Files
omnibot/lib/contrib/linkbot.ex
Alek Ratzloff 9dc00562fd Add linkbot contrib module
Linkbot listens for http:// and https:// links, and attempts to get
their titles.

This also adds the "tesla" dependency to mix.exs

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
2020-06-13 20:59:58 -04:00

39 lines
985 B
Elixir

defmodule Omnibot.Contrib.Linkbot do
use Omnibot.Module
require Logger
defmodule Client do
use Tesla
plug Tesla.Middleware.Headers, [{"user-agent", "Tesla/Omnibot"}]
plug Tesla.Middleware.FollowRedirects, max_redirects: 10
plug Tesla.Middleware.Compression, format: "gzip"
@title_regex ~r"<title>(?<title>.+)</title>"i
def get_title(url) do
if should_get?(url) do
resp = get!(url)
%{"title" => title} = Regex.named_captures(@title_regex, resp.body)
title
end
end
defp should_get?(url) do
resp = head!(url)
Tesla.get_header(resp, "content-type")
|> String.downcase()
|> String.contains?(["html", "text"])
end
end
@url_regex ~r"\bhttps?://[^\s]+"
@impl true
def on_channel_msg(irc, channel, _nick, line) do
Regex.scan(@url_regex, line)
|> Enum.map(fn url -> Client.get_title(url) end)
|> Enum.each(fn title -> Irc.send_to(irc, channel, title) end)
end
end