port(m7): CP simulator 2.0.1 — emit NotifyEvent when a CSMS-installed variable monitor trips

[duyhuynh-vn]

Context

With the inbound CSMS→CP handler wiring for OCPP 2.0.1 now essentially complete (all 39 CSMS-initiated commands are wired or in-flight), the remaining M7 work is the CP→CSMS-initiated async flows the simulator does not yet drive.

The variable-monitoring family is currently a dead-end: the CP accepts and stores monitors via SetVariableMonitoring (#498), ClearVariableMonitoring (#499), SetMonitoringBase (#504), SetMonitoringLevel (#503), and reports the configured set via GetMonitoringReport (#495) → NotifyMonitoringReport. But no monitor ever fires — the CP never emits a NotifyEvent.req. The monitor store in crates/ocpp-cp/src/v201_device_model.rs (monitors: HashMap<i32, MonitorEntry>) even carries a documented "a future emitter can honor it" seam comment for exactly this.

This is the direct async twin of the already-shipped NotifyReport (#487) and NotifyMonitoringReport (#495) streams — same off-CALL-path RemoteCommand queueing discipline.

Python reference

• ocpp/v201/call.py → class NotifyEvent (generated_at, seq_no, event_data: List[EventDataType], tbc)
• ocpp/v201/datatypes.py → class EventDataType (event_id, timestamp, trigger, actual_value, event_notification_type, component, variable, optional cause, tech_code, tech_info, cleared, transaction_id, variable_monitoring_id)
• ocpp/v201/enums.py → EventTriggerEnumType, EventNotificationEnumType

Proposed design

Because a pure simulator has no naturally-changing variable values, the trip must be deterministically injected — matching the simulator's existing opt-in behavior-injection pattern (firmware fault injection, unlock_outcome, etc.):

• A test/sim hook (e.g. trip_variable_monitor(component, variable, actual_value)) that looks up a matching monitor in the store and, if found, queues a RemoteCommand::V201NotifyEvent.
• run_v201_notify_event emits a schema-valid NotifyEvent.req with correctly correlated variable_monitoring_id, the monitor's EventTriggerEnumType (Delta/Periodic/UpperThreshold/LowerThreshold derived from the monitor type), event_notification_type, component/variable, and a monotonically increasing seq_no.
• No matching monitor → no event queued (no-op), consumer-gone rolls the marker back (existing convention).

Acceptance criteria

• RemoteCommand::V201NotifyEvent variant + run_v201_notify_event emitter, queued off the inbound path (never re-entering the receive loop mid-dispatch).
• Pure NotifyEvent.req / EventDataType page builder in v201_command with a schema-validity test against the bundled FINAL JSON Schema.
• Trigger derivation maps each stored MonitorType to the correct EventTriggerEnumType.
• Tests: trip-with-match emits one correlated event; trip-with-no-match is a no-op; seq_no increments across events; hostile/oversized injected actual_value never panics (trust boundary — value is stringly reported, never parsed).
• cargo fmt --check, cargo clippy --all-targets -- -D warnings, cargo test --workspace all green.

Milestone: M7. Target ≤ ~500 LOC; if larger, ship the emitter + happy path and split threshold/delta derivation into a follow-up.

---

Filed by the nightly dev during Sunday issue grooming (2026-08-23). Direction tracked in #256.

[duyhuynh-vn]

🌙 Nightly dev picking this up — 2026-09-08

---

Generated by Claude Code

[duyhuynh-vn]

🌙 PR up: #570 — implements the trip_variable_monitor → NotifyEvent emitter with trigger derivation, monitor-store lookup, and a full test matrix (all green locally: fmt / clippy -D warnings / cargo test --workspace).

One design note for review: the emit is inline via call() rather than the RemoteCommand::V201NotifyEvent queue the issue proposed — the trip is CP-initiated from app/test code (not from inside the inbound-CALL dispatch loop), so there is no receive-loop re-entrancy to avoid, matching the recent inline CP-origination hooks (#563, #568). Every other acceptance criterion is honored in substance. Full rationale in the PR description.

Ready for your review.

---

Generated by Claude Code