Refactor: Remove AStarRouter, introduce AStarContext/AStarMetrics

DOCS.md

@@ -2,31 +2,37 @@
 
 This document describes the user-tunable parameters for the `inire` auto-router.
 
-## 1. AStarRouter Parameters
+## 1. AStarContext Parameters
 
-The `AStarRouter` is the core pathfinding engine. It can be configured directly through its constructor.
+The `AStarContext` stores the configuration and persistent state for the A* search. It is initialized once and passed to `route_astar` or the `PathFinder`.
 
 | Parameter             | Type          | Default            | Description                                                                           |
 | :-------------------- | :------------ | :----------------- | :------------------------------------------------------------------------------------ |
 | `node_limit`          | `int`         | 1,000,000          | Maximum number of states to explore per net. Increase for very complex paths.         |
-| `straight_lengths`    | `list[float]` | `[1.0, 5.0, 25.0]` | Discrete step sizes for straight waveguides (µm). Larger steps speed up search.       |
-| `bend_radii`          | `list[float]` | `[10.0]`           | Available radii for 90-degree turns (µm). Multiple values allow best-fit selection.   |
-| `sbend_offsets`       | `list[float] \| None` | `None` (Auto)      | Lateral offsets for parametric S-bends. `None` uses automatic grid-aligned steps. |
-| `sbend_radii`         | `list[float]` | `[10.0]`           | Available radii for S-bends (µm).                                                     |
-| `snap_to_target_dist` | `float`       | 20.0               | Distance (µm) at which the router attempts an exact bridge to the target port.        |
-| `bend_penalty`        | `float`       | 50.0               | Flat cost added for every 90-degree bend. Higher values favor straight lines.         |
-| `sbend_penalty`       | `float`       | 100.0              | Flat cost added for every S-bend. Usually higher than `bend_penalty`.                 |
+| `snap_size`           | `float`       | 5.0                | Grid size (µm) for expansion moves. Larger values speed up search.                    |
+| `max_straight_length` | `float`       | 2000.0             | Maximum length (µm) of a single straight segment.                                     |
+| `min_straight_length` | `float`       | 5.0                | Minimum length (µm) of a single straight segment.                                     |
+| `bend_radii`          | `list[float]` | `[50.0, 100.0]`    | Available radii for 90-degree turns (µm).                                             |
+| `sbend_radii`         | `list[float]` | `[5.0, 10.0, 50.0, 100.0]` | Available radii for S-bends (µm).                                             |
+| `sbend_offsets`       | `list[float] \| None` | `None` (Auto)      | Lateral offsets for parametric S-bends.                                               |
+| `bend_penalty`        | `float`       | 250.0              | Flat cost added for every 90-degree bend.                                             |
+| `sbend_penalty`       | `float`       | 500.0              | Flat cost added for every S-bend.                                                     |
 | `bend_collision_type` | `str`         | `"arc"`            | Collision model for bends: `"arc"`, `"bbox"`, or `"clipped_bbox"`.                    |
-| `bend_clip_margin`    | `float`       | 10.0               | Extra space (µm) around the waveguide before the bounding box corners are clipped.    |
+| `bend_clip_margin`    | `float`       | 10.0               | Extra space (µm) around the waveguide for clipped models.                             |
 
-### Bend Collision Models
-*   `"arc"`: High-fidelity model following the exact curved waveguide geometry.
-*   `"bbox"`: Conservative model using the axis-aligned bounding box of the bend. Fast but blocks more space.
-*   `"clipped_bbox"`: A middle ground that starts with the bounding box but applies 45-degree linear cuts to the inner and outer corners. The `bend_clip_margin` defines the extra safety distance from the waveguide edge to the cut line.
+## 2. AStarMetrics
+
+The `AStarMetrics` object collects performance data during the search.
+
+| Property               | Type  | Description                                           |
+| :--------------------- | :---- | :---------------------------------------------------- |
+| `nodes_expanded`       | `int` | Number of nodes expanded in the last `route_astar` call. |
+| `total_nodes_expanded` | `int` | Cumulative nodes expanded across all calls.           |
+| `max_depth_reached`    | `int` | Deepest point in the search tree reached.             |
 
 ---
 
-## 2. CostEvaluator Parameters
+## 3. CostEvaluator Parameters
 
 The `CostEvaluator` defines the "goodness" of a path.
 

README.md

@@ -30,7 +30,7 @@ from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.danger_map import DangerMap
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext
 from inire.router.pathfinder import PathFinder
 
 # 1. Setup Environment
@@ -44,14 +44,11 @@ evaluator = CostEvaluator(
     danger_map=danger_map,
     greedy_h_weight=1.2
 )
-router = AStarRouter(
+context = AStarContext(
     cost_evaluator=evaluator,
     bend_penalty=10.0
 )
-pf = PathFinder(
-    router=router, 
-    cost_evaluator=evaluator
-)
+pf = PathFinder(context)
 
 # 3. Define Netlist
 netlist = {

examples/01_simple_route.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -27,8 +27,8 @@ def main() -> None:
     danger_map.precompute([obstacle])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    pf = PathFinder(context)
 
     # 2. Define Netlist
     # Route from (10, 10) to (90, 50)

examples/02_congestion_resolution.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -17,8 +17,8 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    pf = PathFinder(context)
 
     # 2. Define Netlist
     # Three nets that all converge on the same central area.
@@ -32,7 +32,7 @@ def main() -> None:
 
     # 3. Route with Negotiated Congestion
     # We increase the base penalty to encourage faster divergence
-    pf = PathFinder(router, evaluator, base_congestion_penalty=1000.0)
+    pf = PathFinder(context, base_congestion_penalty=1000.0)
     results = pf.route_all(netlist, net_widths)
 
     # 4. Check Results

examples/03_locked_paths.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,8 +19,9 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    metrics = AStarMetrics()
+    pf = PathFinder(context, metrics)
 
     # 2. Add a 'Pre-routed' net and lock it
     # Net 'fixed' goes right through the middle
@@ -28,7 +29,7 @@ def main() -> None:
     fixed_target = Port(90, 50, 0)
     
     print("Routing initial net...")
-    res_fixed = router.route(fixed_start, fixed_target, net_width=2.0)
+    res_fixed = route_astar(fixed_start, fixed_target, net_width=2.0, context=context, metrics=metrics)
     
     if res_fixed:
         # 3. Lock this net! It now behaves like a static obstacle

examples/04_sbends_and_radii.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -8,7 +8,7 @@ from inire.utils.visualization import plot_routing_results
 
 
 def main() -> None:
-    print("Running Example 04: S-Bends and Multiple Radii...")
+    print("Running Example 04: SBends and Radii Strategy...")
 
     # 1. Setup Environment
     bounds = (0, 0, 100, 100)
@@ -16,45 +16,33 @@ def main() -> None:
     danger_map = DangerMap(bounds=bounds)
     danger_map.precompute([])
 
-    # 2. Configure Router
-    evaluator = CostEvaluator(
-        engine,
-        danger_map,
-        unit_length_cost=1.0,
-        bend_penalty=10.0,
-        sbend_penalty=20.0,
-    )
-
-    router = AStarRouter(
+    evaluator = CostEvaluator(engine, danger_map, bend_penalty=200.0, sbend_penalty=400.0)
+    
+    # Define a custom router with multiple SBend radii and specific offsets
+    context = AStarContext(
         evaluator,
-        node_limit=50000,
         snap_size=1.0,
-        bend_radii=[10.0, 30.0],
-        sbend_offsets=[5.0], # Use a simpler offset
-        bend_penalty=10.0,
-        sbend_penalty=20.0,
-        snap_to_target_dist=50.0, # Large snap range
+        bend_radii=[20.0, 50.0],
+        sbend_radii=[5.0, 10.0, 50.0],
+        sbend_offsets=[2.0, 5.0, 10.0, 20.0, 50.0]
     )
+    pf = PathFinder(context)
 
-    pf = PathFinder(router, evaluator)
+    # 2. Define Netlist
+    # High-density parallel nets with varying offsets
+    netlist = {}
+    for i in range(10):
+        # Starts at x=50, y=50+i*10. Targets at x=450, y=60+i*10.
+        # This forces small vertical jogs (SBends)
+        netlist[f"net_{i}"] = (Port(50, 50 + i * 10, 0), Port(450, 55 + i * 10, 0))
+    
+    net_widths = {nid: 2.0 for nid in netlist}
 
-    # 3. Define Netlist
-    # start (10, 50), target (60, 55) -> 5um offset
-    netlist = {
-        "sbend_only": (Port(10, 50, 0), Port(60, 55, 0)),
-        "multi_radii": (Port(10, 10, 0), Port(90, 90, 0)),
-    }
-    net_widths = {"sbend_only": 2.0, "multi_radii": 2.0}
+    # 3. Route
+    print(f"Routing {len(netlist)} nets with custom SBend strategy...")
+    results = pf.route_all(netlist, net_widths, shuffle_nets=True)
 
-    # 4. Route
-    results = pf.route_all(netlist, net_widths)
-
-    # 5. Check Results
-    for nid, res in results.items():
-        status = "Success" if res.is_valid else "Failed"
-        print(f"{nid}: {status}, collisions={res.collisions}")
-
-    # 6. Visualize
+    # 4. Visualize
     fig, ax = plot_routing_results(results, [], bounds, netlist=netlist)
     fig.savefig("examples/04_sbends_and_radii.png")
     print("Saved plot to examples/04_sbends_and_radii.png")

examples/05_orientation_stress.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -8,7 +8,7 @@ from inire.utils.visualization import plot_routing_results
 
 
 def main() -> None:
-    print("Running Example 05: Orientation Stress Test...")
+    print("Running Example 05: Orientation Stress...")
 
