summaryrefslogtreecommitdiffstats
path: root/src/send_mail.rs
blob: c2c0ce312ef3c3ad930c5dd794cc7820ccc52c05 (plain)
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
use std::iter::FromIterator;
use std::vec;

use futures::future::{self, Either, Loop, Future};
use new_tokio_smtp::{Cmd, Connection, ConnectionConfig, SetupTls};
use new_tokio_smtp::send_mail::{self as smtp};

use mail_common::MailType;
use mail_common::encoder::EncodingBuffer;
use mail::Context;
use mail::error::MailError;

use ::resolve_all::ResolveAll;
use ::request::MailRequest;
use ::error::{MailSendError, TransportError};

/// Result of encoding a mail
pub type EncodeMailResult = Result<smtp::MailEnvelop, MailError>;

/// creates a futures which encodes all mails
///
/// To encode the mails this functions turns
/// mail every requests into mails with envelop data,
/// then creates a future resolving when the mail is
/// ready to be encoded and chain this result with
/// offloading the actual encoding of each mail
/// to a thread pool. Lastly all fo this futures
/// are polled in parallel by the returned future.
///
/// # Error
///
/// The futures will never error, but it will
/// resolve to a vector of results, representing
/// the encoding result for each mail in the input
/// separately
///
pub fn encode_mails(
    requests: impl IntoIterator<Item=MailRequest>,
    ctx: impl Context
    //TODO[futures/v>=0.2 | rust/! type]: use Never or !
) -> impl Future<Item=Vec<EncodeMailResult>, Error=()> + Send
{
    let pending = requests
        .into_iter()
        .map(|request| {
            let (mail, envelop_data) =
                match request.into_mail_with_envelop() {
                    Ok(pair) => pair,
                    Err(e) => return Either::A(future::err(e.into()))
                };

            let _ctx = ctx.clone();
            let fut = mail
                .into_encodeable_mail(ctx.clone())
                .and_then(move |enc_mail| _ctx.offload_fn(move || {
                    let (mail_type, requirement) =
                        if envelop_data.needs_smtputf8() {
                            (MailType::Internationalized, smtp::EncodingRequirement::Smtputf8)
                        } else {
                            (MailType::Ascii, smtp::EncodingRequirement::None)
                        };

                    let mut buffer = EncodingBuffer::new(mail_type);
                    enc_mail.encode(&mut buffer)?;

                    let vec_buffer: Vec<_> = buffer.into();
                    let smtp_mail = smtp::Mail::new(requirement, vec_buffer);

                    Ok(smtp::MailEnvelop::from((smtp_mail, envelop_data)))
                }));

            Either::B(fut)
        });

    ResolveAll::from_iter(pending)
}

/// results of sending an encoded mail
pub type SendMailResult = Result<(), MailSendError>;

/// Sends all encoded mails through the given connection
///
/// This methods accepts a iterator of `EncodedMailResult`'s as it's
/// meant to be chained with `encode_mails`.
///
/// # Error
///
/// The returned future resolves to a vector of results, one for each mail
/// send.
///
/// If a transport error happens (e.g. an I/O-Error) a tuple consisting of
/// the Error, the already send mails and and iterator of the remaining mails is
/// returned.
pub fn send_encoded_mails<I>(con: Connection, mails: I)
    -> impl Future<
        Item=(Connection, Vec<SendMailResult>),
        Error=(TransportError, Vec<SendMailResult>, I::IntoIter)>
    where I: IntoIterator<Item=EncodeMailResult>, I::IntoIter: 'static
{
    let iter = mails.into_iter();
    let results = Vec::new();
    let fut = future::loop_fn((con, iter, results), |(con, mut iter, mut results)| match iter.next() {
        None => Either::A(future::ok(Loop::Break((con, results)))),
        Some(Err(err)) => {
            results.push(Err(MailSendError::from(err)));
            Either::A(future::ok(Loop::Continue((con, iter, results))))
        },
        Some(Ok(envelop)) => Either::B(con
            .send_mail(envelop)
            .then(move |res| match res {
                Ok((con, logic_result)) => {
                    results.push(logic_result.map_err(|(_idx, err)| MailSendError::from(err)));
                    Ok(Loop::Continue((con, iter, results)))
                },
                Err(err) => {
                    Err((TransportError::Io(err), results, iter))
                }
            }))
    });

    fut
}

/// Send mails _to a specific mail server_
///
/// This encodes the mails, opens a connection, sends the mails over and
/// closes the connection again.
///
/// While this uses the `To` field of a mail to determine the smtp reveiver
/// it does not resolve the server based on the mail address domain. This
/// means it's best suite for sending to a Mail Submission Agent (MSA), but
/// less for sending to a Mail Exchanger (MX).
///
/// Automatically handling Bcc/Cc is _not yet_ implemented.
///
pub fn send_mails(
    config: ConnectionConfig<impl Cmd, impl SetupTls>,
    requests: impl IntoIterator<Item=MailRequest>,
    ctx: impl Context)
    -> impl Future<
        Item=Vec<SendMailResult>,
        Error=(TransportError, Vec<SendMailResult>, vec::IntoIter<EncodeMailResult>)>
{

    let fut = encode_mails(requests, ctx)
        .map_err(|_| unreachable!())
        .and_then(|mails| {
            if mails.iter().all(|r| r.is_err()) {
                let send_skipped = mails
                    .into_iter()
                    .map(|result| match result {
                        Ok(_) => unreachable!(),
                        Err(err) => Err(MailSendError::Mail(err))
                    })
                    .collect();

                Either::A(future::ok(send_skipped))
            } else {
                let fut = Connection
                    ::connect(config)
                    .then(|result| match result {
                        Err(err) => Either::A(future::err((TransportError::Connecting(err), Vec::new(), mails.into_iter()))),
                        Ok(con) => Either::B(send_encoded_mails(con, mails))
                    })
                    .and_then(|(con, results)| con.quit().then(|_| Ok(results)));

                Either::B(fut)
            }
        });

    fut
}