bivalve

-- valve
-- Pours and retrieves water at specified time intervals
-- Written by HarvDad, June 2014

args = {...}
nArgs = #args

version = "valve: Rev 1.0"
mission = "Pour and retrieve water at intervals."
instructions = "Place full bucket in slot 1, empty bucket in slot 2."
usage1 = "usage: valve <direction> <t1> <t2>"
usage2 = "  direction = up, down, forward"
usage3 = "  t1 = seconds after pour"
usage4 = "  t2 = seconds after retrieval"


secondsAfterPouring = 10
secondsAfterRetrieving = 30

up = 0
down = 1
forward = 2
direction = 0

abort = false

function synchWithServerTime()
	print("Waiting for synch...")
	while true do
		time = os.time()
		timeStr = tostring(time)
		tailStr = string.sub(timeStr, -3)
		tail = tonumber(tailStr)
		if tail > 995 then
			break
		end
		sleep(0)
	end
end

function needWater(direction)
	if direction == up then
		turtle.select(1)
		if turtle.compareTo(3) then
			return true
		end
	elseif direction == down then
		turtle.select(2)
		if turtle.compareTo(3) then
			return true
		end
	end
	return false
end

-- prep: Retrieve any water possibly left over from previous run

function prep()
	turtle.select(1)
	if turtle.compareTo(3) then
		if needWater(up) then
			turtle.placeUp()
		end
		if needWater(down) then
			turtle.placeDown()
		end
	end
end

function updateWater()
	turtle.select(1)
	turtle.placeUp()
	turtle.select(2)
	turtle.placeDown()
end

function doTheRightThing()
local naptime = 0

	turtle.select(1)
	if turtle.compareTo(3) then
		napTime = secondsAfterRetrieving
--		print("Retrieving water. napTime = ", napTime)
	else
		napTime = secondsAfterPouring
--		print("Pouring  water. napTime = ", napTime)
	end
	updateWater()

	return napTime
end

-- Main program


if nArgs == 0 or (nArgs == 1 and args[1]== "help") then
	print(version)
	print(instructions)
	print(usage1)
	print(usage2)
	print(usage3)
	print(usage4)
	return
end

if nArgs < 2 or nArgs > 2 then
  print(usage1)
  print(usage2)
  print(usage3)
  print(usage4)
  return
end

secondsAfterPouring = tonumber(args[1])
if secondsAfterPouring == nil then
  print("\"", args[1], "\" is not a valid time interval")
  return
end
if secondsAfterPouring < 1 then
  print("t1 must be a positive integer")
  return
end

secondsAfterRetrieving= tonumber(args[2])
if secondsAfterRetrieving == nil then
  print("\"", args[2], "\" is not a valid time interval")
  return
end
if secondsAfterRetrieving  < 1 then
  print("t2 must be a positive integer")
  return
end

if turtle.getItemCount(1) == 0 or turtle.getItemCount(2) == 0 then
	print("If no water running yet,")
	print("  place full bucket in slot 1.")
	print("If water is already running,")
	print("  place empty bucket in slot 1.")
	print("Always have empty bucket in slot 2 as comparitor.")
	return
end

prep()
--synchWithServerTime()

-- Main loop


print("Beginning loop...")
print("secondsAfterPouring: ", secondsAfterPouring, " secondsAfterRetrieving: ", secondsAfterRetrieving)
while true do
	if abort then
		break
	end
	napTime = doTheRightThing()
	sleep(napTime)
end