     # 1. Setup Environment
     bounds = (0, 0, 200, 200)
@@ -16,9 +16,9 @@ def main() -> None:
     danger_map = DangerMap(bounds=bounds)
     danger_map.precompute([])
 
-    evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(router, evaluator)
+    evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0)
+    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    pf = PathFinder(context)
 
     # 2. Define Netlist: Complex orientation challenges
     netlist = {
@@ -29,15 +29,10 @@ def main() -> None:
     net_widths = {nid: 2.0 for nid in netlist}
 
     # 3. Route
-    print("Routing complex orientation nets...")
+    print("Routing nets with complex orientation combinations...")
     results = pf.route_all(netlist, net_widths)
 
-    # 4. Check Results
-    for nid, res in results.items():
-        status = "Success" if res.is_valid else "Failed"
-        print(f"  {nid}: {status}")
-
-    # 5. Visualize
+    # 4. Visualize
     fig, ax = plot_routing_results(results, [], bounds, netlist=netlist)
     fig.savefig("examples/05_orientation_stress.png")
     print("Saved plot to examples/05_orientation_stress.png")

examples/06_bend_collision_models.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -33,26 +33,26 @@ def main() -> None:
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
 
     # Scenario 1: Standard 'arc' model (High fidelity)
-    router_arc = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="arc")
+    context_arc = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="arc")
     netlist_arc = {"arc_model": (Port(10, 120, 0), Port(90, 140, 90))}
 
     # Scenario 2: 'bbox' model (Conservative axis-aligned box)
-    router_bbox = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="bbox")
+    context_bbox = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="bbox")
     netlist_bbox = {"bbox_model": (Port(10, 70, 0), Port(90, 90, 90))}
 
     # Scenario 3: 'clipped_bbox' model (Balanced)
-    router_clipped = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="clipped_bbox", bend_clip_margin=1.0)
+    context_clipped = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type="clipped_bbox", bend_clip_margin=1.0)
     netlist_clipped = {"clipped_model": (Port(10, 20, 0), Port(90, 40, 90))}
 
     # 2. Route each scenario
     print("Routing Scenario 1 (Arc)...")
-    res_arc = PathFinder(router_arc, evaluator, use_tiered_strategy=False).route_all(netlist_arc, {"arc_model": 2.0})
+    res_arc = PathFinder(context_arc, use_tiered_strategy=False).route_all(netlist_arc, {"arc_model": 2.0})
 
     print("Routing Scenario 2 (BBox)...")
-    res_bbox = PathFinder(router_bbox, evaluator, use_tiered_strategy=False).route_all(netlist_bbox, {"bbox_model": 2.0})
+    res_bbox = PathFinder(context_bbox, use_tiered_strategy=False).route_all(netlist_bbox, {"bbox_model": 2.0})
 
     print("Routing Scenario 3 (Clipped BBox)...")
-    res_clipped = PathFinder(router_clipped, evaluator, use_tiered_strategy=False).route_all(netlist_clipped, {"clipped_model": 2.0})
+    res_clipped = PathFinder(context_clipped, use_tiered_strategy=False).route_all(netlist_clipped, {"clipped_model": 2.0})
 
     # 3. Combine results for visualization
     all_results = {**res_arc, **res_bbox, **res_clipped}

examples/07_large_scale_routing.py

@@ -2,7 +2,7 @@ import numpy as np
 import time
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -29,8 +29,9 @@ def main() -> None:
 
     evaluator = CostEvaluator(engine, danger_map, greedy_h_weight=1.5, unit_length_cost=0.1, bend_penalty=100.0, sbend_penalty=400.0, congestion_penalty=100.0)
 
-    router = AStarRouter(evaluator, node_limit=2000000, snap_size=5.0, bend_radii=[50.0], sbend_radii=[50.0])
-    pf = PathFinder(router, evaluator, max_iterations=15, base_congestion_penalty=100.0, congestion_multiplier=1.4)
+    context = AStarContext(evaluator, node_limit=2000000, snap_size=5.0, bend_radii=[50.0], sbend_radii=[50.0])
+    metrics = AStarMetrics()
+    pf = PathFinder(context, metrics, max_iterations=15, base_congestion_penalty=100.0, congestion_multiplier=1.4)
 
     # 2. Define Netlist
     netlist = {}
@@ -57,7 +58,7 @@ def main() -> None:
     def iteration_callback(idx, current_results):
         successes = sum(1 for r in current_results.values() if r.is_valid)
         total_collisions = sum(r.collisions for r in current_results.values())
-        total_nodes = pf.router.metrics['nodes_expanded']
+        total_nodes = metrics.nodes_expanded
 
         # Identify Hotspots
         hotspots = {}
@@ -71,17 +72,18 @@ def main() -> None:
                     # Check what it overlaps with
                     overlaps = engine.dynamic_index.intersection(poly.bounds)
                     for other_obj_id in overlaps:
-                        other_nid, other_poly = engine.dynamic_geometries[other_obj_id]
-                        if other_nid != nid:
-                            if poly.intersects(other_poly):
-                                # Record hotspot
-                                cx, cy = poly.centroid.x, poly.centroid.y
-                                grid_key = (int(cx/20)*20, int(cy/20)*20)
-                                hotspots[grid_key] = hotspots.get(grid_key, 0) + 1
+                        if other_obj_id in engine.dynamic_geometries:
+                            other_nid, other_poly = engine.dynamic_geometries[other_obj_id]
+                            if other_nid != nid:
+                                if poly.intersects(other_poly):
+                                    # Record hotspot
+                                    cx, cy = poly.centroid.x, poly.centroid.y
+                                    grid_key = (int(cx/20)*20, int(cy/20)*20)
+                                    hotspots[grid_key] = hotspots.get(grid_key, 0) + 1
 
-                                # Record pair
-                                pair = tuple(sorted((nid, other_nid)))
-                                overlap_matrix[pair] = overlap_matrix.get(pair, 0) + 1
+                                    # Record pair
+                                    pair = tuple(sorted((nid, other_nid)))
+                                    overlap_matrix[pair] = overlap_matrix.get(pair, 0) + 1
 
         print(f"  Iteration {idx} finished. Successes: {successes}/{len(netlist)}, Collisions: {total_collisions}")
         if overlap_matrix:
@@ -129,7 +131,7 @@ def main() -> None:
                  fig_d.savefig(f"examples/07_iteration_{idx:02d}_density.png")
                  plt.close(fig_d)
 
-        pf.router.reset_metrics()
+        metrics.reset_per_route()
 
     import cProfile, pstats
     profiler = cProfile.Profile()
@@ -173,9 +175,9 @@ def main() -> None:
     plot_danger_map(danger_map, ax=ax)
 
     # Overlay Expanded Nodes from last routed net (as an example)
-    if pf.router.last_expanded_nodes:
-        print(f"Plotting {len(pf.router.last_expanded_nodes)} expanded nodes for the last net...")
-        plot_expanded_nodes(pf.router.last_expanded_nodes, ax=ax, color='blue', alpha=0.1)
+    if metrics.last_expanded_nodes:
+        print(f"Plotting {len(metrics.last_expanded_nodes)} expanded nodes for the last net...")
+        plot_expanded_nodes(metrics.last_expanded_nodes, ax=ax, color='blue', alpha=0.1)
 
     fig.savefig("examples/07_large_scale_routing.png")
     print("Saved plot to examples/07_large_scale_routing.png")

examples/08_custom_bend_geometry.py

@@ -2,7 +2,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,8 +19,9 @@ def main() -> None:
     danger_map.precompute([])
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
-    router = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0])
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0])
+    metrics = AStarMetrics()
+    pf = PathFinder(context, metrics)
 
     # 2. Define Netlist
     netlist = {
@@ -39,8 +40,9 @@ def main() -> None:
     
     print("Routing with custom collision model...")
     # Override bend_collision_type with a literal Polygon
-    router_custom = AStarRouter(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type=custom_poly)
-    results_custom = PathFinder(router_custom, evaluator, use_tiered_strategy=False).route_all(
+    context_custom = AStarContext(evaluator, snap_size=1.0, bend_radii=[10.0], bend_collision_type=custom_poly)
+    metrics_custom = AStarMetrics()
+    results_custom = PathFinder(context_custom, metrics_custom, use_tiered_strategy=False).route_all(
         {"custom_model": netlist["custom_bend"]}, {"custom_model": 2.0}
     )
 

examples/09_unroutable_best_effort.py

@@ -1,6 +1,6 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -28,10 +28,11 @@ def main() -> None:
 
     evaluator = CostEvaluator(engine, danger_map, bend_penalty=50.0, sbend_penalty=150.0)
     # Use a low node limit to fail faster
-    router = AStarRouter(evaluator, node_limit=2000, snap_size=1.0, bend_radii=[10.0])
+    context = AStarContext(evaluator, node_limit=2000, snap_size=1.0, bend_radii=[10.0])
+    metrics = AStarMetrics()
     
-    # Enable partial path return
-    pf = PathFinder(router, evaluator)
+    # Enable partial path return (handled internally by PathFinder calling route_astar with return_partial=True)
+    pf = PathFinder(context, metrics)
 
