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
// Copyright 2023 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::sync::Arc;

use as_variant::as_variant;
use imbl::Vector;
use matrix_sdk::crypto::types::events::UtdCause;
use matrix_sdk_base::latest_event::{is_suitable_for_latest_event, PossibleLatestEvent};
use ruma::{
    events::{
        call::{invite::SyncCallInviteEvent, notify::SyncCallNotifyEvent},
        policy::rule::{
            room::PolicyRuleRoomEventContent, server::PolicyRuleServerEventContent,
            user::PolicyRuleUserEventContent,
        },
        poll::unstable_start::{NewUnstablePollStartEventContent, SyncUnstablePollStartEvent},
        room::{
            aliases::RoomAliasesEventContent,
            avatar::RoomAvatarEventContent,
            canonical_alias::RoomCanonicalAliasEventContent,
            create::RoomCreateEventContent,
            encrypted::{EncryptedEventScheme, MegolmV1AesSha2Content, RoomEncryptedEventContent},
            encryption::RoomEncryptionEventContent,
            guest_access::RoomGuestAccessEventContent,
            history_visibility::RoomHistoryVisibilityEventContent,
            join_rules::RoomJoinRulesEventContent,
            member::{Change, RoomMemberEventContent},
            message::{RoomMessageEventContent, SyncRoomMessageEvent},
            name::RoomNameEventContent,
            pinned_events::RoomPinnedEventsEventContent,
            power_levels::RoomPowerLevelsEventContent,
            server_acl::RoomServerAclEventContent,
            third_party_invite::RoomThirdPartyInviteEventContent,
            tombstone::RoomTombstoneEventContent,
            topic::RoomTopicEventContent,
        },
        space::{child::SpaceChildEventContent, parent::SpaceParentEventContent},
        sticker::StickerEventContent,
        AnyFullStateEventContent, AnySyncMessageLikeEvent, AnySyncTimelineEvent,
        BundledMessageLikeRelations, FullStateEventContent, MessageLikeEventType, StateEventType,
    },
    OwnedDeviceId, OwnedMxcUri, OwnedUserId, RoomVersionId, UserId,
};
use tracing::warn;

use crate::timeline::{polls::PollState, TimelineItem};

mod message;

pub use self::message::{InReplyToDetails, Message, RepliedToEvent};

/// The content of an [`EventTimelineItem`][super::EventTimelineItem].
#[derive(Clone, Debug)]
pub enum TimelineItemContent {
    /// An `m.room.message` event or extensible event, including edits.
    Message(Message),

    /// A redacted message.
    RedactedMessage,

    /// An `m.sticker` event.
    Sticker(Sticker),

    /// An `m.room.encrypted` event that could not be decrypted.
    UnableToDecrypt(EncryptedMessage),

    /// A room membership change.
    MembershipChange(RoomMembershipChange),

    /// A room member profile change.
    ProfileChange(MemberProfileChange),

    /// Another state event.
    OtherState(OtherState),

    /// A message-like event that failed to deserialize.
    FailedToParseMessageLike {
        /// The event `type`.
        event_type: MessageLikeEventType,

        /// The deserialization error.
        error: Arc<serde_json::Error>,
    },

    /// A state event that failed to deserialize.
    FailedToParseState {
        /// The event `type`.
        event_type: StateEventType,

