Create a new version of paste:

-- ...use with responsibility.
--
-- Get with
-- pastebin get n3K9Nt3D fakechat
-- std PB n3K9Nt3D fakechat

local names = { --Add names to quickly switch between using PageUP and PageDOWN
    {
        name = "&o&6Jesus",
        prefix = "<",
        suffix = "> ",
    },
    {
        name = "&dServer",
        prefix = "&d[",
        suffix = "&d] ",
        msgprefix = "&d",
        realname = "But nobody"
    },
	{
		name = "&eBagel&6Bot",
		prefix = "<",
		suffix = "> ",
	},
	{
		name = "Lr_",
		prefix = "<",
		suffix = "> ",
	},
	{
		name = "dan200",
		prefix = "<",
		suffix = "> ",
	},
}

local sHistories = {}

local cname = 1

local tArg = {...}

local channel = 1251  --default 1251

local sHistory = {}
local scr_x, scr_y = term.getSize()
local modems
local setModems = function()
	modems = {peripheral.find("modem")}
	for a = 1, #modems do
		if modems[a].isWireless() then
			modem = modems[a]
			modem.open(channel)
			return
		end
	end
	modem = nil
end

setModems()
if (not commands) and (not modem) then
	return printError("You need a modem! Or a command computer!")
end
if commands then isServer = true else isServer = false end

if (not commands) and (not modem) then
  error("This requires a command computer.")
end

local prefix = ""
local suffix = ""

local dnb = function(phunk, ...)
	local t,b = term.getTextColor(), term.getBackgroundColor()
	local x,y = term.getCursorPos()
	local output = {phunk(...)}
	term.setCursorPos(x,y)
	term.setTextColor(t)
	term.setBackgroundColor(b)
	return unpack(output)
end

local prevnames = {}

local colnames = {
	["0"] = "black",
	["1"] = "dark_blue",
	["2"] = "dark_green",
	["3"] = "dark_aqua",
	["4"] = "dark_red",
	["5"] = "dark_purple",
	["6"] = "gold",
	["7"] = "gray",
	["8"] = "dark_gray",
	["9"] = "blue",
	["a"] = "green",
	["b"] = "aqua",
	["c"] = "red",
	["d"] = "light_purple",
	["e"] = "yellow",
	["f"] = "white",
}

local colors_names = { --for use with colors api, you see
	["0"] = colors.black,
	["1"] = colors.blue,
	["2"] = colors.green,
	["3"] = colors.cyan,
	["4"] = colors.red,
	["5"] = colors.purple,
	["6"] = colors.orange,
	["7"] = colors.lightGray,
	["8"] = colors.gray,
	["9"] = colors.blue, --they don't translate perfectly, okay??
	["a"] = colors.lime,
	["b"] = colors.lightBlue,
	["c"] = colors.red,
	["d"] = colors.magenta,
	["e"] = colors.yellow,
	["f"] = colors.white,
}
local codeNames = { --just for checking
	["k"] = "obfuscate",
	["o"] = "italic",
	["l"] = "bold",
	["m"] = "strikethrough",
	["n"] = "underline",
	["r"] = "reset",
}

local filterColors = function(str,doprint)
	local p = 1
	local output = ""
	local code = "&"
	local col = "f"
	local prevT,prevB = term.getTextColor(), term.getBackgroundColor()
	while p <= #str do
		if str:sub(p,p) == code then
			if colors_names[str:sub(p+1,p+1)] then
				col = str:sub(p+1,p+1)
				p = p + 1
			elseif codeNames[str:sub(p+1,p+1)] then
				if str:sub(p+1,p+1) == "r" then
					col = "f"
				end
				p = p + 1
			else
				if doprint then
					if term.isColor() then
						term.setTextColor(colors_names[col])
					end
					write(str:sub(p,p))
				end
			end
			p = p + 1
		else
			output = output..str:sub(p,p)
			if doprint then
				if term.isColor() then
					term.setTextColor(colors_names[col])
				end
				write(str:sub(p,p))
			end
			p = p + 1
		end
	end
	term.setTextColor(prevT)
	term.setBackgroundColor(prevB)
	return output
end

local renderReadBar = function(doReturn)
	local cx,cy = term.getCursorPos()
	local cb,ct = term.getBackgroundColor(), term.getTextColor()
	term.setCursorPos(1,scr_y)
	term.setBackgroundColor(colors.black)
	term.clearLine()
	filterColors(prefix.."&r"..names[cname].prefix.."&r"..names[cname].name.."&r"..names[cname].suffix.."&r"..suffix,true)
	term.setCursorPos(1,scr_y-1)
	if not doReturn then
		term.setBackgroundColor(colors.gray)
		term.clearLine()
		term.setTextColor(colors.white)
	else
		term.setCursorPos(cx,cy)
		term.setBackgroundColor(cb)
		term.setTextColor(ct)
	end
end

