Computercraft Chatroom V2

--Code by bryceio

--Set up login with username.
term.clear()
term.setCursorPos(1, 1)
print("Welcome to the chatroom. Please enter a username.")
user = read()
print("Welcome to the chatroom")
sleep(2)
rednet.broadcast(user, "chatroomlogin")
 mes = {}
messages = 0
userUpdate = false
newUserEntry = false

--Function to color usernames
function usercolor()
    if term.isColor() then
        term.setTextColor(8192)
    end
end

--Function to end color
function endcolor()
    if term.isColor() then
        term.setTextColor(1)
    end
end

--Adds a new message to the terminal
function newMessage(senderName, messageText)
    if userUpdate == true then
        messageText = ("<----Updated name to: "..messageText.."---->")
        userUpdate = false
    elseif newUserEntry == true then
        messageText = ("<----User joined the chat---->")
        newUserEntry = false
    end
    if messages < 7 then
        messages = messages + 1
        newmessage = fs.open("chatroommessages/"..messages, "w")
        newmessage.writeLine(senderName)
        newmessage.writeLine(messageText)
        newmessage.close()
        term.setCursorPos(1, messages*2-1)
        usercolor()
        print("<"..senderName..">                                            ")
        endcolor()
        term.setCursorPos(1, messages*2)
        print(messageText)
    elseif messages >= 7 then
        for i = 1, 6 do
            fs.delete("chatroommessages/"..i)
            fs.copy("chatroommessages/"..i+1, "chatroommessages/"..i)
        end
        newmessage = fs.open("chatroommessages/7", "w")
        newmessage.writeLine(senderName)
        newmessage.writeLine(messageText)
        newmessage.close()
        for i = 1, 7 do
            oldmessage = fs.open("chatroommessages/"..i, "r")
            term.setCursorPos(1, i*2-1)
            usercolor()
            print("<"..oldmessage.readLine()..">                                ")
            endcolor()
            term.setCursorPos(1, i*2)
            print(oldmessage.readLine())
            oldmessage.close()
        end
    end
end

--Set up blank chatroom
bestnumber = 8675309
term.clear()
enter = 257    --The enter key's number code
backspace = 259    --The backspace key's number code
relog = 342         --The relog command key, by default it is left alt
exit = 346          --The exit command key, by default it is right alt
rednet.open("back")   --Change accordingly
cpos = 1     --Cursor x position
chat = 0
--Set up screen
term.setCursorPos(1, 15)
print("---------------------------------------------------")
term.setCursorPos(1, 16)
usercolor()
print("<"..user..">")
endcolor()
fs.delete("chatroomusers")
setup = fs.open("chatroomfiles/outgoing", "w")
setup.write("test")
setup.close()
rednet.broadcast(user, "userQuery")
while true do
        event, x, y, z = os.pullEvent()   --Waits for something to happen
        if event == "char" then        --If a character is typed
           if cpos <= 50 then           --Makes sure the cursor is on screen
            term.setCursorPos(cpos, 17)
            print(x)                     --Displays the character typed in message box
            mes[cpos] = x                --Adds the typed character to a table that holds the message
            cpos = cpos + 1              --Moves cursor forward
           end
        elseif event == "key_up" then        --Checks for other keys pressed
            if x == enter then
                cpos = 1                   --Resets cursor
                for i = 1, 50 do           --Clears message box
                    term.setCursorPos(i, 17)
                    print(" ")
                end
                mess = fs.open("chatroomfiles/outgoing", "w")    --Writes the contents of the table to a file to be read later
                for i = 1,#mes do
                    mess.write(mes[i])
                    mes[i] = " "
                end
                mess.close()
                send = fs.open("chatroomfiles/outgoing", "r")
                finalmes = send.readAll()                           --Puts the message into a variable
                send.close()
                rednet.broadcast(finalmes, "chatroomsend")    --Sends message to other computers if not a command
                newMessage(user, finalmes)
            elseif x == backspace then            --Removes the last character when backspace is pressed
                if cpos > 1 then
                    cpos = cpos-1
                    if cpos <= 50 then
                        term.setCursorPos(cpos, 17)
                        print(" ")
                        mes[cpos] = " "
                    end
                end
            elseif x == relog then              --Allows you to change your username or update it to other chat members
                mes = {}
                term.setCursorPos(1, 16)
                print("Enter Username:         ")
                user = read()
                rednet.broadcast(user, "chatroomlogin")
                sleep(0.5)
                term.setCursorPos(1, 16)
                usercolor()
                print("<"..user..">                                     ")
                endcolor()
                term.setCursorPos(1, 17)
                print("                                                      ")
            elseif x == exit then         --Exits the program
                term.clear()
                term.setCursorPos(1, 1)
                error()
            end
        elseif event == "rednet_message" and z == "chatroomsend" then          --Receives messages
            if fs.exists("chatroomusers/"..x) then
                sentuser = fs.open("chatroomusers/"..x, "r")
                usersent = sentuser.readLine()
                sentuser.close()
            else
                usersent = ("ID: "..x)              --Uses the computer's id if there is no registered username
            end
            newMessage(usersent, y)
        elseif event == "rednet_message" and z == "chatroomlogin" then    --Registers new usernames and changes old ones.
            if fs.exists("chatroomusers/"..x) then
                olduser = fs.open("chatroomusers/"..x, "r")
                userUpdate = true
                newMessage(olduser.readLine(), y)
                olduser.close()
            else
                newUserEntry = true
                newMessage(y, "potatoes")
            end
            newuser = fs.open("chatroomusers/"..x, "w")
            newuser.write(y)
            newuser.close()
        elseif event == "rednet_message" and z == "userQuery" then
            rednet.broadcast(user, "userQueryResponse")
        elseif event == "rednet_message" and z == "userQueryResponse" then
            newuser = fs.open("chatroomusers/"..x, "w")
            newuser.write(y)
            newuser.close()
        end
end