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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
//! For middleware documentation, see [`Logger`].

use std::{
    borrow::Cow,
    collections::HashSet,
    env,
    fmt::{self, Display as _},
    future::Future,
    marker::PhantomData,
    pin::Pin,
    rc::Rc,
    task::{Context, Poll},
};

use actix_service::{Service, Transform};
use actix_utils::future::{ready, Ready};
use bytes::Bytes;
use futures_core::ready;
use log::{debug, warn};
use pin_project_lite::pin_project;
#[cfg(feature = "unicode")]
use regex::Regex;
#[cfg(not(feature = "unicode"))]
use regex_lite::Regex;
use time::{format_description::well_known::Rfc3339, OffsetDateTime};

use crate::{
    body::{BodySize, MessageBody},
    http::header::HeaderName,
    service::{ServiceRequest, ServiceResponse},
    Error, Result,
};

/// Middleware for logging request and response summaries to the terminal.
///
/// This middleware uses the `log` crate to output information. Enable `log`'s output for the
/// "actix_web" scope using [`env_logger`](https://docs.rs/env_logger) or similar crate.
///
/// # Default Format
/// The [`default`](Logger::default) Logger uses the following format:
///
/// ```plain
/// %a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T
///
/// Example Output:
/// 127.0.0.1:54278 "GET /test HTTP/1.1" 404 20 "-" "HTTPie/2.2.0" 0.001074
/// ```
///
/// # Examples
/// ```
/// use actix_web::{middleware::Logger, App};
///
/// // access logs are printed with the INFO level so ensure it is enabled by default
/// env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
///
/// let app = App::new()
///     // .wrap(Logger::default())
///     .wrap(Logger::new("%a %{User-Agent}i"));
/// ```
///
/// # Format
/// Variable | Description
/// -------- | -----------
/// `%%` | The percent sign
/// `%a` | Peer IP address (or IP address of reverse proxy if used)
/// `%t` | Time when the request started processing (in RFC 3339 format)
/// `%r` | First line of request (Example: `GET /test HTTP/1.1`)
/// `%s` | Response status code
/// `%b` | Size of response in bytes, including HTTP headers
/// `%T` | Time taken to serve the request, in seconds to 6 decimal places
/// `%D` | Time taken to serve the request, in milliseconds
/// `%U` | Request URL
/// `%{r}a` | "Real IP" remote address **\***
/// `%{FOO}i` | `request.headers["FOO"]`
/// `%{FOO}o` | `response.headers["FOO"]`
/// `%{FOO}e` | `env_var["FOO"]`
/// `%{FOO}xi` | [Custom request replacement](Logger::custom_request_replace) labelled "FOO"
/// `%{FOO}xo` | [Custom response replacement](Logger::custom_response_replace) labelled "FOO"
///
/// # Security
/// **\*** "Real IP" remote address is calculated using
/// [`ConnectionInfo::realip_remote_addr()`](crate::dev::ConnectionInfo::realip_remote_addr())
///
/// If you use this value, ensure that all requests come from trusted hosts. Otherwise, it is
/// trivial for the remote client to falsify their source IP address.
#[derive(Debug)]
pub struct Logger(Rc<Inner>);

#[derive(Debug, Clone)]
struct Inner {
    format: Format,
    exclude: HashSet<String>,
    exclude_regex: Vec<Regex>,
    log_target: Cow<'static, str>,
}

impl Logger {
    /// Create `Logger` middleware with the specified `format`.
    pub fn new(format: &str) -> Logger {
        Logger(Rc::new(Inner {
            format: Format::new(format),
            exclude: HashSet::new(),
            exclude_regex: Vec::new(),
            log_target: Cow::Borrowed(module_path!()),
        }))
    }

    /// Ignore and do not log access info for specified path.
    pub fn exclude<T: Into<String>>(mut self, path: T) -> Self {
        Rc::get_mut(&mut self.0)
            .unwrap()
            .exclude
            .insert(path.into());
        self
    }

    /// Ignore and do not log access info for paths that match regex.
    pub fn exclude_regex<T: Into<String>>(mut self, path: T) -> Self {
        let inner = Rc::get_mut(&mut self.0).unwrap();
        inner.exclude_regex.push(Regex::new(&path.into()).unwrap());
        self
    }

