deltachat/imap/
session.rs

1use std::collections::BTreeMap;
2use std::ops::{Deref, DerefMut};
3
4use anyhow::{Context as _, Result};
5use async_imap::Session as ImapSession;
6use async_imap::types::Mailbox;
7use futures::TryStreamExt;
8
9use crate::imap::capabilities::Capabilities;
10use crate::net::session::SessionStream;
11
12/// Prefetch:
13/// - Message-ID to check if we already have the message.
14/// - In-Reply-To and References to check if message is a reply to chat message.
15/// - Chat-Version to check if a message is a chat message
16/// - Autocrypt-Setup-Message to check if a message is an autocrypt setup message,
17///   not necessarily sent by Delta Chat.
18/// - Chat-Is-Post-Message to skip it in background fetch or when it is > `DownloadLimit`.
19const PREFETCH_FLAGS: &str = "(UID INTERNALDATE RFC822.SIZE BODY.PEEK[HEADER.FIELDS (\
20                              MESSAGE-ID \
21                              DATE \
22                              X-MICROSOFT-ORIGINAL-MESSAGE-ID \
23                              FROM \
24                              CHAT-VERSION \
25                              CHAT-IS-POST-MESSAGE \
26                              AUTOCRYPT-SETUP-MESSAGE\
27                              )])";
28
29#[derive(Debug)]
30pub(crate) struct Session {
31    transport_id: u32,
32
33    pub(super) inner: ImapSession<Box<dyn SessionStream>>,
34
35    pub capabilities: Capabilities,
36
37    /// Selected folder name.
38    pub selected_folder: Option<String>,
39
40    /// Mailbox structure returned by IMAP server.
41    pub selected_mailbox: Option<Mailbox>,
42
43    pub selected_folder_needs_expunge: bool,
44
45    /// True if currently selected folder has new messages.
46    ///
47    /// Should be false if no folder is currently selected.
48    pub new_mail: bool,
49
50    pub resync_request_sender: async_channel::Sender<()>,
51}
52
53impl Deref for Session {
54    type Target = ImapSession<Box<dyn SessionStream>>;
55
56    fn deref(&self) -> &Self::Target {
57        &self.inner
58    }
59}
60
61impl DerefMut for Session {
62    fn deref_mut(&mut self) -> &mut Self::Target {
63        &mut self.inner
64    }
65}
66
67impl Session {
68    pub(crate) fn new(
69        inner: ImapSession<Box<dyn SessionStream>>,
70        capabilities: Capabilities,
71        resync_request_sender: async_channel::Sender<()>,
72        transport_id: u32,
73    ) -> Self {
74        Self {
75            transport_id,
76            inner,
77            capabilities,
78            selected_folder: None,
79            selected_mailbox: None,
80            selected_folder_needs_expunge: false,
81            new_mail: false,
82            resync_request_sender,
83        }
84    }
85
86    /// Returns ID of the transport for which this session was created.
87    pub(crate) fn transport_id(&self) -> u32 {
88        self.transport_id
89    }
90
91    pub fn can_idle(&self) -> bool {
92        self.capabilities.can_idle
93    }
94
95    pub fn can_move(&self) -> bool {
96        self.capabilities.can_move
97    }
98
99    pub fn can_check_quota(&self) -> bool {
100        self.capabilities.can_check_quota
101    }
102
103    pub fn can_condstore(&self) -> bool {
104        self.capabilities.can_condstore
105    }
106
107    pub fn can_metadata(&self) -> bool {
108        self.capabilities.can_metadata
109    }
110
111    pub fn can_push(&self) -> bool {
112        self.capabilities.can_push
113    }
114
115    // Returns true if IMAP server has `XCHATMAIL` capability.
116    pub fn is_chatmail(&self) -> bool {
117        self.capabilities.is_chatmail
118    }
119
120    /// Returns the names of all folders on the IMAP server.
121    pub async fn list_folders(&mut self) -> Result<Vec<async_imap::types::Name>> {
122        let list = self.list(Some(""), Some("*")).await?.try_collect().await?;
123        Ok(list)
124    }
125
126    /// Prefetch `n_uids` messages starting from `uid_next`. Returns a list of fetch results in the
127    /// order of ascending delivery time to the server (INTERNALDATE).
128    #[expect(clippy::arithmetic_side_effects)]
129    pub(crate) async fn prefetch(
130        &mut self,
131        uid_next: u32,
132        n_uids: u32,
133    ) -> Result<Vec<(u32, async_imap::types::Fetch)>> {
134        let uid_last = uid_next.saturating_add(n_uids - 1);
135        // fetch messages with larger UID than the last one seen
136        let set = format!("{uid_next}:{uid_last}");
137        let mut list = self
138            .uid_fetch(set, PREFETCH_FLAGS)
139            .await
140            .context("IMAP could not fetch")?;
141
142        let mut msgs = BTreeMap::new();
143        while let Some(msg) = list.try_next().await? {
144            if let Some(msg_uid) = msg.uid {
145                msgs.insert((msg.internal_date(), msg_uid), msg);
146            }
147        }
148
149        Ok(msgs.into_iter().map(|((_, uid), msg)| (uid, msg)).collect())
150    }
151}
deltachat/imap/session.rs

deltachat/imap/
session.rs