        /// The state key.
        state_key: String,

        /// The deserialization error.
        error: Arc<serde_json::Error>,
    },

    /// An `m.poll.start` event.
    Poll(PollState),

    /// An `m.call.invite` event
    CallInvite,

    /// An `m.call.notify` event
    CallNotify,
}

impl TimelineItemContent {
    /// If the supplied event is suitable to be used as a `latest_event` in a
    /// message preview, extract its contents and wrap it as a
    /// `TimelineItemContent`.
    pub(crate) fn from_latest_event_content(
        event: AnySyncTimelineEvent,
    ) -> Option<TimelineItemContent> {
        match is_suitable_for_latest_event(&event) {
            PossibleLatestEvent::YesRoomMessage(m) => {
                Some(Self::from_suitable_latest_event_content(m))
            }
            PossibleLatestEvent::YesPoll(poll) => {
                Some(Self::from_suitable_latest_poll_event_content(poll))
            }
            PossibleLatestEvent::YesCallInvite(call_invite) => {
                Some(Self::from_suitable_latest_call_invite_content(call_invite))
            }
            PossibleLatestEvent::YesCallNotify(call_notify) => {
                Some(Self::from_suitable_latest_call_notify_content(call_notify))
            }
            PossibleLatestEvent::NoUnsupportedEventType => {
                // TODO: when we support state events in message previews, this will need change
                warn!("Found a state event cached as latest_event! ID={}", event.event_id());
                None
            }
            PossibleLatestEvent::NoUnsupportedMessageLikeType => {
                // TODO: When we support reactions in message previews, this will need to change
                warn!(
                    "Found an event cached as latest_event, but I don't know how \
                        to wrap it in a TimelineItemContent. type={}, ID={}",
                    event.event_type().to_string(),
                    event.event_id()
                );
                None
            }
            PossibleLatestEvent::NoEncrypted => {
                warn!("Found an encrypted event cached as latest_event! ID={}", event.event_id());
                None
            }
        }
    }

    /// Given some message content that is from an event that we have already
    /// determined is suitable for use as a latest event in a message preview,
    /// extract its contents and wrap it as a `TimelineItemContent`.
    fn from_suitable_latest_event_content(event: &SyncRoomMessageEvent) -> TimelineItemContent {
        match event {
            SyncRoomMessageEvent::Original(event) => {
                // Grab the content of this event
                let event_content = event.content.clone();

                // We don't have access to any relations via the `AnySyncTimelineEvent` (I think
                // - andyb) so we pretend there are none. This might be OK for
                // the message preview use case.
                let relations = BundledMessageLikeRelations::new();

                // If this message is a reply, we would look up in this list the message it was
                // replying to. Since we probably won't show this in the message preview,
                // it's probably OK to supply an empty list here.
                // `Message::from_event` marks the original event as `Unavailable` if it can't
                // be found inside the timeline_items.
                let timeline_items = Vector::new();
                TimelineItemContent::Message(Message::from_event(
                    event_content,
                    relations,
                    &timeline_items,
                ))
            }
            SyncRoomMessageEvent::Redacted(_) => TimelineItemContent::RedactedMessage,
        }
    }

    /// Extracts a `TimelineItemContent` from a poll start event for use as a
    /// latest event in a message preview.
    fn from_suitable_latest_poll_event_content(
        event: &SyncUnstablePollStartEvent,
    ) -> TimelineItemContent {
        match event {
            SyncUnstablePollStartEvent::Original(event) => {
                TimelineItemContent::Poll(PollState::new(NewUnstablePollStartEventContent::new(
                    event.content.poll_start().clone(),
                )))
            }
            SyncUnstablePollStartEvent::Redacted(_) => TimelineItemContent::RedactedMessage,
        }
    }

    fn from_suitable_latest_call_invite_content(
        event: &SyncCallInviteEvent,
    ) -> TimelineItemContent {
        match event {
            SyncCallInviteEvent::Original(_) => TimelineItemContent::CallInvite,
            SyncCallInviteEvent::Redacted(_) => TimelineItemContent::RedactedMessage,
        }
    }

    fn from_suitable_latest_call_notify_content(
        event: &SyncCallNotifyEvent,
    ) -> TimelineItemContent {
        match event {
            SyncCallNotifyEvent::Original(_) => TimelineItemContent::CallNotify,
            SyncCallNotifyEvent::Redacted(_) => TimelineItemContent::RedactedMessage,
        }
    }

    /// If `self` is of the [`Message`][Self::Message] variant, return the inner
    /// [`Message`].
    pub fn as_message(&self) -> Option<&Message> {
        as_variant!(self, Self::Message)
    }

    /// If `self` is of the [`UnableToDecrypt`][Self::UnableToDecrypt] variant,
    /// return the inner [`EncryptedMessage`].
    pub fn as_unable_to_decrypt(&self) -> Option<&EncryptedMessage> {
        as_variant!(self, Self::UnableToDecrypt)
    }

    pub(crate) fn is_redacted(&self) -> bool {
        matches!(self, Self::RedactedMessage)
    }

