RedStuff chat client v0.16 by LBPHacker

-- One program from LBPHacker's RedStuff collection
-- Chat client for RS Chat server (http://pastebin.com/8cgaw0Sm)
-- For ComputerCraft 1.3 or above

function trim(stringT)
    local i=1
    while (string.sub(stringT, i, i)==" ") do
        i=i+1
    end
    local startT=i
    i=string.len(stringT)
    while (string.sub(stringT, i, i)==" ") do
        i=i-1
    end
    local endT=i
    return string.sub(stringT, startT, endT)
end

function toboolean(sBool)
    if (string.find(sBool, "true")) then
        return true
    else
        return false
    end
end

function readLimited(limit, default, printx, printy)
    local input=default
    local inputsize=string.len(input)
    local entered=false
    local preconf=(string.len(default)>0)
    while (not entered) do
        term.setCursorPos(printx, printy)
        term.write("["..input..string.rep(" ", 16-string.len(input)).."]")
        event, arg1=os.pullEvent()
        if (event=="char" and inputsize<16 and string.byte(arg1)>31 and string.byte(arg1)<128) then
            input=input..arg1
            inputsize=inputsize+1
        end
        if (event=="key" and arg1==14 and inputsize>0) then
            if (preconf) then
                input=""
                inputsize=0
                preconf=false
            else
                input=string.sub(input, 1, string.len(input)-1)
                inputsize=inputsize-1
            end
        end
        if (event=="key" and arg1==28 and inputsize>0) then
            entered=true
        end
    end
    return input, inputsize
end

function refreshServerList(username)
    term.clear()
    term.setCursorPos(1, 3)
    term.write(string.rep("-", termWidth))
    term.setCursorPos(1, termHeight-2)
    term.write(string.rep("-", termWidth))
    term.setCursorPos(math.floor(termWidth/2)-11, math.floor(termHeight/2)-1)
    term.write("Searching for servers...")
    term.setCursorPos(math.floor(termWidth/2)-15, math.floor(termHeight/2))
    term.write("["..string.rep(" ", 30).."]")
    term.setCursorPos(math.floor(termWidth/2)-13, math.floor(termHeight/2)+1)
    term.write("Press X to close the program")
    term.setCursorPos(math.floor(termWidth/2)-13, math.floor(termHeight/2)+2)
    term.write("Username:"..string.rep(" ", 19-string.len(username))..username)
    local scanning=true
    local serverList={{}, {}}
    local serverCounter=0
    local timerCounter=0
    local timer=os.startTimer(0.1)
    rednet.broadcast("/rcsping")
    while (scanning) do
        event, arg1, arg2=os.pullEvent()
        term.setCursorPos(math.floor(termWidth/2)-14+timerCounter, math.floor(termHeight/2))
        term.write("#")
        if (event=="timer" and arg1==timer) then
            timerCounter=timerCounter+1
            if (timerCounter==30) then
                scanning=false
            else
                timer=os.startTimer(0.1)
            end
        end
        if (event=="rednet_message" and string.sub(arg2, 1, 8)=="/rcsresp") then
            serverCounter=serverCounter+1
            serverList[1][serverCounter]=arg1
            serverList[2][serverCounter]=string.sub(arg2, 10, string.len(arg2))
        end
        if (event=="char" and string.lower(arg1)=="x") then
            return -1
        end
    end
    sleep(0.1)
    return serverCounter, serverList
end

