Grand Unified Radio Apparatus Installer

-- grand unified installer

local function install(file, data)
    local handle = fs.open(file, "w")
    handle.write(data)
    handle.close()
end

local radioAPI = [[
math.randomseed(os.time())
local currentFrequency = 0

local chars = {
    "a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"," ","_",
    "#","@","!","*","^","1","2","3","4","5","6","7","8","9","0","+","-","~","`","%","$","{","}","\\","/",">","<",";",":",
}


function run()
    while true do
        local id, msg, distance = rednet.receive()
        msg = textutils.unserialize(msg)
        if type(msg) == "table" then
            local freq = msg[1]
            local data = msg[2]
            local offset = math.abs(currentFrequency-freq)
            --print("Got a message from "..id..", frequency "..freq.." data "..data.." freqOffset "..offset.." our freq is "..currentFrequency)
            if offset < 10 then
                local doScramble = true
                if distance <= 100 then
                    if offset == 1 then
                        if math.random(1,10) < 5 then
                            doScramble = false
                        end
                    elseif offset == 2 then
                        if math.random(1,100) < 25 then
                            doScramble = false
                        end
                    end
                end
                local scrambleAmt = 0
                if doScramble then
                    scrambleAmt = math.ceil(#data * (offset/10))
                end
                if distance > 100 then
                    scrambleAmt = scrambleAmt + math.ceil(#data * (distance-100 / 100))
                end
                if scrambleAmt < #data then
                    --print("Scrambling "..scrambleAmt.." characters")
                    local scrambledPositions = {}
                    for i=1, #data do
                        scrambledPositions[i] = string.sub(data,i, i)
                    end
                    if doScramble then
                        for i=1, scrambleAmt do
                            local scramblePos = math.random(1, #data)
                            if scrambledPositions[scramblePos] == string.sub(data, scramblePos, scramblePos) then
                                if math.random(1,2) == 2 then
                                    scrambledPositions[scramblePos] = string.upper(chars[math.random(1, #chars)])
                                else
                                    scrambledPositions[scramblePos] = chars[math.random(1, #chars)]
                                end
                            end
                        end
                    end
                    local newData = ""
                    for i=1, #scrambledPositions do
                        newData = newData..scrambledPositions[i]
                    end
                    --print("Received radio transmission from "..id.." data: "..newData)
                    os.queueEvent("radio_received", id, newData, distance, freq)
                end
            end
        end
    end
end

function receive(timeout)
    local timer = -1
    if timeout then
        timer = os.startTimer(timeout)
    end
    while true do
        local event, p1, p2, p3, p4 = os.pullEvent()
        if event == "timer" and p1 == timer then
            return
        elseif event == "radio_received" then
            return p1, p2, p3, p4
        end
    end
end

function transmit(message)
    rednet.broadcast(textutils.serialize({currentFrequency, message}))
end

function setFrequency(newFreq)
    currentFrequency = newFreq
end

function getFrequency()
    return currentFrequency
end
]]

local startup = [[
    if rednetRadio == nil then
        -- do first time init
        os.loadAPI("rednetRadio")
        parallel.waitForAll(rednetRadio.run, function() shell.run("shell") end)
    end
]]

local reciever = [[
-- listener/decrypter
local args = {...}
local decryptedRecv = {}
local recv = {}

if #args ~= 2 then
    print("USAGE: "..fs.getName(shell.getRunningProgram()).." [key] [frequency]")
    return
end

local function printCentered(input)
    local maxX = term.getSize()
    print(string.rep(" ", math.floor((maxX - string.len(input))/2))..input)
end

local function drawStream(key)
    local maxX, maxY = term.getSize()
    local itrFrom = 1
    if #recv > maxY then
        itrFrom = #recv-(maxY-1)
    end
    term.clear()
    term.setCursorPos(1,1)
    for i=itrFrom, #recv do
        local decrypted = ""
        for i2=1, #recv[i] do
            decrypted = decrypted..string.char(bit.bxor(string.byte(string.sub(recv[i],i2,i2)), key))
        end
        decryptedRecv[i] = decrypted
        if decrypted ~= "\n" then
            printCentered(decrypted)
        end
    end
end

rednetRadio.setFrequency(tonumber(args[2]))

while true do
    local event, id, msg, distance, freq = os.pullEvent()
    if event == "radio_received" then
        drawStream(tonumber(args[1]))
        if id then
            table.insert(recv, msg)
            local handle = fs.open(args[2], "a")
            handle.write(decryptedRecv[#decryptedRecv])
            handle.close()
        end
        local maxX, maxY = term.getSize()
        term.setCursorPos(1,maxY)
        if id then
            term.setTextColor(colors.lime)
            write("Currently recieving from "..id)
        else
            term.setTextColor(colors.red)
            write("No stations active.")
        end
        term.setTextColor(colors.white)
        term.setCursorPos(maxX-20, maxY)
        write("Press SPACE to quit.")
    elseif event == "key" and id == 57 then
        term.clear()
        term.setCursorPos(1,1)
        return
    end
end
]]

local transmitter = [[
os.loadAPI("rednetRadio")
local args = {...}
-- args[1]: file to transmit
-- args[2]: Frequency
-- args[3]: Transmit rate (wait this many seconds after each message)
-- args[4]: Key

if #args ~= 4 then
    print("USAGE: "..fs.getName(shell.getRunningProgram()).." [file] [frequency] [rate] [key]")
    return
end

rednetRadio.setFrequency(tonumber(args[2]))

local function transmitEncrypted(data)
    local encrypted = ""
    for i=1, #data do
        encrypted = encrypted..string.char(bit.bxor(string.byte(string.sub(data,i,i)), tonumber(args[4])))
    end
    rednetRadio.transmit(encrypted)
end

if fs.exists(args[1]) then
    local handle = io.open(args[1], "r")
    local lines = {}
    for line in handle:lines() do
        table.insert(lines, line)
    end
    handle:close()
    local transNo = 1
    while true do
        transmitEncrypted("BEGIN TRANSMISSION #"..transNo)
        transmitEncrypted("\n")
        os.sleep(tonumber(args[3]))
        for i,v in ipairs(lines) do
            for block in string.gmatch(v, "[%S\n]+") do
                transmitEncrypted(block.." ")
                os.sleep(tonumber(args[3]))
            end
            transmitEncrypted("\n")
        end
        transmitEncrypted("END TRANSMISSION #"..transNo)
        transmitEncrypted("\n")
        os.sleep(5)
        transNo = transNo+1
    end
else
    print("USAGE: "..fs.getName(shell.getRunningProgram()).." [file] [frequency] [rate] [key]")
end
]]

textutils.slowPrint("Radio Based Communications Suite Installer")
textutils.slowPrint("(C) 2012 KillaVanilla Industries")
textutils.slowPrint("Select an option:")
textutils.slowPrint("1. Install Prerequisites")
textutils.slowPrint("2. Install Transmitter Software")
textutils.slowPrint("3. Install Reciever Software")
textutils.slowWrite("selection> ")
local selection = 0
while true do
    local select = tonumber(read())
    if select then
        if select > 0 and select < 4 then
            selection = select
            break
        end
    end
end
if select == 1 then
    install("rednetRadio", radioAPI)
    if fs.exists("startup") then
        fs.move("startup", "startup2")
    end
    install("startup", startup)
elseif select == 2 then
    install("transmitter", transmitter)
else
    install("reciever", reciever)
end
textutils.slowPrint("Software installed.")
textutils.slowPrint("This terminal will now reboot.")
os.sleep(1.5)
os.reboot()