    // These constructors could also be `From` implementations, but that would
    // allow users to call them directly, which should not be supported
    pub(crate) fn message(
        c: RoomMessageEventContent,
        relations: BundledMessageLikeRelations<AnySyncMessageLikeEvent>,
        timeline_items: &Vector<Arc<TimelineItem>>,
    ) -> Self {
        Self::Message(Message::from_event(c, relations, timeline_items))
    }

    #[cfg(not(tarpaulin_include))] // debug-logging functionality
    pub(crate) fn debug_string(&self) -> &'static str {
        match self {
            TimelineItemContent::Message(_) => "a message",
            TimelineItemContent::RedactedMessage => "a redacted messages",
            TimelineItemContent::Sticker(_) => "a sticker",
            TimelineItemContent::UnableToDecrypt(_) => "an encrypted message we couldn't decrypt",
            TimelineItemContent::MembershipChange(_) => "a membership change",
            TimelineItemContent::ProfileChange(_) => "a profile change",
            TimelineItemContent::OtherState(_) => "a state event",
            TimelineItemContent::FailedToParseMessageLike { .. }
            | TimelineItemContent::FailedToParseState { .. } => "an event that couldn't be parsed",
            TimelineItemContent::Poll(_) => "a poll",
            TimelineItemContent::CallInvite => "a call invite",
            TimelineItemContent::CallNotify => "a call notification",
        }
    }

    pub(crate) fn unable_to_decrypt(content: RoomEncryptedEventContent, cause: UtdCause) -> Self {
        Self::UnableToDecrypt(EncryptedMessage::from_content(content, cause))
    }

    pub(crate) fn room_member(
        user_id: OwnedUserId,
        full_content: FullStateEventContent<RoomMemberEventContent>,
        sender: OwnedUserId,
    ) -> Self {
        use ruma::events::room::member::MembershipChange as MChange;
        match &full_content {
            FullStateEventContent::Original { content, prev_content } => {
                let membership_change = content.membership_change(
                    prev_content.as_ref().map(|c| c.details()),
                    &sender,
                    &user_id,
                );

                if let MChange::ProfileChanged { displayname_change, avatar_url_change } =
                    membership_change
                {
                    Self::ProfileChange(MemberProfileChange {
                        user_id,
                        displayname_change: displayname_change.map(|c| Change {
                            new: c.new.map(ToOwned::to_owned),
                            old: c.old.map(ToOwned::to_owned),
                        }),
                        avatar_url_change: avatar_url_change.map(|c| Change {
                            new: c.new.map(ToOwned::to_owned),
                            old: c.old.map(ToOwned::to_owned),
                        }),
                    })
                } else {
                    let change = match membership_change {
                        MChange::None => MembershipChange::None,
                        MChange::Error => MembershipChange::Error,
                        MChange::Joined => MembershipChange::Joined,
                        MChange::Left => MembershipChange::Left,
                        MChange::Banned => MembershipChange::Banned,
                        MChange::Unbanned => MembershipChange::Unbanned,
                        MChange::Kicked => MembershipChange::Kicked,
                        MChange::Invited => MembershipChange::Invited,
                        MChange::KickedAndBanned => MembershipChange::KickedAndBanned,
                        MChange::InvitationAccepted => MembershipChange::InvitationAccepted,
                        MChange::InvitationRejected => MembershipChange::InvitationRejected,
                        MChange::InvitationRevoked => MembershipChange::InvitationRevoked,
                        MChange::Knocked => MembershipChange::Knocked,
                        MChange::KnockAccepted => MembershipChange::KnockAccepted,
                        MChange::KnockRetracted => MembershipChange::KnockRetracted,
                        MChange::KnockDenied => MembershipChange::KnockDenied,
                        MChange::ProfileChanged { .. } => unreachable!(),
                        _ => MembershipChange::NotImplemented,
                    };

