local dirt = "minecraft:dirt"
local sapling = "minecraft:oak_sapling"
local meal = "minecraft:bone_meal"
local log = "minecraft:oak_log"
local apple = "minecraft:apple"
local stick = "minecraft:stick"
local items = {
  sapling, meal, log, apple, stick
}

local mealCount = 16

function selectItem(item)
  for i = 1, 16 do
    info = turtle.getItemDetail(i)
    if info and info.name == item then
      turtle.select(i)
      return i
    end
  end
end

Farmer = {}
function Farmer:new(invName)
  local t = setmetatable({}, { __index = Farmer })
  t.invName = invName
  return t
end

function Farmer:connectInv()
  local m = peripheral.find("modem")
  self.mName= m.getNameLocal()
  self.inv = peripheral.wrap(self.invName)
end

function Farmer:unload(item)
  for i = 1, 16 do
    info = turtle.getItemDetail(i)
    if info and info.name == item then
      -- print(item, self.mName, i)
      self.inv.pullItems(self.mName, i)
      sleep(0.5)
    end
  end
end

function Farmer:yoink(item, count)
  for i, info in pairs(self.inv.list()) do
    if info.name == item then
      if info.count >= count then
        self.inv.pushItems(self.mName, i, count)
        sleep(0.5)
        return true
      end
    end
  end

  return false
end

function Farmer:farmTree(noMeal)
  assert(turtle.turnRight())
  assert(turtle.turnRight())
  assert(turtle.forward())
  assert(turtle.forward())
  assert(turtle.down())

  assert(selectItem(dirt))
  assert(turtle.place())
  assert(turtle.up())
  assert(selectItem(sapling))
  assert(turtle.place())

  if noMeal then
    while true do
      local present, info = turtle.inspect()
      assert(present)
      if info.name == log then
        break
      end
      sleep(20)
    end
  else
    assert(selectItem(meal))
    local grown = false
    for i = 1, mealCount do
      turtle.place()
      sleep(1)
      local present, info = turtle.inspect()
      assert(present)
      if info.name == log then
        grown = true
        break
      end
    end
    if not grown then
      assert(false, "failed to grow tree")
    end
  end

  turtle.select(1)
  assert(turtle.dig())
  assert(turtle.down())
  assert(turtle.dig())
  assert(turtle.up())
  sleep(5)
  assert(turtle.down())
  for i = 1, 8 do
    sleep(0.5)
    turtle.suck()
  end

  assert(turtle.up())
  assert(turtle.turnRight())
  assert(turtle.turnRight())
  assert(turtle.forward())
  assert(turtle.forward())
  sleep(0.5)
end

function Farmer:xchgItems()
  self:connectInv()
  for _, i in pairs(items) do
    self:unload(i)
  end
  assert(self:yoink(sapling, 1))
  return self:yoink(meal, mealCount)
end

local f = Farmer:new("ae2:interface_0")
while true do
  local noMeal = not f:xchgItems()
  f:farmTree(noMeal)
end