View difference between Paste ID: hmcwYu7i and sLP4qc9S

 local chats = {}
 
 -- File path for saving chats
 filePath = "chats.txt"
 userFilePath = "users.txt"
 
 adminu = "username"
 adminp = "password"
 
 local function getFirstWord(str)
     local firstWord = str:match("^(%S+)")
     return firstWord
 end
 
 function twoInputStrip(str)
     first, second = str:match("(%S+)%s+(%S+)")
     return first, second
 end
 
 function threeInputStrip(str)
     first, second, third = str:match("(%S+)%s+(%S+)%s+(%S+)")
     return first, second, third
 end
 
 function fourInputStrip(str)
     local first, second, third, fourth = str:match("(%S+)%s+(%S+)%s+(%S+)%s+(.*)")
     return first, second, third, fourth
 end
 
 local function cutSpaces(str)
     local substrings = {}
     for substring in str:gmatch("%S+") do
         table.insert(substrings, substring)
     end
     return substrings
 end
 
 -- Function to save chats to a file
 local function saveChats()
     local file = fs.open(filePath, "w")
     file.write(textutils.serialize(chats))
     file.close()
     print("Chats saved.")
 end
 
 -- Function to print the first key of each sub-array
 local function getChannelIds()
 	chatnames = {}
     for _, subArray in ipairs(chats) do
         for chatname, _ in pairs(subArray) do
 			print(chatname)
             table.insert(chatnames, chatname)
             break  -- Only print the first key
         end
     end
 	return chatnames
 end
 
 -- Function to save chats to a file
 local function addUser(user, userID)
     local file = fs.open(userFilePath, "a")
     file.writeLine(user .. " " .. userID)
     file.close()
     print("Users saved.")
 end
 
 -- Function to save chats to a file
 local function removeUser(user, userID)
     success = false
 	if fs.exists(userFilePath) then
 		local file = fs.open(userFilePath, "r")
 		local line = file.readLine()
     	while line do
 			print(line)
 			name = twoInputStrip(line)
 			if name == user then
 				success = true
 			else
 				table.insert(newfile, line)
 			end
 			line = file.readLine()
 		end
 		file.close()
 		file = fs.open(userFilePath, "w")
 		for _, line in pairs(newfile) do
 			file.writeLine(line)
 		end
 		file.close()
 	end
 	return success
 end
 
 local function findUser(user)
     if fs.exists(userFilePath) then
         local file = fs.open(userFilePath, "r")
         if file then
             line = file.readLine()
             while line do
                 local name, nid = twoInputStrip(line)
                 if name ~= nil and name == user then
                     file.close()
                     return nid
                 end
 				line = file.readLine()
             end
             file.close()
         end
     end
     return nil
 end
 
 local function checkChat(chat, ruser)
     users = cutSpaces(chat[1])
     for _, user in pairs(users) do
 	    if user == ruser then
 	        return true
         end
 	end
     return false
 end
 
 local function getUsersChats(chats, newruser)
 	userchats = {}
 	newid = findUser(newruser)
     if newid == nil then
 	    return "no"
 	end
 	for chatname, array in pairs(chats) do
 		if checkChat(chats[chatname], newruser) then
 			table.insert(userchats, chatname)
 		end
 	end
 	if userchats == nil then
     	return "none"
     else
 	    return userchats
    	end
 	return nil
 end
 
 local function ping(chatID)
 	users = cutSpaces(chats[chatID][1])
 	for _, user in pairs(users) do
 		userid = findUser(user)
 		if userid ~= nil then
 			rednet.send(tonumber(userid), "update")
 		end
 	end
 end
 
 -- Function to load chats from a file
 local function loadChats()
     if fs.exists(filePath) then
         local file = fs.open(filePath, "r")
         local content = file.readAll()
         chats = textutils.unserialize(content) or {}
         file.close()
         print("Chats loaded.")
 		return chats
     else
         print("No saved chats found.")
 		return nil
     end
 end
 
