chat_server

-- CHAT SERVER
-- by mcprog

SERVER_CHAN = 5
CLIENT_CHAN = 1
version = "s1.0.2"

SERVER_MSG = "serverMsg"
SUPER_CHAT = "/superchat"
WHISPER = "/whisper"
CMD = "cmd"

SRC_SERVER = "server"

users = {}
userCount = 0
op = "mc1030"

local modem = peripheral.wrap("left")

function resetLine()
    term.clearLine()
    x,y = term.getCursorPos()
    term.setCursorPos(1, y)
end

function printColor(msg,textColor)
    term.setTextColor(textColor)
    resetLine()
    print(msg)
end

function split(s, delimiter)
    result = {};
    for match in (s..delimiter):gmatch("(.-)"..delimiter) do
        table.insert(result, match);
    end
    return result;
end

function join(array, delimiter, indexStart)
    result = ""
    for i,v in ipairs(array) do
        if i >= indexStart then
            result = result + " " + i
        end
    end
    return result
end

function post(message)
    modem.transmit(CLIENT_CHAN, SERVER_CHAN, message)
end

function addUser(id, loginTime)
    users[id] = loginTime
    userCount = userCount + 1

    printColor(id.." joined at "..textutils.formatTime(loginTime, false)..".", colors.lightBlue)
end

function removeUser(id, logoutTime)
    users[id] = nil
    userCount = userCount - 1
    if userCount < 0 then
        userCount = 0
    end
    printColor(id.." left at "..textutils.formatTime(logoutTime, false)..".", colors.blue)
end

function listen()
    local event, side, senderChan, replyChan, message, dist = os.pullEvent("modem_message")
    if message then
        local currentTime = os.time()
        if message.type == "join" then
            addUser(message.id, currentTime)

            post(message)
        elseif message.type == "left" then
            removeUser(message.id, currentTime)
            post(message)
        elseif message.type == "chat" then
            if users[message.id] == nil then
               addUser(message.id, currentTime)
            end
            post(message)
        elseif message.type == CMD then
            if message.id == op then
                -- use src as command name
                command(message.src, message.id, message.value, message.extra) --cmd, from, to
            else -- client asks to run cmd but is rejected
                whisper = {
                    type = WHISPER,
                    src = SRC_SERVER,
                    id = message.id,
                    value = "You are not opped, " ..(message.id).."."
                }
                post(whisper)
                printColor(message.id.. "tried to run "..message.src..", but is not opped.", colors.white)
            end
        else
            printColor("Error! Bad message:", colors.red)
            printColor(textutils.serialize(message), colors.red)
        end
    end
end

function command(cmdName, from, to, meta)
    if cmdName == "/kick" then
        serverMsg = {
            type = SERVER_MSG,
            src = from,
            id = to,
            value = "/kicked"
        }
        printColor("Trying to kick: ".. to, colors.orange)
        post(serverMsg)
    elseif cmdName == SUPER_CHAT then
        superChat = {
            type = SUPER_CHAT,
            src = from,
            value = meta
        }
        post(superChat)
    elseif cmdName == "/shutdown" then
        serverMsg = {
            type = SERVER_MSG,
            src = from,
            value = "/shutdown"
        }
        post(serverMsg)
        print("Shuting down chat_server.")
        error()
    elseif cmdName == WHISPER then
        whisper = {
            type = WHISPER,
            src = from,
            id = to,
            value = meta
        }
        post(whisper)
    elseif cmdName == "users" then
        onlineMsg = "Users online: " ..tostring(userCount).."."
        if from == SRC_SERVER then
            printColor(onlineMsg, colors.white)
        else
            serverWhisper(from, "Unknown command: " ..cmdName)
        end
    else
        serverWhisper(from, "Unknown command: " ..cmdName)
    end
end

function serverWhisper(to, msg)
    whisper = {
        type = WHISPER,
        src = SRC_SERVER,
        id = to,
        value = msg
    }
    post(whisper)
end

function acceptLocalCommands()
    resetLine()
    term.setTextColor(colors.white)
    write("$ ")
    input = read()
    parsed = split(input, " ")
    if parsed then
        if parsed[1] == "kick" and #parsed == 2 then
            command("/kick", SRC_SERVER, parsed[2])
        elseif parsed[1] == "shutdown" then
            command("/shutdown", SRC_SERVER)
        elseif parsed[1] == "users" then
            command("users", SRC_SERVER) --server side only
        elseif parsed[1] == SUPER_CHAT and #parsed == 2 then
            command(SUPER_CHAT, SRC_SERVER, parsed[2])
        elseif parsed[1] == "whisper" and #parsed > 3 then
            command("/whisper", SRC_SERVER, parsed[2], join(parsed, " ", 3))
        end
    else
        print("Invalid command: " ..input)
    end
end

function start()
    modem.open(CLIENT_CHAN)
    term.clear()
    term.setCursorPos(1, 1)

    printColor("Server version: "..version, colors.white)

    while true do
        parallel.waitForAny(acceptLocalCommands, listen)
    end
end

start()