path: root/melib/src/backends/imap/watch.rs

/*
 * meli - imap module.
 *
 * Copyright 2019 Manos Pitsidianakis
 *
 * This file is part of meli.
 *
 * meli is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * meli is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with meli. If not, see <http://www.gnu.org/licenses/>.
 */
use super::*;
use crate::backends::SpecialUsageMailbox;
use std::sync::Arc;

/// Arguments for IMAP watching functions
pub struct ImapWatchKit {
    pub conn: ImapConnection,
    pub main_conn: Arc<FutureMutex<ImapConnection>>,
    pub uid_store: Arc<UIDStore>,
}

pub async fn poll_with_examine(kit: ImapWatchKit) -> Result<()> {
    debug!("poll with examine");
    let ImapWatchKit {
        mut conn,
        main_conn: _,
        uid_store,
    } = kit;
    conn.connect().await?;
    let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
        let mailboxes_lck = timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
        mailboxes_lck.clone()
    };
    loop {
        for (_, mailbox) in mailboxes.clone() {
            examine_updates(mailbox, &mut conn, &uid_store).await?;
        }
        //FIXME: make sleep duration configurable
        smol::Timer::after(std::time::Duration::from_secs(3 * 60)).await;
    }
}

pub async fn idle(kit: ImapWatchKit) -> Result<()> {
    debug!("IDLE");
    /* IDLE only watches the connection's selected mailbox. We will IDLE on INBOX and every ~5
     * minutes wake up and poll the others */
    let ImapWatchKit {
        mut conn,
        main_conn,
        uid_store,
    } = kit;
    conn.connect().await?;
    let mailbox: ImapMailbox = match uid_store
        .mailboxes
        .lock()
        .await
        .values()
        .find(|f| f.parent.is_none() && (f.special_usage() == SpecialUsageMailbox::Inbox))
        .map(std::clone::Clone::clone)
    {
        Some(mailbox) => mailbox,
        None => {
            return Err(MeliError::new("INBOX mailbox not found in local mailbox index. meli may have not parsed the IMAP mailboxes correctly"));
        }
    };
    let mailbox_hash = mailbox.hash();
    let mut response = Vec::with_capacity(8 * 1024);
    let select_response = conn
        .examine_mailbox(mailbox_hash, &mut response, true)
        .await?
        .unwrap();
    {
        let mut uidvalidities = uid_store.uidvalidity.lock().unwrap();

        if let Some(v) = uidvalidities.get(&mailbox_hash) {
            if *v != select_response.uidvalidity {
                if uid_store.keep_offline_cache {
                    #[cfg(not(feature = "sqlite3"))]
                    let mut cache_handle = super::cache::DefaultCache::get(uid_store.clone())?;
                    #[cfg(feature = "sqlite3")]
                    let mut cache_handle = super::cache::Sqlite3Cache::get(uid_store.clone())?;
                    cache_handle.clear(mailbox_hash, &select_response)?;
                }
                conn.add_refresh_event(RefreshEvent {
                    account_hash: uid_store.account_hash,
                    mailbox_hash,
                    kind: RefreshEventKind::Rescan,
                });
                /*
                uid_store.uid_index.lock().unwrap().clear();
                uid_store.hash_index.lock().unwrap().clear();
                uid_store.byte_cache.lock().unwrap().clear();
                */
            }
        } else {
            uidvalidities.insert(mailbox_hash, select_response.uidvalidity);
        }
    }
    let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
        let mailboxes_lck = timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
        mailboxes_lck.clone()
    };
    for (h, mailbox) in mailboxes.clone() {
        if mailbox_hash == h {
            continue;
        }
        examine_updates(mailbox, &mut conn, &uid_store).await?;
    }
    conn.send_command(b"IDLE").await?;
    let mut blockn = ImapBlockingConnection::from(conn);
    let mut watch = std::time::Instant::now();
    /* duration interval to send heartbeat */
    const _10_MINS: std::time::Duration = std::time::Duration::from_secs(10 * 60);
    /* duration interval to check other mailboxes for changes */
    const _5_MINS: std::time::Duration = std::time::Duration::from_secs(5 * 60);
    loop {
        let line = match timeout(Some(_10_MINS), blockn.as_stream()).await {
            Ok(Some(line)) => line,
            Ok(None) => {
                debug!("IDLE connection dropped: {:?}", &blockn.err());
                blockn.conn.connect().await?;
                let mut main_conn_lck = timeout(uid_store.timeout, main_conn.lock()).await?;
                main_conn_lck.connect().await?;
                continue;
            }
            Err(_) => {
                /* Timeout */
                blockn.conn.send_raw(b"DONE").await?;
                blockn
                    .conn
                    .read_response(&mut response, RequiredResponses::empty())
                    .await?;
                blockn.conn.send_command(b"IDLE").await?;
                let mut main_conn_lck = timeout(uid_store.timeout, main_conn.lock()).await?;
                main_conn_lck.connect().await?;
                continue;
            }
        };
        let now = std::time::Instant::now();
        if now.duration_since(watch) >= _5_MINS {
            /* Time to poll all inboxes */
            let mut conn = timeout(uid_store.timeout, main_conn.lock()).await?;
            for (h, mailbox) in mailboxes.clone() {
                if mailbox_hash == h {
                    continue;
                }
                examine_updates(mailbox, &mut conn, &uid_store).await?;
            }
            watch = now;
        }
        if line
            .split_rn()
            .filter(|l| {
                !l.starts_with(b"+ ")
                    && !l.starts_with(b"* ok")
                    && !l.starts_with(b"* ok")
                    && !l.starts_with(b"* Ok")
                    && !l.starts_with(b"* OK")
            })
            .count()
            == 0
        {
            continue;
        }
        {
            blockn.conn.send_raw(b"DONE").await?;
            blockn
                .conn
                .read_response(&mut response, RequiredResponses::empty())
                .await?;
            for l in line.split_rn() {
                debug!("process_untagged {:?}", &l);
                if l.starts_with(b"+ ")
                    || l.starts_with(b"* ok")
                    || l.starts_with(b"* ok")
                    || l.starts_with(b"* Ok")
                    || l.starts_with(b"* OK")
                {
                    debug!("ignore continuation mark");
                    continue;
                }
                blockn.conn.process_untagged(l).await?;
            }
            blockn.conn.send_command(b"IDLE").await?;
        }
    }
}

pub async fn examine_updates(
    mailbox: ImapMailbox,
    conn: &mut ImapConnection,
    uid_store: &Arc<UIDStore>,
) -> Result<()> {
    if mailbox.no_select {
        return Ok(());
    }
    let mailbox_hash = mailbox.hash();
    debug!("examining mailbox {} {}"