Turtle

Turtle = Class.new();

function Turtle.new.default()
    local self = setmetatable({}, Turtle);
    self.eventListeners = {};

    return self;
end

function Turtle.new.number.number.number.number(x, y, z, f)
    local self = Turtle()
    self.x, self.y, self.z, self.f = x, y, z, f
    return self
end

local function _turn(object, hand, n)
    for i = 1, n do
        turtle["turn" .. hand]();
        object:notify("turned", hand:lower(), i - 1);
    end
end

local function _move(object, move, n, dig, attack)
    for i = n, 1, -1 do
        while not turtle[move]() do
            if not dig(object) then
                if not attack(object) then return i - 1 end
            end
        end
        object:notify("moved", move, i - 1);
    end
end

local function _dig(detect, dig)
    while detect() do
        dig()
        if not (dig == turtle.digDown) then
            sleep(0.5)
        end
    end
end

function Turtle:forward(n)
    _move(self, "forward", n or 1, turtle.dig, turtle.detect, turtle.attack);
end

function Turtle:up(n)
    _move(self, "up", n or 1, turtle.digUp, turtle.detectUp, turtle.attackUp);
end

function Turtle:down(n)
    _move(self, "down", n or 1, turtle.digDown, turtle.detectDown, turtle.attackDown);
end

function Turtle:right(n)
    _turn(self, "Right", n or 1);
end

function Turtle:left(n)
    _turn(self, "Left", n or 1);
end

local function _dig_back(object)
    _turn(object, "Right", 2);
    local success = turtle.dig()
    _turn(object, "Right", 2);
    return success
end

local function _attack_back()
    _turn("Right", 2);
    return turtle.attack()
end

function Turtle:dig()
    _dig(turtle.detect, turtle.dig);
end

function Turtle:digUp()
    _dig(turtle.detectUp, turtle.digUp);
end

function Turtle:digDown()
    _dig(turtle.detectDown, turtle.digDown);
end

function Turtle:_suck()
    if turtle.suck() or turtle.suckDown() or turtle.suckUp() then
        self:notify("inventoryChanged");
    end
end

function Turtle:back(n)
    _move(self, "back", n or 1, _dig_back, _attack_back)
end

function Turtle:addEventListener(event, listener)
    if not self.eventListeners[event] then
        self.eventListeners[event] = {};
    end

    table.insert(self.eventListeners[event], listener);
end

function Turtle:removeLastListener(event)
    table.remove(self.eventListeners[event], #self.eventListeners[event] - 1);
end

function Turtle:notify(event, ...)
    if (self.eventListeners[event]) then
        for _, v in pairs(self.eventListeners[event]) do
            v(...);
        end
    end
end