network_util.lua

--[[
    pastebin get PFC9cjHM network_util
    lua
    net = require("network_util.lua")
    net.example()
]]
peripheral.find("modem", rednet.open)

protocol = "strippy"

function find_host(my_job, position)
    print("Looking for "..protocol.." Hosts!")
    local computers = {rednet.lookup(protocol)}
    print("\tFound "..tostring(#computers).." potential hosts!")

    local my_data = {
        job=my_job,
        pos=position
    }

    for _, computer in pairs(computers) do
        print("Pinging "..computer)
        rednet.send(computer, textutils.serialize(my_data), protocol)

        local id, response = rednet.receive(protocol, 10)
        if id == computer and response == "true" then
            print("Found Host!")
            return computer
        else
            print("Denied: ")
            print(response)
        end
    end
    print("Could not find Host!")
    return nil
end

function start_host(my_job, position)
    print("Hosting "..protocol.."!")
    rednet.host(protocol, tostring(os.computerID()))

    count = 1
    partners = {}
    partners[my_job] = os.computerID()

    repeat
        local id, message = rednet.receive(protocol)
        local partner = textutils.unserialize(message)

        print("Just received request from:", id, "\nWho is a:", partner.job, "\nWho is at:", partner.pos)

        local dist = partner.pos.x - position.x + partner.pos.y - position.y + partner.pos.z - position.z

        print(dist)

        if dist < 10 then
            print("Found Partner!")
            partners[partner.job] = id
            rednet.send(id, "true", protocol)
            count = count + 1
        else
            rednet.send(id, "false", protocol)
        end

    until count == 3
    rednet.unhost(protocol)

    print("Found All Partners!")
    for job, partner in pairs(partners) do
        rednet.send(partner, textutils.serialize(partners), protocol)
    end

    return partners
end

function wait_for_partners(partner_id)
    print("Waiting for Host!")
    while true do
        local id, message = rednet.receive(protocol)
        if id == partner_id then
            return textutils.unserialize(message)  -- This should return the list of partners
        end
    end
end

function example(job)
    job = job or "chunker"
    local position = vector.new(gps.locate())

    local host = find_host(job, position)
    if host then
        return wait_for_partners(host)
    end

    return start_host(job, position)
end

return {
    find_host = find_host,
    start_host = start_host,
    wait_for_partners = wait_for_partners,
    example = example
}