Sauci/docs/data-retrieval-tasks.md

Mobile data retrieval review: task list

This task list targets the Home, Swipe, and Matches flows in apps/mobile, focusing on correctness, performance, and realtime consistency.

Overview (current state)

• Data fetching is split between Zustand stores (useMatchStore, usePacksStore) and screen-local Supabase RPC calls (notably SwipeScreen).
• Realtime updates are centralized in apps/mobile/app/(app)/_layout.tsx (matches/messages/profile/pack-settings subscriptions).
• Main risks today: missing query filters & error/loading states, redundant fetches, state races on param changes, and unread-count drift between realtime and the matches list.

Scope

• Screens
  • Home: apps/mobile/app/(app)/index.tsx
  • Swipe: apps/mobile/app/(app)/swipe.tsx
  • Matches: apps/mobile/app/(app)/matches.tsx
• Stores
  • Matches: apps/mobile/src/store/matchStore.ts
  • Packs: apps/mobile/src/store/packsStore.ts
  • Messages: apps/mobile/src/store/messageStore.ts
• Realtime orchestration
  • apps/mobile/app/(app)/_layout.tsx

Priority 0 — correctness (must fix)

• Home: fix packs count source-of-truth

  • Current: enabledPacksCount = packs.length (counts available packs).
  • Decide + implement:
    • If label means enabled: use enabledPackIds.length.
    • If label means available: rename the variable + label.
  • Acceptance: packs number matches user expectations and store state.

• Swipe: normalize packId and reset state on param changes

  • Normalize packId from useLocalSearchParams() (string | string[]) before sending to RPC.
  • Reset currentIndex, isLoading, and any derived UI state when packId changes.
  • Acceptance: switching packs never shows stale index/loading/UI.

• Swipe: add race protection for overlapping async fetches

  • Use a request-id guard (or abort pattern) so older fetchQuestions() results cannot overwrite newer results.
  • Acceptance: rapid navigation/focus changes never clobber newer state.

• Swipe: prevent stale “blocked” state on answer-gap errors

  • Ensure checkAnswerGap() clears/updates isBlocked + gapInfo deterministically even when RPC errors.
  • Acceptance: blocked UI never “sticks” due to transient failures.

Priority 1 — UX and data freshness

• Home: ensure data freshness on revisit

  • Add useFocusEffect or a simple staleness TTL in stores.
  • Acceptance: counts (matches/new/packs) refresh when returning to Home.

• Home: align “Recent Matches” semantics

  • useMatchStore.fetchMatches() sorts unread first; Home slices top 3.
  • Decide:
    • True recent by created_at, or
    • “Top matches” by unread-first.
  • Acceptance: section name and behavior match.

• Matches screen: wire up pull-to-refresh correctly

  • Add isLoading/isRefreshing + error to useMatchStore.
  • Use those flags for RefreshControl.refreshing.
  • Acceptance: pull-to-refresh shows spinner and recovers from errors.

Priority 2 — performance and query efficiency

• MatchStore: add explicit filtering and guard empty in(...) lists

  • Filter matches by couple_id (in addition to RLS) for clarity/perf.
  • If no matches, avoid calling .in('question_id', []).
  • Acceptance: fewer noisy requests; no empty-list edge behavior.

• MatchStore: reduce unread-count work

  • Current approach fetches one row per unread message and counts on client.
  • Options:
    • Add RPC/view that returns per-match unread counts.
    • Or store a denormalized unread_count per match (if acceptable).
  • Acceptance: fetching matches scales with large message histories.

• Swipe: remove heavy dependency on fetchPacks()

  • Swipe often only needs enabledPackIds.
  • Add lightweight ensureEnabledPacksLoaded() or call fetchEnabledPacks() directly.
  • Acceptance: less data fetched when entering Swipe.

• Swipe: replace random comparator sort

  • Replace Array.sort() comparator using Math.random() with a stable score/shuffle pass.
  • Acceptance: consistent ordering logic; avoids comparator contract violations.

Priority 3 — realtime correctness and consistency

• Realtime messages: tighten subscription filter

  • Current messages subscription listens without a filter.
  • Improve by filtering to the user’s couple scope (schema permitting) or alternative channel strategy.
  • Acceptance: avoids noise; reduces risk of unintended cross-couple events.

• Sync per-match unread counts with realtime events

  • Currently global unread count updates live; per-match counts update only on fetchMatches().
  • Options:
    • Update useMatchStore unreadCount per match when realtime message arrives.
    • Or trigger a targeted refresh when new partner message arrives.
  • Acceptance: Matches list ordering/badges update as messages arrive.

Optional: structural improvements (bigger refactors)

• Consolidate fetching into a query layer (e.g., TanStack Query) with caching, invalidation, retries, and focus refetch.
• Create a single “matches list” RPC that returns:
  • match + question
  • who-answered-first info (for two-part display)
  • per-match unread counts
  • new match flag
• Add lightweight integration tests around:
  • packId parsing
  • request race guards
  • unread count updates

Suggested implementation order

1. P0 correctness (Home packs count, Swipe param/reset/races, gap-state)
2. Matches loading/refresh UX
3. Query efficiency (couple filters, unread-count optimization)
4. Realtime tightening + unread sync
5. Optional refactors