ComputerCraft Turtle Miner

local fuel = turtle.getFuelLevel()
local size = 4
local layers = 1
local y = 0

function mineInFront()
    while turtle.detect() do
        print("Mining In Front")
        turtle.dig()
    end
    turtle.up()
    while turtle.detect() do
        turtle.dig()
        print("Mining In Front(Top)")
    end
    turtle.down()
    while turtle.detect() do
        turtle.dig()
        print("Mining In Front(Bottom)")
    end
end

function mineDown()
    turtle.digDown()
    turtle.down()
    turtle.digDown()
    turtle.down()
        print("Mining Down")
end

function mineCurrent()
    while turtle.detectUp() do
        print("Mining Current(Up)")
        turtle.digUp()
    end
end

function mineLayer()
    for x=1,size,1 do
        for z=2,size,1 do
        print("Mining: ".."Row:"..x.."| Column:"..z)
            mineInFront()
            turtle.forward()
        end
        if x == size then

        elseif x%2==0 then
            turtle.turnLeft()
            mineInFront()
            turtle.forward()
            turtle.turnLeft()
        else
            turtle.turnRight()
            mineInFront()
            turtle.forward()
            turtle.turnRight()
        end
    end
end

function returnToChest()
        print("Returning to chest")
    if size%2==0 then
        turtle.turnRight()
        for i=1,size-1,1 do
            turtle.forward()
        end
        turtle.turnRight()
    else
        turtle.turnLeft()
        for i=1,size,1 do
            turtle.forward()
        end
        turtle.turnLeft()
        for i=1,size-1,1 do
            turtle.forward()
        end
    end
    if y > 0 then
        for i=1,y,1 do
            turtle.up()
        end
    end
end

function dropItems()
        print("Dropping Items")
   turtle.turnLeft()
   turtle.turnLeft()
   for i=1,15,1 do
        turtle.select(i)
        if turtle.compareTo(16) then
            turtle.transferTo(16)
        end
    turtle.drop()
    end
    turtle.select(1)
    turtle.turnLeft()
    turtle.turnLeft()
end

 function fuelUp()
    if fuel < 10 then
        turtle.select(16)
        turtle.refuel()
        turtle.select(1)
    end
end
function getValues()
    print("Size: ")
    size = read()
    print("Layers: ")
    layers = read()
    layers = (layers+1)/2
end

function start()
    getValues()
    print("Starting")
    fuelUp()
    mineCurrent()
    for i=1,layers,1 do
        fuelUp()
        print("Mining Layer: "..i)
        mineLayer()
        returnToChest()
        dropItems()
        if i < layers then
            for i=1,y,1 do
                turtle.down()
            end
            mineDown()
            y = y+2
        end
   end
end

start()