local colorFormat = function(str)
	local color = "f"
	local obfuscated = false
	local bold = false
	local strikethrough = false
	local underline = false
	local italic = false
	
	local code = "&" --ONE CHARACTER
	local pos = 1
	local opos = 1
	local output = {}
	
	while pos <= #str do
		output[opos] = {}
		if str:sub(pos,pos) == code and pos < #str then
			local changed = false
			if colnames[str:sub(pos+1,pos+1)] then
				color = str:sub(pos+1,pos+1)
				changed = true
			else
				if str:sub(pos+1,pos+1) == "r" then
					color = "f"
					obfuscated = false
					bold = false
					strikethrough = false
					underline = false
					italic = false
					changed = true
				end
				if str:sub(pos+1,pos+1) == "k" then
					obfuscated = true
					changed = true
				end
				if str:sub(pos+1,pos+1) == "l" then
					bold = true
					changed = true
				end
				if str:sub(pos+1,pos+1) == "m" then
					strikethrough = true
					changed = true
				end
				if str:sub(pos+1,pos+1) == "n" then
					underline = true
					changed = true
				end
				if str:sub(pos+1,pos+1) == "o" then
					italic = true
					changed = true
				end
			end
			if changed then
				output[opos].text = ""
				pos = pos + 2
			else
				output[opos].text = str:sub(pos,pos)
				pos = pos + 1
			end
		else
			output[opos].text = str:sub(pos,pos)
			pos = pos + 1
		end
		output[opos].color = colnames[color]
		output[opos].obfuscated = obfuscated
		output[opos].bold = bold
		output[opos].strikethrough = strikethrough
		output[opos].underline = underline
		output[opos].italic = italic
		opos = opos + 1
	end
	return textutils.serialiseJSON(output)
end

local players = { --Add playernames here if you want to filter who receives messages
	"dan200",
	"EldidiStroyrr",
}

local doFilter = false --If true, filters according to 'players' table

local send = function(name,msg,np,ns,realname,doprint)
	local compiled --compiled message, not compiled program
	local filtmsg = filterColors(msg)
	if filtmsg:sub(1,3) == "___" then --should this be a client option? hmm...
		if filtmsg == "___join" then
			compiled = "&e"..filterColors(realname).." joined the game."
		elseif filtmsg == "___notjoin" then
			compiled = "&e"..filterColors(realname).." hasn't joined the game."
		elseif filtmsg == "___leave" then
			compiled = "&e"..filterColors(realname).." left the game."
		elseif filtmsg == "___notleave" then
			compiled = "&e"..filterColors(realname).." hasn't left the game."
		elseif filtmsg:sub(1,8) == "___medal" then
			compiled = realname.."&r has made the achievement &a["..msg:sub(10).."&a]"
		else
			compiled = msg:sub(4)
		end
	else
		compiled = prefix.."&r"..np.."&r"..name.."&r"..ns.."&r"..suffix.."&r"..msg
	end
	compiled = colorFormat(compiled)
	if doFilter then
		for a = 1, #players do
			commands.tellraw(players[a],compiled)
		end
	else
		commands.tellraw("@a",compiled)
	end
end

local netsend = function(n,m,p,s,mp,rn) --name, message, prefix, suffix
	local data = {
		name = n,
		realname = rn or n,
		msg = mp..m,
		prefix = p or "<",
		suffix = s or "> ",
	}
	if modem then modem.transmit(channel,channel,data) end
end

term.setBackgroundColor(colors.black)
term.clear()
term.setCursorPos(1,1)
local name
if tArg[1] then
    name = tArg[1]
    if name:gsub(" ","") ~= "" and prevnames[#prevnames] ~= name then
      table.insert(prevnames,name)
    end
else
    print("Enter a name:")
    write(">")
	dnb(function() write("\n\nUse PageUP and PageDOWN to switch names.\nDo '/exit' to exit.\nDo '___join' or '___leave' to simulate doing either.\nPrefix any other message with '___' to do raw chat.\n\nUse responsibly") if term.isColor() then print(".") else print(", and it'd be preferable to use a golden computer. Not required, but...") end end)
    name = read(nil,prevnames)
    if name:gsub(" ","") ~= "" and prevnames[#prevnames] ~= name then
      table.insert(prevnames,name)
    end
end
if name:gsub(" ","") == "" then name = "Scabby cunt" end --enter in a fucking name
table.insert(names,1,{
	name = name,
	prefix = "<",
	suffix = "> ",
	realname = name
})

