ServerEdition

local computerId = os.getComputerID()
local monitor = peripheral.find("monitor")
local modem = peripheral.find("modem")

local function generateRandomHostname()
    local randomSuffix = ""
    local randomLength = 5
    local characters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

    for i = 1, randomLength do
        local randomIndex = math.random(1, #characters)
        randomSuffix = randomSuffix .. string.sub(characters, randomIndex, randomIndex)
    end

    local hostname = "NetTchat-" .. randomSuffix
    return hostname
end

local function findEnderModem()
    for _, side in ipairs({"left", "right", "top", "bottom", "front", "back"}) do
        if peripheral.isPresent(side) and peripheral.getType(side) == "modem" then
            return side
        end
    end
    error("No modem found")
end

local function displayServerInfo(monitor, computerId, hostname, protocol)
    monitor.clear()
    monitor.setCursorPos(1, 1)
    monitor.setTextScale(1)

    local title = string.format("Serveur NetTchat démarré sur le Computer #%s :", computerId)
    local underline = string.rep("-", #title)

    monitor.write(title)
    monitor.setCursorPos(1, 2)
    monitor.write(underline)

    monitor.setCursorPos(1, 4)
    monitor.write(string.format("Hostname : %s", hostname))

    monitor.setCursorPos(1, 5)
    monitor.write(string.format("Protocol : %s", protocol))
end

local function updateClientList(monitor, clients)
    monitor.clear()
    monitor.setCursorPos(1, 1)
    monitor.setTextScale(1)

    local title = string.format("Serveur NetTchat démarré sur le Computer #%s :", computerId)
    local underline = string.rep("-", #title)

    monitor.write(title)
    monitor.setCursorPos(1, 2)
    monitor.write(underline)

    monitor.setCursorPos(1, 4)
    monitor.write(string.format("Hostname : %s", hostname))

    monitor.setCursorPos(1, 5)
    monitor.write(string.format("Protocol : %s", protocol))

    monitor.setCursorPos(1, 7)
    monitor.write("Clients connectés:")
    monitor.setCursorPos(1, 8)
    monitor.write(string.rep("-", 20))

    local y = 9
    for clientId, client in pairs(clients) do
        monitor.setCursorPos(1, y)
        if client.connected then
            monitor.write(client.name .. " (Online)")
        else
            monitor.write(client.name .. " (Disconnected)")
        end
        y = y + 1
    end
end


local function startOnServer()
    term.clear()
    local protocol = "chat"
    local hostname = generateRandomHostname()

    local credits = "NetTchat Server Edition, created and designed by _Tsyke_ | Ver: 0.3"
    local creditsScale = 0.8
    monitor.setTextScale(creditsScale)

    local width, height = monitor.getSize()
    local creditsX = math.floor((width - #credits) / 2)
    local creditsY = math.floor(height / 2)

    monitor.clear()
    monitor.setCursorPos(creditsX, creditsY)
    monitor.write(credits)

    os.sleep(5)

    displayServerInfo(monitor, computerId, hostname, protocol)

    local modemSide = findEnderModem()
    rednet.open(modemSide)
    rednet.host(protocol, hostname)

    print("Serveur démarré. Attente des connexions...")
    print("Protocole: " .. protocol)
    print("Hostname: " .. hostname)
    print("Modem sur: " .. modemSide)

    local clients = {}
    local clientLastPing = {}

    local function checkClientPing()
        while true do
            local currentTime = os.time()
            for clientId, client in pairs(clients) do
                if client.connected then
                    rednet.send(clientId, "Ping", protocol)
                    local _, message = rednet.receive(protocol, 2)  -- Attend une réponse pendant 2 secondes

                    if not message or message ~= "Pong" then
                        print("Client déconnecté: #" .. clientId)
                        clients[clientId] = nil
                        updateClientList(monitor, clients)  -- Mettre à jour la liste des clients sur le moniteur
                    end
                end
            end
            os.sleep(5)
        end
    end


    parallel.waitForAll(
        function()
            while true do
                local senderId, message, receivedProtocol = rednet.receive(protocol)

                if receivedProtocol == protocol then
                    if message == "Demande de connexion" then
                        clients[senderId] = { name = "Client #" .. senderId, connected = true }
                        updateClientList(monitor, clients)
                        print("Client connecté: #" .. senderId)
                        rednet.send(senderId, "Connexion acceptée", protocol)
                    elseif message == "Ping" then
                        -- Le serveur ne devrait pas recevoir "Ping" directement ici, donc rien n'est fait ici.
                    else
                        print("Message reçu de #" .. senderId .. ": " .. message)
                    end
                end
            end
        end,
        checkClientPing
    )
end

startOnServer()