clientMessage

-- Set up modem
rednet.open("back") -- Replace "right" with the side your modem is attached to

-- Function to send a message to a chat
local function sendMessage(serverID, command, chatID, username, text)
    rednet.send(serverID, command .. " " .. chatID .. " " .. username .. " " .. text)
    local id, reply = rednet.receive()
    if reply == "true" then
        print("Message sent successfully!")
    else
        print("Failed to send message.")
    end
end

-- Function to retrieve messages from a chat
local function retrieveMessages(serverID, chatID, username)
    rednet.send(serverID, "retrieve " .. chatID .. " " .. username)
    local _, reply = rednet.receive(nil, 2)
    return reply
end


local function updateChat()
    while true do
        local _, reply = rednet.receive()
        if reply == "update" then
            start = true
        end
    end
end

local function chatControls(serverID, chatID, username)
    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(#dmessages - maxLines + 1, scrollPosition + 1)
    elseif key == keys.backspace then
        exitloop = true
    end
    if scrollPosition >= #dmessages - maxLines + 1 then
        bottom = true
        if key == keys.enter then
            local text = read()
            sendMessage(serverID, "send", chatID, username, text)
        end
    else
        bottom = false
    end
end

local function displayNewChat(serverID, chatID, username)
    while true do
        if start then
            dmessages = retrieveMessages(serverID, chatID, username)
            if dmessages == nil then
                start = false
                print("Error")
                os.sleep(2)
                return nil
            elseif dmessages == "false" then
                start = false
                print("Access Denied")
                os.sleep(2)
                return nil
            else
                dmessages[1] = "Users in Chat: " .. dmessages[1] .. "\n"
                table.insert(dmessages, "----------------------")
                table.insert(dmessages, " ")
                if bottom then
                    scrollPosition = math.min(#dmessages - maxLines + 1, scrollPosition + 1)
                end
                startIndex = math.max(1, scrollPosition)
                endIndex = math.min(#dmessages, scrollPosition + maxLines - 1)
                term.clear()
                term.setCursorPos(1, 1)
                for i = startIndex, endIndex do
                    print(dmessages[i])
                end
                start = false
            end
        end
        os.sleep(0.001)
    end
end

local function displayMessages(serverID, chatID, username)
    start = false
    exitloop = false
    scrollPosition = 1
    dmessages = retrieveMessages(serverID, chatID, username)
    dmessages[1] = "Users in Chat: " .. dmessages[1] .. "\n"
    table.insert(dmessages, "----------------------")
    table.insert(dmessages, " ")
    maxLines = 15
    local startIndex = math.max(1, scrollPosition)
    local endIndex = math.min(#dmessages, scrollPosition + maxLines - 1)
    while true do
        term.clear()
        term.setCursorPos(1, 1)
        -- Display the database content after the instruction
        for i = startIndex, endIndex do
            print(dmessages[i])
        end

        parallel.waitForAny(
        function() chatControls(serverID, chatID, username) end,
        function() displayNewChat(serverID, chatID, username) end
        )
        startIndex = math.max(1, scrollPosition)
        endIndex = math.min(#dmessages, scrollPosition + maxLines - 1)
        if exitloop then
            break
        end
    end
end


-- Function to create a chat
local function createChat(serverID, chatID, username)
    rednet.send(serverID, "create " .. chatID .. " " .. username)
    local _, reply = rednet.receive(nil, 3)
    print(reply)
    os.sleep(1)
    if reply == "true" then
        print("Chat " .. chatID .. " created successfully!")
    else
        print("Failed to create chat " .. chatID .. ".")
    end
end

-- Function to delete a chat
local function deleteChat(serverID, chatID, username)
    rednet.send(serverID, "delete " .. chatID .. " " .. username)
    local _, reply = rednet.receive(nil, 3)
    if reply == nil then
        print("Failed to delete chat " .. chatID .. ".")
    elseif reply == "denied" then
        print("Failed to delete chat " .. chatID .. ". Not Owner of Chat")
    else
        print("Chat " .. chatID .. " deleted successfully!")
    end
end

local function printChats(serverID, username)
    rednet.send(serverID, "chats " .. " " .. username)
    local _, reply = rednet.receive(nil, 3)
    if type(reply) == "String" then
        if reply == "no" then
            print("Failed to connect to Server")
        elseif reply == "none" then
            print("No Chats Found")
        end
    else
        for _, chatname in pairs(reply) do
            print(chatname)
        end
    end
end


function text(sender, serverID)
    while true do
        print("Select an action: ")
        print("1. Display Chats")
        print("2. Enter a Chat")
        print("3. Create a chat")
        print("4. Delete a chat")
        print("5. Add User to Chat")
        print("6. Remove User from Chat")
        print("7. Exit")

        local choice = tonumber(read())

        if choice == 1 then
            print("Chats Available: ")
            printChats(serverID, sender)
            print("Type Anything to Continue")
            read()
            term.clear()
            term.setCursorPos(1, 1)
        elseif choice == 2 then
            print("Enter chat ID to retrieve messages from:")
            local chatID = read()
            reply = retrieveMessages(serverID, chatID, sender)
            if reply == nil then
                print("Chat does not Exist")
                os.sleep(3)
            elseif reply == "false" then
                print("Access to Chat Denied")
                os.sleep(3)
                term.clear()
                term.setCursorPos(1, 1)
            else
                term.clear()
                term.setCursorPos(1, 1)
                print("Text Controls are: \n")
                print("Up and Down to Scroll \n")
                print("Enter at Bottom of Chat to type \n")
                print("Backspace to Leave Chat \n")
                print("Type Anything to Continue")
                read()
                term.clear()
                term.setCursorPos(1, 1)
                parallel.waitForAny(
                    function() displayMessages(serverID, chatID, sender) end,
                    function() updateChat() end
                )
            end
        elseif choice == 3 then
            print("Enter chat ID to create:")
            local chatID = read()
            createChat(serverID, chatID, sender)
        elseif choice == 4 then
            print("Enter chat ID to delete:")
            local chatID = read()
            deleteChat(serverID, chatID, sender)
        elseif choice == 5 then
            print("Enter chat ID:")
            local chatID = read()
            print("Enter User to Add:")
            local auser = read()
            sendMessage(serverID, "add", chatID, sender, auser)
        elseif choice == 6 then
            print("Enter chat ID:")
            local chatID = read()
            print("Enter User to Remove:")
            local ruser = read()
            sendMessage(serverID, "remove", chatID, sender, ruser)

        elseif choice == 7 then
            break
        else
            print("Invalid choice. Please try again.")
        end
    end
end