engine refactor

internal/engine/profile.go

@@ -3,21 +3,26 @@ package engine
 // Profile is an ordered chain of propagators executed sequentially. Each
 // propagator picks up where the previous one finished.
 type Profile struct {
-	// Stages are run in order. For Direction=Reverse they are still iterated
-	// from index 0 onwards, but each propagator integrates with negative dt.
+	// Stages are run in order. For Direction=Reverse they are still
+	// iterated from index 0 onwards but each propagator integrates with
+	// negative dt.
 	Stages []*Propagator
 
-	// Direction controls the sign of dt across the whole profile.
+	// Direction controls the sign of dt across the profile.
 	Direction Direction
 
-	// Globals are constraints evaluated alongside each stage's local Constraints.
-	// Useful for profile-wide bounds like "stop after N hours total".
+	// Globals are constraints evaluated alongside each stage's local
+	// Constraints. Useful for profile-wide bounds like "stop after N hours".
 	Globals []Constraint
 }
 
-// Run executes the profile from the given launch point. Returns one Result
-// per executed stage, including any Fallback chains that were activated.
-func (p *Profile) Run(t0 float64, launch State) []Result {
+// Run executes the profile from the given launch point. Returns one
+// Result per executed stage, including any Fallback chains that were
+// activated. The supplied EventSink is shared across stages and aggregates
+// non-fatal observations.
+//
+// events may be nil; pass NewEventSink() to capture observations.
+func (p *Profile) Run(t0 float64, launch State, events *EventSink) []Result {
 	if p.Direction == 0 {
 		p.Direction = Forward
 	}
@@ -27,28 +32,36 @@ func (p *Profile) Run(t0 float64, launch State) []Result {
 
 	for i := 0; i < len(p.Stages); i++ {
 		stage := p.Stages[i]
-		res := stage.run(t, s, p.Direction, p.Globals)
+		ctx := StageContext{
+			ProfileStart:    t0,
+			PropagatorStart: t,
+			Launch:          launch,
+			PropagatorState: s,
+			Direction:       p.Direction,
+		}
+		res := stage.run(ctx, t, s, p.Globals, events)
 		results = append(results, res)
 
 		last := res.Points[len(res.Points)-1]
 		t = last.Time
 		s = State{Lat: last.Lat, Lng: last.Lng, Altitude: last.Altitude}
 
-		// Follow Fallback chains until none remains. Each fallback consumes
-		// from the same point the previous stage stopped at.
+		// Follow Fallback chains until none remains.
 		for res.Outcome == OutcomeFallback && stage.Fallback != nil {
 			stage = stage.Fallback
-			res = stage.run(t, s, p.Direction, p.Globals)
+			ctx = StageContext{
+				ProfileStart:    t0,
+				PropagatorStart: t,
+				Launch:          launch,
+				PropagatorState: s,
+				Direction:       p.Direction,
+			}
+			res = stage.run(ctx, t, s, p.Globals, events)
 			results = append(results, res)
 			last = res.Points[len(res.Points)-1]
 			t = last.Time
 			s = State{Lat: last.Lat, Lng: last.Lng, Altitude: last.Altitude}
 		}
-
-		// If a propagator's stop fired (not a fallback), end the profile.
-		if res.Outcome == OutcomeStopped {
-			continue
-		}
 	}
 
 	return results