Computercraft turtle dig_room

local tArgs = { ... }
if #tArgs ~= 3 then
        print( "Usage: dig_roomV2 <Width><Length><0/1>" )
        return
end

local goTo
local checkFuel
local chackInv

local width    = tonumber( tArgs[1] )
local length    = tonumber( tArgs[2] )
local DIRECT    = tonumber( tArgs[3] )
if width < 1 then
    print( "X size must be positive" )
    return
end
if length < 1 then
    print( "Depth must be positive" )
    return
end
if DIRECT ~= 0 and DIRECT ~= 1 then
    print( "Direct left = 0, right = 1" )
    return
end

local xPos = 0
local yPos = 0
local xDir = 1
local yDir = 0

local function checkInv()
    if turtle.getItemCount(16) > 0 then
        buf_x, buf_y, buf_xDir, buf_yDir = xPos, yPos, xDir, yDir
        goTo(0, 0, -1, 0)
        dropItems()
        goTo(buf_x, buf_y, buf_xDir, buf_yDir)
        return true
    end
    return false
end

local function checkFuel()
    if turtle.getFuelLevel() == 0 then
        print("Low fuel, wait fuel...")
        while turtle.getFuelLevel() == 0 do
            turtle.refuel()
            sleep(1)
        end
    end
end

local function dig(noCenter)
    while turtle.detectUp() do turtle.digUp() end
    checkInv()
    while turtle.detect() and not noCenter do turtle.dig() end
    checkInv()
    turtle.digDown()
    checkInv()
end

local function forward()
    if not turtle.forward() then
        checkFuel()
        turtle.attack()
        return false
    end
    xPos = xPos + xDir
    yPos = yPos + yDir
    -- print(xPos, yPos, xDir, yDir)
    return true
end

local function turnRight()
    if not turtle.turnRight() then
        checkFuel()
        turtle.attack()
        return false
    end
    xDir, yDir = -yDir, xDir
    return true
end

local function turnLeft()
    if not turtle.turnLeft() then
        checkFuel()
        turtle.attack()
        return false
    end
    xDir, yDir = yDir, -xDir
    return true
end

function fastTurn(xd, yd)
    local turnsLeft = 0
    local turnsRight = 0
    local buf_xDir = xDir
    local buf_yDir = yDir
    while buf_xDir ~= xd or buf_yDir ~= yd do
        buf_xDir, buf_yDir = buf_yDir, -buf_xDir
        turnsLeft = turnsLeft + 1
    end
    buf_xDir = xDir
    buf_yDir = yDir
    while buf_xDir ~= xd or buf_yDir ~= yd do
        buf_xDir, buf_yDir = -buf_yDir, buf_xDir
        turnsRight = turnsRight + 1
    end
    if turnsRight < turnsLeft then
        return true
    else
        return false
    end
end

function goTo(x, y, xd, yd)
    if x > xPos then
        turn = fastTurn(1, 0)
        while xDir ~= 1 do
            if turn then
                turnRight()
            else
                turnLeft()
            end
        end
        while xPos ~= x do
            forward()
        end
        --------------------------------
        if y > yPos then
            turn = fastTurn(0, 1)
            while yDir ~= 1 do
                if turn then
                    turnRight()
                else
                    turnLeft()
                end
            end
            while yPos ~= y do
                forward()
            end
        else
            turn = fastTurn(0, -1)
            while yDir ~= -1 do
                if turn then
                    turnRight()
                else
                    turnLeft()
                end
            end
            while yPos ~= y do
                forward()
            end
        end
    else
        if y > yPos then
            turn = fastTurn(0, 1)
            while yDir ~= 1 do
                if turn then
                    turnRight()
                else
                    turnLeft()
                end
            end
            while yPos ~= y do
                forward()
            end
        else
            turn = fastTurn(0, -1)
            while yDir ~= -1 do
                if turn then
                    turnRight()
                else
                    turnLeft()
                end
            end
            while yPos ~= y do
                forward()
            end
        end
        --------------------------------
        turn = fastTurn(-1, 0)
        while xDir ~= -1 do
            if turn then
                turnRight()
            else
                turnLeft()
            end
        end
        while xPos ~= x do
            forward()
        end
    end
    --------------------------------
    turn = fastTurn(xd, yd)
    while xDir ~= xd or yDir ~= yd  do
        if turn then
            turnRight()
        else
            turnLeft()
        end
    end
end

function dropItems()
    local i = 1
    while i <= 16 do
        turtle.select(i)
        turtle.drop()
        i = i + 1
    end
    turtle.select(1)
    return true
end

Inc = 0
turnEd = false
while Inc < length do
    Jinc = 0
    while Jinc < width-1 do
        -- print(Inc, Jinc)
        dig()
        forward()
        Jinc = Jinc + 1
    end
    Inc = Inc + 1
    if Inc == length then
        dig(true)
        break
    end
    if not turnEd then
        if DIRECT == 0 then
            turnLeft()
            dig()
            forward()
            turnLeft()
        else
            turnRight()
            dig()
            forward()
            turnRight()
        end
        turnEd = true
    else
        if DIRECT ~= 0 then
            turnLeft()
            dig()
            forward()
            turnLeft()
        else
            turnRight()
            dig()
            forward()
            turnRight()
        end
        turnEd = false
    end
end

goTo(0,0,-1,0)
dropItems()
turnRight()
turnRight()