    /// Sets the logging target to `target`.
    ///
    /// By default, the log target is `module_path!()` of the log call location. In our case, that
    /// would be `actix_web::middleware::logger`.
    ///
    /// # Examples
    /// Using `.log_target("http_log")` would have this effect on request logs:
    /// ```diff
    /// - [2015-10-21T07:28:00Z INFO  actix_web::middleware::logger] 127.0.0.1 "GET / HTTP/1.1" 200 88 "-" "dmc/1.0" 0.001985
    /// + [2015-10-21T07:28:00Z INFO  http_log] 127.0.0.1 "GET / HTTP/1.1" 200 88 "-" "dmc/1.0" 0.001985
    ///                               ^^^^^^^^
    /// ```
    pub fn log_target(mut self, target: impl Into<Cow<'static, str>>) -> Self {
        let inner = Rc::get_mut(&mut self.0).unwrap();
        inner.log_target = target.into();
        self
    }

    /// Register a function that receives a ServiceRequest and returns a String for use in the
    /// log line. The label passed as the first argument should match a replacement substring in
    /// the logger format like `%{label}xi`.
    ///
    /// It is convention to print "-" to indicate no output instead of an empty string.
    ///
    /// # Examples
    /// ```
    /// # use actix_web::http::{header::HeaderValue};
    /// # use actix_web::middleware::Logger;
    /// # fn parse_jwt_id (_req: Option<&HeaderValue>) -> String { "jwt_uid".to_owned() }
    /// Logger::new("example %{JWT_ID}xi")
    ///     .custom_request_replace("JWT_ID", |req| parse_jwt_id(req.headers().get("Authorization")));
    /// ```
    pub fn custom_request_replace(
        mut self,
        label: &str,
        f: impl Fn(&ServiceRequest) -> String + 'static,
    ) -> Self {
        let inner = Rc::get_mut(&mut self.0).unwrap();

        let ft = inner.format.0.iter_mut().find(
            |ft| matches!(ft, FormatText::CustomRequest(unit_label, _) if label == unit_label),
        );

        if let Some(FormatText::CustomRequest(_, request_fn)) = ft {
            // replace into None or previously registered fn using same label
            request_fn.replace(CustomRequestFn {
                inner_fn: Rc::new(f),
            });
        } else {
            // non-printed request replacement function diagnostic
            debug!(
                "Attempted to register custom request logging function for nonexistent label: {}",
                label
            );
        }

        self
    }

    /// Register a function that receives a `ServiceResponse` and returns a string for use in the
    /// log line.
    ///
    /// The label passed as the first argument should match a replacement substring in
    /// the logger format like `%{label}xo`.
    ///
    /// It is convention to print "-" to indicate no output instead of an empty string.
    ///
    /// The replacement function does not have access to the response body.
    ///
    /// # Examples
    /// ```
    /// # use actix_web::{dev::ServiceResponse, middleware::Logger};
    /// fn log_if_error(res: &ServiceResponse) -> String {
    ///     if res.status().as_u16() >= 400 {
    ///         "ERROR".to_string()
    ///     } else {
    ///         "-".to_string()
    ///     }
    /// }
    ///
    /// Logger::new("example %{ERROR_STATUS}xo")
    ///     .custom_response_replace("ERROR_STATUS", |res| log_if_error(res) );
    /// ```
    pub fn custom_response_replace(
        mut self,
        label: &str,
        f: impl Fn(&ServiceResponse) -> String + 'static,
    ) -> Self {
        let inner = Rc::get_mut(&mut self.0).unwrap();

        let ft = inner.format.0.iter_mut().find(
            |ft| matches!(ft, FormatText::CustomResponse(unit_label, _) if label == unit_label),
        );

        if let Some(FormatText::CustomResponse(_, res_fn)) = ft {
            *res_fn = Some(CustomResponseFn {
                inner_fn: Rc::new(f),
            });
        } else {
            debug!(
                "Attempted to register custom response logging function for non-existent label: {}",
                label
            );
        }

        self
    }
}

impl Default for Logger {
    /// Create `Logger` middleware with format:
    ///
    /// ```plain
    /// %a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T
    /// ```
    fn default() -> Logger {
        Logger(Rc::new(Inner {
            format: Format::default(),
            exclude: HashSet::new(),
            exclude_regex: Vec::new(),
            log_target: Cow::Borrowed(module_path!()),
        }))
    }
}