function chooseServer(serverCounter, serverList, default)
    term.clear()
    term.setCursorPos(math.floor(termWidth/2)-12, 1)
    term.write("Choose a server to connect")
    term.setCursorPos(math.floor(termWidth/2)-22, 2)
    term.write("Server list will be refreshed after 90 seconds")
    term.setCursorPos(1, 3)
    term.write(string.rep("-", termWidth))
    term.setCursorPos(1, termHeight-2)
    term.write(string.rep("-", termWidth))
    term.setCursorPos(math.floor(termWidth/2)-18, termHeight-1)
    term.write("Navigate with arrow keys - Exit with X")
    term.setCursorPos(math.floor(termWidth/2)-21, termHeight)
    term.write("Press Enter to connect, or R to refresh list")
    local selection=1
    local viewPoint=0
    local cursorUI=1
    local fieldsUI=termHeight-6
    for i=1, serverCounter do
        if (serverList[i]==default) then
            selection=i
        end
    end
    local entered=false
    local timer=os.startTimer(90)
    while (not entered) do
        if (serverCounter>0) then
            for i=1, fieldsUI do
                term.setCursorPos(5, i+3)
                term.write(serverList[2][i+viewPoint])
                term.setCursorPos(2, i+3)
                if (cursorUI==i) then
                    term.write("[")
                else
                    term.write(" ")
                end
                term.setCursorPos(termWidth-1, i+3)
                if (cursorUI==i) then
                    term.write("]")
                else
                    term.write(" ")
                end
            end
        else
            term.setCursorPos(math.floor(termWidth/2)-15, 4)
            term.write("No active servers found in range")
        end
        event, arg1=os.pullEvent()
        if (event=="key" and arg1==28 and serverCounter>0) then
            entered=true
        end
        if ((event=="key" and arg1==19) or (event=="timer" and timer==arg1)) then
            return 0
        end
        if (event=="char" and string.lower(arg1)=="x") then
            return -1
        end
        if (event=="key" and arg1==200 and selection>1) then
            selection=selection-1
            if (cursorUI==1) then
                viewPoint=viewPoint-1
            else
                cursorUI=cursorUI-1
            end
        end
        if (event=="key" and arg1==208 and selection<serverCounter) then
            selection=selection+1
            if (cursorUI==fieldsUI) then
                viewPoint=viewPoint+1
            else
                cursorUI=cursorUI+1
            end
        end
    end
    return selection
end

function addToMessageUI(messageUI, message)
    local lines={}
    for i=1, messageSize do
        lines[i]=""
    end
    local lineNum=1
    local lineSize=0
    local word=""
    for i=1, string.len(message) do
        if (string.sub(message, i, i)==" " or string.len(message)==i or lineSize==termWidth) then
            if (string.len(message)==i) then
                word=word..string.sub(message, i, i)
            end
            if (lineSize+string.len(word)+1>termWidth) then
                lineNum=lineNum+1
                lines[lineNum]=word
                lineSize=string.len(word)
            else
                lines[lineNum]=lines[lineNum].." "..word
                lineSize=lineSize+string.len(word)+1
            end
            word=""
        else
            word=word..string.sub(message, i, i)
        end
    end
    for i=messageSize, 1+lineNum, -1 do
        messageUI[i]=messageUI[i-lineNum]
    end
    for i=1, lineNum do
        messageUI[i]=string.sub(lines[i], 2, string.len(lines[i]))
    end
    return messageUI
end

termWidth, termHeight=term.getSize()
local username, usernamesize, remember, dserver, serverCounter, serverList, cursorTS
local config, selectedServer, selectedConnection, connClosed, messageTS, messageTSsize
local exitprogram=false
local messageUI={}
messageSize=termHeight-4
event=""
arg1=0
arg2=0

if (fs.exists("rsccConfig")) then
    config=fs.open("rsccConfig", "r")
    username=config.readLine()
    usernamesize=string.len(username)
    dserver=config.readLine()
    config.close()
else
    username=""
    usernamesize=0
    dserver=1
end

term.clear()
term.setCursorPos(1, 1)
local modemOnSide=0
local modems=rs.getSides()
for i=1, #modems do
    if (peripheral.isPresent(modems[i]) and peripheral.getType(modems[i])=="modem") then
        modemOnSide=i
    end
end
if (modemOnSide==0) then
    print("-- No modems found. Place a RedNet modem on one side of the computer, then restart this program.")
    print("Press Enter to exit")
    local key=0
    local event=""
    while (key~=28 or event~="key") do
        event, key=os.pullEvent()
    end
    term.clear()
    term.setCursorPos(1, 1)
    return 1
end
rednet.open(modems[modemOnSide])