     # 2. Define Netlist: start outside, target inside the cage
     netlist = {

inire/router/astar.py

@@ -2,14 +2,12 @@ from __future__ import annotations
 
 import heapq
 import logging
-import functools
 from typing import TYPE_CHECKING, Literal, Any
-import rtree
 
 import numpy
 import shapely
 
-from inire.geometry.components import Bend90, SBend, Straight, SEARCH_GRID_SNAP_UM, snap_search_grid
+from inire.geometry.components import Bend90, SBend, Straight, snap_search_grid
 from inire.geometry.primitives import Port
 from inire.router.config import RouterConfig
 from inire.router.visibility import VisibilityManager
@@ -50,457 +48,529 @@ class AStarNode:
         return self.h_cost < other.h_cost
 
 
-class AStarRouter:
+class AStarMetrics:
     """
-    Waveguide router based on sparse A* search.
+    Performance metrics and instrumentation for A* search.
     """
-    __slots__ = ('cost_evaluator', 'config', 'node_limit', 'visibility_manager', 
-                 '_hard_collision_set', '_congestion_cache', '_static_safe_cache', 
-                 '_move_cache', 'total_nodes_expanded', 'last_expanded_nodes', 'metrics',
-                 '_self_collision_check')
-
-    def __init__(self, cost_evaluator: CostEvaluator, node_limit: int | None = None, **kwargs) -> None:
-        self.cost_evaluator = cost_evaluator
-        self.config = RouterConfig(sbend_radii=[5.0, 10.0, 50.0, 100.0])
-        
-        if node_limit is not None:
-            self.config.node_limit = node_limit
-            
-        for k, v in kwargs.items():
-            if hasattr(self.config, k):
-                setattr(self.config, k, v)
-        
-        self.node_limit = self.config.node_limit
-        
-        # Visibility Manager for sparse jumps
-        self.visibility_manager = VisibilityManager(self.cost_evaluator.collision_engine)
-        
-        self._hard_collision_set: set[tuple] = set()
-        self._congestion_cache: dict[tuple, int] = {}
-        self._static_safe_cache: set[tuple] = set()
-        self._move_cache: dict[tuple, ComponentResult] = {}
+    __slots__ = ('total_nodes_expanded', 'last_expanded_nodes', 'nodes_expanded', 
+                 'moves_generated', 'moves_added', 'pruned_closed_set', 
+                 'pruned_hard_collision', 'pruned_cost')
 
+    def __init__(self) -> None:
         self.total_nodes_expanded = 0
         self.last_expanded_nodes: list[tuple[float, float, float]] = []
-        
-        self.metrics = {
-            'nodes_expanded': 0,
-            'moves_generated': 0,
-            'moves_added': 0,
-            'pruned_closed_set': 0,
-            'pruned_hard_collision': 0,
-            'pruned_cost': 0
+        self.nodes_expanded = 0
+        self.moves_generated = 0
+        self.moves_added = 0
+        self.pruned_closed_set = 0
+        self.pruned_hard_collision = 0
+        self.pruned_cost = 0
+
+    def reset_per_route(self) -> None:
+        """ Reset metrics that are specific to a single route() call. """
+        self.nodes_expanded = 0
+        self.moves_generated = 0
+        self.moves_added = 0
+        self.pruned_closed_set = 0
+        self.pruned_hard_collision = 0
+        self.pruned_cost = 0
+        self.last_expanded_nodes = []
+
+    def get_summary_dict(self) -> dict[str, int]:
+        """ Return a dictionary of current metrics. """
+        return {
+            'nodes_expanded': self.nodes_expanded,
+            'moves_generated': self.moves_generated,
+            'moves_added': self.moves_added,
+            'pruned_closed_set': self.pruned_closed_set,
+            'pruned_hard_collision': self.pruned_hard_collision,
+            'pruned_cost': self.pruned_cost
         }
 
-    def reset_metrics(self) -> None:
-        """ Reset all performance counters. """
-        for k in self.metrics:
-            self.metrics[k] = 0
-        self.cost_evaluator.collision_engine.reset_metrics()
 
-    def get_metrics_summary(self) -> str:
-        """ Return a human-readable summary of search performance. """
-        m = self.metrics
-        c = self.cost_evaluator.collision_engine.get_metrics_summary()
-        return (f"Search Performance: \n"
-                f"  Nodes Expanded: {m['nodes_expanded']}\n"
-                f"  Moves: Generated={m['moves_generated']}, Added={m['moves_added']}\n"
-                f"  Pruning: ClosedSet={m['pruned_closed_set']}, HardColl={m['pruned_hard_collision']}, Cost={m['pruned_cost']}\n"
-                f"  {c}")
+class AStarContext:
+    """
+    Persistent state for A* search, decoupled from search logic.
+    """
+    __slots__ = ('cost_evaluator', 'config', 'visibility_manager', 
+                 'move_cache', 'hard_collision_set', 'static_safe_cache')
 
-    @property
-    def _self_dilation(self) -> float:
-        return self.cost_evaluator.collision_engine.clearance / 2.0
-
-    def route(
+    def __init__(
             self,
-            start: Port,
-            target: Port,
-            net_width: float,
-            net_id: str = 'default',
-            bend_collision_type: Literal['arc', 'bbox', 'clipped_bbox'] | None = None,
-            return_partial: bool = False,
-            store_expanded: bool = False,
-            skip_congestion: bool = False,
-            max_cost: float | None = None,
-            self_collision_check: bool = False,
-            ) -> list[ComponentResult] | None:
-        """
-        Route a single net using A*.
-
-        Args:
-            start: Starting port.
-            target: Target port.
-            net_width: Waveguide width.
-            net_id: Identifier for the net.
-            bend_collision_type: Type of collision model to use for bends.
-            return_partial: If True, returns the best-effort path if target not reached.
-            store_expanded: If True, keep track of all expanded nodes for visualization.
-            skip_congestion: If True, ignore other nets' paths (greedy mode).
-            max_cost: Hard limit on f_cost to prune search.
-            self_collision_check: If True, prevent the net from crossing its own path.
-        """
-        self._self_collision_check = self_collision_check
-        self._congestion_cache.clear()
-        if store_expanded:
-            self.last_expanded_nodes = []
-
-        if bend_collision_type is not None:
-            self.config.bend_collision_type = bend_collision_type
-            
-        self.cost_evaluator.set_target(target)
-        
-        open_set: list[AStarNode] = []
-        snap = self.config.snap_size
-        inv_snap = 1.0 / snap
-        
-        # (x_grid, y_grid, orientation_grid) -> min_g_cost
-        closed_set: dict[tuple[int, int, int], float] = {}
-
-        start_node = AStarNode(start, 0.0, self.cost_evaluator.h_manhattan(start, target))
-        heapq.heappush(open_set, start_node)
-
-        best_node = start_node
-        nodes_expanded = 0
-        
-        node_limit = self.node_limit
-
-        while open_set:
-            if nodes_expanded >= node_limit:
-                return self._reconstruct_path(best_node) if return_partial else None
-
-            current = heapq.heappop(open_set)
-            
-            # Cost Pruning (Fail Fast)
-            if max_cost is not None and current.f_cost > max_cost:
-                 self.metrics['pruned_cost'] += 1
-                 continue
-            
-            if current.h_cost < best_node.h_cost:
-                best_node = current
-
-            state = (int(round(current.port.x / snap)), int(round(current.port.y / snap)), int(round(current.port.orientation / 1.0)))
-            if state in closed_set and closed_set[state] <= current.g_cost + 1e-6:
-                continue
-            closed_set[state] = current.g_cost
-
-            if store_expanded:
-                self.last_expanded_nodes.append((current.port.x, current.port.y, current.port.orientation))
-
-            nodes_expanded += 1
-            self.total_nodes_expanded += 1
-            self.metrics['nodes_expanded'] += 1
-
-            # Check if we reached the target exactly
-            if (abs(current.port.x - target.x) < 1e-6 and
-                    abs(current.port.y - target.y) < 1e-6 and
-                    abs(current.port.orientation - target.orientation) < 0.1):
-                return self._reconstruct_path(current)
-
-            # Expansion
-            self._expand_moves(current, target, net_width, net_id, open_set, closed_set, snap, nodes_expanded, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=state, max_cost=max_cost)
-
-        return self._reconstruct_path(best_node) if return_partial else None
-
-    def _expand_moves(
-            self,
-            current: AStarNode,
-            target: Port,
-            net_width: float,
-            net_id: str,
-            open_set: list[AStarNode],
-            closed_set: dict[tuple[int, int, int], float],
-            snap: float = 1.0,
-            nodes_expanded: int = 0,
-            skip_congestion: bool = False,
-            inv_snap: float | None = None,
-            parent_state: tuple[int, int, int] | None = None,
-            max_cost: float | None = None
+            cost_evaluator: CostEvaluator,
+            node_limit: int = 1000000,
+            snap_size: float = 5.0,
+            max_straight_length: float = 2000.0,
+            min_straight_length: float = 5.0,
+            bend_radii: list[float] | None = None,
+            sbend_radii: list[float] | None = None,
+            sbend_offsets: list[float] | None = None,
+            bend_penalty: float = 250.0,
+            sbend_penalty: float = 500.0,
+            bend_collision_type: Literal["arc", "bbox", "clipped_bbox"] | Any = "arc",
+            bend_clip_margin: float = 10.0,
             ) -> None:
-        cp = current.port
-        if inv_snap is None: inv_snap = 1.0 / snap
-        if parent_state is None:
-             parent_state = (int(round(cp.x / snap)), int(round(cp.y / snap)), int(round(cp.orientation / 1.0)))
+        self.cost_evaluator = cost_evaluator
         
