trails/openspec/changes/planner-features/design.md
Ullrich Schäfer c7c1c275df
Add 8 proposed changes and old trails analysis
Proposed changes (all with proposal, design, specs, tasks):
- app-navigation (9 tasks) — nav bars for both apps
- planner-landing-page (7 tasks) — standalone landing page
- planner-multiplayer-awareness (13 tasks) — participants, cursors, names
- changelog (13 tasks) — public changelog with "what's new"
- transactional-emails (15 tasks) — magic link + welcome emails
- planner-features (18 tasks) — no-go areas, notes, recovery, rate limits
- komoot-import (23 tasks) — Komoot tour import
- route-features (37 tasks) — sharing, multi-day, spatial, photos

Also adds docs/old-trails-analysis.md with feature analysis from the
older trails project.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-25 03:57:20 +01:00

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2.7 KiB
Markdown

## Context
The Planner architecture defines noGoAreas, notes, and crash recovery in the
Yjs data model but none are implemented. The public instance also lacks rate
limiting — anyone can create unlimited sessions or hammer BRouter.
## Goals / Non-Goals
**Goals:**
- Draw no-go polygons on the map, synced via Yjs, sent to BRouter
- Shared notes (Y.Text) visible in sidebar for planning discussion
- localStorage backup of Yjs state, merged on reconnect
- Rate limits: 10 sessions/IP/hour, 60 BRouter calls/session/hour
**Non-Goals:**
- Complex polygon editing (holes, multi-polygon) — just simple polygons
- Rich text in notes (just plain text)
- Cross-tab Yjs sync via localStorage (handled by WebSocket)
- Rate limiting dashboard or admin UI
## Decisions
### D1: No-go areas as Yjs Y.Array of polygon coordinates
```typescript
// Yjs doc structure addition
noGoAreas: Y.Array<Y.Map<{
points: Array<{lat: number, lon: number}>,
name?: string
}>>
```
Each polygon is a closed ring of lat/lon points. BRouter accepts no-go areas
as a `nogo` parameter: `lon,lat,radius` for circles or polygon coordinates
depending on the BRouter version. We'll convert our polygons to BRouter's
expected format in the routing request.
### D2: Leaflet.draw for polygon drawing
Use `leaflet-draw` (or `@geoman-io/leaflet-geoman-free`) for drawing polygons
on the map. When a polygon is completed, add it to the Y.Array. Existing
polygons render as semi-transparent red overlays.
### D3: Notes as Y.Text in sidebar tab
Add a "Notes" tab to the sidebar (alongside waypoints). Uses Y.Text for
collaborative editing — simple textarea bound to Y.Text. Changes sync in
real-time. No markdown rendering — plain text only.
### D4: localStorage crash recovery
Every 10 seconds, save `Y.encodeStateAsUpdate(doc)` to
`localStorage['trails:session:${id}']`. On page load, if localStorage has
state for the current session, apply it as an update before connecting to
the server. Yjs CRDTs merge automatically — no conflicts.
Clear localStorage entry when session is closed or after successful sync.
### D5: In-memory rate limiter
Simple Map-based rate limiter in `server.ts`:
- Session creation: Track IP → count + window. Reject with 429 after 10/hour.
- BRouter proxy: Track session ID → count + window. Reject after 60/hour.
- No Redis needed — single server, in-memory is fine. Resets on restart
(acceptable).
## Risks / Trade-offs
- **leaflet-draw adds bundle size** → ~50KB gzipped. Acceptable for polygon
drawing functionality. Can lazy-load.
- **localStorage size limit** → ~5MB per origin. Yjs state is typically
10-100KB. No risk.
- **In-memory rate limiter resets on deploy** → Acceptable for current scale.
Redis-backed when needed.