[pheromoneprev] = make([][]float32, e.width)
	for x := range e.state[pheromoneprev] {
		e.state[pheromoneprev][x] = make([]float32, e.height)
	}
	for x := 0; x < e.width; x++ {
		for y := 0; y < e.height; y++ {
			e.state[pheromoneprev][x][y] = e.state[pheromone][x][y] * rate
		}
	}

	pheromoneMap := e.state[pheromoneprev]
	for x := 0; x < e.width; x++ {
		for y := 0; y < e.height; y++ {
			amount := e.state[pheromoneprev][x][y]

			totalAmount := amount + e.sniffNormalized(x-1, y-1, pheromoneMap) + e.sniffNormalized(x, y-1, pheromoneMap) + e.sniffNormalized(x+1, y-1, pheromoneMap) + e.sniffNormalized(x-1, y, pheromoneMap) + e.sniffNormalized(x+1, y, pheromoneMap)
			totalAmount += e.sniffNormalized(x-1, y+1, pheromoneMap) + e.sniffNormalized(x, y+1, pheromoneMap) + e.sniffNormalized(x+1, y+1, pheromoneMap)

			e.state[pheromone][x][y] = totalAmount / 9
		}
	}
}

// Internal optimaization to avoid slow map access
func (e *Environment) sniffNormalized(x int, y int, pheromonemap [][]float32) float32 {
	x, y = e.normXY(x, y)
	return pheromonemap[x][y]
}

func (e *Environment) SniffNormalized(x int, y int, pheromone string) float32 {
	x, y = e.normXY(x, y)
	return e.state[pheromone][x][y]
}