Simple WOW addon to reply to whispers with an AFK message if you're set /afk. Thank you ChatGPT for making this since I was too lazy.

AutoAFKMessage.lua

-- Define the addon name and version
local ADDON_NAME, ADDON_VERSION = "AutoAFKMessage", "1.0"

-- Create a frame to handle events
local frame = CreateFrame("Frame")

-- Register for events
frame:RegisterEvent("CHAT_MSG_WHISPER")

-- Set the away message
local awayMessage = "[AutoMsg] Hey! I am currently away right now."

-- Addon enabled flag
local addonEnabled = true

-- Event handler function
local function eventHandler(self, event, ...)
    if event == "CHAT_MSG_WHISPER" then
        if addonEnabled then
            local message, sender = ...
            -- Check if the message is whisper and the player is AFK
            if UnitIsAFK("player") and not UnitIsDND("player") then
                -- Reply to the whisper
                SendChatMessage(awayMessage, "WHISPER", nil, sender)
            end
        end
    end
end

-- Slash command handler
local function SlashCmdHandler(msg)
    if msg == "toggle" then
        addonEnabled = not addonEnabled
        if addonEnabled then
            print(ADDON_NAME.." enabled.")
        else
            print(ADDON_NAME.." disabled.")
        end
    else
        print("Usage: /afkm toggle - to enable/disable the addon.")
    end
end

-- Register slash command
SLASH_AFKM1 = "/afkm"
SlashCmdList["AFKM"] = SlashCmdHandler

-- Assign the event handler function to the frame
frame:SetScript("OnEvent", eventHandler)

-- Display a message when the addon is loaded
print(ADDON_NAME.." v"..ADDON_VERSION.." loaded.")

AutoAFKMessage.toc

## Interface: 90005
## Title: AutoAFKMessage
## Author: ChatGPT
## Version: 1.0
## Notes: Automatically replies to whispers when the player is AFK.
## DefaultState: Enabled

AutoAFKMessage.lua