local x1 = -37;
local y1 = 97;
local z1 = 188;
local x2 = -51;
local y2 = 98;
local z2 = 200;

local xDir = math.abs(x2 - x1);
local yDir = math.abs(y2 - y1);
local zDir = math.abs(z2 - z1);

local movedX = 0;
local movedY = 0;
local movedZ = 0;

local left = true;

function log(message)
    term.write(message);
    local cursorX, cursorY = term.getCursorPos();
    term.setCursorPos(cursorX, cursorY + 1);
end

function isComplete()
    return movedX >= xDir and movedY >= yDir and movedZ >= zDir;
end

function shouldMoveZ()
    return movedX >= xDir;
end

function shouldMoveY()
    return movedZ >= zDir;
end

function moveX()
    if turtle.detect() then
        turtle.dig();
    end

    log("Moving in X direction!");
    checkFuel();
    turtle.forward();

    movedX = movedX + 1;
    if not shouldMoveZ() then
        return;
    end

    moveZ();
end

function moveZ()
    if shouldMoveY() then
        moveY();
        return;
    end

    if left then
        turtle.turnLeft();
    else
        turtle.turnRight();
    end

    if turtle.detect() then
        turtle.dig();
    end

    log("Moving in Z direction!");
    checkFuel();
    turtle.forward();

    movedZ = movedZ + 1;

    if left then
        turtle.turnLeft();
    else
        turtle.turnRight();
    end

    left = not left;
    movedX = 1;
end

function moveY()
    if isComplete() then
        log("Completed!");
        return;
    end

    if turtle.detectUp() then
        log("Digging up!");
        turtle.digUp();
    end

    log("Moving up!");
    checkFuel();
    turtle.moveUp();

    turtle.turnLeft();
    turtle.turnLeft();

    left = not left;

    movedZ = 1;
    movedX = 1;
    movedY = movedY + 1;
end

function checkFuel()
    if turtle.getFuelLevel() > 0 then
        return;
    end

    log("Refuelling!");
    turtle.refuel(1);
end

while not isComplete() do
    moveX();
end