-- to be used with plant_trees
-- this turtle should be placed one block behind and to the right
-- note: this script is actually written with the linter _enabled_
-- todo: switch to turtle.suckDown()

local mv = require("movement")

local function stepOver(go_around)
  mv.up()
  if go_around then mv.moveLeft(mv.forward) end
  mv.nTimes(2, mv.forward)
  if go_around then mv.moveRight(mv.forward) end
  mv.down()
end

local function safeSuck()
  local success, data = turtle.inspect()
  if success and data.name:find("turtle") then return end
  turtle.suck()
end

local function suck()
  for i=1,4 do
    safeSuck()
    turtle.turnRight()
  end
  mv.forward()
end

local function scanRow(n)
  local inner_size = (n-1)*4
  mv.nTimes(inner_size, suck)
  turtle.turnRight()
  stepOver(false)
  turtle.turnRight()
  mv.nTimes(inner_size, suck)
  turtle.turnLeft()
  stepOver(true)
  turtle.turnLeft()
end

local function main(n,m)
  stepOver(false)
  for i=1,(m-1) do
    scanRow(n)
  end
  mv.turnAround()
  stepOver(false)
  turtle.turnRight()
  mv.nTimes((m-1)*4, mv.forward)
  turtle.turnRight()
end

local args = {...}
main(tonumber(args[1] or 5), tonumber(args[2] or 5))