use anyhow::{
anyhow,
Result,
};
use async_std::task;
use samotop::{
mail::{
Builder,
DebugService,
MailDir,
Name
},
smtp::{
SmtpParser,
Prudence,
},
};
use teloxide::{
Bot,
prelude::{
Requester,
RequesterExt,
},
types::{
ChatId,
InputMedia,
Message,
ParseMode::MarkdownV2,
},
};
use std::{
borrow::Cow,
collections::{
HashMap,
HashSet,
},
io::Read,
os::unix::fs::{
FileTypeExt,
PermissionsExt,
},
path::{
Path,
PathBuf
},
time::Duration,
vec::Vec,
};
fn address_into_iter<'a>(addr: &'a mail_parser::Address<'a, >) -> impl Iterator<Item = Cow<'a, str>> {
addr.clone().into_list().into_iter().map(|a| a.address.unwrap())
}
async fn relay_mails(maildir: &Path, core: &TelegramTransport) -> Result<()> {
let new_dir = maildir.join("new");
std::fs::create_dir_all(&new_dir)?;
let files = std::fs::read_dir(new_dir)?;
for file in files {
let file = file?;
let mut buf: String = Default::default();
std::fs::File::open(file.path())?.read_to_string(&mut buf)?;
let mail = mail_parser::MessageParser::new().parse(&buf)
.ok_or(anyhow!("Failed to parse mail `{:?}`.", file))?;
// Fetching address lists from fields we know
let mut to = HashSet::new();
if let Some(addr) = mail.to() {
let _ = address_into_iter(addr).map(|x| to.insert(x));
};
if let Some(addr) = mail.header("X-Samotop-To") {
match addr {
mail_parser::HeaderValue::Address(addr) => {
let _ = address_into_iter(addr).map(|x| to.insert(x));
},
mail_parser::HeaderValue::Text(text) => {
to.insert(text.clone());
},
_ => {}
}
};
// Adding all known addresses to recipient list, for anyone else adding default
// Also if list is empty also adding default
let mut rcpt: HashSet<&ChatId> = HashSet::new();
for item in to {
let item = item.into_owned();
match core.recipients.get(&item) {
Some(addr) => rcpt.insert(addr),
None => {
core.debug(format!("Recipient [{}] not found.", &item)).await?;
rcpt.insert(core.recipients.get("_")
.ok_or(anyhow!("Missing default address in recipient table."))?)
}
};
};
if rcpt.is_empty() {
core.debug("No recipient or envelope address.").await?;
rcpt.insert(core.recipients.get("_")
.ok_or(anyhow!("Missing default address in recipient table."))?);
};
// prepating message header
let mut reply: Vec<Cow<'_, str>> = vec![];
if let Some(subject) = mail.subject() {
reply.push(format!("**Subject:** `{}`", subject).into());
} else if let Some(thread) = mail.thread_name() {
reply.push(format!("**Thread:** `{}`", thread).into());
}
if let Some(from) = mail.from() {
reply.push(format!("**From:** `{:?}`", address_into_iter(from).collect::<Vec<_>>().join(", ")).into());
}
if let Some(sender) = mail.sender() {
reply.push(format!("**Sender:** `{:?}`", address_into_iter(sender).collect::<Vec<_>>().join(", ")).into());
}
reply.push("".into());
let header_size = reply.join("\n").len() + 1;
let html_parts = mail.html_body_count();
let text_parts = mail.text_body_count();
let attachments = mail.attachment_count();
if html_parts != text_parts {
core.debug(format!("Hm, we have {} HTML parts and {} text parts.", html_parts, text_parts)).await?;
}
//let mut html_num = 0;
let mut text_num = 0;
let mut file_num = 0;
// let's display first html or text part as body
let mut body = "".into();
/*
* actually I don't wanna parse that html stuff
if html_parts > 0 {
let text = mail.body_html(0).unwrap();
if text.len() < 4096 - header_size {
body = text;
html_num = 1;
}
};
*/
if body == "" && text_parts > 0 {
let text = mail.body_text(0)
.ok_or(anyhow!("Failed to extract text from message."))?;
if text.len() < 4096 - header_size {
body = text;
text_num = 1;
}
};
reply.push("```".into());
reply.extend(body.lines().map(|x| x.into()));
reply.push("```".into());
// and let's collect all other attachment parts
let mut files_to_send = vec![];
/*
* let's just skip html parts for now, they just duplicate text?