impl<S, B> Transform<S, ServiceRequest> for Logger
where
    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
    B: MessageBody,
{
    type Response = ServiceResponse<StreamLog<B>>;
    type Error = Error;
    type Transform = LoggerMiddleware<S>;
    type InitError = ();
    type Future = Ready<Result<Self::Transform, Self::InitError>>;

    fn new_transform(&self, service: S) -> Self::Future {
        for unit in &self.0.format.0 {
            if let FormatText::CustomRequest(label, None) = unit {
                warn!(
                    "No custom request replacement function was registered for label: {}",
                    label
                );
            }

            if let FormatText::CustomResponse(label, None) = unit {
                warn!(
                    "No custom response replacement function was registered for label: {}",
                    label
                );
            }
        }

        ready(Ok(LoggerMiddleware {
            service,
            inner: self.0.clone(),
        }))
    }
}

/// Logger middleware service.
pub struct LoggerMiddleware<S> {
    inner: Rc<Inner>,
    service: S,
}

impl<S, B> Service<ServiceRequest> for LoggerMiddleware<S>
where
    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
    B: MessageBody,
{
    type Response = ServiceResponse<StreamLog<B>>;
    type Error = Error;
    type Future = LoggerResponse<S, B>;

    actix_service::forward_ready!(service);

    fn call(&self, req: ServiceRequest) -> Self::Future {
        let excluded = self.inner.exclude.contains(req.path())
            || self
                .inner
                .exclude_regex
                .iter()
                .any(|r| r.is_match(req.path()));

        if excluded {
            LoggerResponse {
                fut: self.service.call(req),
                format: None,
                time: OffsetDateTime::now_utc(),
                log_target: Cow::Borrowed(""),
                _phantom: PhantomData,
            }
        } else {
            let now = OffsetDateTime::now_utc();
            let mut format = self.inner.format.clone();

            for unit in &mut format.0 {
                unit.render_request(now, &req);
            }

            LoggerResponse {
                fut: self.service.call(req),
                format: Some(format),
                time: now,
                log_target: self.inner.log_target.clone(),
                _phantom: PhantomData,
            }
        }
    }
}

pin_project! {
    pub struct LoggerResponse<S, B>
    where
        B: MessageBody,
        S: Service<ServiceRequest>,
    {
        #[pin]
        fut: S::Future,
        time: OffsetDateTime,
        format: Option<Format>,
        log_target: Cow<'static, str>,
        _phantom: PhantomData<B>,
    }
}

impl<S, B> Future for LoggerResponse<S, B>
where
    B: MessageBody,
    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
{
    type Output = Result<ServiceResponse<StreamLog<B>>, Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        let this = self.project();

        let res = match ready!(this.fut.poll(cx)) {
            Ok(res) => res,
            Err(err) => return Poll::Ready(Err(err)),
        };

        if let Some(error) = res.response().error() {
            debug!("Error in response: {:?}", error);
        }

        let res = if let Some(ref mut format) = this.format {
            // to avoid polluting all the Logger types with the body parameter we swap the body
            // out temporarily since it's not usable in custom response functions anyway

            let (req, res) = res.into_parts();
            let (res, body) = res.into_parts();

            let temp_res = ServiceResponse::new(req, res.map_into_boxed_body());

            for unit in &mut format.0 {
                unit.render_response(&temp_res);
            }

            // re-construct original service response
            let (req, res) = temp_res.into_parts();
            ServiceResponse::new(req, res.set_body(body))
        } else {
            res
        };

        let time = *this.time;
        let format = this.format.take();
        let log_target = this.log_target.clone();

        Poll::Ready(Ok(res.map_body(move |_, body| StreamLog {
            body,
            time,
            format,
            size: 0,
            log_target,
        })))
    }
}

pin_project! {
    pub struct StreamLog<B> {
        #[pin]
        body: B,
        format: Option<Format>,
        size: usize,
        time: OffsetDateTime,
        log_target: Cow<'static, str>,
    }

    impl<B> PinnedDrop for StreamLog<B> {
        fn drop(this: Pin<&mut Self>) {
            if let Some(ref format) = this.format {
                let render = |fmt: &mut fmt::Formatter<'_>| {
                    for unit in &format.0 {
                        unit.render(fmt, this.size, this.time)?;
                    }
                    Ok(())
                };

                log::info!(
                    target: this.log_target.as_ref(),
                    "{}", FormatDisplay(&render)
                );
            }
        }
    }
}

impl<B: MessageBody> MessageBody for StreamLog<B> {
    type Error = B::Error;

