aboutsummaryrefslogtreecommitdiff
path: root/src/mail/namespace.rs
blob: 5e671736cd51352de1e1f09b64cdf3c864b044e5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
use std::collections::{BTreeMap, HashMap};
use std::sync::{Arc, Weak};

use anyhow::{anyhow, bail, Result};
use lazy_static::lazy_static;
use serde::{Deserialize, Serialize};
use tokio::sync::watch;

use crate::cryptoblob::{open_deserialize, seal_serialize};
use crate::login::Credentials;
use crate::mail::incoming::incoming_mail_watch_process;
use crate::mail::mailbox::Mailbox;
use crate::mail::uidindex::ImapUidvalidity;
use crate::mail::unique_ident::{gen_ident, UniqueIdent};
use crate::storage;
use crate::timestamp::now_msec;

pub const MAILBOX_HIERARCHY_DELIMITER: char = '.';

/// INBOX is the only mailbox that must always exist.
/// It is created automatically when the account is created.
/// IMAP allows the user to rename INBOX to something else,
/// in this case all messages from INBOX are moved to a mailbox
/// with the new name and the INBOX mailbox still exists and is empty.
/// In our implementation, we indeed move the underlying mailbox
/// to the new name (i.e. the new name has the same id as the previous
/// INBOX), and we create a new empty mailbox for INBOX.
pub const INBOX: &str = "INBOX";

/// For convenience purpose, we also create some special mailbox
/// that are described in RFC6154 SPECIAL-USE
/// @FIXME maybe it should be a configuration parameter
/// @FIXME maybe we should have a per-mailbox flag mechanism, either an enum or a string, so we
/// track which mailbox is used for what.
/// @FIXME Junk could be useful but we don't have any antispam solution yet so...
/// @FIXME IMAP supports virtual mailbox. \All or \Flagged are intended to be virtual mailboxes.
/// \Trash might be one, or not one. I don't know what we should do there.
pub const DRAFTS: &str = "Drafts";
pub const ARCHIVE: &str = "Archive";
pub const SENT: &str = "Sent";
pub const TRASH: &str = "Trash";

pub(crate) const MAILBOX_LIST_PK: &str = "mailboxes";
pub(crate) const MAILBOX_LIST_SK: &str = "list";

// ---- User's mailbox list (serialized in K2V) ----

#[derive(Serialize, Deserialize)]
pub(crate) struct MailboxList(BTreeMap<String, MailboxListEntry>);

#[derive(Serialize, Deserialize, Clone, Copy, Debug)]
pub(crate) struct MailboxListEntry {
    id_lww: (u64, Option<UniqueIdent>),
    uidvalidity: ImapUidvalidity,
}

impl MailboxListEntry {
    fn merge(&mut self, other: &Self) {
        // Simple CRDT merge rule
        if other.id_lww.0 > self.id_lww.0
            || (other.id_lww.0 == self.id_lww.0 && other.id_lww.1 > self.id_lww.1)
        {
            self.id_lww = other.id_lww;
        }
        self.uidvalidity = std::cmp::max(self.uidvalidity, other.uidvalidity);
    }
}

impl MailboxList {
    pub(crate) fn new() -> Self {
        Self(BTreeMap::new())
    }

    pub(crate) fn merge(&mut self, list2: Self) {
        for (k, v) in list2.0.into_iter() {
            if let Some(e) = self.0.get_mut(&k) {
                e.merge(&v);
            } else {
                self.0.insert(k, v);
            }
        }
    }

    pub(crate) fn existing_mailbox_names(&self) -> Vec<String> {
        self.0
            .iter()
            .filter(|(_, v)| v.id_lww.1.is_some())
            .map(|(k, _)| k.to_string())
            .collect()
    }

    pub(crate) fn has_mailbox(&self, name: &str) -> bool {
        matches!(
            self.0.get(name),
            Some(MailboxListEntry {
                id_lww: (_, Some(_)),
                ..
            })
        )
    }

    pub(crate) fn get_mailbox(&self, name: &str) -> Option<(ImapUidvalidity, Option<UniqueIdent>)> {
        self.0.get(name).map(
            |MailboxListEntry {
                 id_lww: (_, mailbox_id),
                 uidvalidity,
             }| (*uidvalidity, *mailbox_id),
        )
    }

    /// Ensures mailbox `name` maps to id `id`.
    /// If it already mapped to that, returns None.
    /// If a change had to be done, returns Some(new uidvalidity in mailbox).
    pub(crate) fn set_mailbox(&mut self, name: &str, id: Option<UniqueIdent>) -> Option<ImapUidvalidity> {
        let (ts, id, uidvalidity) = match self.0.get_mut(name) {
            None => {
                if id.is_none() {
                    return None;
                } else {
                    (now_msec(), id, ImapUidvalidity::new(1).unwrap())
                }
            }
            Some(MailboxListEntry {
                id_lww,
                uidvalidity,
            }) => {
                if id_lww.1 == id {
                    return None;
                } else {
                    (
                        std::cmp::max(id_lww.0 + 1, now_msec()),
                        id,
                        ImapUidvalidity::new(uidvalidity.get() + 1).unwrap(),
                    )
                }
            }
        };

        self.0.insert(
            name.into(),
            MailboxListEntry {
                id_lww: (ts, id),
                uidvalidity,
            },
        );
        Some(uidvalidity)
    }

    pub(crate) fn update_uidvalidity(&mut self, name: &str, new_uidvalidity: ImapUidvalidity) {
        match self.0.get_mut(name) {
            None => {
                self.0.insert(
                    name.into(),
                    MailboxListEntry {
                        id_lww: (now_msec(), None),
                        uidvalidity: new_uidvalidity,
                    },
                );
            }
            Some(MailboxListEntry { uidvalidity, .. }) => {
                *uidvalidity = std::cmp::max(*uidvalidity, new_uidvalidity);
            }
        }
    }

    pub(crate) fn create_mailbox(&mut self, name: &str) -> CreatedMailbox {
        if let Some(MailboxListEntry {
            id_lww: (_, Some(id)),
            uidvalidity,
        }) = self.0.get(name)
        {
            return CreatedMailbox::Existed(*id, *uidvalidity);
        }

        let id = gen_ident();
        let uidvalidity = self.set_mailbox(name, Some(id)).unwrap();
        CreatedMailbox::Created(id, uidvalidity)
    }

    pub(crate) fn rename_mailbox(&mut self, old_name: &str, new_name: &str) -> Result<()> {
        if let Some((uidvalidity, Some(mbid))) = self.get_mailbox(old_name) {
            if self.has_mailbox(new_name) {
                bail!(
                    "Cannot rename {} into {}: {} already exists",
                    old_name,
                    new_name,
                    new_name
                );
            }

            self.set_mailbox(old_name, None);
            self.set_mailbox(new_name, Some(mbid));
            self.update_uidvalidity(new_name, uidvalidity);
            Ok(())
        } else {
            bail!(
                "Cannot rename {} into {}: {} doesn't exist",
                old_name,
                new_name,
                old_name
            );
        }
    }
}

pub(crate) enum CreatedMailbox {
    Created(UniqueIdent, ImapUidvalidity),
    Existed(UniqueIdent, ImapUidvalidity),
}