fn clear() {
	JS.console.clear()
}

const w = 30
const h = 30

fn get(game [][]bool, x int, y int) bool {
	if y < 0 || x < 0 {
		return false
	}
	if y >= h || x >= w {
		return false
	}

	return game[y][x]
}

fn neighbours(game [][]bool, x int, y int) int {
	mut count := 0
	if get(game, x - 1, y - 1) {
		count++
	}
	if get(game, x, y - 1) {
		count++
	}
	if get(game, x + 1, y - 1) {
		count++
	}
	if get(game, x - 1, y) {
		count++
	}
	if get(game, x + 1, y) {
		count++
	}
	if get(game, x - 1, y + 1) {
		count++
	}
	if get(game, x, y + 1) {
		count++
	}
	if get(game, x + 1, y + 1) {
		count++
	}
	return count
}

fn step(game [][]bool) [][]bool {
	mut new_game := [][]bool{}
	for y, row in game {
		mut new_row := []bool{}
		new_game[y] = new_row
		for x, cell in row {
			count := neighbours(game, x, y)
			new_row[x] = (cell && count in [2, 3]) || count == 3
		}
	}
	return new_game
}

fn row_str(row []bool) string {
	mut str := ''
	for cell in row {
		if cell {
			str += '◼ '
		} else {
			str += '◻ '
		}
	}
	return str
}

fn show(game [][]bool) {
	clear()
	for row in game {
		println(row_str(row))
	}
}

// TODO: Remove `fn main` once vet supports scripts
fn main() {
	mut game := [][]bool{len: h, init: []bool{len: w}}

	game[11][15] = true
	game[11][16] = true
	game[12][16] = true
	game[10][21] = true
	game[12][20] = true
	game[12][21] = true
	game[12][22] = true

	JS.setInterval(fn () {
		show(game)
		game = step(game)
	}, 500)
}
