local drone = component.proxy(component.list("drone")())

local FARM_DIRECTION_NS = 0
local FARM_DIRECTION_EW = -1
local FARM_WIDTH  = 8
local FARM_HEIGHT  = 8

local function sleep(timeout)
    checkArg(1, timeout, "number", "nil")
    local deadline = computer.uptime() + (timeout or 0)
    repeat
        computer.pullSignal(deadline - computer.uptime())
    until computer.uptime() >= deadline
end

local function checkE()
  local en = computer.energy()
  return en
end

local function drop()
  drone.drop(2)
end

local function dropAll()
  for i=4,2,-1
  do
    drone.select(i)
    drop()
  end
  drone.select(1)
end

local function move(x,y,z)
  drone.move(x,y,z)
  travelx = travelx + x
  travely = travely + y
  travelz = travelz + z
end

local function swing()
  for i=5,0,-1 do
    drone.swing(i)
  end
  sleep(0.2)
end

local function swingHor()
  for i=1,5,1 do
    drone.swing(i)
  end
  sleep(0.2)
end

local function suck(x)
  drone.suck(x)
end

local function suckAll()
  for i=0,5,1 do
    suck(i)
  end
end

local function layer(n)
    for i=3,1,-1 do
      suckAll()
      swingHor()
      move(-1,0,0)
    end
end

local function placeD()
  drone.place(0)
end

local function plant()
  drone.setStatusText("PLANTING")
  drone.select(1)
  move(-8,1,0)
  sleep(2)
  placeD()

  move(-1,0,0)
  sleep(0.3)
  placeD()

  move(0,0,-1)
  sleep(0.3)
  placeD()

  move(1,0,0)
  sleep(0.3)
  placeD()
  returnHome()
end

local function harvest()
  drone.setStatusText("CUTTING")
  move(0,30,0)
  sleep(3)
  move(-7,0,1)
  sleep(2)

  layer(30)

  swingHor()

  move(0,0,-1)
  for i=1,4,1 do
    move(1,0,0)
    swingHor()
    suckAll()
  end
  returnHome()
  dropAll()
  sleep(2)
end

local function resetP()
  travelx, travely, travelz = 0,0,0
end

function returnHome()
  travelx = travelx * -1
  travely = travely * -1
  travelz = travelz * -1
  sleep(1)
  move(travelx,travely,travelz)
  sleep(2)
  resetP()
end

local function getToPosition()
  for i=1,20,1 do
    local somethingInFront = drone.detect(4)
    if somethingInFront then
        -- Move on top of the fence
        sleep(0.5)
        move(0, 0, 1)
        sleep(0.5)
        move(FARM_DIRECTION_EW, FARM_DIRECTION_NS, 1)
        sleep(0.5)

        -- Move to the left corner of the farm
        for i=1,20,1 do
            local somethingBelow = drone.detect(0)
            -- Then we went past the fence, go back in
            if not somethingBelow then
                sleep(0.5)
                if FARM_DIRECTION_EW ~= 0 then
                    move(0, -2, 0)
                else
                    move(-2, 0, 0)
                end
                sleep(0.5)
                move(FARM_DIRECTION_EW, FARM_DIRECTION_NS, 1)
                sleep(0.5)
                return
            end

            -- Go left until we find the end
            sleep(0.5)
            if FARM_DIRECTION_EW ~= 0 then
                move(0, 1, 0)
            else
                move(1, 0, 0)
            end
            sleep(0.5)
        end
    end

    sleep(0.5)
    move(FARM_DIRECTION_EW, FARM_DIRECTION_NS, 0)
    sleep(0.5)
  end
  returnHome()
end

local function checkPlants()
  resetP()
  job = 0
  drone.setStatusText("CHECKING")
  for i=1,20,0 do
      local seedsBelow = drone.compare(0, true)
      drone.select(1)
      if seedsBelow then
          job = 1
          break
      end
      drone.select(2)
      local wheatBelow = drone.compare(0, true)
      if wheatBelow then
          job = 2
          break
      end
      move(FARM_DIRECTION_EW, FARM_DIRECTION_NS, 0)
  end
  returnHome()
end

--start
resetP()
job = 0
drone.setStatusText("ROM\nOK.v4.14.")
sleep(1)

-- Main loop

checkPlants()
drone.setStatusText(tostring(job))