    #[inline]
    fn size(&self) -> BodySize {
        self.body.size()
    }

    fn poll_next(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<Option<Result<Bytes, Self::Error>>> {
        let this = self.project();

        match ready!(this.body.poll_next(cx)) {
            Some(Ok(chunk)) => {
                *this.size += chunk.len();
                Poll::Ready(Some(Ok(chunk)))
            }
            Some(Err(err)) => Poll::Ready(Some(Err(err))),
            None => Poll::Ready(None),
        }
    }
}

/// A formatting style for the `Logger` consisting of multiple concatenated `FormatText` items.
#[derive(Debug, Clone)]
struct Format(Vec<FormatText>);

impl Default for Format {
    /// Return the default formatting style for the `Logger`:
    fn default() -> Format {
        Format::new(r#"%a "%r" %s %b "%{Referer}i" "%{User-Agent}i" %T"#)
    }
}

impl Format {
    /// Create a `Format` from a format string.
    ///
    /// Returns `None` if the format string syntax is incorrect.
    pub fn new(s: &str) -> Format {
        log::trace!("Access log format: {}", s);
        let fmt = Regex::new(r"%(\{([A-Za-z0-9\-_]+)\}([aioe]|x[io])|[%atPrUsbTD]?)").unwrap();

        let mut idx = 0;
        let mut results = Vec::new();
        for cap in fmt.captures_iter(s) {
            let m = cap.get(0).unwrap();
            let pos = m.start();
            if idx != pos {
                results.push(FormatText::Str(s[idx..pos].to_owned()));
            }
            idx = m.end();

            if let Some(key) = cap.get(2) {
                results.push(match cap.get(3).unwrap().as_str() {
                    "a" => {
                        if key.as_str() == "r" {
                            FormatText::RealIpRemoteAddr
                        } else {
                            unreachable!("regex and code mismatch")
                        }
                    }
                    "i" => FormatText::RequestHeader(HeaderName::try_from(key.as_str()).unwrap()),
                    "o" => FormatText::ResponseHeader(HeaderName::try_from(key.as_str()).unwrap()),
                    "e" => FormatText::EnvironHeader(key.as_str().to_owned()),
                    "xi" => FormatText::CustomRequest(key.as_str().to_owned(), None),
                    "xo" => FormatText::CustomResponse(key.as_str().to_owned(), None),
                    _ => unreachable!(),
                })
            } else {
                let m = cap.get(1).unwrap();
                results.push(match m.as_str() {
                    "%" => FormatText::Percent,
                    "a" => FormatText::RemoteAddr,
                    "t" => FormatText::RequestTime,
                    "r" => FormatText::RequestLine,
                    "s" => FormatText::ResponseStatus,
                    "b" => FormatText::ResponseSize,
                    "U" => FormatText::UrlPath,
                    "T" => FormatText::Time,
                    "D" => FormatText::TimeMillis,
                    _ => FormatText::Str(m.as_str().to_owned()),
                });
            }
        }
        if idx != s.len() {
            results.push(FormatText::Str(s[idx..].to_owned()));
        }

        Format(results)
    }
}

/// A string of text to be logged.
///
/// This is either one of the data fields supported by the `Logger`, or a custom `String`.
#[non_exhaustive]
#[derive(Debug, Clone)]
enum FormatText {
    Str(String),
    Percent,
    RequestLine,
    RequestTime,
    ResponseStatus,
    ResponseSize,
    Time,
    TimeMillis,
    RemoteAddr,
    RealIpRemoteAddr,
    UrlPath,
    RequestHeader(HeaderName),
    ResponseHeader(HeaderName),
    EnvironHeader(String),
    CustomRequest(String, Option<CustomRequestFn>),
    CustomResponse(String, Option<CustomResponseFn>),
}

#[derive(Clone)]
struct CustomRequestFn {
    inner_fn: Rc<dyn Fn(&ServiceRequest) -> String>,
}

impl CustomRequestFn {
    fn call(&self, req: &ServiceRequest) -> String {
        (self.inner_fn)(req)
    }
}

impl fmt::Debug for CustomRequestFn {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str("custom_request_fn")
    }
}