while html_num < html_parts {
files_to_send.push(mail.html_part(html_num).unwrap());
html_num += 1;
}
*/
while text_num < text_parts {
files_to_send.push(mail.text_part(text_num)
.ok_or(anyhow!("Failed to get text part from message"))?);
text_num += 1;
}
while file_num < attachments {
files_to_send.push(mail.attachment(file_num)
.ok_or(anyhow!("Failed to get file part from message"))?);
file_num += 1;
}
let msg = reply.join("\n");
for chat in rcpt {
if !files_to_send.is_empty() {
let mut files = vec![];
let mut first_one = true;
for chunk in &files_to_send {
let data = chunk.contents();
let mut filename: Option<String> = None;
for header in chunk.headers() {
if header.name() == "Content-Type" {
match header.value() {
mail_parser::HeaderValue::ContentType(contenttype) => {
if let Some(fname) = contenttype.attribute("name") {
filename = Some(fname.to_owned());
}
},
_ => {
core.debug("Attachment has bad ContentType header.").await?;
},
};
};
};
let filename = if let Some(fname) = filename {
fname
} else {
"Attachment.txt".into()
};
let item = teloxide::types::InputMediaDocument::new(
teloxide::types::InputFile::memory(data.to_vec())
.file_name(filename));
let item = if first_one {
first_one = false;
item.caption(&msg).parse_mode(MarkdownV2)
} else {
item
};
files.push(InputMedia::Document(item));
}
core.sendgroup(chat, files).await?;
} else {
core.send(chat, &msg).await?;
}
}
std::fs::remove_file(file.path())?;
}
Ok(())
}
fn my_prudence() -> Prudence {
Prudence::default().with_read_timeout(Duration::from_secs(60)).with_banner_delay(Duration::from_secs(1))
}
pub struct TelegramTransport {
tg: teloxide::adaptors::DefaultParseMode<teloxide::adaptors::Throttle<Bot>>,
recipients: HashMap<String, ChatId>,
}
impl TelegramTransport {
pub fn new(settings: config::Config) -> TelegramTransport {
let tg = Bot::new(settings.get_string("api_key")
.expect("[smtp2tg.toml] missing \"api_key\" parameter.\n"))
.throttle(teloxide::adaptors::throttle::Limits::default())
.parse_mode(MarkdownV2);
let recipients: HashMap<String, ChatId> = settings.get_table("recipients")
.expect("[smtp2tg.toml] missing table \"recipients\".\n")
.into_iter().map(|(a, b)| (a, ChatId (b.into_int()
.expect("[smtp2tg.toml] \"recipient\" table values should be integers.\n")
))).collect();
if !recipients.contains_key("_") {
eprintln!("[smtp2tg.toml] \"recipient\" table misses \"default_recipient\".\n");
panic!("no default recipient");
}
TelegramTransport {
tg,
recipients,
}
}
pub async fn debug<'b, S>(&self, msg: S) -> Result<Message>
where S: Into<String> {
Ok(self.tg.send_message(*self.recipients.get("_").unwrap(), msg).await?)
}
pub async fn send<'b, S>(&self, to: &ChatId, msg: S) -> Result<Message>
where S: Into<String> {
Ok(self.tg.send_message(*to, msg).await?)
}
pub async fn sendgroup<M>(&self, to: &ChatId, media: M) -> Result<Vec<Message>>
where M: IntoIterator<Item = InputMedia> {
Ok(self.tg.send_media_group(*to, media).await?)
}
}
#[async_std::main]
async fn main() {
let settings: config::Config = config::Config::builder()
.add_source(config::File::with_name("smtp2tg.toml"))
.build()
.expect("[smtp2tg.toml] there was an error reading config\n\
\tplease consult \"smtp2tg.toml.example\" for details");
let maildir: PathBuf = settings.get_string("maildir")
.expect("[smtp2tg.toml] missing \"maildir\" parameter.\n").into();
let listen_on = settings.get_string("listen_on")
.expect("[smtp2tg.toml] missing \"listen_on\" parameter.\n");
let core = TelegramTransport::new(settings);
let sink = Builder + Name::new("smtp2tg") + DebugService +
my_prudence() + MailDir::new(maildir.clone()).unwrap();
task::spawn(async move {
loop {
// relay mails
if let Err(err) = relay_mails(&maildir, &core).await {
// in case that fails - inform default recipient
if let Err(err) = core.debug(format!("Sending emails failed:\n{:?}", err)).await {
// in case that also fails - write some logs and bail
eprintln!("Failed to contact Telegram:\n{:?}", err);
};
task::sleep(Duration::from_secs(5 * 60)).await;
};
task::sleep(Duration::from_secs(5)).await;
}
});
match listen_on.as_str() {
"socket" => {
let socket_path = "./smtp2tg.sock";
match std::fs::symlink_metadata(socket_path) {
Ok(metadata) => {
if metadata.file_type().is_socket() {
std::fs::remove_file(socket_path)
.expect("[smtp2tg] failed to remove old socket.\n");
} else {
eprintln!("[smtp2tg] \"./smtp2tg.sock\" we wanted to use is actually not a socket.\n\
[smtp2tg] please check the file and remove it manually.\n");
panic!("socket path unavailable");
}
},
Err(err) => {
match err.kind() {
std::io::ErrorKind::NotFound => {},
_ => {
eprintln!("{:?}", err);
panic!("unhandled file type error");
}
};
}
};
let sink = sink + samotop::smtp::Lmtp.with(SmtpParser);
task::spawn(async move {
// Postpone mode change on the socket. I can't actually change
// other way, as UnixServer just grabs path, and blocks
task::sleep(Duration::from_secs(1)).await;
std::fs::set_permissions(socket_path, std::fs::Permissions::from_mode(0o777)).unwrap();
});
samotop::server::UnixServer::on(socket_path)
.serve(sink.build()).await.unwrap();
},
_ => {
let sink = sink + samotop::smtp::Esmtp.with(SmtpParser);
samotop::server::TcpServer::on(listen_on)
.serve(sink.build()).await.unwrap();
},
};
}