Improve reactor controls, reactions, and maintenance UI

src/reactor_sim/simulation.py

@@ -27,6 +27,29 @@ def _default_state_path() -> Path:
     return Path(custom) if custom else Path("artifacts/last_state.json")
 
 
+def _poison_log_path() -> Path:
+    custom = os.getenv("FISSION_POISON_LOG")
+    return Path(custom) if custom else Path("artifacts/poisons.json")
+
+
+def _write_poison_log(path: Path, state: PlantState | None, snapshots: list[dict[str, float]] | None = None) -> None:
+    if state is None and snapshots:
+        latest = snapshots[-1]
+        inventory = latest.get("products", {})
+        particles = latest.get("particles", {})
+        time_elapsed = latest.get("time_elapsed", 0.0)
+    elif state is not None:
+        inventory = state.core.fission_product_inventory
+        particles = state.core.emitted_particles
+        time_elapsed = state.time_elapsed
+    else:
+        return
+    path.parent.mkdir(parents=True, exist_ok=True)
+    payload = {"time_elapsed": time_elapsed, "products": inventory, "particles": particles}
+    path.write_text(json.dumps(payload, indent=2))
+    LOGGER.info("Wrote poison snapshot to %s", path)
+
+
 @dataclass
 class ReactorSimulation:
     reactor: Reactor
@@ -113,6 +136,7 @@ def main() -> None:
             snapshots = sim.log()
             LOGGER.info("Captured %d snapshots", len(snapshots))
             print(json.dumps(snapshots[-5:], indent=2))
+            _write_poison_log(_poison_log_path(), sim.last_state, snapshots)
     except KeyboardInterrupt:
         sim.stop()
         LOGGER.warning("Simulation interrupted by user")