#[derive(Clone)]
struct CustomResponseFn {
    inner_fn: Rc<dyn Fn(&ServiceResponse) -> String>,
}

impl CustomResponseFn {
    fn call(&self, res: &ServiceResponse) -> String {
        (self.inner_fn)(res)
    }
}

impl fmt::Debug for CustomResponseFn {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str("custom_response_fn")
    }
}

impl FormatText {
    fn render(
        &self,
        fmt: &mut fmt::Formatter<'_>,
        size: usize,
        entry_time: OffsetDateTime,
    ) -> Result<(), fmt::Error> {
        match self {
            FormatText::Str(ref string) => fmt.write_str(string),
            FormatText::Percent => "%".fmt(fmt),
            FormatText::ResponseSize => size.fmt(fmt),
            FormatText::Time => {
                let rt = OffsetDateTime::now_utc() - entry_time;
                let rt = rt.as_seconds_f64();
                fmt.write_fmt(format_args!("{:.6}", rt))
            }
            FormatText::TimeMillis => {
                let rt = OffsetDateTime::now_utc() - entry_time;
                let rt = (rt.whole_nanoseconds() as f64) / 1_000_000.0;
                fmt.write_fmt(format_args!("{:.6}", rt))
            }
            FormatText::EnvironHeader(ref name) => {
                if let Ok(val) = env::var(name) {
                    fmt.write_fmt(format_args!("{}", val))
                } else {
                    "-".fmt(fmt)
                }
            }
            _ => Ok(()),
        }
    }

    fn render_response(&mut self, res: &ServiceResponse) {
        match self {
            FormatText::ResponseStatus => {
                *self = FormatText::Str(format!("{}", res.status().as_u16()))
            }

            FormatText::ResponseHeader(ref name) => {
                let s = if let Some(val) = res.headers().get(name) {
                    if let Ok(s) = val.to_str() {
                        s
                    } else {
                        "-"
                    }
                } else {
                    "-"
                };
                *self = FormatText::Str(s.to_string())
            }

            FormatText::CustomResponse(_, res_fn) => {
                let text = match res_fn {
                    Some(res_fn) => FormatText::Str(res_fn.call(res)),
                    None => FormatText::Str("-".to_owned()),
                };

                *self = text;
            }

            _ => {}
        }
    }

    fn render_request(&mut self, now: OffsetDateTime, req: &ServiceRequest) {
        match self {
            FormatText::RequestLine => {
                *self = if req.query_string().is_empty() {
                    FormatText::Str(format!(
                        "{} {} {:?}",
                        req.method(),
                        req.path(),
                        req.version()
                    ))
                } else {
                    FormatText::Str(format!(
                        "{} {}?{} {:?}",
                        req.method(),
                        req.path(),
                        req.query_string(),
                        req.version()
                    ))
                };
            }
            FormatText::UrlPath => *self = FormatText::Str(req.path().to_string()),
            FormatText::RequestTime => *self = FormatText::Str(now.format(&Rfc3339).unwrap()),
            FormatText::RequestHeader(ref name) => {
                let s = if let Some(val) = req.headers().get(name) {
                    if let Ok(s) = val.to_str() {
                        s
                    } else {
                        "-"
                    }
                } else {
                    "-"
                };
                *self = FormatText::Str(s.to_string());
            }
            FormatText::RemoteAddr => {
                let s = if let Some(peer) = req.connection_info().peer_addr() {
                    FormatText::Str((*peer).to_string())
                } else {
                    FormatText::Str("-".to_string())
                };
                *self = s;
            }
            FormatText::RealIpRemoteAddr => {
                let s = if let Some(remote) = req.connection_info().realip_remote_addr() {
                    FormatText::Str(remote.to_string())
                } else {
                    FormatText::Str("-".to_string())
                };
                *self = s;
            }
            FormatText::CustomRequest(_, request_fn) => {
                let s = match request_fn {
                    Some(f) => FormatText::Str(f.call(req)),
                    None => FormatText::Str("-".to_owned()),
                };

                *self = s;
            }
            _ => {}
        }
    }
}

/// Converter to get a String from something that writes to a Formatter.
pub(crate) struct FormatDisplay<'a>(&'a dyn Fn(&mut fmt::Formatter<'_>) -> Result<(), fmt::Error>);

impl<'a> fmt::Display for FormatDisplay<'a> {
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
        (self.0)(fmt)
    }
}

#[cfg(test)]
mod tests {
    use actix_service::IntoService;
    use actix_utils::future::ok;

    use super::*;
    use crate::{
        http::{header, StatusCode},
        test::{self, TestRequest},
        HttpResponse,
    };

