Mikubot-2/plugins/help.lua

 -- This plugin should go at the end of your plugin list in
 -- config.lua, but not after greetings.lua.

local commandlist = {}
for i,v in ipairs(plugins) do
	if v.command then
		table.insert(commandlist, v.command)
	end
end

table.insert(commandlist, 'help [command]')
table.sort(commandlist)

local help_text = '*Available commands:*\n• /' .. table.concat(commandlist,'\n• /') .. '\nArguments: <required> [optional]'

help_text = help_text:gsub('%[', '\\[')

local triggers = {
	'^/help[@'..bot.username..']*',
	'^/h[@'..bot.username..']*$'
}

local action = function(msg)

	local input = msg.text_lower:input()

	-- Attempts to send the help message via PM.
	-- If msg is from a group, it tells the group whether the PM was successful.
	if not input then
		local res = sendMessage(msg.from.id, help_text, true, nil, true)
		if not res then
			sendReply(msg, 'Please message me privately for a list of commands.')
		elseif msg.chat.type ~= 'private' then
			sendReply(msg, 'I have sent you the requested information in a private message.')
		end
		return
	end

	for i,v in ipairs(plugins) do
		if v.command and get_word(v.command, 1) == input and v.doc then
			local output = '*Help for* _' .. get_word(v.command, 1) .. '_ *:*\n' .. v.doc
			sendMessage(msg.chat.id, output, true, nil, true)
			return
		end
	end

	sendReply(msg, 'Sorry, there is no help for that command.')

end

return {
	action = action,
	triggers = triggers
}