rednet.open("right")

local mainID = 15
local trees = 4    --Number of trees per row

local function forward(count)
	for k = 1,count do
		turtle.forward()
	end
end

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

local function harvest()
	turtle.dig()
	for k = 1,6 do
		turtle.digUp()
		turtle.up()
		turtle.dig()
	end
	for k = 1,6 do
		turtle.down()
	end
	turtle.select(2)
	turtle.place()
end

local function checkTree()
	turtle.turnRight()
	turtle.select(1)
	if turtle.compare() then
		harvest()
	end
	turtle.turnLeft()
end

local function checkTrees(count)
	checkTree()
	for m = 1,(count - 1) do
		forward(6)
		checkTree()
	end
end

while true do
	if turtle.getFuelLevel() < (turtle.getFuelLimit() - 5120) then    --Check fuel
		turnAround()
		turtle.forward()
		turtle.select(16)
		turtle.suck()
		turtle.refuel()
		turnAround()
		turtle.forward()
		turtle.select(1)
	end
	
	--Check and harvest trees
	rednet.send(mainID, "away")
	forward(5)
	checkTrees(trees)
	turtle.turnLeft()
	forward(4)
	turtle.turnLeft()
	checkTrees(trees)
	forward(5)
	
	if turtle.getItemCount(2) < (2 * trees) then    --Check saplings
		turtle.select(2)
		turtle.suck(64 - (2 * trees))
		turtle.select(1)
	end
	
	for k = 1,14 do --Dump inventory
		turtle.select(k+2)
		turtle.dropDown()
	end
	
	--Return Home
	turtle.turnLeft()
	forward(4)
	turtle.turnLeft()
	rednet.send(mainID, "home")
	local a = 15
	while a ~= 0 do
		rednet.send(mainID, tostring(a))
		print(tostring(a))
		sleep(60)
		a = a - 1
	end
	rednet.send(mainID, tostring(a))
end

rednet.close("right")