darkfi/openspec/changes/app-chatview/tasks.md

Every phase below ends at a logically atomic commit point and closes with a review gate: run the phase verification (unit tests and/or netdebug + trace logs + visual inspection), then a thorough code review by the owner with possible amendments or clarifications, then commit. The next phase does not start before the gate passes. Tooling: unit tests (cargo test in bin/app), netdebug zeromq CLI (CallMethod, GetPropertyValue, signal subscriptions), trace logs (ui::chatview2*), and visual inspection on the schema-chatview dev screen. See design.md → Development Protocol.

1. Fenwick tree util

• 1.1 Implement src/util/fenwick.rs (new, get, add, set, push, prefix, range, lower_bound, rebuild) with randomized unit tests comparing every operation against brute-force sums over a reference Vec<f32>; verify cargo test in bin/app passes
• 1.2 Gate: review tests + implementation with the owner, apply amendments, commit as one atomic unit

2. Buffer: records and ordering

• 2.1 Implement src/ui/chatview2/buffer.rs record store: slotmap arena, order index sorted by (timestamp, msg_id), dedup set, removal by id; verify unit tests pass: insert at any position, duplicate insert ignored, same-millisecond coexistence, removal, ordered iteration
• 2.2 Gate: review + amendments + atomic commit

3. Buffer: geometry

• 3.1 Wire the Fenwick tree into the buffer: total_height, visible_range(scroll, view_h), pos_of(msg_id), set_height point-updates, insert_batch single-rebuild, plus the below-viewport compensation math helper; verify randomized unit tests pass comparing geometry against a linear scan and compensation below/inside/above viewport and at scroll==0
• 3.2 Gate: review + amendments + atomic commit

4. Wire codec and legacy decode

• 4.1 Implement the tagged value codec ([u8 tag][type bytes], privmsg payload = nick, text encoding + confirmed flag): a fixed #[repr(u8)] MsgType enum whose discriminants are the wire tags (encode via as u8, decode via a from_u8 match, no factories); verify unit tests pass for encode/decode round-trip and that an unknown tag or undecodable payload panics with an identifying message (corrupt data is never silently skipped)
• 4.2 Gate: review + amendments + atomic commit

5. Scroll controller

• 5.1 Implement src/ui/chatview2/scroll.rs: internal pixels-from-bottom scroll (no scene property), Idle/Drag/Glide/Anim state machine with intents fed from the gesture subsystem's drag lifecycle (drag start/move/end; flick = threshold on the session's DragEnd velocity — no local sampling; page tick, scroll_to_bottom), clamping, is_at_bottom indication, height-change compensation application, anchor snapshot/resolve with bottom shortcut and clamped fallback; verify unit tests pass for state transitions (grab cancels motion, wheel coalescing extends the target, flick fed a DragEnd-style velocity decays to stop, clamps at 0 and top, scroll_to_bottom, anchor round-trip with inserts above and below)
• 5.2 Gate: review + amendments + atomic commit

6. Chatview2 skeleton + dev schema screen

• 6.1 Create the src/ui/chatview2/ module skeleton and the ChatView2 UIObject: properties (rect, shared styling, is_at_bottom bool), view-wide method stubs (set_channel, set_filter, copy_select, unselect, scroll_to_bottom, get_line_ids, delete_line), the gesture contract (gesture_set chatview-shaped: tap + long-press + vertical drag; exact-rect gesture_hit_test; handle_gesture stub), empty-buffer draw running the visible-window loop, and the node factory; verify make compile-dev succeeds and the dev screen renders an empty view
• 6.2 Create the src/app/schema/test_chatview.rs dev schema (modeled on schema/test.rs) hosting the chatview2 node for development, gated behind a new schema-test-chatview cargo feature following the existing schema-test-* convention (mutually exclusive with schema-app via the one-schema compile guard); verify by running the app with the feature enabled: screen shows, and a netdebug scene dump lists the chatview2 node with its properties and methods
• 6.3 Gate: review + amendments + atomic commit