                    Self::MembershipChange(RoomMembershipChange {
                        user_id,
                        content: full_content,
                        change: Some(change),
                    })
                }
            }
            FullStateEventContent::Redacted(_) => Self::MembershipChange(RoomMembershipChange {
                user_id,
                content: full_content,
                change: None,
            }),
        }
    }

    pub(in crate::timeline) fn redact(&self, room_version: &RoomVersionId) -> Self {
        match self {
            Self::Message(_)
            | Self::RedactedMessage
            | Self::Sticker(_)
            | Self::Poll(_)
            | Self::CallInvite
            | Self::CallNotify
            | Self::UnableToDecrypt(_) => Self::RedactedMessage,
            Self::MembershipChange(ev) => Self::MembershipChange(ev.redact(room_version)),
            Self::ProfileChange(ev) => Self::ProfileChange(ev.redact()),
            Self::OtherState(ev) => Self::OtherState(ev.redact(room_version)),
            Self::FailedToParseMessageLike { .. } | Self::FailedToParseState { .. } => self.clone(),
        }
    }
}

/// Metadata about an `m.room.encrypted` event that could not be decrypted.
#[derive(Clone, Debug)]
pub enum EncryptedMessage {
    /// Metadata about an event using the `m.olm.v1.curve25519-aes-sha2`
    /// algorithm.
    OlmV1Curve25519AesSha2 {
        /// The Curve25519 key of the sender.
        sender_key: String,
    },
    /// Metadata about an event using the `m.megolm.v1.aes-sha2` algorithm.
    MegolmV1AesSha2 {
        /// The Curve25519 key of the sender.
        #[deprecated = "this field still needs to be sent but should not be used when received"]
        #[doc(hidden)] // Included for Debug formatting only
        sender_key: String,

        /// The ID of the sending device.
        #[deprecated = "this field still needs to be sent but should not be used when received"]
        #[doc(hidden)] // Included for Debug formatting only
        device_id: OwnedDeviceId,

        /// The ID of the session used to encrypt the message.
        session_id: String,

        /// What we know about what caused this UTD. E.g. was this event sent
        /// when we were not a member of this room?
        cause: UtdCause,
    },
    /// No metadata because the event uses an unknown algorithm.
    Unknown,
}

impl EncryptedMessage {
    fn from_content(content: RoomEncryptedEventContent, cause: UtdCause) -> Self {
        match content.scheme {
            EncryptedEventScheme::OlmV1Curve25519AesSha2(s) => {
                Self::OlmV1Curve25519AesSha2 { sender_key: s.sender_key }
            }
            #[allow(deprecated)]
            EncryptedEventScheme::MegolmV1AesSha2(s) => {
                let MegolmV1AesSha2Content { sender_key, device_id, session_id, .. } = s;

                Self::MegolmV1AesSha2 { sender_key, device_id, session_id, cause }
            }
            _ => Self::Unknown,
        }
    }
}

/// An `m.sticker` event.
#[derive(Clone, Debug)]
pub struct Sticker {
    pub(in crate::timeline) content: StickerEventContent,
}

impl Sticker {
    /// Get the data of this sticker.
    pub fn content(&self) -> &StickerEventContent {
        &self.content
    }
}

/// An event changing a room membership.
#[derive(Clone, Debug)]
pub struct RoomMembershipChange {
    pub(in crate::timeline) user_id: OwnedUserId,
    pub(in crate::timeline) content: FullStateEventContent<RoomMemberEventContent>,
    pub(in crate::timeline) change: Option<MembershipChange>,
}

impl RoomMembershipChange {
    /// The ID of the user whose membership changed.
    pub fn user_id(&self) -> &UserId {
        &self.user_id
    }

    /// The full content of the event.
    pub fn content(&self) -> &FullStateEventContent<RoomMemberEventContent> {
        &self.content
    }

    /// The membership change induced by this event.
    ///
    /// If this returns `None`, it doesn't mean that there was no change, but
    /// that the change could not be computed. This is currently always the case
    /// with redacted events.
    // FIXME: Fetch the prev_content when missing so we can compute this with
    // redacted events?
    pub fn change(&self) -> Option<MembershipChange> {
        self.change
    }

    fn redact(&self, room_version: &RoomVersionId) -> Self {
        Self {
            user_id: self.user_id.clone(),
            content: FullStateEventContent::Redacted(self.content.clone().redact(room_version)),
            change: self.change,
        }
    }
}

/// An enum over all the possible room membership changes.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum MembershipChange {
    /// No change.
    None,

