Stop a bolus at a fault and keep reporting what it left undelivered

README.md

@@ -8,7 +8,7 @@ Fake pod implementation
 
 * This version also mimics a behavior we see in some DASH pods where the pod disconnects every 3 minutes; this can be used with iOS hooks to make a heartbeat to run Loop in situations where a BLE CGM is not available. 
 
-* It serves a control panel at http://<host>:8080/ (`-api` changes the address): the pod's reservoir, delivery, age, alerts and fault, with controls to set the reservoir and pod age, raise alerts, trigger or clear a fault, and crash on the next command to test unacknowledged commands. The panel drives a JSON API: `GET /status`, and `POST /command` with `{"command": "changeReservoir", "value": 45}` (also `setActiveTime` in minutes, `setAlerts` as a slot mask, `setFault` with a fault code, 0 to clear, `crashNextCommand` with `"beforeProcessing": true|false`, `ignoreNextMessages` with a count, which keeps the link up but leaves that many messages unanswered, as a pod that didn't hear them would, and `failNextConnects` with a count and an optional `hangUpAfter` in seconds, 7 by default, which leaves service discovery unanswered on that many connects and then hangs up with CoreBluetooth's "peripheral disconnected" error, as some pods do in the field; this needs `-transport impossible` and an ImpossiBLE that passes `errorDomain` and `errorCode` through on a disconnect).
+* It serves a control panel at http://<host>:8080/ (`-api` changes the address): the pod's reservoir, delivery, age, alerts and fault, with controls to set the reservoir and pod age, raise alerts, trigger or clear a fault, and crash on the next command to test unacknowledged commands. The panel drives a JSON API: `GET /status`, and `POST /command` with `{"command": "changeReservoir", "value": 45}` (also `setActiveTime` in minutes, `setAlerts` as a slot mask, `setFault` with a fault code, 0 to clear, `crashNextCommand` with `"beforeProcessing": true|false`, `ignoreNextMessages` with a count, which keeps the link up but leaves that many messages unanswered, as a pod that didn't hear them would, and `failNextConnects` with a count and an optional `hangUpAfter` in seconds, 7 by default, which leaves service discovery unanswered on that many connects and then hangs up with CoreBluetooth's "peripheral disconnected" error, as some pods do in the field; this needs `-transport impossible` and an ImpossiBLE that passes `errorDomain` and `errorCode` through on a disconnect). A fault stops a bolus in progress, and the pod reports the part left undelivered however late it is read, as a real pod does.
 
 * The websocket API at `/ws`, used by the separate [NodeJS/React frontend](https://github.com/ps2/pod_simulator_frontend), is still there.
 

pkg/pod/pod.go

@@ -832,8 +832,7 @@ func (p *Pod) SetAlerts(newVal uint8) {
 
 func (p *Pod) SetFault(newVal uint8) {
 	p.mtx.Lock()
-	p.state.FaultEvent = newVal
-	p.state.FaultTime = p.state.MinutesActive()
+	p.state.SetFault(newVal)
 	p.state.Save()
 	p.takeSnapshot()
 	p.mtx.Unlock()

pkg/pod/state.go

@@ -35,6 +35,10 @@ type PODState struct {
 	FaultTime        uint16 `toml:"fault_time"`
 	Delivered        uint16 `toml:"delivered"`
 
+	// FaultBolusRemaining is the bolus a fault left undelivered. A faulted
+	// pod keeps reporting it, however late it is read.
+	FaultBolusRemaining uint16 `toml:"fault_bolus_remaining"`
+
 	TriggerTimes [8]uint16 `toml:"trigger_times"`
 
 	// At some point these could be replaced with details
@@ -116,8 +120,27 @@ func (p *PODState) MinutesActive() uint16 {
 	return uint16(time.Now().Sub(p.ActivationTime).Round(time.Minute).Minutes())
 }
 
+// SetFault stops the bolus where it is, so what it left undelivered is not
+// counted as delivered. Clearing the fault (0) forgets it.
+func (p *PODState) SetFault(code uint8) {
+	if code == 0 {
+		p.FaultBolusRemaining = 0
+	} else if p.FaultEvent == 0 {
+		remaining := p.BolusRemaining()
+		p.FaultBolusRemaining = remaining
+		p.Delivered -= remaining
+		p.Reservoir += remaining
+		p.BolusEnd = time.Time{}
+	}
+	p.FaultEvent = code
+	p.FaultTime = p.MinutesActive()
+}
+
 // NOTE: only handles immediate boluses; any extended bolus is not accounted for
 func (p *PODState) BolusRemaining() uint16 {
+	if p.FaultEvent != 0 {
+		return p.FaultBolusRemaining
+	}
 	now := time.Now()
 	var secondsPerPulse uint16
 	if p.BolusEnd.After(now) {

pkg/pod/state_test.go

@@ -0,0 +1,57 @@
+package pod
+
+import (
+	"testing"
+	"time"
+
+	"github.com/avereha/pod/pkg/response"
+)
+
+func TestAFaultFreezesTheBolusRemaining(t *testing.T) {
+	// An 80 pulse (4 U) bolus, 20 s in: 70 pulses still to go
+	s := &PODState{
+		PodProgress:    response.PodProgressRunningAbove50U,
+		ActivationTime: time.Now().Add(-2 * time.Hour),
+		Delivered:      1080,
+		Reservoir:      920,
+		BolusEnd:       time.Now().Add(140 * time.Second),
+	}
+
+	s.SetFault(0x18)
+
+	if got := s.BolusRemaining(); got != 70 {
+		t.Fatalf("bolus remaining after the fault = %d, want 70", got)
+	}
+	if s.Delivered != 1010 || s.Reservoir != 990 {
+		t.Fatalf("delivered %d, reservoir %d; want 1010 and 990", s.Delivered, s.Reservoir)
+	}
+	if !s.BolusEnd.IsZero() {
+		t.Fatalf("the bolus is still running after the fault, until %v", s.BolusEnd)
+	}
+
+	// A second fault code doesn't take the remainder again
+	s.SetFault(0x14)
+	if got := s.BolusRemaining(); got != 70 || s.Delivered != 1010 {
+		t.Fatalf("after a second fault: remaining %d, delivered %d; want 70 and 1010", got, s.Delivered)
+	}
+
+	s.SetFault(0)
+	if got := s.BolusRemaining(); got != 0 {
+		t.Fatalf("bolus remaining after clearing the fault = %d, want 0", got)
+	}
+}
+
+func TestAFaultWithNoBolusLeavesNothingUndelivered(t *testing.T) {
+	s := &PODState{
+		PodProgress:    response.PodProgressRunningAbove50U,
+		ActivationTime: time.Now().Add(-2 * time.Hour),
+		Delivered:      1080,
+		BolusEnd:       time.Now().Add(-time.Minute),
+	}
+
+	s.SetFault(0x18)
+
+	if got := s.BolusRemaining(); got != 0 || s.Delivered != 1080 {
+		t.Fatalf("remaining %d, delivered %d; want 0 and 1080", got, s.Delivered)
+	}
+}