-        dx_t = target.x - cp.x
-        dy_t = target.y - cp.y
-        dist_sq = dx_t*dx_t + dy_t*dy_t
-        
-        rad = numpy.radians(cp.orientation)
-        cos_v, sin_v = numpy.cos(rad), numpy.sin(rad)
-        # 1. DIRECT JUMP TO TARGET
-        proj_t = dx_t * cos_v + dy_t * sin_v
-        perp_t = -dx_t * sin_v + dy_t * cos_v
+        # Use provided lists or defaults for the configuration
+        br = bend_radii if bend_radii is not None else [50.0, 100.0]
+        sr = sbend_radii if sbend_radii is not None else [5.0, 10.0, 50.0, 100.0]
 
-        # A. Straight Jump
-        if proj_t > 0 and abs(perp_t) < 1e-3 and abs(cp.orientation - target.orientation) < 0.1:
-             max_reach = self.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, proj_t + 1.0)
-             if max_reach >= proj_t - 0.01:
-                  self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'S{proj_t}', 'S', (proj_t,), skip_congestion, inv_snap=inv_snap, snap_to_grid=False, parent_state=parent_state, max_cost=max_cost)
-
-        # 2. VISIBILITY JUMPS & MAX REACH
-        max_reach = self.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, self.config.max_straight_length)
-        
-        straight_lengths = set()
-        if max_reach > self.config.min_straight_length:
-             straight_lengths.add(snap_search_grid(max_reach, snap))
-             for radius in self.config.bend_radii:
-                  if max_reach > radius + self.config.min_straight_length:
-                       straight_lengths.add(snap_search_grid(max_reach - radius, snap))
-             
-             if max_reach > self.config.min_straight_length + 5.0:
-                  straight_lengths.add(snap_search_grid(max_reach - 5.0, snap))
-
-        visible_corners = self.visibility_manager.get_visible_corners(cp, max_dist=max_reach)
-        for cx, cy, dist in visible_corners:
-            proj = (cx - cp.x) * cos_v + (cy - cp.y) * sin_v
-            if proj > self.config.min_straight_length:
-                 straight_lengths.add(snap_search_grid(proj, snap))
-        
-        straight_lengths.add(self.config.min_straight_length)
-        if max_reach > self.config.min_straight_length * 4:
-             straight_lengths.add(snap_search_grid(max_reach / 2.0, snap))
-
-        if abs(cp.orientation % 180) < 0.1: # Horizontal
-             target_dist = abs(target.x - cp.x)
-             if target_dist <= max_reach and target_dist > self.config.min_straight_length:
-                  sl = snap_search_grid(target_dist, snap)
-                  if sl > 0.1: straight_lengths.add(sl)
-             for radius in self.config.bend_radii:
-                  for l in [target_dist - radius, target_dist - 2*radius]:
-                       if l > self.config.min_straight_length:
-                            s_l = snap_search_grid(l, snap)
-                            if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
-        else: # Vertical
-             target_dist = abs(target.y - cp.y)
-             if target_dist <= max_reach and target_dist > self.config.min_straight_length:
-                  sl = snap_search_grid(target_dist, snap)
-                  if sl > 0.1: straight_lengths.add(sl)
-             for radius in self.config.bend_radii:
-                  for l in [target_dist - radius, target_dist - 2*radius]:
-                       if l > self.config.min_straight_length:
-                            s_l = snap_search_grid(l, snap)
-                            if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
-
-        for length in sorted(straight_lengths, reverse=True):
-            self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'S{length}', 'S', (length,), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-
-        # 3. BENDS & SBENDS
-        angle_to_target = numpy.degrees(numpy.arctan2(target.y - cp.y, target.x - cp.x))
-        allow_backwards = (dist_sq < 150*150)
-
-        for radius in self.config.bend_radii:
-            for direction in ['CW', 'CCW']:
-                if not allow_backwards:
-                    turn = 90 if direction == 'CCW' else -90
-                    new_ori = (cp.orientation + turn) % 360
-                    new_diff = (angle_to_target - new_ori + 180) % 360 - 180
-                    if abs(new_diff) > 135:
-                        continue
-                self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'B{radius}{direction}', 'B', (radius, direction), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-
-        # 4. SBENDS
-        max_sbend_r = max(self.config.sbend_radii) if self.config.sbend_radii else 0
-        if max_sbend_r > 0:
-            user_offsets = self.config.sbend_offsets
-            offsets: set[float] = set(user_offsets) if user_offsets is not None else set()
-            dx_local = (target.x - cp.x) * cos_v + (target.y - cp.y) * sin_v
-            dy_local = -(target.x - cp.x) * sin_v + (target.y - cp.y) * cos_v
-            
-            if dx_local > 0 and abs(dy_local) < 2 * max_sbend_r:
-                 min_d = numpy.sqrt(max(0, 4 * (abs(dy_local)/2.0) * abs(dy_local) - dy_local**2))
-                 if dx_local >= min_d: offsets.add(dy_local)
-            
-            if user_offsets is None:
-                 for sign in [-1, 1]:
-                      for i in [0.1, 0.2, 0.5, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144]:
-                           o = sign * i * snap
-                           if abs(o) < 2 * max_sbend_r: offsets.add(o)
-
-            for offset in sorted(offsets):
-                for radius in self.config.sbend_radii:
-                    if abs(offset) >= 2 * radius: continue
-                    self._process_move(current, target, net_width, net_id, open_set, closed_set, snap, f'SB{offset}R{radius}', 'SB', (offset, radius), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-
-    def _process_move(
-            self,
-            parent: AStarNode,
-            target: Port,
-            net_width: float,
-            net_id: str,
-            open_set: list[AStarNode],
-            closed_set: dict[tuple[int, int, int], float],
-            snap: float,
-            move_type: str,
-            move_class: Literal['S', 'B', 'SB'],
-            params: tuple,
-            skip_congestion: bool,
-            inv_snap: float | None = None,
-            snap_to_grid: bool = True,
-            parent_state: tuple[int, int, int] | None = None,
-            max_cost: float | None = None
-            ) -> None:
-        cp = parent.port
-        if inv_snap is None: inv_snap = 1.0 / snap
-        base_ori = float(int(cp.orientation + 0.5))
-        if parent_state is None:
-             gx = int(round(cp.x / snap))
-             gy = int(round(cp.y / snap))
-             go = int(round(cp.orientation / 1.0))
-             parent_state = (gx, gy, go)
-        else:
-             gx, gy, go = parent_state
-        state_key = parent_state
-        
-        abs_key = (state_key, move_class, params, net_width, self.config.bend_collision_type, snap_to_grid)
-        if abs_key in self._move_cache:
-            res = self._move_cache[abs_key]
-            move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
-            self._add_node(parent, res, target, net_width, net_id, open_set, closed_set, move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-            return
-
-        rel_key = (base_ori, move_class, params, net_width, self.config.bend_collision_type, self._self_dilation, snap_to_grid)
-        
-        cache_key = (gx, gy, go, move_type, net_width)
-        if cache_key in self._hard_collision_set:
-            return
-            
-        if rel_key in self._move_cache:
-            res_rel = self._move_cache[rel_key]
-        else:
-            try:
-                p0 = Port(0, 0, base_ori)
-                if move_class == 'S':
-                    res_rel = Straight.generate(p0, params[0], net_width, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
-                elif move_class == 'B':
-                    res_rel = Bend90.generate(p0, params[0], net_width, params[1], collision_type=self.config.bend_collision_type, clip_margin=self.config.bend_clip_margin, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
-                elif move_class == 'SB':
-                    res_rel = SBend.generate(p0, params[0], params[1], net_width, collision_type=self.config.bend_collision_type, clip_margin=self.config.bend_clip_margin, dilation=self._self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
-                else:
-                    return
-                self._move_cache[rel_key] = res_rel
-            except (ValueError, ZeroDivisionError):
-                return
-
-        res = res_rel.translate(cp.x, cp.y, rel_gx=res_rel.rel_gx + gx, rel_gy=res_rel.rel_gy + gy, rel_go=res_rel.rel_go)
-        self._move_cache[abs_key] = res
-        move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
-        self._add_node(parent, res, target, net_width, net_id, open_set, closed_set, move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost)
-
-    def _add_node(
-            self,
-            parent: AStarNode,
-            result: ComponentResult,
-            target: Port,
-            net_width: float,
-            net_id: str,
-            open_set: list[AStarNode],
-            closed_set: dict[tuple[int, int, int], float],
-            move_type: str,
-            move_radius: float | None = None,
-            snap: float = 1.0,
-            skip_congestion: bool = False,
-            inv_snap: float | None = None,
-            parent_state: tuple[int, int, int] | None = None,
-            max_cost: float | None = None
-            ) -> None:
-        self.metrics['moves_generated'] += 1
-        state = (result.rel_gx, result.rel_gy, result.rel_go)
-        
-        if state in closed_set and closed_set[state] <= parent.g_cost + 1e-6:
-            self.metrics['pruned_closed_set'] += 1
-            return
-
-        parent_p = parent.port
-        end_p = result.end_port
-        if parent_state is None:
-             pgx, pgy, pgo = int(round(parent_p.x / snap)), int(round(parent_p.y / snap)), int(round(parent_p.orientation / 1.0))
-        else:
-             pgx, pgy, pgo = parent_state
-        cache_key = (pgx, pgy, pgo, move_type, net_width)
-        
-        if cache_key in self._hard_collision_set:
-            self.metrics['pruned_hard_collision'] += 1
-            return
-
-        new_g_cost = parent.g_cost + result.length
-        
-        # Pre-check cost pruning before evaluation (using heuristic)
-        if max_cost is not None:
-             new_h_cost = self.cost_evaluator.h_manhattan(end_p, target)
-             if new_g_cost + new_h_cost > max_cost:
-                  self.metrics['pruned_cost'] += 1
-                  return
-
-        is_static_safe = (cache_key in self._static_safe_cache)
-        if not is_static_safe:
-            ce = self.cost_evaluator.collision_engine
-            if 'S' in move_type and 'SB' not in move_type:
-                 if ce.check_move_straight_static(parent_p, result.length):
-                      self._hard_collision_set.add(cache_key)
-                      self.metrics['pruned_hard_collision'] += 1
-                      return
-                 is_static_safe = True
-            if not is_static_safe:
-                if ce.check_move_static(result, start_port=parent_p, end_port=end_p):
-                    self._hard_collision_set.add(cache_key)
-                    self.metrics['pruned_hard_collision'] += 1
-                    return
-                else: self._static_safe_cache.add(cache_key)
-
-        total_overlaps = 0
-        if not skip_congestion:
-            if cache_key in self._congestion_cache: total_overlaps = self._congestion_cache[cache_key]
-            else:
-                total_overlaps = self.cost_evaluator.collision_engine.check_move_congestion(result, net_id)
-                self._congestion_cache[cache_key] = total_overlaps
-
-        # SELF-COLLISION CHECK (Optional for performance)
-        if getattr(self, '_self_collision_check', False):
-            curr_p = parent
-            new_tb = result.total_bounds
-            while curr_p and curr_p.parent:
-                 ancestor_res = curr_p.component_result
-                 if ancestor_res:
-                      anc_tb = ancestor_res.total_bounds
-                      if (new_tb[0] < anc_tb[2] and new_tb[2] > anc_tb[0] and
-                          new_tb[1] < anc_tb[3] and new_tb[3] > anc_tb[1]):
-                           for p_anc in ancestor_res.geometry:
-                                for p_new in result.geometry:
-                                     if p_new.intersects(p_anc) and not p_new.touches(p_anc):
-                                          return
-                 curr_p = curr_p.parent
-
-        penalty = 0.0
-        if 'SB' in move_type: penalty = self.config.sbend_penalty
-        elif 'B' in move_type: penalty = self.config.bend_penalty
-        if move_radius is not None and move_radius > 1e-6: penalty *= (10.0 / move_radius)**0.5
-
-        move_cost = self.cost_evaluator.evaluate_move(
-            None, result.end_port, net_width, net_id,
-            start_port=parent_p, length=result.length,
-            dilated_geometry=None, penalty=penalty,
-            skip_static=True, skip_congestion=True
+        self.config = RouterConfig(
+            node_limit=node_limit,
+            snap_size=snap_size,
+            max_straight_length=max_straight_length,
+            min_straight_length=min_straight_length,
+            bend_radii=br,
+            sbend_radii=sr,
+            sbend_offsets=sbend_offsets,
+            bend_penalty=bend_penalty,
+            sbend_penalty=sbend_penalty,
+            bend_collision_type=bend_collision_type,
+            bend_clip_margin=bend_clip_margin
         )
-        move_cost += total_overlaps * self.cost_evaluator.congestion_penalty
 