local insend = function(n,m,p,s,mp,rn) --name, message, prefix, suffix. Sends a message inwards to simulate receiving a message from a client
    local data = {
        name = n,
        realname = rn or n,
        msg = mp..m,
        prefix = p or "<",
        suffix = s or "> ",
    }
    os.queueEvent("modem_message","top",channel,channel,data,0)
end

local client = function() --this is where you enter in your awesome messages! it also happens to be where *you* enter in your shitty messages
	while true do
		term.setBackgroundColor(colors.black) --dats rasist
		term.clear()
		renderReadBar()
		write(">")
		local msg = read(nil,sHistories[cname] or {"I like to eat pubes I find in urinals.","One of my hobbies is to kick small dogs and see how far they go.","Have you reddit","My child-sized skin suit it starting to smell."})
		if msg:gsub(" ","") == "/exit" then
			return
		end
		if msg:gsub(" ","") ~= "" then
			if not sHistories[cname] then
				sHistories[cname] = {msg}
			else
				if sHistories[cname][#sHistories[cname]] ~= msg then
					sHistories[cname][#sHistories[cname]+1] = msg
				end
			end
		end
		if isServer then --if you are a command computer, fuck that netsend() function!!! that's for pussies!!
			if msg:gsub(" ","") ~= "" then
				local sdata = {
					names[cname].name,
					msg,
					prefix..names[cname].prefix or "<",
					suffix..names[cname].suffix or "> ",
					names[cname].msgprefix or "",
				}
				if type(names[cname].realname) == "string" then
					table.insert(sdata,names[cname].realname)
				end
				insend(unpack(sdata))
			end
		else --if you're a client, studies have shown that you're the type of fuck who makes positive acronyms out of insults that are thrown your way
			local sdata = {
				names[cname].name,
				msg,
				prefix..names[cname].prefix or "<",
				suffix..names[cname].suffix or "> ",
				names[cname].msgprefix or "",
			}
			if type(names[cname].realname) == "string" then
				table.insert(sdata,names[cname].realname)
			end
			netsend(unpack(sdata))
		end
	end
end

local renderHistory = function() --this shows all the latest and greatest (optional) messages sent by fakechat clients!
	local y = scr_y-2
	local r = "&r"
	term.setBackgroundColor(colors.black)
	for a = #sHistory, #sHistory-(scr_y-2), -1 do
		if not sHistory[a] then break end
		term.setCursorPos(1,y)
		term.clearLine()
		filterColors(sHistory[a].p..r..sHistory[a].n..r..sHistory[a].s..r..sHistory[a].m,true)
		y = y - 1
	end
end

local server = function() --now THIS is what I call a quality function! servers are where it's at! *it* being command computers, of course...
  while true do
    local evt = {os.pullEvent("modem_message")}
    if type(evt[5]) == "table" then
      local i = evt[5]
      if type(i.name) == "string" and type(i.msg) == "string" and type(i.prefix) == "string" and type(i.suffix) == "string" and type(i.realname) == "string" then
        table.insert(sHistory,{n=i.name, m=i.msg, p=i.prefix, s=i.suffix})
        send( i.name, i.msg, i.prefix, i.suffix, i.realname, true)
        dnb(function() return renderHistory() end)
      end
    end
  end
end

moreModems = function() --keep them modems loaded!
	while true do
		setModems()
		sleep(0)
	end
end

switchNames = function() --in case you happen to be named harry kuntz, and want to change that right away
	local evt, key, rerender
	while true do
		rerender = false
		evt, key = os.pullEvent("key")
		if key == keys.pageUp then
			cname = cname - 1
			rerender = true
		elseif key == keys.pageDown then
			cname = cname + 1
			rerender = true
		end
		if cname <= 0 then
			cname = #names
		elseif cname > #names then
			cname = 1
		end
		if rerender then renderReadBar(true) end
	end
end

local funclist = { --this is the funciest list I've ever laid eyes upon
	client,
	moreModems,
	switchNames,
}
if isServer then table.insert(funclist,server) end --clients are not servers, you thick idiot

parallel.waitForAny(unpack(funclist)) --execute the SHIT out of this!

term.setCursorPos(1,scr_y)
term.setBackgroundColor(colors.black)
term.clearLine() --the last line is always the hardest...*sniffle*