Dig

curPos = {
    x = 0,
    y = 0,
    z = 0,
    rot = 0
}

function Forward(num)
    local i = 0

    while i < num do
        if curPos.rot == 0 then
            if turtle.forward() then
                curPos.z = curPos.z + 1
            end
        elseif curPos.rot == 180 then
            if turtle.forward() then
                curPos.z = curPos.z - 1
            end
        elseif curPos.rot == -90 then
            if turtle.forward() then
                curPos.x = curPos.x - 1
            end
        elseif curPos.rot == 90 then
            if turtle.forward() then
                curPos.x = curPos.x + 1
            end
        end
        i = i + 1
    end
end

function Up(num)
    local i = 0

    while i < num do
        if turtle.up() then
            curPos.y = curPos.y + 1
        end
        i = i + 1
    end
end

function Down(num)
    local i = 0

    while i < num do
        if turtle.down() then
            curPos.y = curPos.y - 1
        end
        i = i + 1
    end
end

function RotateLeft(num)
    local i = 0

    while i < num do
        if turtle.turnLeft() then
            curPos.rot = curPos.rot - 90
        end
        if curPos.rot == -180 then
            curPos.rot = 180
        end
        i = i + 1
    end
end

function RotateRight(num)
    local i = 0

    while i < num do
        if turtle.turnRight() then
            curPos.rot = curPos.rot + 90
        end
        if curPos.rot > 180 then
            curPos.rot = -90
        end
        i = i + 1
    end
end

function ReturnHome()
    while curPos.x ~= 0 do
        if curPos.x > 0 then
            if curPos.rot ~= -90 then
                RotateLeft(1)
            else
                Forward(curPos.x)
            end
        elseif curPos.x < 0 then
            if curPos.rot ~= 90 then
                RotateRight(1)
            else
                Forward(curPos.x)
            end
        end
    end

    while curPos.y ~= 0 do
        if curPos.y > 0 then
            Down(curPos.y)
        elseif curPos.y < 0 then
            Up(curPos.y)
        end
    end

    while curPos.z ~= 0 do
        if curPos.z > 0 then
            if curPos.rot ~= 180 then
                RotateLeft(1)
            else
                Forward(curPos.z)
            end
        elseif curPos.z < 0 then
            if curPos.rot ~= 0 then
                RotateRight(1)
            else
                Forward(curPos.z)
            end
        end
    end

    RotateLeft(2)
end

function Dig(UpDownOnly)
    turtle.digUp()
    turtle.digDown()
    if not UpDownOnly then
        turtle.dig()
    end
end

function FuelCheck(x, y, z)
    if turtle.getFuelLevel() < x*y*z then
        print("Turtle needs atleast " .. x*y*z .. " more fuel")
        while turtle.getFuelLevel() < x*y*z do
            turtle.refuel()
            sleep(1)
        end
    end
end

function Clear(x, y, z)
    FuelCheck(x, y, z)

    Up(1)
    Dig()
    Digging = true
    while Digging do
        Forward(1)
        Dig(false)

        if curPos.x == x and curPos.z == z and CurPos.y == y then
            ReturnHome()
        elseif curPos.x == x and curPos.z == z then
            ReturnHome()
            RotateLeft(2)
            Up(1)
            Dig(true)
            Up(1)
            Dig(false)
        elseif curPos.x == x then
            RotateLeft(1)
            Dig(false)
            Forward(1)
            RotateLeft(1)
            Dig(false)
        elseif curPos.x == 0 then
            RotateRight(1)
            Dig(false)
            Forward(1)
            RotateRight(1)
            Dig(false)
        end
    end
end

Clear(60, 20, 60)