Beacon API

local modem
for k,v in pairs(peripheral.getNames()) do
	if peripheral.getType(v)=="modem" and peripheral.call(v,"isWireless") then
		modem=peripheral.wrap(v)
	end
end
assert(modem,"No wireless modem found")

local up=function()
local tries=0
while (not e or tries>10) do
local e=turtle.up()
if not e then turtle.digUp() turtle.attackUp() tries=tries+1 end
end
if tries==10 then error("Something in way... Cannot continue.",3) end
return true
end
local fd=function()
local tries=0
while (not e or tries>10) do
local e=turtle.forward()
if not e then turtle.dig() turtle.attack() tries=tries+1 end
end
if tries==10 then error("Something in way... Cannot continue.",3) end
return true
end
local down=function()
local tries=0
while (not e or tries>10) do
local e=turtle.down()
if not e then turtle.digDown() turtle.attackDown() tries=tries+1 end
end
if tries==10 then error("Something in way... Cannot continue.",3) end
return true
end

function goTo(channel, msg)
if not turtle then error("Can't go with a computer. Shtewpid",2) end
local isGPS
if channel==true and msg==nil then
	channel=65534
	isGPS=true
end
modem.closeAll()
modem.open(channel)
local distanceT={}
local function checkIfBeacon(ch,msg) --Checks if there is a beacon with that channel and message
	local e,s,c,r,m,d
	if not modem.isOpen(ch) then modem.open(ch) end
	modem.transmit(ch,ch,"PING")
	local id=os.startTimer(2)
	repeat
		 e,s,c,r,m,d=os.pullEventRaw()
	until (e=="modem_message" and c==ch and (not msg or msg==m)) or (e=="timer" and s==id) --If it matches or times out then end the loop.
	if e=="timer" then return false end
	return true
end
if not checkIfBeacon(channel,msg) then
	return false, "Invalid beacon."
end
turtle.up() --start moving out of the way
turtle.turnRight()--^
turtle.turnRight()--^
turtle.forward()  --^
local function getData() --Get data
modem.transmit(channel,channel,"PING")
local eventData
local tID=os.startTimer(5)
repeat
  eventData={os.pullEventRaw()}
  if eventData[1]=="modem_message" and (eventData[5]==msg or msg==nil) then return eventData end
  --print("test")
until eventData[1]=="terminate" or (eventData[1]=="timer" and eventData[2]==tID)
return (eventData[1]=="terminate" and error("Terminated",0)) or error("Lost signal.",2)--
end
local function getCloser(func)
	while true do
		func()
		local nDat=getData()
		if nDat[6]>distanceT[#distanceT] or nDat[6]==1 then break --If it got farther or its next to it then exit the loop.
		else
			table.insert(distanceT,nDat[6]) --Insert to the distance table.
		end
	end
end
local eventData=getData() --Get the data
if isGPS then msg=eventData[5] end --if its a gps then the message is that message
table.insert(distanceT,eventData[6])
turtle.up()
local nData=getData()
table.insert(distanceT,nData[6])
if distanceT[#distanceT-1]>distanceT[#distanceT] then
--This means its higher
	getCloser(up)
	turtle.digDown()
	turtle.down()
else
	--Lower
	getCloser(down)
	turtle.digUp()
	turtle.up()
end
local eventData=getData()
table.insert(distanceT,eventData[6])
turtle.forward()
local nData=getData()
table.insert(distanceT,nData[6])
if distanceT[#distanceT-1]>distanceT[#distanceT] then
	--Keep going forward
	getCloser(fd)
	turtle.back()
else
	--Moonwalk
	turtle.turnRight()
	turtle.turnRight()
	getCloser(fd)
	turtle.back()
	--turtle.turnRight()
	--turtle.turnRight()
end
--Turn right and do (almost) the same thing
turtle.turnRight()

local eventData=getData()
table.insert(distanceT,eventData[6])
turtle.forward()
local nData=getData()
table.insert(distanceT,nData[6])
if distanceT[#distanceT-1]>distanceT[#distanceT] then
	--Keep going forward
	getCloser(function() repeat turtle.dig() turtle.attack() until (turtle.forward()) end)
else
	--Moonwalk
	turtle.turnRight()
	turtle.turnRight()
	getCloser(function() repeat turtle.dig() turtle.attack() until (turtle.forward()) end)
end
return peripheral.getType("front")=="computer" or peripheral.getType("front")=="turtle" --Return true if its an actual host.
end


function host(channel, msg) --Host a beacon
	modem.closeAll()
	modem.open(channel)
	repeat
		local eventData={os.pullEventRaw("modem_message")}
		if eventData[1]=="modem_message" and eventData[3]==channel and eventData[5]=="PING" then --If its pinged send the message
			modem.transmit(channel,channel,msg)
		end
	until eventData[1]=="terminate"
	return error("Terminated",0)
end