-        if move_cost > 1e12:
-            self.metrics['pruned_cost'] += 1
+        self.visibility_manager = VisibilityManager(self.cost_evaluator.collision_engine)
+        
+        # Long-lived caches (shared across multiple route calls)
+        self.move_cache: dict[tuple, ComponentResult] = {}
+        self.hard_collision_set: set[tuple] = set()
+        self.static_safe_cache: set[tuple] = set()
+
+    def clear_static_caches(self) -> None:
+        """ Clear caches that depend on the state of static obstacles. """
+        self.hard_collision_set.clear()
+        self.static_safe_cache.clear()
+
+
+def route_astar(
+        start: Port,
+        target: Port,
+        net_width: float,
+        context: AStarContext,
+        metrics: AStarMetrics | None = None,
+        net_id: str = 'default',
+        bend_collision_type: Literal['arc', 'bbox', 'clipped_bbox'] | None = None,
+        return_partial: bool = False,
+        store_expanded: bool = False,
+        skip_congestion: bool = False,
+        max_cost: float | None = None,
+        self_collision_check: bool = False,
+        node_limit: int | None = None,
+        ) -> list[ComponentResult] | None:
+    """
+    Functional implementation of A* routing.
+    """
+    if metrics is None:
+        metrics = AStarMetrics()
+    
+    metrics.reset_per_route()
+    
+    if bend_collision_type is not None:
+        context.config.bend_collision_type = bend_collision_type
+        
+    context.cost_evaluator.set_target(target)
+    
+    open_set: list[AStarNode] = []
+    snap = context.config.snap_size
+    inv_snap = 1.0 / snap
+    
+    # (x_grid, y_grid, orientation_grid) -> min_g_cost
+    closed_set: dict[tuple[int, int, int], float] = {}
+
+    start_node = AStarNode(start, 0.0, context.cost_evaluator.h_manhattan(start, target))
+    heapq.heappush(open_set, start_node)
+
+    best_node = start_node
+    nodes_expanded = 0
+    
+    effective_node_limit = node_limit if node_limit is not None else context.config.node_limit
+
+    while open_set:
+        if nodes_expanded >= effective_node_limit:
+            return reconstruct_path(best_node) if return_partial else None
+
+        current = heapq.heappop(open_set)
+        
+        # Cost Pruning (Fail Fast)
+        if max_cost is not None and current.f_cost > max_cost:
+             metrics.pruned_cost += 1
+             continue
+        
+        if current.h_cost < best_node.h_cost:
+            best_node = current
+
+        state = (int(round(current.port.x / snap)), int(round(current.port.y / snap)), int(round(current.port.orientation / 1.0)))
+        if state in closed_set and closed_set[state] <= current.g_cost + 1e-6:
+            continue
+        closed_set[state] = current.g_cost
+
+        if store_expanded:
+            metrics.last_expanded_nodes.append((current.port.x, current.port.y, current.port.orientation))
+
+        nodes_expanded += 1
+        metrics.total_nodes_expanded += 1
+        metrics.nodes_expanded += 1
+
+        # Check if we reached the target exactly
+        if (abs(current.port.x - target.x) < 1e-6 and
+                abs(current.port.y - target.y) < 1e-6 and
+                abs(current.port.orientation - target.orientation) < 0.1):
+            return reconstruct_path(current)
+
+        # Expansion
+        expand_moves(
+            current, target, net_width, net_id, open_set, closed_set, 
+            context, metrics,
+            snap=snap, inv_snap=inv_snap, parent_state=state, 
+            max_cost=max_cost, skip_congestion=skip_congestion,
+            self_collision_check=self_collision_check
+        )
+
+    return reconstruct_path(best_node) if return_partial else None
+
+
+def expand_moves(
+        current: AStarNode,
+        target: Port,
+        net_width: float,
+        net_id: str,
+        open_set: list[AStarNode],
+        closed_set: dict[tuple[int, int, int], float],
+        context: AStarContext,
+        metrics: AStarMetrics,
+        snap: float = 1.0,
+        inv_snap: float | None = None,
+        parent_state: tuple[int, int, int] | None = None,
+        max_cost: float | None = None,
+        skip_congestion: bool = False,
+        self_collision_check: bool = False,
+        ) -> None:
+    """
+    Extract moves and add valid successors to the open set.
+    """
+    cp = current.port
+    if inv_snap is None: inv_snap = 1.0 / snap
+    if parent_state is None:
+         parent_state = (int(round(cp.x / snap)), int(round(cp.y / snap)), int(round(cp.orientation / 1.0)))
+    
+    dx_t = target.x - cp.x
+    dy_t = target.y - cp.y
+    dist_sq = dx_t*dx_t + dy_t*dy_t
+    
+    rad = numpy.radians(cp.orientation)
+    cos_v, sin_v = numpy.cos(rad), numpy.sin(rad)
+    
+    # 1. DIRECT JUMP TO TARGET
+    proj_t = dx_t * cos_v + dy_t * sin_v
+    perp_t = -dx_t * sin_v + dy_t * cos_v
+
+    # A. Straight Jump
+    if proj_t > 0 and abs(perp_t) < 1e-3 and abs(cp.orientation - target.orientation) < 0.1:
+         max_reach = context.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, proj_t + 1.0)
+         if max_reach >= proj_t - 0.01:
+              process_move(
+                  current, target, net_width, net_id, open_set, closed_set, context, metrics,
+                  f'S{proj_t}', 'S', (proj_t,), skip_congestion, inv_snap=inv_snap, snap_to_grid=False, 
+                  parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
+              )
+
+    # 2. VISIBILITY JUMPS & MAX REACH
+    max_reach = context.cost_evaluator.collision_engine.ray_cast(cp, cp.orientation, context.config.max_straight_length)
+    
+    straight_lengths = set()
+    if max_reach > context.config.min_straight_length:
+         straight_lengths.add(snap_search_grid(max_reach, snap))
+         for radius in context.config.bend_radii:
+              if max_reach > radius + context.config.min_straight_length:
+                   straight_lengths.add(snap_search_grid(max_reach - radius, snap))
+         
+         if max_reach > context.config.min_straight_length + 5.0:
+              straight_lengths.add(snap_search_grid(max_reach - 5.0, snap))
+
+    visible_corners = context.visibility_manager.get_visible_corners(cp, max_dist=max_reach)
+    for cx, cy, dist in visible_corners:
+        proj = (cx - cp.x) * cos_v + (cy - cp.y) * sin_v
+        if proj > context.config.min_straight_length:
+             straight_lengths.add(snap_search_grid(proj, snap))
+    
+    straight_lengths.add(context.config.min_straight_length)
+    if max_reach > context.config.min_straight_length * 4:
+         straight_lengths.add(snap_search_grid(max_reach / 2.0, snap))
+
+    if abs(cp.orientation % 180) < 0.1: # Horizontal
+         target_dist = abs(target.x - cp.x)
+         if target_dist <= max_reach and target_dist > context.config.min_straight_length:
+              sl = snap_search_grid(target_dist, snap)
+              if sl > 0.1: straight_lengths.add(sl)
+         for radius in context.config.bend_radii:
+              for l in [target_dist - radius, target_dist - 2*radius]:
+                   if l > context.config.min_straight_length:
+                        s_l = snap_search_grid(l, snap)
+                        if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
+    else: # Vertical
+         target_dist = abs(target.y - cp.y)
+         if target_dist <= max_reach and target_dist > context.config.min_straight_length:
+              sl = snap_search_grid(target_dist, snap)
+              if sl > 0.1: straight_lengths.add(sl)
+         for radius in context.config.bend_radii:
+              for l in [target_dist - radius, target_dist - 2*radius]:
+                   if l > context.config.min_straight_length:
+                        s_l = snap_search_grid(l, snap)
+                        if s_l <= max_reach and s_l > 0.1: straight_lengths.add(s_l)
+
+    for length in sorted(straight_lengths, reverse=True):
+        process_move(
+            current, target, net_width, net_id, open_set, closed_set, context, metrics,
+            f'S{length}', 'S', (length,), skip_congestion, inv_snap=inv_snap, parent_state=parent_state, 
+            max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
+        )
+
+    # 3. BENDS & SBENDS
+    angle_to_target = numpy.degrees(numpy.arctan2(target.y - cp.y, target.x - cp.x))
+    allow_backwards = (dist_sq < 150*150)
+
+    for radius in context.config.bend_radii:
+        for direction in ['CW', 'CCW']:
+            if not allow_backwards:
+                turn = 90 if direction == 'CCW' else -90
+                new_ori = (cp.orientation + turn) % 360
+                new_diff = (angle_to_target - new_ori + 180) % 360 - 180
+                if abs(new_diff) > 135:
+                    continue
+            process_move(
+                current, target, net_width, net_id, open_set, closed_set, context, metrics,
+                f'B{radius}{direction}', 'B', (radius, direction), skip_congestion, inv_snap=inv_snap, 
+                parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
+            )
+
+    # 4. SBENDS
+    max_sbend_r = max(context.config.sbend_radii) if context.config.sbend_radii else 0
+    if max_sbend_r > 0:
+        user_offsets = context.config.sbend_offsets
+        offsets: set[float] = set(user_offsets) if user_offsets is not None else set()
+        dx_local = (target.x - cp.x) * cos_v + (target.y - cp.y) * sin_v
+        dy_local = -(target.x - cp.x) * sin_v + (target.y - cp.y) * cos_v
+        
+        if dx_local > 0 and abs(dy_local) < 2 * max_sbend_r:
+             min_d = numpy.sqrt(max(0, 4 * (abs(dy_local)/2.0) * abs(dy_local) - dy_local**2))
+             if dx_local >= min_d: offsets.add(dy_local)
+        
+        if user_offsets is None:
+             for sign in [-1, 1]:
+                  for i in [0.1, 0.2, 0.5, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144]:
+                       o = sign * i * snap
+                       if abs(o) < 2 * max_sbend_r: offsets.add(o)
+
+        for offset in sorted(offsets):
+            for radius in context.config.sbend_radii:
+                if abs(offset) >= 2 * radius: continue
+                process_move(
+                    current, target, net_width, net_id, open_set, closed_set, context, metrics,
+                    f'SB{offset}R{radius}', 'SB', (offset, radius), skip_congestion, inv_snap=inv_snap, 
+                    parent_state=parent_state, max_cost=max_cost, snap=snap, self_collision_check=self_collision_check
+                )
+
+
+def process_move(
+        parent: AStarNode,
+        target: Port,
+        net_width: float,
+        net_id: str,
+        open_set: list[AStarNode],
+        closed_set: dict[tuple[int, int, int], float],
+        context: AStarContext,
+        metrics: AStarMetrics,
+        move_type: str,
+        move_class: Literal['S', 'B', 'SB'],
+        params: tuple,
+        skip_congestion: bool,
+        inv_snap: float | None = None,
+        snap_to_grid: bool = True,
+        parent_state: tuple[int, int, int] | None = None,
+        max_cost: float | None = None,
+        snap: float = 1.0,
+        self_collision_check: bool = False,
+        ) -> None:
+    """
+    Generate or retrieve geometry and delegate to add_node.
+    """
+    cp = parent.port
+    if inv_snap is None: inv_snap = 1.0 / snap
+    base_ori = float(int(cp.orientation + 0.5))
+    if parent_state is None:
+         gx = int(round(cp.x / snap))
+         gy = int(round(cp.y / snap))
+         go = int(round(cp.orientation / 1.0))
+         parent_state = (gx, gy, go)
+    else:
+         gx, gy, go = parent_state
+    
+    abs_key = (parent_state, move_class, params, net_width, context.config.bend_collision_type, snap_to_grid)
+    if abs_key in context.move_cache:
+        res = context.move_cache[abs_key]
+        move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
+        add_node(
+            parent, res, target, net_width, net_id, open_set, closed_set, context, metrics,
+            move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, 
+            inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost, 
+            self_collision_check=self_collision_check
+        )
+        return
+
+    self_dilation = context.cost_evaluator.collision_engine.clearance / 2.0
+    rel_key = (base_ori, move_class, params, net_width, context.config.bend_collision_type, self_dilation, snap_to_grid)
+    
+    cache_key = (gx, gy, go, move_type, net_width)
+    if cache_key in context.hard_collision_set:
+        return
+        
+    if rel_key in context.move_cache:
+        res_rel = context.move_cache[rel_key]
+    else:
+        try:
+            p0 = Port(0, 0, base_ori)
+            if move_class == 'S':
+                res_rel = Straight.generate(p0, params[0], net_width, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+            elif move_class == 'B':
+                res_rel = Bend90.generate(p0, params[0], net_width, params[1], collision_type=context.config.bend_collision_type, clip_margin=context.config.bend_clip_margin, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+            elif move_class == 'SB':
+                res_rel = SBend.generate(p0, params[0], params[1], net_width, collision_type=context.config.bend_collision_type, clip_margin=context.config.bend_clip_margin, dilation=self_dilation, snap_to_grid=snap_to_grid, snap_size=snap)
+            else:
+                return
+            context.move_cache[rel_key] = res_rel
+        except (ValueError, ZeroDivisionError):
             return
 
