The "permit/lejet" feature is really a subscription. Full rename of the mutable master data, plus a recurring monthly price. - DB (migration 0004, data-preserving ALTER RENAME): permits→subscriptions, permit_credentials/_plates→subscription_*, sessions.permit_id→subscription_id. - Pricing: per-subscription priceMinor + period(monthly) + currency, with a site default (site_config.subscription_monthly_price_minor) pre-filling the form. - Server: subscription-flow.ts (SubscriptionFlow), routes/subscriptions.ts (/api/subscriptions). Web: SubscriptionManager, route, i18n (sq Abonimet/en). - The signed ledger `permitId` payload is intentionally kept — immutable hash-chained history; renaming it would break verification of past events. Deferred (wiki notes): fee collection into the ledger/shift (a shift-attributed payment), LPR/ANPR plate source, time-of-day access windows (overnight subscriber). Also carries the device-footer UI surface (api DeviceStatus, router mount, i18n devices) due to shared-file overlap with the preceding footer commit. Verified end-to-end on a fresh DB and migration on a live-DB copy (sessions preserved). Live DB migrated. Full monorepo builds clean. Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V
3.6 KiB
type, tags, sources, updated, status
| type | tags | sources | updated | status | ||||
|---|---|---|---|---|---|---|---|---|
| concept |
|
2026-06-15 | open |
Capacity & Occupancy
How many vehicles are inside, how many spaces remain, and what happens when the lot is full.
Occupancy is a projection (like everything else)
occupancy = count(open [[parking-session|sessions]]) — an entry with no matching exit. It is a
fold over the signed append-only-event-chain, never a hand-maintained counter (a counter is
editable and drifts; the chain is the truth). Spaces-free = capacity − occupancy.
capacityis admin-set per site (and per zone/level if the lot has sections — model azoneon capacity + on the entry so multi-level is a later addition, not a rewrite).- Permit concurrency (
maxConcurrent, see subscription) is the same kind of fold, scoped to one permit's open sessions.
Full → refuse entry + FULL sign
- When
occupancy ≥ capacity, the entry flow refuses (novehicle_entry, no barrier open) and can drive a "FULL" sign (a relay/output, via the device adapter layer). - Safety/policy nuance: "full" blocks entry only — exit always works (fail-state-safety: exit fails open; never trap a vehicle). Permit holders may be allowed in past a "transient full" threshold (reserve spaces for subscribers) — an optional policy knob.
- Counting drift is real: tailgating (two cars, one entry) and missed reads make the live count diverge from physical reality. The count is the system's occupancy; periodic ground-truth (a loop count, or the opencv-anpr-service count) reconciles it — surfaced as an anomaly, not silently corrected.
"Full" is a soft, operator-configurable policy
Refusing at capacity is the default, not an absolute. An operator may opt into valet-overcapacity — accept the car into operator custody (keys handed over, stacked beyond the marked count) instead of refusing. So the FULL gate is a policy knob (refuse vs. valet-accept), set by the operator per site. Valet is a manned-mode feature with its own custody/session shape — see valet-overcapacity (deferred).
As-built (2026-06-16)
- Occupancy =
occupancyCount(apps/server/src/occupancy.ts): a fold over the ledger — entries minus exits per identity, count those> 0.getOccupancyreturns{count, capacity, free, full}. - Capacity is a single-row
site_configtable (admin-set;null= uncapped). Routes (routes/site.ts):GET /api/occupancy+GET /api/site-config(any role),PUT /api/site-config(admin; non-negative int or null). - FULL gate is in the transient entry flow:
occupancy.full→ refuse (no ticket, novehicle_entry, no open) + signedanomaly. Permit entry is NOT gated here — subscribers are admitted past transient-full (their ownmaxConcurrentstill applies); occupancy can read over-capacity (freenegative) when permits enter a full lot, as intended. - UI
SiteSettings: live occupancy + FULL badge (everyone); capacity editor (admin). - Verified: fill to cap → 3rd transient refused; permit still admitted past full; exit frees a slot; RBAC (operator can't set capacity); verifyChain ok. Physical FULL-sign relay output is deferred (needs a sign device).
Open
- Zone/level granularity at launch vs. single capacity number.
- Reserve-for-permits threshold (a soft transient cap below the hard capacity) — currently permits are simply ungated; a tunable threshold is the richer version.
- Physical FULL-sign relay output (a sign-device role).
- The valet over-capacity mode + custody model (valet-overcapacity).