 -- Function to handle creating a new chat
 local function handleCreateChat(chatID, username)
     if not chats[chatID] and username ~= nil then
         chats[chatID] = {username .. " "}
         print("Chat " .. chatID .. " created.")
         saveChats()
 		return "true"
     else
         print("Chat " .. chatID .. " already exists.")
 		return "exists"
     end
 end
 
 -- Function to save chats to a file
 local function handleAddUser(user, chatID)
 	if chats[chatID] then
     	chats[chatID][1] = chats[chatID][1] .. user .. " "
 		local wfile = fs.open(filePath, "w")
     	wfile.write(textutils.serialize(chats))
     	wfile.close()
 		return "true"
     end
 	return nil
 end
 
 -- Function to save chats to a file
 local function handleRemoveUser(username, ruser, chatID)
 	print(chats[chatID][1])
 	owner = getFirstWord(chats[chatID][1])
 	if owner ~= nil and owner == username then
 		if chats[chatID] then
     		users = cutSpaces(chats[chatID][1])
 			for _, user in pairs(users) do
 				if user == ruser then
 					chats[chatID][1] = chats[chatID][1]:gsub("%f[%a]" .. user .. "%f[%A]%s*", "")
 					local wfile = fs.open(filePath, "w")
 	    			wfile.write(textutils.serialize(chats))
     				wfile.close()
 					return "true"
 				end
 			end
 		end
     end
 	return nil
 end
 
 -- Function to handle deleting a chat
 local function handleDeleteChat(chatID, username)
     if chats[chatID] then
 		owner = getFirstWord(chats[chatID][1])
 		if owner ~= nil and owner == username then
         	chats[chatID] = nil
         	print("Chat " .. chatID .. " deleted.")
         	saveChats()
 			return "true"
 		end
 		return "denied"
     else
         print("Chat " .. chatID .. " does not exist.")
 		return nil
     end
 end
 
 -- Function to handle incoming messages
 local function handleIncomingMessage(chatID, username, text)
     if not chats[chatID] then
         print("Chat " .. chatID .. " does not exist.")
         return nil
     end
     table.insert(chats[chatID], username .. ": " .. text)
     print("Message in chat " .. chatID .. " from " .. username .. ": " .. text)
     saveChats()
 	return "true"
 end
 
 -- Function to print all messages in a chat
 local function printChatMessages(chatID)
     if not chats[chatID] then
         print("Chat " .. chatID .. " does not exist.")
         return nil
     end
 
     term.clear()
     term.setCursorPos(1, 1)
     for _, line in ipairs(chats[chatID]) do
         print(line)
     end
 	return "true"
 end
 
 local function messageRequests()
 	-- Main server loop
 	while true do
 	    id, message = rednet.receive()
     	command = twoInputStrip(message)
 	    if command == "create" then
 			command, chatid, username = threeInputStrip(message)
 			newid = findUser(username)
         	if newid == nil then
 				addUser(username, id)
 			elseif newid ~= id then
 				removeUser(username, newid)
 				addUser(username, id)
 			end
 			success = handleCreateChat(chatid, username)
 			rednet.send(id, success)
 		elseif command == "add" then
 			success = nil
 			command, chatid, username, nusername = fourInputStrip(message)
 			if findUser(nusername) == nil then
 				print("User does not Exist")
 			end
 			print(handleAddUser(nusername, chatid))
 			rednet.send(id, success)
 
 		elseif command == "remove" then
 			command, chatid, username, ruser = fourInputStrip(message)
 			success = handleRemoveUser(username, ruser, chatid)
 			rednet.send(id, success)
 
 	    elseif command == "delete" then
 			command, chatid, username, dusername = fourInputStrip(message)
 			success = handleDeleteChat(chatid, dusername)
 			rednet.send(id, success)
 
 	    elseif command == "send" then
 			command, chatid, username, text = fourInputStrip(message)
         	success = handleIncomingMessage(chatid, username, text)
 	        if success == "true" then
 				ping(chatid)
 			end
 			rednet.send(id, success)
 