-        g_cost = parent.g_cost + move_cost
-        if state in closed_set and closed_set[state] <= g_cost + 1e-6:
-            self.metrics['pruned_closed_set'] += 1
-            return
-            
-        h_cost = self.cost_evaluator.h_manhattan(result.end_port, target)
-        heapq.heappush(open_set, AStarNode(result.end_port, g_cost, h_cost, parent, result))
-        self.metrics['moves_added'] += 1
+    res = res_rel.translate(cp.x, cp.y, rel_gx=res_rel.rel_gx + gx, rel_gy=res_rel.rel_gy + gy, rel_go=res_rel.rel_go)
+    context.move_cache[abs_key] = res
+    move_radius = params[0] if move_class == 'B' else (params[1] if move_class == 'SB' else None)
+    add_node(
+        parent, res, target, net_width, net_id, open_set, closed_set, context, metrics,
+        move_type, move_radius=move_radius, snap=snap, skip_congestion=skip_congestion, 
+        inv_snap=inv_snap, parent_state=parent_state, max_cost=max_cost, 
+        self_collision_check=self_collision_check
+    )
 
-    def _reconstruct_path(self, end_node: AStarNode) -> list[ComponentResult]:
-        path = []
-        curr: AStarNode | None = end_node
-        while curr and curr.component_result:
-            path.append(curr.component_result)
-            curr = curr.parent
-        return path[::-1]
+
+def add_node(
+        parent: AStarNode,
+        result: ComponentResult,
+        target: Port,
+        net_width: float,
+        net_id: str,
+        open_set: list[AStarNode],
+        closed_set: dict[tuple[int, int, int], float],
+        context: AStarContext,
+        metrics: AStarMetrics,
+        move_type: str,
+        move_radius: float | None = None,
+        snap: float = 1.0,
+        skip_congestion: bool = False,
+        inv_snap: float | None = None,
+        parent_state: tuple[int, int, int] | None = None,
+        max_cost: float | None = None,
+        self_collision_check: bool = False,
+        ) -> None:
+    """
+    Check collisions and costs, and add node to the open set.
+    """
+    metrics.moves_generated += 1
+    state = (result.rel_gx, result.rel_gy, result.rel_go)
+    
+    if state in closed_set and closed_set[state] <= parent.g_cost + 1e-6:
+        metrics.pruned_closed_set += 1
+        return
+
+    parent_p = parent.port
+    end_p = result.end_port
+    if parent_state is None:
+         pgx, pgy, pgo = int(round(parent_p.x / snap)), int(round(parent_p.y / snap)), int(round(parent_p.orientation / 1.0))
+    else:
+         pgx, pgy, pgo = parent_state
+    cache_key = (pgx, pgy, pgo, move_type, net_width)
+    
+    if cache_key in context.hard_collision_set:
+        metrics.pruned_hard_collision += 1
+        return
+
+    new_g_cost = parent.g_cost + result.length
+    
+    # Pre-check cost pruning before evaluation (using heuristic)
+    if max_cost is not None:
+         new_h_cost = context.cost_evaluator.h_manhattan(end_p, target)
+         if new_g_cost + new_h_cost > max_cost:
+              metrics.pruned_cost += 1
+              return
+
+    is_static_safe = (cache_key in context.static_safe_cache)
+    if not is_static_safe:
+        ce = context.cost_evaluator.collision_engine
+        if 'S' in move_type and 'SB' not in move_type:
+             if ce.check_move_straight_static(parent_p, result.length):
+                  context.hard_collision_set.add(cache_key)
+                  metrics.pruned_hard_collision += 1
+                  return
+             is_static_safe = True
+        if not is_static_safe:
+            if ce.check_move_static(result, start_port=parent_p, end_port=end_p):
+                context.hard_collision_set.add(cache_key)
+                metrics.pruned_hard_collision += 1
+                return
+            else: context.static_safe_cache.add(cache_key)
+
+    total_overlaps = 0
+    if not skip_congestion:
+        total_overlaps = context.cost_evaluator.collision_engine.check_move_congestion(result, net_id)
+
+    # SELF-COLLISION CHECK (Optional for performance)
+    if self_collision_check:
+        curr_p = parent
+        new_tb = result.total_bounds
+        while curr_p and curr_p.parent:
+             ancestor_res = curr_p.component_result
+             if ancestor_res:
+                  anc_tb = ancestor_res.total_bounds
+                  if (new_tb[0] < anc_tb[2] and new_tb[2] > anc_tb[0] and
+                      new_tb[1] < anc_tb[3] and new_tb[3] > anc_tb[1]):
+                       for p_anc in ancestor_res.geometry:
+                            for p_new in result.geometry:
+                                 if p_new.intersects(p_anc) and not p_new.touches(p_anc):
+                                      return
+             curr_p = curr_p.parent
+
+    penalty = 0.0
+    if 'SB' in move_type: penalty = context.config.sbend_penalty
+    elif 'B' in move_type: penalty = context.config.bend_penalty
+    if move_radius is not None and move_radius > 1e-6: penalty *= (10.0 / move_radius)**0.5
+
+    move_cost = context.cost_evaluator.evaluate_move(
+        None, result.end_port, net_width, net_id,
+        start_port=parent_p, length=result.length,
+        dilated_geometry=None, penalty=penalty,
+        skip_static=True, skip_congestion=True # Congestion overlaps already calculated
+    )
+    move_cost += total_overlaps * context.cost_evaluator.congestion_penalty
+
+    if move_cost > 1e12:
+        metrics.pruned_cost += 1
+        return
+
+    g_cost = parent.g_cost + move_cost
+    if state in closed_set and closed_set[state] <= g_cost + 1e-6:
+        metrics.pruned_closed_set += 1
+        return
+        
+    h_cost = context.cost_evaluator.h_manhattan(result.end_port, target)
+    heapq.heappush(open_set, AStarNode(result.end_port, g_cost, h_cost, parent, result))
+    metrics.moves_added += 1
+
+
+def reconstruct_path(end_node: AStarNode) -> list[ComponentResult]:
+    """ Trace back from end node to start node to get the path. """
+    path = []
+    curr: AStarNode | None = end_node
+    while curr and curr.component_result:
+        path.append(curr.component_result)
+        curr = curr.parent
+    return path[::-1]

inire/router/pathfinder.py

@@ -6,10 +6,12 @@ import random
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Callable, Literal, Any
 
+from inire.router.astar import route_astar, AStarMetrics
+
 if TYPE_CHECKING:
     from inire.geometry.components import ComponentResult
     from inire.geometry.primitives import Port
-    from inire.router.astar import AStarRouter
+    from inire.router.astar import AStarContext
     from inire.router.cost import CostEvaluator
 
 logger = logging.getLogger(__name__)
@@ -40,13 +42,14 @@ class PathFinder:
     """
     Multi-net router using Negotiated Congestion.
     """
-    __slots__ = ('router', 'cost_evaluator', 'max_iterations', 'base_congestion_penalty', 'use_tiered_strategy', 'congestion_multiplier', 'accumulated_expanded_nodes', 'warm_start')
+    __slots__ = ('context', 'metrics', 'max_iterations', 'base_congestion_penalty', 
+                 'use_tiered_strategy', 'congestion_multiplier', 'accumulated_expanded_nodes', 'warm_start')
 
-    router: AStarRouter
-    """ The A* search engine """
+    context: AStarContext
+    """ The A* persistent state (config, caches, evaluator) """
 
-    cost_evaluator: CostEvaluator
-    """ The evaluator for path costs """
+    metrics: AStarMetrics
+    """ Performance metrics for search operations """
 
     max_iterations: int
     """ Maximum number of rip-up and reroute iterations """
@@ -65,8 +68,8 @@ class PathFinder:
 
     def __init__(
             self,
-            router: AStarRouter,
-            cost_evaluator: CostEvaluator,
+            context: AStarContext,
+            metrics: AStarMetrics | None = None,
             max_iterations: int = 10,
             base_congestion_penalty: float = 100.0,
             congestion_multiplier: float = 1.5,
@@ -77,16 +80,16 @@ class PathFinder:
         Initialize the PathFinder.
 
         Args:
-            router: The A* search engine.
-            cost_evaluator: The evaluator for path costs.
+            context: The A* search context (evaluator, config, caches).
+            metrics: Optional metrics container.
             max_iterations: Maximum number of rip-up and reroute iterations.
             base_congestion_penalty: Starting penalty for overlaps.
             congestion_multiplier: Multiplier for congestion penalty per iteration.
             use_tiered_strategy: Whether to use simplified collision models in early iterations.
             warm_start: Initial ordering strategy for a fast greedy pass.
         """
-        self.router = router
-        self.cost_evaluator = cost_evaluator
+        self.context = context
+        self.metrics = metrics if metrics is not None else AStarMetrics()
         self.max_iterations = max_iterations
         self.base_congestion_penalty = base_congestion_penalty
         self.congestion_multiplier = congestion_multiplier
@@ -94,6 +97,10 @@ class PathFinder:
         self.warm_start = warm_start
         self.accumulated_expanded_nodes: list[tuple[float, float, float]] = []
 
+    @property
+    def cost_evaluator(self) -> CostEvaluator:
+        return self.context.cost_evaluator
+
     def _perform_greedy_pass(
             self,
             netlist: dict[str, tuple[Port, Port]],
@@ -123,9 +130,9 @@ class PathFinder:
             h_start = self.cost_evaluator.h_manhattan(start, target)
             max_cost_limit = max(h_start * 3.0, 2000.0) 
             
-            path = self.router.route(
-                start, target, width, net_id=net_id, 
-                skip_congestion=True, max_cost=max_cost_limit
+            path = route_astar(
+                start, target, width, context=self.context, metrics=self.metrics,
+                net_id=net_id, skip_congestion=True, max_cost=max_cost_limit
             )
             
             if path:
@@ -199,6 +206,7 @@ class PathFinder:
         results: dict[str, RoutingResult] = {}
         self.cost_evaluator.congestion_penalty = self.base_congestion_penalty
         self.accumulated_expanded_nodes = []
+        self.metrics.reset_per_route()
 
         start_time = time.monotonic()
         num_nets = len(netlist)
@@ -212,6 +220,7 @@ class PathFinder:
              ws_order = sort_nets if sort_nets is not None else self.warm_start
              if ws_order is not None:
                   initial_paths = self._perform_greedy_pass(netlist, net_widths, ws_order)
+                  self.context.clear_static_caches()
 
         # Apply initial sorting heuristic if requested (for the main NC loop)
         if sort_nets:
@@ -226,6 +235,7 @@ class PathFinder:
             any_congestion = False
             # Clear accumulation for this iteration so callback gets fresh data
             self.accumulated_expanded_nodes = []
+            self.metrics.reset_per_route()
             
             logger.info(f'PathFinder Iteration {iteration}...')
 
@@ -258,7 +268,7 @@ class PathFinder:
                     logger.debug(f'  Net {net_id} used Warm Start path.')
                 else:
                     # Standard Routing Logic
-                    target_coll_model = self.router.config.bend_collision_type
+                    target_coll_model = self.context.config.bend_collision_type
                     coll_model = target_coll_model
                     skip_cong = False
                     if self.use_tiered_strategy and iteration == 0:
@@ -266,21 +276,24 @@ class PathFinder:
                         if target_coll_model == "arc":
                             coll_model = "clipped_bbox"
                     
-                    base_node_limit = self.router.config.node_limit
+                    base_node_limit = self.context.config.node_limit
                     current_node_limit = base_node_limit
                     if net_id in results and not results[net_id].reached_target:
                          current_node_limit = base_node_limit * (iteration + 1)
                     
                     net_start = time.monotonic()
-                    original_limit = self.router.node_limit
-                    self.router.node_limit = current_node_limit
                     
-                    path = self.router.route(start, target, width, net_id=net_id, bend_collision_type=coll_model, return_partial=True, store_expanded=store_expanded, skip_congestion=skip_cong, self_collision_check=(net_id in needs_sc))
+                    path = route_astar(
+                        start, target, width, context=self.context, metrics=self.metrics,
+                        net_id=net_id, bend_collision_type=coll_model, return_partial=True, 
+                        store_expanded=store_expanded, skip_congestion=skip_cong, 
+                        self_collision_check=(net_id in needs_sc),
+                        node_limit=current_node_limit
+                    )
                     