7. Loader pipeline + live-testing methods

• 7.1 Implement src/ui/chatview2/loader.rs: single kvdb-owning bg task, coverage invariant (live bottom + viewport + preload margin), wake-ups (set_channel, near-top scroll, insert, filter, rect change), filter application at load, plus working get_line_ids and delete_line methods on the chatview; verify via netdebug on a fixture tree: set_channel then get_line_ids returns the expected (ts, id) list in display order, delete_line removes a record and it stays gone after re-set_channel; trace logs show load batches and Fenwick rebuilds as designed
• 7.2 Gate: review + amendments + atomic commit

8. Message type framework

• 8.1 Implement src/ui/chatview2/msg/mod.rs: MessageType trait (materialize/release/regen/height/draw/hit_test/copy_text) and the hardcoded MsgType enum dispatch (no factories, no placeholder — unknown type ids panic at decode), height reporting into the buffer; verify unit tests pass for materialize→release→materialize state rebuild, height report, and cache lifecycle (state cached across draws, invalidated by width/styling/data changes); visually confirm records render on the dev screen and trace logs show materialize/release as the window moves
• 8.2 Gate: review + amendments + atomic commit

9. Privmsg I: insertion and basic rendering

• 9.1 Implement msg/privmsg.rs part 1: the type's insert_line/insert_unconf_line/confirm methods (persist via the loader, dedup, buffer insert, confirm rewrites the payload in place and regens, materialize if visible) and basic rendering (nick colors, timestamp, plain text layout at the wrapped width); verify unit tests pass for layout cache behavior (layout reused across repeated measures, re-wrapped on width change, invalidated on styling/data change) and the unconfirmed→confirm in-place update; verify via netdebug CallMethod insert_line feeding batches of lines and confirm on one: trace logs show dedup, fenwick pushes, layout cache hit/miss behavior; visual inspection against the old chatview for basic lines and unconfirmed→confirmed restyling
• 9.2 Gate: review + amendments + atomic commit

10. Privmsg II: URLs, signals, variants

• 10.1 Implement privmsg part 2: URL spans with backgrounds, click/tap open, right-click/long-press copy with the toast overlay, nick_clicked signal carrying msg id + nick, CTCP ACTION rendering, NOTICE styling, unconfirmed gray; verify netdebug-driven inserts of urls/actions/notices render correctly (visual), the nick_clicked signal is observable on the netdebug pub socket, and toast behavior matches the old chatview
• 10.2 Gate: review + amendments + atomic commit

11. Selection across types

• 11.1 Implement selection: chatview-owned selected set, chatview-drawn highlight (no per-type cache invalidation), mouse click toggle, Tap toggle, long-press entering selection mode with subsequent DragMove extending the selection instead of scrolling, drag sweep, selection-mode taps, per-type copy_text joined in display order, unselect, select_changed transitions; verify unit test for mixed-type copy ordering passes, netdebug copy_select/unselect behave per spec, and manual drag/toggle/long-press selection works visually on the dev screen
• 11.2 Gate: review + amendments + atomic commit

12. Date separators

• 12.1 Implement msg/datemsg.rs and derived records: synthetic (midnight, [0;32]) keys, sync_separators on insert/load/delete, orphan cleanup, selectable with date-label copy text; verify unit tests pass for separator sync and orphan removal, netdebug delete_line of a day's only message removes its separator, and visual day-boundary rendering matches the old chatview
• 12.2 Gate: review + amendments + atomic commit