    /// Must never happen.
    Error,

    /// User joined the room.
    Joined,

    /// User left the room.
    Left,

    /// User was banned.
    Banned,

    /// User was unbanned.
    Unbanned,

    /// User was kicked.
    Kicked,

    /// User was invited.
    Invited,

    /// User was kicked and banned.
    KickedAndBanned,

    /// User accepted the invite.
    InvitationAccepted,

    /// User rejected the invite.
    InvitationRejected,

    /// User had their invite revoked.
    InvitationRevoked,

    /// User knocked.
    Knocked,

    /// User had their knock accepted.
    KnockAccepted,

    /// User retracted their knock.
    KnockRetracted,

    /// User had their knock denied.
    KnockDenied,

    /// Not implemented.
    NotImplemented,
}

/// An event changing a member's profile.
///
/// Note that profile changes only occur in the timeline when the user's
/// membership is already `join`.
#[derive(Clone, Debug)]
pub struct MemberProfileChange {
    pub(in crate::timeline) user_id: OwnedUserId,
    pub(in crate::timeline) displayname_change: Option<Change<Option<String>>>,
    pub(in crate::timeline) avatar_url_change: Option<Change<Option<OwnedMxcUri>>>,
}

impl MemberProfileChange {
    /// The ID of the user whose profile changed.
    pub fn user_id(&self) -> &UserId {
        &self.user_id
    }

    /// The display name change induced by this event.
    pub fn displayname_change(&self) -> Option<&Change<Option<String>>> {
        self.displayname_change.as_ref()
    }

    /// The avatar URL change induced by this event.
    pub fn avatar_url_change(&self) -> Option<&Change<Option<OwnedMxcUri>>> {
        self.avatar_url_change.as_ref()
    }

    fn redact(&self) -> Self {
        Self {
            user_id: self.user_id.clone(),
            // FIXME: This isn't actually right, the profile is reset to an
            // empty one when the member event is redacted. This can't be
            // implemented without further architectural changes and is a
            // somewhat rare edge case, so it should be fine for now.
            displayname_change: None,
            avatar_url_change: None,
        }
    }
}

/// An enum over all the full state event contents that don't have their own
/// `TimelineItemContent` variant.
#[derive(Clone, Debug)]
pub enum AnyOtherFullStateEventContent {
    /// m.policy.rule.room
    PolicyRuleRoom(FullStateEventContent<PolicyRuleRoomEventContent>),

    /// m.policy.rule.server
    PolicyRuleServer(FullStateEventContent<PolicyRuleServerEventContent>),

    /// m.policy.rule.user
    PolicyRuleUser(FullStateEventContent<PolicyRuleUserEventContent>),

    /// m.room.aliases
    RoomAliases(FullStateEventContent<RoomAliasesEventContent>),

    /// m.room.avatar
    RoomAvatar(FullStateEventContent<RoomAvatarEventContent>),

    /// m.room.canonical_alias
    RoomCanonicalAlias(FullStateEventContent<RoomCanonicalAliasEventContent>),

    /// m.room.create
    RoomCreate(FullStateEventContent<RoomCreateEventContent>),

    /// m.room.encryption
    RoomEncryption(FullStateEventContent<RoomEncryptionEventContent>),

    /// m.room.guest_access
    RoomGuestAccess(FullStateEventContent<RoomGuestAccessEventContent>),

    /// m.room.history_visibility
    RoomHistoryVisibility(FullStateEventContent<RoomHistoryVisibilityEventContent>),

    /// m.room.join_rules
    RoomJoinRules(FullStateEventContent<RoomJoinRulesEventContent>),

    /// m.room.name
    RoomName(FullStateEventContent<RoomNameEventContent>),

    /// m.room.pinned_events
    RoomPinnedEvents(FullStateEventContent<RoomPinnedEventsEventContent>),

    /// m.room.power_levels
    RoomPowerLevels(FullStateEventContent<RoomPowerLevelsEventContent>),

    /// m.room.server_acl
    RoomServerAcl(FullStateEventContent<RoomServerAclEventContent>),

    /// m.room.third_party_invite
    RoomThirdPartyInvite(FullStateEventContent<RoomThirdPartyInviteEventContent>),