    #[actix_rt::test]
    async fn test_logger() {
        let srv = |req: ServiceRequest| {
            ok(req.into_response(
                HttpResponse::build(StatusCode::OK)
                    .insert_header(("X-Test", "ttt"))
                    .finish(),
            ))
        };
        let logger = Logger::new("%% %{User-Agent}i %{X-Test}o %{HOME}e %D test");

        let srv = logger.new_transform(srv.into_service()).await.unwrap();

        let req = TestRequest::default()
            .insert_header((
                header::USER_AGENT,
                header::HeaderValue::from_static("ACTIX-WEB"),
            ))
            .to_srv_request();
        let _res = srv.call(req).await;
    }

    #[actix_rt::test]
    async fn test_logger_exclude_regex() {
        let srv = |req: ServiceRequest| {
            ok(req.into_response(
                HttpResponse::build(StatusCode::OK)
                    .insert_header(("X-Test", "ttt"))
                    .finish(),
            ))
        };
        let logger =
            Logger::new("%% %{User-Agent}i %{X-Test}o %{HOME}e %D test").exclude_regex("\\w");

        let srv = logger.new_transform(srv.into_service()).await.unwrap();

        let req = TestRequest::default()
            .insert_header((
                header::USER_AGENT,
                header::HeaderValue::from_static("ACTIX-WEB"),
            ))
            .to_srv_request();
        let _res = srv.call(req).await.unwrap();
    }

    #[actix_rt::test]
    async fn test_escape_percent() {
        let mut format = Format::new("%%{r}a");

        let req = TestRequest::default()
            .insert_header((
                header::FORWARDED,
                header::HeaderValue::from_static("for=192.0.2.60;proto=http;by=203.0.113.43"),
            ))
            .to_srv_request();

        let now = OffsetDateTime::now_utc();
        for unit in &mut format.0 {
            unit.render_request(now, &req);
        }

        let req = TestRequest::default().to_http_request();
        let res = ServiceResponse::new(req, HttpResponse::Ok().finish());
        for unit in &mut format.0 {
            unit.render_response(&res);
        }

        let entry_time = OffsetDateTime::now_utc();
        let render = |fmt: &mut fmt::Formatter<'_>| {
            for unit in &format.0 {
                unit.render(fmt, 1024, entry_time)?;
            }
            Ok(())
        };
        let s = format!("{}", FormatDisplay(&render));
        assert_eq!(s, "%{r}a");
    }

    #[actix_rt::test]
    async fn test_url_path() {
        let mut format = Format::new("%T %U");
        let req = TestRequest::default()
            .insert_header((
                header::USER_AGENT,
                header::HeaderValue::from_static("ACTIX-WEB"),
            ))
            .uri("/test/route/yeah")
            .to_srv_request();

        let now = OffsetDateTime::now_utc();
        for unit in &mut format.0 {
            unit.render_request(now, &req);
        }

        let req = TestRequest::default().to_http_request();
        let res = ServiceResponse::new(req, HttpResponse::Ok().force_close().finish());
        for unit in &mut format.0 {
            unit.render_response(&res);
        }

        let render = |fmt: &mut fmt::Formatter<'_>| {
            for unit in &format.0 {
                unit.render(fmt, 1024, now)?;
            }
            Ok(())
        };
        let s = format!("{}", FormatDisplay(&render));
        assert!(s.contains("/test/route/yeah"));
    }

    #[actix_rt::test]
    async fn test_default_format() {
        let mut format = Format::default();

        let req = TestRequest::default()
            .insert_header((
                header::USER_AGENT,
                header::HeaderValue::from_static("ACTIX-WEB"),
            ))
            .peer_addr("127.0.0.1:8081".parse().unwrap())
            .to_srv_request();

        let now = OffsetDateTime::now_utc();
        for unit in &mut format.0 {
            unit.render_request(now, &req);
        }

        let req = TestRequest::default().to_http_request();
        let res = ServiceResponse::new(req, HttpResponse::Ok().force_close().finish());
        for unit in &mut format.0 {
            unit.render_response(&res);
        }

        let entry_time = OffsetDateTime::now_utc();
        let render = |fmt: &mut fmt::Formatter<'_>| {
            for unit in &format.0 {
                unit.render(fmt, 1024, entry_time)?;
            }
            Ok(())
        };
        let s = format!("{}", FormatDisplay(&render));
        assert!(s.contains("GET / HTTP/1.1"));
        assert!(s.contains("127.0.0.1"));
        assert!(s.contains("200 1024"));
        assert!(s.contains("ACTIX-WEB"));
    }