13. Scroll input integration

• 13.1 Wire input on the dev screen: touch via handle_gesture mapping to the scroll controller per design's gesture integration table (Down pauses inertia and resets long-press mode, DragStart grabs (kills motion), DragMove 1:1 on the chat axis (scroll = scroll0 + dy), DragEnd flick on the session velocity, Up clears touch-active state), plus handle_mouse_wheel and PageUp/PageDown keys feeding page_tick (animated half-page with coalescing), clamps, a visible scroll-to-bottom arrow layer (priority +1 above the view) driven by is_at_bottom calling scroll_to_bottom, and the animator deadline-cadence task; verify the slop dead-zone, 20ms move cadence, and single-fire long-press come from the session (no local recognition), trace logs show the intended state transitions per gesture, netdebug GetPropertyValue is_at_bottom flips as expected, the overlaid arrow receives its taps (arbitration), and visual inspection confirms pixel-exact drag, smooth wheel animation, correct stops at both clamps, and the arrow toggling with position
• 13.2 Gate: review + amendments + atomic commit

14. Materialization lifecycle and eviction

• 14.1 Implement the virtualization window with soft margin and LRU eviction budget: materialize on window enter, release on exit (render-scoped tasks cancelled), bounded render resources; verify a unit test for the LRU/budget policy passes (eviction order under pressure, window membership), trace logs show materialize/release while scrolling a large fixture history, renderer debug stats show bounded memory/GPU resources after long scrolls, and visual inspection shows no ghost lines or missing lines around the window edges
• 14.2 Gate: review + amendments + atomic commit

15. Cap/expand for long messages

• 15.1 Implement the collapsed default height with expand affordance and toggle: height change flows through regen + compensation; verify a unit test for capped measurement and expand height reporting passes, and visual toggle on very long messages keeps surrounding content stable per the compensation rules
• 15.2 Gate: review + amendments + atomic commit

16. Reflow

• 16.1 Implement the reflow protocol (anchor snapshot → invalidate rendered state → re-wrap visible-first → single Fenwick rebuild → anchor restore; height-only rect changes just re-clamp); verify via netdebug SetPropertyValue on font_size and by resizing the window: trace logs show visible-first regen order and one rebuild, visual inspection confirms the anchored message stays put and bottom stays pinned
• 16.2 Gate: review + amendments + atomic commit

17. Filemsg, content-scoped tasks, i18n

• 17.1 Implement msg/filemsg.rs: set_file_status method, status lifecycle rendering, fud URL derivation, download_request/ fileurl_detected/status_changed signals, downloaded image display with fit bounds, and the content-scoped key → Task map surviving eviction; wire i18n_fish into type constructors and translate file status strings; verify a fud round-trip with the plugin enabled (visual image + statuses), trace logs show task dedup/attach on re-materialization, eviction mid-download continues the task, and a language switch translates the status text
• 17.2 Gate: review + amendments + atomic commit

18. Single-screen cutover

• 18.1 Rework src/app/schema/chat.rs to a single chat screen with one chatview2: set_channel on channel selection, channel label binding, scroll-to-bottom arrow driven by is_at_bottom + scroll_to_bottom; remove the per-channel screen loop in schema/mod.rs; retarget relay paths in main.rs and plugins (darkirc insert/confirm to the privmsg node, fud status fan-out to the filemsg node); set explicit node priorities for every interactive layer floating over the chatview (scroll-to-bottom arrow, cmd-hint popup) above it, per the gesture session's priority-ordered targeting; verify on desktop with darkirc: receiving messages updates the active channel, switching channels clears/reloads and restores each channel's position, and unread indication works via signals
• 18.2 Gate: review + amendments + atomic commit

19. Old module removal + full validation

• 19.1 Delete src/ui/chatview/ and all old-chatview references (ui/mod.rs re-exports, test schemas using create_chatview); verify make compile-dev and make compile-apk both succeed
• 19.2 Full validation: parity checklist from specs/chatview/spec.md (URLs, selection/copy incl. separators, file messages, actions/notices, unconfirmed, date separators, keys, touch incl. slop dead-zone, grab-to-stop, long-press select mode, wheel, restore, reflow) on desktop; performance pass scrolling a large history (no slowdown, bounded memory via renderer debug stats); android device smoke test (drag, flick, grab-stop, long-press select/copy, channel switching)
• 19.3 Gate: final review + atomic commit closing the change