Turtle

local function GoUp()
    turtle.digUp();
    turtle.up();
end

local function GoDown()
    turtle.digDown();
    turtle.down();
end

local function GoLeft()
    turtle.turnLeft();
    turtle.dig();
    turtle.forward();
    turtle.turnRight();
end

local function GoRight()
    turtle.turnRight();
    turtle.dig();
    turtle.forward();
    turtle.turnLeft();
end

local function PlaceTorch()
    turtle.select(1);
    turtle.placeDown();
end

local direction = true; -- true = same as start, false = opposite
local turnBool = true; -- False go left, True go right

local function TurnAround()
    turtle.turnLeft();
    turtle.turnLeft();
    direction = not direction;
end

local function GoToStart(length, width, height, startDirection)
    for i = 1, height do
        if i ~= height then
            GoDown();
        end
    end

    for i = 1, width do
        if i ~= width then
            GoLeft();
        end
    end

    if direction == true then -- True = same as start
        for i = 1, length do
            if i ~= length then
                turtle.back();
            end
        end
    end
end

local function checkFuel(length, width, height)
    local neededFuel = (length * 2 * width) * (height * 2);
    if turtle.getFuelLevel() < neededFuel then
        turtle.select(2);
        if turtle.refuel() ~= false then
            turtle.refuel();
            print("Success! Fuel level is " .. turtle.getFuelLevel() .. ". Starting mining...");
        else
            term.clear();
            print("Unable to refuel,\nCurrent fuel is " .. turtle.getFuelLevel() .. "\nNeeded fuel is " .. neededFuel ..
                      "\nPlease fill slot 2 with at least " .. ((neededFuel - turtle.getFuelLevel()) / 80) ..
                      " Coal.\nor at least " .. (neededFuel / 1000) .. " Lava Buckets.");
            checkFuel(length, width, height);
        end
    end
end

local function stripMine(length, width, height)
    local startDirection = turnBool;
    local canStart = false;
    local neededFuel = (length * 2 * width) * (height * 2);

    if turtle.getFuelLevel() < neededFuel then
        checkFuel(length, width, height);
        stripMine(length, width, height);
    else
        for p = 1, height do
            for i = 1, width do -- width
                local t = 0;
                for j = 1, length do -- Length
                    if t == 5 and turnBool == true and p == 2 then
                        PlaceTorch();
                        t = 0;
                    end
                    turtle.dig();
                    turtle.forward();
                    t = t + 1;
                end
                if i ~= width then
                    if turnBool == true then
                        GoRight();
                    elseif turnBool == false then
                        GoLeft();
                    end
                    turnBool = not turnBool;
                end
                TurnAround();
            end
            print("New direction: " .. tostring(turnBool) .. " - False left, True right");
            if p ~= height then
                GoUp();
            end
        end
        GoToStart(length, width, height, startDirection);
    end
end

stripMine(60, 11, 3);