-- cow control program
local server = "cowsensor2"
local side = "top"
local cowSensor = nperi.wrap(server, side)
local cows = {}

local function updateCows()
    local tResults = cowSensor.getTargets()
    if tResult ~= nil then
        cows = {}
        for k,v in pairs do
            if type(k) == "string" and string.len(k) > 3 and string.sub(k, 1, 3) == "Cow" then
                cows[k] = v
            end
        end
    else
        print("Unable to update cows, sensor result nil.")
    end
end

local function countCows()
    if cows == nil then
        return 0
    else
        local result = 0
        for k,v in pairs(cows) do
            result = result + 1
        end
        return result
    end
end

------------------------------------------
--
--
--[[
txt.sPrint("IsPresent: ", nperi.isPresent(server, side))
local p = nperi.wrap(server, side)
txt.sPrint("Wrap: ", p)
local tm = nperi.getMethods(server, side)
if tm ~= nil then
    textutils.tabulate(tm)
else
    print("getMethods nil")
end

local tt = p.getTargets()

txt.sPrint(tt)

if tt ~= nil then
    print(serial.serialize(tt))
else
    print("getMethods nil")
end




while true do
    updateCows()
    txt.sPrint("There are ", countCows(), " cows in the farm.")
end






-- test
txt.sPrint("IsPresent: ", peripheral.isPresent("top"))
local p = sensor.wrap("top")
txt.sPrint("Wrap: ", p)
local tm = peripheral.getMethods("top")
if tm ~= nil then
    textutils.tabulate(tm)
else
    print("getMethods nil")
end

local tt = p.getTargets()

txt.sPrint(tt)

if tt ~= nil then
    print(serial.serialize(tt))
else
    print("getMethods nil")
end
]]--