#! /usr/bin/lua5.1

-- Some crappy IMAP functions in LUA 5.1
-- Copyright (C) 2009 Matous Jan Fialka, <http://mjf.cz/>
-- Released under the terms of The MIT License

-- TODO: properly handle IMAP errors

assert(require("socket"))

local imap_accounts = {}

function set_imap_accounts(a)
	assert(a)
	a.host, a.user, a.pass, a.sock = nil
	a.port = a.port or 143
	imap_accounts = a
end
 
local function imap_login(n)
	assert(type(assert(n)) == "string")
	local a = assert(imap_accounts[n])
	local h,u,p = assert(a.host), assert(a.user), assert(a.pass)
	local s = assert(socket.connect(h, a.port))
	imap_accounts[n].sock = s
	if s:receive() then
		if s:send(". login "..u.." "..p.."\r\n") then
			if s:receive() then
				return true
			end
		end
	end
	return false
end

local function imap_logout(n)
	assert(type(assert(n)) == "string")
	local a = assert(imap_accounts[n])
	assert(a.sock)
	if a.sock:send(". logout\r\n") then
		if a.sock:close() then
			a.sock = nil
			return true
		end
	end
	return false
end
 
local function imap_status(n,q)
	assert(type(assert(n)) == "string")
	local q,a,r = string.lower(assert(q)), assert(imap_accounts[n])
	if a.sock:send(". status INBOX ("..q..")\r\n") then
		r = a.sock:receive()
		if not a.sock:receive() or not r then
			return -1
		end
		r = string.match(r, string.upper(q).."%s+(%d+)")
	end
	return r or 0
end

set_imap_accounts({
	example1 = {
		host = "mail.example1.tld",
		user = "user@example1.tld",
		pass = "xxxxxxxx",
	},
	example2 = {
		host = "mail.example2.tld",
		user = "user@example2.tld",
		pass = "xxxxxxxx",
	},
})

local u = nil
local m = nil

if imap_login("example2") then
	m = imap_status("example2", "messages")
	u = imap_status("example2", "unseen")
	imap_logout("example1")
end

print("Messages: "..m.." New: "..u)