--[[
        DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

        Copyright (C) 2019 Yui <notyui@yui.pet>

        Everyone is permitted to copy and distribute verbatim or modified
        copies of this license document, and changing it is allowed as long
        as the name is changed.

                    DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
        TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

        0. You just DO WHAT THE FUCK YOU WANT TO.
]]--

local LEFT = 1
local RIGHT = 0

-- CONFIG START --

local end_pos = {
    x = 17,
    y = 60,
    z = 17
}

local direction = LEFT

--- CONFIG END ---

local pos = {
    x = 0,
    y = 0,
    z = 0
}

function move_forward(steps)
    for i = 1, steps do
        if turtle.detect() then
            turtle.dig()
        end

        turtle.forward()
    end
end

function turn_left()
    turtle.turnLeft()

    move_forward(1)

    turtle.turnLeft()
end

function turn_right()
    turtle.turnRight()

    move_forward(1)

    turtle.turnRight()
end

function dig_layer()
    while pos.z ~= end_pos.z do
        move_forward(end_pos.x - 1)

        pos.z = pos.z + 1
        direction = not direction

        if pos.z ~= end_pos.z then
            if direction then
                turn_left()
            else
                turn_right()
            end
        end
    end
end

function move_down(steps)
    for i = 1, steps do
        if turtle.detectDown() then
            turtle.digDown()
        end

        turtle.down()
    end
end

function main()
    while pos.y ~= end_pos.y do
        dig_layer()

        pos = {x = 0, y = pos.y + 1, z = 0}
        direction = not direction

        if pos.y ~= end_pos.y then
            turtle.turnLeft()
            turtle.turnLeft()

            move_down(1)
        end
    end
end

main()