Ringchat Server

--@version 1.2

local version = 1.2
local ht_up = http.get("https://pastebin.com/raw/nQ7rSYbN")
local up_A = ht_up.readLine()
local up_B = ht_up.readAll()
local up = up_A .. up_B
ht_up.close()
local their_version = tonumber(up_A:sub(12))
if (their_version > version) then
    local fi_up = fs.open(shell.getRunningProgram(), "w")
    fi_up.write(up)
    fi_up.close()
    shell.run(shell.getRunningProgram())
    return
end

local name = "NONAME"
local output = nil
local password = nil
if not fs.exists("/.rc_name") then
    repeat
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        term.clear()
        term.setCursorPos(1, 1)
        write("Server name (min 3 length): ")
        name = tostring(read())
        sleep(0.1)
    until name ~= "nil" and #name > 2
    local rc = fs.open("/.rc_name", "w")
    rc.write(name)
    rc.close()
else
    local rc = fs.open("/.rc_name", "r")
    name = tostring(rc.readAll())
    rc.close()
end

if not fs.exists("/.rc_key") then
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setCursorPos(1, 1)
    write("Password (blank for none): ")
    password = tostring(read())
    if password == "" or password == nil or password == "blank" then --yeah i know you smartasses will enter blank
        local f = fs.open("/.rc_key", "w")
        f.write("blank")
        f.close()
    else
        local f = fs.open("/.rc_key", "w")
        f.write(password)
        f.close()
    end
else
    local f = fs.open("/.rc_key", "r")
    password = f.readAll()
    f.close()
    if password == "blank" then
        password = nil
    end
end

local pingdata_channel = 895
local connect_channel = 885

local our_connections = {}
local chatLog = {}
for i = 1, 18 do
    table.insert(chatLog, "")
end
local d = false
local mod = nil
for k, v in pairs(peripheral.getNames()) do
    if peripheral.getType(v) == "modem" then
        rednet.open(v)
        mod = peripheral.wrap(v)
        d = true
    end
end
if not d or not mod then
    error("A modem is required!")
end

local function download_file(url, target)
    local ht = http.get(url)
    local data = ht.readAll()
    ht.close()
    local file = fs.open(target, "w")
    file.write(data)
    file.close()
end

local function read_file(target)
    local file = fs.open(target, "r")
    local data = file.readAll()
    file.close()
    return data
end

-- API Loading
local function getAPI(name, url)
    local apiloc = "/" .. name
    if (not fs.exists(apiloc)) then
        local newapiloc = shell and shell.resolveProgram(name) or nil
        if type(newapiloc) ~= "string" then
            download_file(url, apiloc)
        else
            apiloc = newapiloc
        end
    end
    return apiloc
end

local function tFind(a, b)
    for k, v in pairs(a) do
        if b == v then
            return k
        end
    end
    return nil
end

local function add_chat(mes)
    table.remove(chatLog, 1)
    table.insert(chatLog, mes)
end

local names = {}
local ringnet = require(getAPI("ringnet", "https://pastebin.com/raw/tUe94t9J"))
getAPI("aeslua", "https://git.io/aeslua")
os.loadAPI("aeslua")
--ringnet.setDebug(true)
ringnet.openChannel(pingdata_channel)
ringnet.openChannel(connect_channel)

local challenge_string = nil

if password ~= nil and password ~= "" and password ~= "blank" then
    challenge_string = aeslua.encrypt(password, "_A_COMMON_ENCRYPTION_STRING", aeslua.AES128, aeslua.CFBMODE)
end

local function name_exists(n)
    for k, v in pairs(names) do
        if v == n then
            return true
        end
    end
    return fase
end

local function sendData(a, b)
    if password then
        b = aeslua.encrypt(password, b, aeslua.AES128, aeslua.CFBMODE)
    end
    ringnet.sendData(a, b)
end

parallel.waitForAll(
    ringnet.connectionHandler,
    function()
        while true do
            local _, side, sfrq, rfrq, mes, dist = os.pullEvent()
            if (_ == "modem_message") then
                if (type(mes) == "string") then
                    mes = textutils.unserialize(mes)
                end
                if (type(mes) == "table") then
                    if (mes.type == "SERVER_DATA" and type(mes.rid) == "number") then
                        mod.transmit(
                            sfrq,
                            sfrq,
                            textutils.serialize(
                                {
                                    type = "SERVER_RETURNDATA",
                                    to = mes.rid,
                                    name = name,
                                    fingerprint = ringnet.get_fingerprint(),
                                    hid = ringnet.get_handshakeID(),
                                    locked = challenge_string
                                }
                            )
                        )
                    end
                end
            elseif (_ == "tunnel_finish") then
                table.insert(our_connections, side)
            elseif (_ == "secure_receive") then
                local data = sfrq
                local cid = side
                if (type(data) == "string") then
                    data = textutils.unserialize(data)
                end
                if (type(data) == "table") then
                    if (data.type == "CHAT_LOGIN" and type(data.name) == "string") then
                        local current_num = 1
                        local actual_name = data.name
                        if (name_exists(data.name)) then
                            repeat
                                actual_name = tostring(data.name) .. tostring(current_num)
                                current_num = current_num + 1
                            until (not name_exists(actual_name))
                        end
                        names[cid] = actual_name
                        add_chat(
                            {
                                mes = actual_name .. " has joined.",
                                raw = true
                            }
                        )
                        sendData(
                            cid,
                            textutils.serialize(
                                {
                                    type = "CHAT_LOG",
                                    log = chatLog
                                }
                            )
                        )
                    elseif (data.type == "CHAT_LOGOUT" and type(names[cid]) == "string") then
                        add_chat(
                            {
                                mes = tostring(names[cid]) .. " has left.",
                                raw = true
                            }
                        )
                        for k, v in pairs(our_connections) do
                            sendData(
                                v,
                                textutils.serialize(
                                    {
                                        type = "CHAT_LOG",
                                        log = chatLog
                                    }
                                )
                            )
                        end
                        names[cid] = nil
                        local ccid = tFind(our_connections, cid)
                        if ccid then
                            table.remove(our_connections, ccid)
                        end
                    elseif (data.type == "CHAT_CHAT" and type(names[cid]) == "string" and type(data.message) == "string") then
                        local name = names[cid]
                        add_chat(
                            {
                                name = name,
                                mes = tostring(data.message)
                            }
                        )
                        local prefix = (name .. ": ")
                        local dje = (tostring(data.message) .. "\n")
                        local combined = (prefix .. dje)
                        term.blit(combined, (string.rep("0", #prefix) .. string.rep("8", #dje)), string.rep("f", #combined))
                        --print("ALLCONNECTIONS!")
                        --print(textutils.serialize(our_connections))
                        for k, v in pairs(our_connections) do
                            sendData(
                                v,
                                textutils.serialize(
                                    {
                                        type = "CHAT_LOG",
                                        log = chatLog
                                    }
                                )
                            )
                        end
                    end
                end
            end
        end
    end
)