farm

local blockX = 1
local blocksX = 16
local blocksXSkip = {1,8,9,10}
local blockY = 1
local blocksY = 37

local slotsRef = {14,15,16}
local slotsRefDump = {14}
local slotsSeed = {15,16}
local slotsDump = {5,6,7,8,9,10,11,12,13}

local dirAway = true

local function organizeSpace()
 for countA=1,13 do
  if turtle.getItemCount(countA) > 0 and turtle.getItemCount(countA) < 64 then
   turtle.select(countA)
   for countB=1,countA do
    turtle.transferTo(countB)
   end
  end
 end
end

local function checkSpace()
 local spaceAvail = 0
 for count=1,16 do
  spaceAvail = spaceAvail + turtle.getItemSpace(count)
 end
 return spaceAvail
end

local function moveForward()
 if turtle.getFuelLevel() > 0 then
  if turtle.forward() == false then
   os.sleep(5)
   moveForward()
  end
 else
  while turtle.getFuelLevel() == 0 do
    os.sleep(30)
  end

  if turtle.forward() == false then
   os.sleep(5)
   moveForward()
  end
 end
end

local function isBlockPlantable()
 local isPlantable = true
 for i=1,#blocksXSkip do
  if blockX==blocksXSkip[i] then
   isPlantable=false
  end
 end
 return isPlantable
end

local function selectSlot(slotRef)
 turtle.select(slotRef)
 for count=13,1,-1 do
  if turtle.compareTo(count) == true then
   turtle.select(count)
   return
  end
 end
end

local function plantItem()
 if isBlockPlantable(blockX) then
  turtle.digDown()
  if blockX % 2 == 0 then
   selectSlot(slotsSeed[1])
  else
   selectSlot(slotsSeed[2])
  end
  turtle.placeDown()
 end
end

local function turnRight()
 turtle.turnRight()
 moveForward()
 turtle.turnRight()
end

local function turnLeft()
 turtle.turnLeft()
 moveForward()
 turtle.turnLeft()
end

local function dropItems()
 turtle.down()
 for i=1,#slotsRefDump do
  turtle.select(slotsRefDump[i])
  for j=1,13 do
   if turtle.compareTo(j) then
    turtle.select(j)
    turtle.dropDown()
   end
  end
 end

 organizeSpace()

 for i=1,#slotsDump do
  turtle.select(slotsDump[i])
  turtle.dropDown()
 end
 turtle.up()
end

local function returnToStart()
 if (blockX == 1) and (blockY == 1) then
  dropItems()
 else
  if dirAway == true then
   if blockX > 2 then
    turtle.turnRight()
    turtle.turnRight()
    for count=1,blockX - 1 do
     moveForward()
    end
   end

   if blockY > 1 then
    turtle.turnRight()
    for count=1,blockY - 1 do
     moveForward()
    end
    turtle.turnRight()
   else
    turtle.turnRight()
    turtle.turnRight()
   end
  else
   if blockX > 2 then
    for count=1,blockX - 1 do
     moveForward()
    end
   end

   if blockY > 1 then
    turtle.turnRight()
    for count=1,blockY - 1 do
     moveForward()
    end
    turtle.turnRight()
   else
    turtle.turnRight()
    turtle.turnRight()
   end
  end
  dropItems()
 end
end

local function returnToBlock()
 if blockY==1 then
  if blockX > 1 then
   for count=1, blockX - 1 do
    moveForward()
   end
  end
 else
  turtle.turnRight()
  for count=1, blockY - 1 do
   moveForward()
  end
  turtle.turnLeft()

  if blockX > 1 then
   for count=1, blockX - 1 do
    moveForward()
   end

   if dirAway == false then
    turtle.turnRight()
    turtle.turnRight()
   end
  end
 end
end

local function start()
 for countY=1, blocksY do
  blockY = countY
  for countX=1, blocksX - 1 do
   local spaceAvail = checkSpace()
   if spaceAvail < 128 then
    returnToStart()
    returnToBlock()
   end

   plantItem()

   moveForward()

   if dirAway == true then
    blockX = blockX + 1
   else
    blockX = blockX - 1
   end
  end

  plantItem()

  if blockY == blocksY then
   returnToStart()
  else
   organizeSpace()

   if dirAway == true then
    turnRight()
    dirAway = false
   else
    turnLeft()
    dirAway = true
   end
  end
 end
end

while true == true do
 blockX = 1
 blockY = 1
 dirAway = true

 start()
 os.sleep(60*30)
end