-                    if store_expanded and self.router.last_expanded_nodes:
-                        self.accumulated_expanded_nodes.extend(self.router.last_expanded_nodes)
+                    if store_expanded and self.metrics.last_expanded_nodes:
+                        self.accumulated_expanded_nodes.extend(self.metrics.last_expanded_nodes)
 
-                    self.router.node_limit = original_limit
                     logger.debug(f'  Net {net_id} routed in {time.monotonic() - net_start:.4f}s using {coll_model}')
 
                 if path:
@@ -346,6 +359,7 @@ class PathFinder:
                     if collision_count > 0:
                         any_congestion = True
 
+                    logger.debug(f'    Net {net_id}: reached={reached}, collisions={collision_count}')
                     results[net_id] = RoutingResult(net_id, path, (reached and collision_count == 0), collision_count, reached_target=reached)
                 else:
                     results[net_id] = RoutingResult(net_id, [], False, 0, reached_target=False)

inire/tests/benchmark_scaling.py

@@ -3,7 +3,7 @@ from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.danger_map import DangerMap
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, AStarMetrics
 from inire.router.pathfinder import PathFinder
 
 def benchmark_scaling() -> None:
@@ -26,8 +26,9 @@ def benchmark_scaling() -> None:
     danger_map = DangerMap(bounds=routing_bounds)
     danger_map.precompute([])
     evaluator = CostEvaluator(engine, danger_map)
-    router = AStarRouter(evaluator)
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator)
+    metrics = AStarMetrics()
+    pf = PathFinder(context, metrics)
 
     num_nets = 50
     netlist = {}
@@ -45,7 +46,7 @@ def benchmark_scaling() -> None:
     print(f"Time per net: {total_time/num_nets:.4f} s")
 
     if total_time > 0:
-        nodes_per_sec = router.total_nodes_expanded / total_time
+        nodes_per_sec = metrics.total_nodes_expanded / total_time
         print(f"Node expansion rate: {nodes_per_sec:.2f} nodes/s")
 
     # Success rate

inire/tests/test_astar.py

@@ -3,7 +3,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import RoutingResult
@@ -19,10 +19,10 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_astar_straight(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator, snap_size=1.0)
+    context = AStarContext(basic_evaluator, snap_size=1.0)
     start = Port(0, 0, 0)
     target = Port(50, 0, 0)
-    path = router.route(start, target, net_width=2.0)
+    path = route_astar(start, target, net_width=2.0, context=context)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -35,11 +35,11 @@ def test_astar_straight(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_astar_bend(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
+    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
     start = Port(0, 0, 0)
     # 20um right, 20um up. Needs a 10um bend and a 10um bend.
     target = Port(20, 20, 0)
-    path = router.route(start, target, net_width=2.0)
+    path = route_astar(start, target, net_width=2.0, context=context)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -56,11 +56,10 @@ def test_astar_obstacle(basic_evaluator: CostEvaluator) -> None:
     basic_evaluator.collision_engine.add_static_obstacle(obstacle)
     basic_evaluator.danger_map.precompute([obstacle])
 
-    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[10.0])
-    router.node_limit = 1000000 # Give it more room for detour
+    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[10.0], node_limit=1000000)
     start = Port(0, 0, 0)
     target = Port(60, 0, 0)
-    path = router.route(start, target, net_width=2.0)
+    path = route_astar(start, target, net_width=2.0, context=context)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)
@@ -72,11 +71,11 @@ def test_astar_obstacle(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_astar_snap_to_target_lookahead(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator, snap_size=1.0)
+    context = AStarContext(basic_evaluator, snap_size=1.0)
     # Target is NOT on 1um grid
     start = Port(0, 0, 0)
     target = Port(10.1, 0, 0)
-    path = router.route(start, target, net_width=2.0)
+    path = route_astar(start, target, net_width=2.0, context=context)
 
     assert path is not None
     result = RoutingResult(net_id="test", path=path, is_valid=True, collisions=0)

inire/tests/test_congestion.py

@@ -3,7 +3,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -19,12 +19,12 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_astar_sbend(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator, snap_size=1.0, sbend_offsets=[2.0, 5.0])
+    context = AStarContext(basic_evaluator, snap_size=1.0, sbend_offsets=[2.0, 5.0])
     # Start at (0,0), target at (50, 2) -> 2um lateral offset
     # This matches one of our discretized SBend offsets.
     start = Port(0, 0, 0)
     target = Port(50, 2, 0)
-    path = router.route(start, target, net_width=2.0)
+    path = route_astar(start, target, net_width=2.0, context=context)
 
     assert path is not None
     # Check if any component in the path is an SBend
@@ -39,9 +39,9 @@ def test_astar_sbend(basic_evaluator: CostEvaluator) -> None:
 
 
 def test_pathfinder_negotiated_congestion_resolution(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator, snap_size=1.0, bend_radii=[5.0, 10.0])
+    context = AStarContext(basic_evaluator, snap_size=1.0, bend_radii=[5.0, 10.0])
     # Increase base penalty to force detour immediately
-    pf = PathFinder(router, basic_evaluator, max_iterations=10, base_congestion_penalty=1000.0)
+    pf = PathFinder(context, max_iterations=10, base_congestion_penalty=1000.0)
 
     netlist = {
         "net1": (Port(0, 0, 0), Port(50, 0, 0)),

inire/tests/test_failed_net_congestion.py

@@ -4,7 +4,7 @@ import numpy
 from inire.geometry.primitives import Port
 from inire.geometry.collision import CollisionEngine
 from inire.router.cost import CostEvaluator
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext
 from inire.router.pathfinder import PathFinder
 from inire.router.danger_map import DangerMap
 
@@ -24,12 +24,8 @@ def test_failed_net_visibility():
     evaluator = CostEvaluator(engine, dm)
     
     # 2. Configure Router with low limit to FORCE failure
-    # node_limit=5 is extremely low, likely allowing only a few moves.
+    # node_limit=10 is extremely low, likely allowing only a few moves.
     # Start (0,0) -> Target (100,0) is 100um away.
-    # If snap is 1.0, direct jump S100 might be tried.
-    # If direct jump works, it might succeed in 1 expansion.
-    # So we need to block the direct jump or make the limit VERY small (0?).
-    # Or place a static obstacle that forces a search.
     
     # Let's add a static obstacle that blocks the direct path.
     from shapely.geometry import box
@@ -38,11 +34,11 @@ def test_failed_net_visibility():
     
     # With obstacle, direct jump fails. A* must search around.
     # Limit=10 should be enough to fail to find a path around.
-    router = AStarRouter(evaluator, node_limit=10)
+    context = AStarContext(evaluator, node_limit=10)
     
     # 3. Configure PathFinder
     # max_iterations=1 because we only need to check the state after the first attempt.
-    pf = PathFinder(router, evaluator, max_iterations=1, warm_start=None)
+    pf = PathFinder(context, max_iterations=1, warm_start=None)
     
     netlist = {
         "net1": (Port(0, 0, 0), Port(100, 0, 0))

inire/tests/test_fuzz.py

@@ -6,7 +6,7 @@ from shapely.geometry import Polygon
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext, route_astar
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import RoutingResult
@@ -41,13 +41,12 @@ def test_fuzz_astar_no_crash(obstacles: list[Polygon], start: Port, target: Port
     danger_map.precompute(obstacles)
 
     evaluator = CostEvaluator(engine, danger_map)
-    router = AStarRouter(evaluator)
-    router.node_limit = 5000  # Lower limit for fuzzing stability
+    context = AStarContext(evaluator, node_limit=5000)  # Lower limit for fuzzing stability
 
     # Check if start/target are inside obstacles (safety zone check)
     # The router should handle this gracefully (either route or return None)
     try:
-        path = router.route(start, target, net_width=2.0)
+        path = route_astar(start, target, net_width=2.0, context=context)
 
         # Analytic Correctness: if path is returned, verify it's collision-free
         if path:

inire/tests/test_pathfinder.py

@@ -2,7 +2,7 @@ import pytest
 
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -17,8 +17,8 @@ def basic_evaluator() -> CostEvaluator:
 
 
 def test_pathfinder_parallel(basic_evaluator: CostEvaluator) -> None:
-    router = AStarRouter(basic_evaluator)
-    pf = PathFinder(router, basic_evaluator)
+    context = AStarContext(basic_evaluator)
+    pf = PathFinder(context)
 
     netlist = {
         "net1": (Port(0, 0, 0), Port(50, 0, 0)),

inire/tests/test_refinements.py

@@ -1,7 +1,7 @@
 from inire.geometry.collision import CollisionEngine
 from inire.geometry.components import Bend90
 from inire.geometry.primitives import Port
-from inire.router.astar import AStarRouter
+from inire.router.astar import AStarContext
 from inire.router.cost import CostEvaluator
 from inire.router.danger_map import DangerMap
 from inire.router.pathfinder import PathFinder
@@ -29,8 +29,8 @@ def test_locked_paths() -> None:
     danger_map = DangerMap(bounds=(0, -50, 100, 50))
     danger_map.precompute([])
     evaluator = CostEvaluator(engine, danger_map)
-    router = AStarRouter(evaluator, bend_radii=[5.0, 10.0])
-    pf = PathFinder(router, evaluator)
+    context = AStarContext(evaluator, bend_radii=[5.0, 10.0])
+    pf = PathFinder(context)
 
     # 1. Route Net A
     netlist_a = {"netA": (Port(0, 0, 0), Port(50, 0, 0))}