    /// m.room.tombstone
    RoomTombstone(FullStateEventContent<RoomTombstoneEventContent>),

    /// m.room.topic
    RoomTopic(FullStateEventContent<RoomTopicEventContent>),

    /// m.space.child
    SpaceChild(FullStateEventContent<SpaceChildEventContent>),

    /// m.space.parent
    SpaceParent(FullStateEventContent<SpaceParentEventContent>),

    #[doc(hidden)]
    _Custom { event_type: String },
}

impl AnyOtherFullStateEventContent {
    /// Create an `AnyOtherFullStateEventContent` from an
    /// `AnyFullStateEventContent`.
    ///
    /// Panics if the event content does not match one of the variants.
    // This could be a `From` implementation but we don't want it in the public API.
    pub(crate) fn with_event_content(content: AnyFullStateEventContent) -> Self {
        let event_type = content.event_type();

        match content {
            AnyFullStateEventContent::PolicyRuleRoom(c) => Self::PolicyRuleRoom(c),
            AnyFullStateEventContent::PolicyRuleServer(c) => Self::PolicyRuleServer(c),
            AnyFullStateEventContent::PolicyRuleUser(c) => Self::PolicyRuleUser(c),
            AnyFullStateEventContent::RoomAliases(c) => Self::RoomAliases(c),
            AnyFullStateEventContent::RoomAvatar(c) => Self::RoomAvatar(c),
            AnyFullStateEventContent::RoomCanonicalAlias(c) => Self::RoomCanonicalAlias(c),
            AnyFullStateEventContent::RoomCreate(c) => Self::RoomCreate(c),
            AnyFullStateEventContent::RoomEncryption(c) => Self::RoomEncryption(c),
            AnyFullStateEventContent::RoomGuestAccess(c) => Self::RoomGuestAccess(c),
            AnyFullStateEventContent::RoomHistoryVisibility(c) => Self::RoomHistoryVisibility(c),
            AnyFullStateEventContent::RoomJoinRules(c) => Self::RoomJoinRules(c),
            AnyFullStateEventContent::RoomName(c) => Self::RoomName(c),
            AnyFullStateEventContent::RoomPinnedEvents(c) => Self::RoomPinnedEvents(c),
            AnyFullStateEventContent::RoomPowerLevels(c) => Self::RoomPowerLevels(c),
            AnyFullStateEventContent::RoomServerAcl(c) => Self::RoomServerAcl(c),
            AnyFullStateEventContent::RoomThirdPartyInvite(c) => Self::RoomThirdPartyInvite(c),
            AnyFullStateEventContent::RoomTombstone(c) => Self::RoomTombstone(c),
            AnyFullStateEventContent::RoomTopic(c) => Self::RoomTopic(c),
            AnyFullStateEventContent::SpaceChild(c) => Self::SpaceChild(c),
            AnyFullStateEventContent::SpaceParent(c) => Self::SpaceParent(c),
            AnyFullStateEventContent::RoomMember(_) => unreachable!(),
            _ => Self::_Custom { event_type: event_type.to_string() },
        }
    }

    /// Get the event's type, like `m.room.create`.
    pub fn event_type(&self) -> StateEventType {
        match self {
            Self::PolicyRuleRoom(c) => c.event_type(),
            Self::PolicyRuleServer(c) => c.event_type(),
            Self::PolicyRuleUser(c) => c.event_type(),
            Self::RoomAliases(c) => c.event_type(),
            Self::RoomAvatar(c) => c.event_type(),
            Self::RoomCanonicalAlias(c) => c.event_type(),
            Self::RoomCreate(c) => c.event_type(),
            Self::RoomEncryption(c) => c.event_type(),
            Self::RoomGuestAccess(c) => c.event_type(),
            Self::RoomHistoryVisibility(c) => c.event_type(),
            Self::RoomJoinRules(c) => c.event_type(),
            Self::RoomName(c) => c.event_type(),
            Self::RoomPinnedEvents(c) => c.event_type(),
            Self::RoomPowerLevels(c) => c.event_type(),
            Self::RoomServerAcl(c) => c.event_type(),
            Self::RoomThirdPartyInvite(c) => c.event_type(),
            Self::RoomTombstone(c) => c.event_type(),
            Self::RoomTopic(c) => c.event_type(),
            Self::SpaceChild(c) => c.event_type(),
            Self::SpaceParent(c) => c.event_type(),
            Self::_Custom { event_type } => event_type.as_str().into(),
        }
    }