term.setCursorPos(math.floor(termWidth/2)-12, math.floor(termHeight/2)-2)
term.write("RedStuff chat client v0.16")
term.setCursorPos(math.floor(termWidth/2)-5, math.floor(termHeight/2)-1)
term.write("by LBPHacker")
term.setCursorPos(math.floor(termWidth/2)-16, math.floor(termHeight/2))
term.write("Report bugs at lbphacker@gmail.com")
term.setCursorPos(math.floor(termWidth/2)-4, math.floor(termHeight/2)+2)
term.write("Username?:")
term.setCursorPos(math.floor(termWidth/2)-8, math.floor(termHeight/2)+3)
term.write("["..string.rep(" ", 16).."]")
username, usernamesize=readLimited(16, username, math.floor(termWidth/2)-8, math.floor(termHeight/2)+3)

while (not exitprogram) do
    selectedConnection=false
    while (not selectedConnection) do
        serverCounter, serverList=refreshServerList(username)
        if (serverCounter<0) then
            exitprogram=true
            selectedServer=0
            selectedConnection=true
        else
            selectedServer=chooseServer(serverCounter, serverList, dserver)
            if (selectedServer>0) then
                selectedConnection=true
            else
                if (selectedServer<0) then
                    exitprogram=true
                    selectedConnection=true
                end
            end
        end
    end
    if (selectedServer>0) then
        messageTS=""
        for i=1, messageSize do
            messageUI[i]=""
        end
        messageTSsize=0
        cursorTS=1
        connClosed=false
        rednet.send(serverList[1][selectedServer], username)
        term.setCursorBlink(true)
        while (not connClosed) do
            event, arg1, arg2=os.pullEvent()
            if (event=="rednet_message" and arg1==serverList[1][selectedServer]) then
                --if printable then
                    messageUI=addToMessageUI(messageUI, arg2)
                --end
            end
            if (event=="char" and string.byte(arg1)>31 and string.byte(arg1)<128) then
                messageTS=messageTS..arg1
                messageTSsize=messageTSsize+1
            end
            if (event=="key" and arg1==14 and messageTSsize>0) then
                messageTS=string.sub(messageTS, 1, string.len(messageTS)-1)
                messageTSsize=messageTSsize-1
            end
            if (event=="key" and arg1==211) then
                messageTS=""
                messageTSsize=0
            end
            if (event=="key" and arg1==28 and messageTSsize>0) then
                messageTS=trim(messageTS)
                rednet.send(serverList[1][selectedServer], messageTS)
                if (messageTS=="/exit") then
                    connClosed=true
                end
                messageTS=""
                messageTSsize=0
            end
            term.clear()
            term.setCursorPos(1, 1)
            term.write("Server:"..string.rep(" ", termWidth-7-string.len(serverList[2][selectedServer]))..serverList[2][selectedServer])
            term.setCursorPos(1, 2)
            term.write(string.rep("-", termWidth))
            term.setCursorPos(1, termHeight-1)
            term.write(string.rep("-", termWidth))
            for i=1, messageSize do
                term.setCursorPos(1, i+2)
                term.write(messageUI[messageSize+1-i])
            end
            term.setCursorPos(1, termHeight)
            if (string.len(messageTS)>termWidth-1) then
                term.write(string.sub(messageTS, string.len(messageTS)-termWidth+2, string.len(messageTS)))
                cursorTS=termWidth
            else
                term.write(string.sub(messageTS, 1, string.len(messageTS)))
                cursorTS=string.len(messageTS)+1
            end
            term.setCursorPos(cursorTS, termHeight)
        end
        term.setCursorBlink(false)
    end
end

config=fs.open("rsccConfig", "w")
config.writeLine(username)
config.writeLine(dserver)
config.close()
rednet.close(modems[modemOnSide])
term.clear()
term.setCursorPos(1, 1)