    #[actix_rt::test]
    async fn test_request_time_format() {
        let mut format = Format::new("%t");
        let req = TestRequest::default().to_srv_request();

        let now = OffsetDateTime::now_utc();
        for unit in &mut format.0 {
            unit.render_request(now, &req);
        }

        let req = TestRequest::default().to_http_request();
        let res = ServiceResponse::new(req, HttpResponse::Ok().force_close().finish());
        for unit in &mut format.0 {
            unit.render_response(&res);
        }

        let render = |fmt: &mut fmt::Formatter<'_>| {
            for unit in &format.0 {
                unit.render(fmt, 1024, now)?;
            }
            Ok(())
        };
        let s = format!("{}", FormatDisplay(&render));
        assert!(s.contains(&now.format(&Rfc3339).unwrap()));
    }

    #[actix_rt::test]
    async fn test_remote_addr_format() {
        let mut format = Format::new("%{r}a");

        let req = TestRequest::default()
            .insert_header((
                header::FORWARDED,
                header::HeaderValue::from_static("for=192.0.2.60;proto=http;by=203.0.113.43"),
            ))
            .to_srv_request();

        let now = OffsetDateTime::now_utc();
        for unit in &mut format.0 {
            unit.render_request(now, &req);
        }

        let req = TestRequest::default().to_http_request();
        let res = ServiceResponse::new(req, HttpResponse::Ok().finish());
        for unit in &mut format.0 {
            unit.render_response(&res);
        }

        let entry_time = OffsetDateTime::now_utc();
        let render = |fmt: &mut fmt::Formatter<'_>| {
            for unit in &format.0 {
                unit.render(fmt, 1024, entry_time)?;
            }
            Ok(())
        };
        let s = format!("{}", FormatDisplay(&render));
        assert!(s.contains("192.0.2.60"));
    }

    #[actix_rt::test]
    async fn test_custom_closure_req_log() {
        let mut logger = Logger::new("test %{CUSTOM}xi")
            .custom_request_replace("CUSTOM", |_req: &ServiceRequest| -> String {
                String::from("custom_log")
            });
        let mut unit = Rc::get_mut(&mut logger.0).unwrap().format.0[1].clone();

        let label = match &unit {
            FormatText::CustomRequest(label, _) => label,
            ft => panic!("expected CustomRequest, found {:?}", ft),
        };

        assert_eq!(label, "CUSTOM");

        let req = TestRequest::default().to_srv_request();
        let now = OffsetDateTime::now_utc();

        unit.render_request(now, &req);

        let render = |fmt: &mut fmt::Formatter<'_>| unit.render(fmt, 1024, now);

        let log_output = FormatDisplay(&render).to_string();
        assert_eq!(log_output, "custom_log");
    }

    #[actix_rt::test]
    async fn test_custom_closure_response_log() {
        let mut logger = Logger::new("test %{CUSTOM}xo").custom_response_replace(
            "CUSTOM",
            |res: &ServiceResponse| -> String {
                if res.status().as_u16() == 200 {
                    String::from("custom_log")
                } else {
                    String::from("-")
                }
            },
        );
        let mut unit = Rc::get_mut(&mut logger.0).unwrap().format.0[1].clone();

        let label = match &unit {
            FormatText::CustomResponse(label, _) => label,
            ft => panic!("expected CustomResponse, found {:?}", ft),
        };

        assert_eq!(label, "CUSTOM");

        let req = TestRequest::default().to_http_request();
        let resp_ok = ServiceResponse::new(req, HttpResponse::Ok().finish());
        let now = OffsetDateTime::now_utc();
        unit.render_response(&resp_ok);

        let render = |fmt: &mut fmt::Formatter<'_>| unit.render(fmt, 1024, now);

        let log_output = FormatDisplay(&render).to_string();
        assert_eq!(log_output, "custom_log");
    }

    #[actix_rt::test]
    async fn test_closure_logger_in_middleware() {
        let captured = "custom log replacement";

        let logger = Logger::new("%{CUSTOM}xi")
            .custom_request_replace("CUSTOM", move |_req: &ServiceRequest| -> String {
                captured.to_owned()
            });

        let srv = logger.new_transform(test::ok_service()).await.unwrap();

        let req = TestRequest::default().to_srv_request();
        srv.call(req).await.unwrap();
    }
}