api_network.lua

--[[
    Install: /api/network.lua
--]]



--[[
    Retuns the hostname for the given computer id on the given protocol
--]]
function lookupHostName(id, protocol)
    local res = nil

    -- Do rednet lookup until we find what we need
    rednet.send(id, {sType = "lookup", sProtocol = protocol}, "dns")
    local message
    repeat
            message = {rednet.receive("dns")}
    until type(message) == "table" and message[1] == id
        and type(message[2]) == "table"
        and message[2].sType == "lookup response"

    return message[2].sHostname
end

--[[
    Loops through computer sides to find a modem and then opens rednet
--]]
function openNetwork()
    local sides = rs.getSides()
    for i = 1, #sides, 1 do
        local side = sides[i]
        if peripheral.getType(side) == "modem" then
            rednet.open(side)
            return true
        end
    end
    return false
end

--[[
    Builds host name and registers host on rednet.
    Throws error if host already exists
--]]
function registerHost(protocol, type)

    -- Build host name
    local hostType = nil
    if type == "mainframe" then hostType = "main"
    elseif type == "server" then hostType = "svr"
    elseif type == "client" then hostType = "cl" end
    if not hostType then error("Invalid host type: " .. type) end
    local hostName = protocol.."_"..hostType.."_"..os.getComputerID()

    -- Make sure host doesn't exist
    if rednet.lookup(protocol, hostName) then
        error("Hostname '"..hostName.."' already exists on '"..protocol.."'")
    end

    -- Good to go
    rednet.host(protocol, hostName)
    return hostName

end


--[[
    Splits the given command
--]]
function splitCommand(cmd)

    local baseCmd = nil
    local args = { }
    local cnt = 0

    if cmd then
        for word in cmd:gmatch('%S+') do
            if word:len() > 0 then
                if cnt == 0 then
                    baseCmd = word
                else
                    args[cnt] = word
                end
                cnt = cnt + 1
            end
        end
    end

    return { cmd = baseCmd, args = args }

end

function parseArgs(args, startAt)
    local res = {}
    local resCnt = 1

    -- Split args on colon. IE: status:Running
    for i = startAt, #args, 1 do
        local arg = args[i]
        local paramName = nil
        local paramVal = nil
        for word in arg:gmatch('([^:]+)') do
            if not paramName then
                paramName = word
            else
                paramVal = word
                break
            end
        end
        res[resCnt] = { name = paramName, val = paramVal }
        resCnt = resCnt + 1
    end

    return res
end