ComputerCraft: BasketNet API

-- apis/BasketNet

local iMasterControlID

local iConversationPartnerID
local sConversationKey

function broadcast(sMessage, sProtocol)
    if sProtocol == nil then
        sProtocol = "BasketNet"
    end
    if not rednet.isOpen("left") then
        rednet.open("left")
    end
    rednet.broadcast(sMessage, sProtocol)
end

function send(id, sMessage, sProtocol)
    if sProtocol == nil then
        sProtocol = "BasketNet"
    end
    if not rednet.isOpen("left") then
        rednet.open("left")
    end
    id = id + 0
    if id ~= nil and id ~= 0 then
        return rednet.send(id, sMessage, sProtocol)
    end
    return false
end

function sendToMasterControl(sMessage, sProtocol)
    if sProtocol == nil then
        sProtocol = "BasketNet"
    end
    if not rednet.isOpen("left") then
        rednet.open("left")
    end
    return rednet.send(getMasterControlID(), sMessage, sProtocol)
end

-- Return local iSenderId, sMessage, sProtocol
-- on timeout returns nil
function receive(iTimeout, sProtocol)
    if sProtocol == nil then
        sProtocol = "BasketNet"
    end
    return rednet.receive(sProtocol, iTimeout)
end

-- Return local iSenderId, sMessage, sProtocol
-- on timeout returns nil
function receiveFromMasterControl(iTimeout, sProtocol)
    local iSenderID, sMessage, sReceivedProtocol
    while true do
        if sProtocol == nil then
            sProtocol = "BasketNet"
        end
        iSenderID, sMessage, sReceivedProtocol= rednet.receive(sProtocol, iTimeout)
        if iSenderID == nil then
            return nil
        end
        if iSenderID == getMasterControlID() then
            break
        end
    end

    return iSenderID, sMessage, sReceivedProtocol
end

function getMasterControlID()
    if iMasterControlID == nil or not iMasterControlID then
        while true do
            iMasterControlID = rednet.lookup("BasketNet", "MasterControl")
            if not iMasterControlID then
                print("Unable to find Master Control.")
                sleep(5)
            else
                break
            end
        end
    end
    return iMasterControlID
end

function registerAsMasterControl()
    rednet.host("BasketNet", "MasterControl")
end

function startConversation(iComputerID)
    sConversationKey = getConversationKey(10)
    iConversationPartnerID = iComputerID
    local iAttempts = 0
    while iAttempts < 5 do
        send(iComputerID, "StartConversation " .. sConversationKey, "BasketNet")
        local iSenderID, sMessage, sProtocol = receiveFromConversation(1)
        if iSenderID ~= nil and sMessage == "JoinedConversation" then
            iAttempts = 0
            break
        end
        iAttempts = iAttempts + 1
    end
    if iAttempts == 0 then
        return true
    else
        return false
    end
end

function startConversationWithMasterControl()
    return startConversation(getMasterControlID())
end

function joinConversation(iNewConversationPartnerID, sNewConversationKey)
    iConversationPartnerID = iNewConversationPartnerID
    sConversationKey = sNewConversationKey
    sendToConversation("JoinedConversation")
end

function endConversation()
    sendToConversation("EndConversation")
    iConversationPartnerID = 0
    sConversationKey = ""
end

-- Return local iSenderID, sMessage, sProtocol
-- on timeout returns nil
function receiveFromConversation(iTimeout)
    if iTimeout == nil then
        iTimeout = 2
    end
    return rednet.receive("BasketNet" .. sConversationKey, iTimeout)
end

function sendToConversation(sMessage)
    if iConversationPartnerID ~= 0 then
        send(iConversationPartnerID, sMessage, "BasketNet" .. sConversationKey)
    end
end

function getConversationKey(l)
        if l < 1 then
        return nil
    end
        local sKey = ""
        for i = 1, l do
                sKey = sKey .. string.char(math.random(string.byte("a"), string.byte("z")))
        end
        return sKey
end