New chat architecture + chat relay

[mahibi]

WIP

• resolve Chat relay via High-performance backend #5633

• resolve get rid of forked ChatKit #1552

This PR will

• Use signaling to receive chat messages instead of long polling when hpb is used

• Introduce a regular insurance request if somehow a signaling messages did not make it through

• Change the chat architecture from an event based message handling to a state based messages handling. This change was done in this PR because adding two more ways how messages can be received (signaling and insurance request) would have made the event based messages Handling even more complex.

  • Before:
    messages were passed to ui directly from responses (as well to DB). This was necessary as the chatkit library required different processing depending on if messages from the past or future were received

  • Now:
    Received messages are just written to database no matter where they come from (initial request / request for scrolling into past /long polling / signaling / insurance request).
    Messages are observed on database to be shown in UI via flows.
    The database is the single source of truth, so no events are needed to update the ui.
    To avoid messages gaps in UI, the chat block handling is used: the flow is implemented so that always the messages from the newest chat block are emitted. For this, the database is observed for the newest chat block and whenever it changes, the messages of it are emitted.

• Refactor and improve the Jetpack Compose code for messages that was used for the message search window to be able to handle flows. (for now it was only able to handle a single response with a chat message list)

• Add a new solution to automatically mark messages as read.

  • Before:
    messages were marked as read as soon as they were received.
  • Now:
    messages are marked as read until the newest message that was shown on the screen. This is transmitted whenever the user manually scrolls or when the chat is closed/brought to background.
    This change was planned for ages and it was now necessary because of the signaling handling.

• improve scope handling of the flows from database

TODO

• avatars
• determinePreviousMessageIds + handleExpandableSystemMessages + collapseSystemMessages()
• quoted messages
• chat relay
  • support multiple message handling via chat-relay https://nextcloud-spreed-signaling.readthedocs.io/en/latest/standalone-signaling-api-v1/#send-chat-room-message
  • implement signaling handling for chat-relay
    • add features to HelloWebSocketMessage
  • implement insurance request
• special system messages handling regarding signaling?
  • handle and translate the important ones
  • request server via insurance request for others instead to handle the message
    ref https://github.com/nextcloud/spreed/blob/fd1807d0017d736b3d058a830f720defc670a6a0/lib/Signaling/Listener.php#L80-L101
    ref https://github.com/nextcloud/spreed/blob/bf0f5f05e42b9d94449970c09836978650b1a514/lib/Chat/Parser/SystemMessage.php#L118
• implement new mark as read handling
  • handle actually shown newest messages on screen
• last read handling
• show unread chat item. Add in viewmodel
• message context menu
  • add temporary solution to get ChatMessage for this
• show play button for audio/video with preview
• reactions
  • different handling for chatRelay?
    • fix(messagesStore): process reactionsSelf for relayed reactions spreed#16349
• implement all message types
  • media files
  • voice message playback
  • location
  • deck
  • link preview
  • poll
• temp messages
• check New features. Scheduled messaages / fixed messages
• threads handling
• reply handling
  • get single message from offline stored messages
  • get single message from server if ot stored offline
  • scroll to message when clicked
• bugfix: sometimes jumping to newest message when scrolling up?!
  • empty list passed??
  • ViewCompositionStrategy ??
• move all logic from UI to viewModel or to domain->uiModel mapper
• make new ui model for chat message immutable to work better with Compose
• rewrite handling of message parameters / rich object type handling / "selectedIndividualHashMap"?
  • reimplement mention chips
• send chat-relay feature offer to HPB
• handle chat-relay feature response from HPB
• migrate database for unique reference id's
• partly reimplement message editing
• add theming to chatComponents by CompositionLocalProvider
• implement own stickyHeader for reversed list
  • Compose only offers stickyHeader when the list is not reverted. But i use "reverseLayout = true" as it fits best for a chatapp. To have a stickyHeader anyway i implemented a stickyHeader for reversed lists
  • do never show it when chat is scrolled to bottom
• reimplement temorary messages
  • change ChatMessages database table: make referenceIds unique
• reimplement message read indicator
• reimplement message status icon handling
• introduce MessageTypeContent for type-safe rendering
• reimplement parent message handling
  • load parent messages from same flow that are already contained in latest chat block
    • load missing parent messages from api or older chatBlocks
• reimplement markdown
  • improve it
• reimplement links handling
• reimplement unread message marker between chat messages
• reimplement unread messages bubble
  • use latestKnownMessageIdFromSync ? -> move to viewmodel
• Set Read marker
• add message counter for unread messages bubble
• comment in openHelperFactory again
• reimplement search feature
• delete old chatkit stuff

might be done in followup PRs

• swipe to answer..
• reimplement/fix lobby
• Performance optimizations
  • pagination /Paging3
• Grouping of bubbles
  • bubble design
  • show only one avatar per bubble-group
• playback voice messages in service. Playback in ConversationList was removed. There mst be an overall solution to play voice messages in OS notification panel.
• reimplement GIF autoplay (GIF animations autoplay in chat messages #5969 was merged for legacy code)

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔖 Capability is checked or not needed
• 🔙 Backport requests are created or not needed: /backport to stable-xx.x
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

[github-actions]

Codacy

Lint

Type	master	PR
Warnings	93	93
Errors	0	0

SpotBugs

Category	Base	New
Bad practice	6	6
Correctness	10	10
Dodgy code	54	56
Internationalization	3	3
Malicious code vulnerability	3	3
Performance	4	4
Security	1	1
Total	81	83

SpotBugs increased!

[github-actions]

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/5635.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.