Messenger Server / startup

---messenger server

if fs.exists("API") == false then
shell.run("pastebin", "get", "EzkfU5ZM", "API")
end
shaka = require("API")
shaka.connectModem()
shaka.clearScreen()
term.setBackgroundColor(colors.green)
term.setTextColor(colors.black)
term.clearLine()
shaka.centerText("Server up and running.", 1)
shaka.resetColors()
term.setCursorPos(1, 2)

local function saveNotifications(name)
    local notifications = shaka.readFile(".notifications", false)
    if notifications == false then
        notifications = {}
    end
    if notifications[name] then
        notifications[name] = notifications[name] + 1
    else
    notifications[name] = 1
    end
    shaka.writeFile(".notifications", notifications)
end

local function deleteNotifications(name)
    local notifications = shaka.readFile(".notifications")
    if notifications ~= false then
        notifications[name] = nil
        shaka.writeFile(".notifications", notifications)
    end
end


function saveUsers(userName, senderID)
  -- Check if the ".users" file exists
  if fs.exists(".users") then
    -- If it does, load the existing table of users
    local file = fs.open(".users", "r")
    local users = textutils.unserialize(file.readAll())
    file.close()

    if users == nil then
        users = {}
    end

    -- Check if the userName already exists in the table with a different ID
    for _, user in ipairs(users) do
      if user.name == userName and user.id ~= senderID then
        -- If it does, return false
        return false
      end
    end

    -- Check if the senderID is already in the table
    local found = false
    for i, user in ipairs(users) do
      if user.id == senderID then
        users[i] = {name=userName, id=senderID} -- Replace the whole entry
        found = true
        break
      end
    end

    -- If the senderID is not already in the table, insert the new user into the table
    if not found then
      table.insert(users, {name=userName, id=senderID})
    end

    -- Save the updated table to the file
    file = fs.open(".users", "w")
    file.write("{\n")
    for i, user in ipairs(users) do
      file.writeLine(textutils.serialize(user) .. (i == #users and "" or ","))
    end
    file.write("}\n")
    file.close()
    print("Saved " ..userName.. ": " ..senderID)
    -- Return true to indicate success
    return true
  else
    -- If the ".users" file does not exist, create a new table with the new user and save it to the file
    local users = {{name=userName, id=senderID}}
    local file = fs.open(".users", "w")
    file.write("{\n")
    for i, user in ipairs(users) do
      file.writeLine(textutils.serialize(user) .. (i == #users and "" or ","))
    end
    file.write("}\n")
    file.close()

    -- Return true to indicate success
    print("Saved " ..userName.. ": " ..senderID)
    return true
  end
end


function supplyUsers()
    if fs.exists(".users") then
        local file = fs.open(".users", "r")
        local users = file.readAll()
        rednet.broadcast(users, "userRequestAnswer")
        file.close()
    else
        rednet.broadcast("noUsers", "userRequestAnswer")
    end
end

function filterTable(name, id)
  local result = {}
  if fs.exists(".messages") then
    local file = fs.open(".messages", "r")
    local contents = file.readAll()
    file.close()
    result = textutils.unserialize(contents)
  end

  local filtered = {}
  local savedID = findSenderIdByName(name)
  for _, message in ipairs(result) do
    if message.sender == name or message.receiver == name or id == savedID then
      table.insert(filtered, message)
    end
  end
  return filtered
end

function findSenderIdByName(name)
    if fs.exists(".users") then
        local file = fs.open(".users", "r")
        existingNames = file.readAll()
        existingNames = textutils.unserialize(existingNames)
        file.close()
    end
  for _, user in ipairs(existingNames) do
    if user.name == name then
      return user.id
    end
  end
  return nil
end


function sendFilteredTable(name, id)
    local tableToSend = filterTable(name, id)
    tableToSend = textutils.serialize(tableToSend)
    if id ~= nil then
        print("Sending messageList to ID " ..id.. ": " ..name)
        rednet.send(id, tableToSend, "allMessages")
    end
end

function deleteNotifications(name)
    local notis = shaka.readFile(".notifications")
    if notis[name] then
        notis[name] = nil
    end
    shaka.writeFile(".notifications", notis)
end

local function remindNotifications(name)
    local list = shaka.readFile(".notifications")
    if type(list) == "table" then
    for k, v in pairs(list) do
        if k == name then
            local id = findSenderIdByName(k)
            rednet.send(id, v, "notificationReminder")
            print("Sent notification reminder to " ..name.. ": " ..v)
            return
        end
    end
    end
    local id = findSenderIdByName(name)
    if id ~= nil then
        rednet.send(id, "0", "notificationReminder")
    end
end

function receiveMessages()

  -- Initialize the messages table
  local messages = {}

  -- Check if the ".messages" file exists and load its contents into the messages table
  if fs.exists(".messages") then
    local file = fs.open(".messages", "r")
    local contents = file.readAll()
    file.close()
    messages = textutils.unserialize(contents)
  end


  -- Split the message into sender, text, and receiver
  local result = shaka.split(message, "+|")
  local sender = result[1]
  local text = result[2]
  local receiver = result[3]


            local function checkExistingUser(userName)
            -- Check if the ".users" file exists and read it
                if fs.exists(".users") then
                -- If it does, load the existing table of users
                local file = fs.open(".users", "r")
                local users = textutils.unserialize(file.readAll())
                file.close()

                -- Check if the userName already exists in the table
                for _, user in ipairs(users) do
                  if user.name == userName then
                    -- If it does, return false
                    return true
                  end
                end
            end
            return false
            end
    if checkExistingUser(sender) == false then
        return false
    end

saveNotifications(receiver)

  local now = os.date("*t")
  local date = string.format("%02d.%02d.%04d", now.day, now.month, now.year)
  local time = string.format("%02d:%02d", now.hour, now.min)

  table.insert(messages, {sender=sender, text=text, receiver=receiver, date=date, time=time})
  -- print("\nMessage received from " .. sender .. " to " .. receiver .. ":")
  -- print(text)



  -- Save the updated messages table to the ".messages" file
  local file = fs.open(".messages", "w")
  plzWrite = textutils.serialize(messages)
  file.write(plzWrite)
  file.close()
  return true
end


-- Enter the main program loop
local function main()
        sender, message, protocol = rednet.receive()
        -------------------------------------------
        if protocol == "newMessage" then
            if receiveMessages() then
                rednet.broadcast("worked", "messageConfirm")
            else
                rednet.broadcast("failed", "messageConfirm")
            end
        elseif protocol == "newUser" then
            if saveUsers(message, sender) then
                rednet.broadcast("worked", "userConfirm")
            else
                rednet.broadcast("fail", "userConfirm")
            end
        elseif protocol == "requestUserList" then
            supplyUsers()
        elseif protocol == "messageUpdate" then
            sendFilteredTable(message, sender)
        elseif protocol == "serverID" then
            rednet.broadcast("yeah yeah", "idSupply")
        elseif protocol == "delNotifications" then
            deleteNotifications(message)
        elseif protocol == "anyMessages?" then
            remindNotifications(message)
        end
end


while true do

main()

end