     	elseif command == "retrieve" then
 			command, chatid, ruser = threeInputStrip(message)
 	        if chats[chatid] then
 				rsuccess = false
 				users = cutSpaces(chats[chatid][1])
             	for _, user in pairs(users) do
                 	if user == ruser then
     	        		rednet.send(id, chats[chatid])
 						rsuccess = true
 						break
 					end
 				end
 				if not rsuccess then
 					rednet.send(id, "false")
 				end
         	else
             	rednet.send(id, nil)
         	end
 		elseif command == "find" then
 			command, user = twoInputStrip(message)
 			rednet.send(id, findUser(user))
     	elseif command == "chats" then
 			command, user = twoInputStrip(message)
 			rednet.send(id, getUsersChats(chats, user))
 		end
 	end
 end
 
 local function displayOptions()
 	print("1. Display ChatID's")
 	print("2. Display Chat")
 	print("3. Display Users")
 	print("4. Add User to Chat")
 	print("5. Remove User to Chat")
 	print("6. Get User's Chats")
 	print("7. Exit to Login")
 	print("8. Exit to OS")
 end
 
 local function userSwitch(choice, chats)
 	if choice == 1 then
 		print("\n")
 		for idname, array in pairs(chats) do
 			print(idname)
 		end
 		read()
 		return 1
 	elseif choice == 2 then
 		print("Input Chat ID")
 		newid = read()
 
 		scrollPosition = 1
 		maxLines = 15
     	local startIndex = math.max(1, scrollPosition)
     	local endIndex = math.min(#chats[newid], scrollPosition + maxLines - 1)
 
     	while true do
         	term.clear()
 
     	    -- Display the database content after the instruction
     	    for i = startIndex, endIndex do
     	        print(chats[newid][i])
         	end
 
 	        local event, key = os.pullEvent("key")
     	    if key == keys.up then
         	    scrollPosition = math.max(1, scrollPosition - 1)
  	       elseif key == keys.down then
     	        scrollPosition = math.min(#chats[newid] - maxLines + 1, scrollPosition + 1)
     	    elseif key == keys.backspace then
         	    break  -- Exit loop on backspace key press
       		end
 
         	startIndex = math.max(1, scrollPosition)
         	endIndex = math.min(#chats[newid], scrollPosition + maxLines - 1)
     	end
 		return 2
 	elseif choice == 3 then
 		if fs.exists(userFilePath) then
 			local file = fs.open(userFilePath, "r")
 			local line = file.readLine()
     		while line do
 				print(line)
 				line = file.readLine()
 			end
 		end
 		read()
 		return 3
 	elseif choice == 4 then
 		print("User to Add")
 		nusername = read()
 		print("Chat ID: ")
 		chatid = read()
 		print(handleAddUser(nusername, chatid))
 		read()
 		return 4
 	elseif choice == 5 then
 		print("User to Remove")
 		ruser = read()
 		print("Chat ID: ")
 		chatid = read()
 		handleRemoveUser(getFirstWord(chats[chatid][1]), ruser, chatid)
 		read()
 		return 5
 	elseif choice == 6 then
 		print("Enter Username: ")
 		newruser = read()
 		chatnames = getUsersChats(chats, newruser)
 		if chatnames == "no" then
 			print("No User Found")
 			read()
 		elseif chatnames == "none" then
 			print("No Chat's Found")
 			read()
 		else
 			for _, chatname in pairs(chatnames) do
    				print(chatname)
     		end
 			read()
 		end
 		return 6
 	elseif choice == 7 then
 		term.clear()
 		return 7
 	elseif choice == 8 then
 		term.clear()
 		return 8
 	else
 		print("Incorrect Input")
 		return -1
 	end
 end
 
 local function login(chats)
 	while true do
 		print("Enter Username: ")
 		u = read()
 		print("Enter Password: ")
 		p = read('*')
 		if u == adminu and p == adminp then
 			while true do
 				displayOptions()
 				result = tonumber(read())
 				userSwitch(result, chats)
 				if result == 7 or result == 8 then
 					break
 				end
 				shell.run("clear")
 			end
 			if result == 8 then
 				break
 			end
 		end
 	end
 end
 
 shell.run("clear")
 loadChats()
 rednet.open("top")
 parallel.waitForAny(
 	function() messageRequests() end,
 	function() login(chats) end
 )