    fn redact(&self, room_version: &RoomVersionId) -> Self {
        match self {
            Self::PolicyRuleRoom(c) => Self::PolicyRuleRoom(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::PolicyRuleServer(c) => Self::PolicyRuleServer(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::PolicyRuleUser(c) => Self::PolicyRuleUser(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::RoomAliases(c) => {
                Self::RoomAliases(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomAvatar(c) => {
                Self::RoomAvatar(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomCanonicalAlias(c) => Self::RoomCanonicalAlias(
                FullStateEventContent::Redacted(c.clone().redact(room_version)),
            ),
            Self::RoomCreate(c) => {
                Self::RoomCreate(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomEncryption(c) => Self::RoomEncryption(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::RoomGuestAccess(c) => Self::RoomGuestAccess(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::RoomHistoryVisibility(c) => Self::RoomHistoryVisibility(
                FullStateEventContent::Redacted(c.clone().redact(room_version)),
            ),
            Self::RoomJoinRules(c) => {
                Self::RoomJoinRules(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomName(c) => {
                Self::RoomName(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomPinnedEvents(c) => Self::RoomPinnedEvents(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::RoomPowerLevels(c) => Self::RoomPowerLevels(FullStateEventContent::Redacted(
                c.clone().redact(room_version),
            )),
            Self::RoomServerAcl(c) => {
                Self::RoomServerAcl(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomThirdPartyInvite(c) => Self::RoomThirdPartyInvite(
                FullStateEventContent::Redacted(c.clone().redact(room_version)),
            ),
            Self::RoomTombstone(c) => {
                Self::RoomTombstone(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::RoomTopic(c) => {
                Self::RoomTopic(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::SpaceChild(c) => {
                Self::SpaceChild(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::SpaceParent(c) => {
                Self::SpaceParent(FullStateEventContent::Redacted(c.clone().redact(room_version)))
            }
            Self::_Custom { event_type } => Self::_Custom { event_type: event_type.clone() },
        }
    }
}

/// A state event that doesn't have its own variant.
#[derive(Clone, Debug)]
pub struct OtherState {
    pub(in crate::timeline) state_key: String,
    pub(in crate::timeline) content: AnyOtherFullStateEventContent,
}

impl OtherState {
    /// The state key of the event.
    pub fn state_key(&self) -> &str {
        &self.state_key
    }

    /// The content of the event.
    pub fn content(&self) -> &AnyOtherFullStateEventContent {
        &self.content
    }

    fn redact(&self, room_version: &RoomVersionId) -> Self {
        Self { state_key: self.state_key.clone(), content: self.content.redact(room_version) }
    }
}

#[cfg(test)]
mod tests {
    use assert_matches2::assert_let;
    use matrix_sdk_test::ALICE;
    use ruma::{
        assign,
        events::{
            room::member::{MembershipState, RoomMemberEventContent},
            FullStateEventContent,
        },
        RoomVersionId,
    };

    use super::{MembershipChange, RoomMembershipChange, TimelineItemContent};

    #[test]
    fn redact_membership_change() {
        let content = TimelineItemContent::MembershipChange(RoomMembershipChange {
            user_id: ALICE.to_owned(),
            content: FullStateEventContent::Original {
                content: assign!(RoomMemberEventContent::new(MembershipState::Ban), {
                    reason: Some("🤬".to_owned()),
                }),
                prev_content: Some(RoomMemberEventContent::new(MembershipState::Join)),
            },
            change: Some(MembershipChange::Banned),
        });

        let redacted = content.redact(&RoomVersionId::V11);
        assert_let!(TimelineItemContent::MembershipChange(inner) = redacted);
        assert_eq!(inner.change, Some(MembershipChange::Banned));
        assert_let!(FullStateEventContent::Redacted(inner_content_redacted) = inner.content);
        assert_eq!(inner_content_redacted.membership, MembershipState::Ban);
    }
}