Auto picks min-time mode + per-leg breakdown (#21)

_route_auto now probes every eligible candidate (eligibility filter unchanged) and
picks the one with the smallest summary.total_effort_minutes, instead of returning the
first that succeeds. Fixes the case where a wilderness start + on-road end fell through
to foot and computed the entire network leg at foot pace. selected_mode = winning
candidate; ties keep AUTO_MODE_PRIORITY order; all-fail still returns the last error.
Wilderness leg still always foot (unchanged).

Per-leg breakdown: summary now carries wilderness_minutes + network_minutes (mirrors the
existing wilderness_effort_minutes/network_duration_minutes) in _build_response (A/B/C)
and _route_D. Frontend DirectionsPanel shows a transition badge "Auto: Foot Xmin +
<mode> Ymin" when wilderness_minutes>0 and selected_mode!=foot, else the existing
"Auto chose <mode>".

Tests: add min-time pick + per-leg breakdown; update probe-all assertions (no early
return) and make the selected-mode test time-based.

Co-authored-by: Matt <mj@k7zvx.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/services/navi_offroute/router.py

@@ -751,9 +751,9 @@ class OffrouteRouter:
 
         Each endpoint's eligible modes come from its category type-hint
         (CATEGORY_ELIGIBLE_MODES); an untyped endpoint falls back to a spatial
-        Valhalla-snap probe. Auto probes only the intersection of both endpoints'
-        eligible sets, in AUTO_MODE_PRIORITY order, returning the first route() that
-        succeeds. selected_mode + selected_mode_set are added for visibility.
+        Valhalla-snap probe. Auto probes the intersection of both endpoints'
+        eligible sets and returns the candidate that minimises total trip time.
+        selected_mode + selected_mode_set are added for visibility.
         """
         snap_cache = {}
         start_typed = self._eligible_modes_from_category(start_category)
@@ -788,6 +788,13 @@ class OffrouteRouter:
 
         priority = [m for m in AUTO_MODE_PRIORITY if m in intersection]
 
+        # Probe every eligible candidate and pick the one that minimises total trip
+        # time, NOT the first that succeeds. When the start is in wilderness and the
+        # end is on-road, falling through to foot would compute the whole network leg
+        # at foot pace. The wilderness leg always uses foot regardless; the candidate
+        # only changes the network leg.
+        best_result = None
+        best_minutes = None
         last_error = None
         for candidate in priority:
             result = self.route(
@@ -795,11 +802,19 @@ class OffrouteRouter:
                 mode=candidate, boundary_mode=boundary_mode
             )
             if result.get("status") == "ok":
-                result["selected_mode"] = candidate
-                result["selected_mode_set"] = mode_set
-                return result
+                minutes = (result.get("summary") or {}).get(
+                    "total_effort_minutes", float("inf"))
+                if best_minutes is None or minutes < best_minutes:
+                    best_minutes = minutes
+                    best_result = result
+                    best_result["selected_mode"] = candidate
+            else:
                 last_error = result
 
+        if best_result is not None:
+            best_result["selected_mode_set"] = mode_set
+            return best_result
+
         if last_error is not None:
             last_error["selected_mode_set"] = mode_set
             return last_error
@@ -898,6 +913,8 @@ class OffrouteRouter:
                     "wilderness_effort_minutes": 0.0,
                     "network_distance_km": float(distance_km),
                     "network_duration_minutes": float(duration_min),
+                    "wilderness_minutes": 0.0,
+                    "network_minutes": float(duration_min),
                     "on_trail_pct": 100.0,
                     "barrier_crossings": 0,
                     "network_mode": mode,
@@ -1800,6 +1817,8 @@ class OffrouteRouter:
             "wilderness_effort_minutes": float(wilderness_effort_minutes),
             "network_distance_km": float(network_distance_km),
             "network_duration_minutes": float(network_duration_minutes),
+            "wilderness_minutes": float(wilderness_effort_minutes),
+            "network_minutes": float(network_duration_minutes),
             "on_trail_pct": float(on_trail_pct),
             "barrier_crossings": barrier_crossings,
             "boundary_mode": boundary_mode,

backend/services/navi_offroute/tests/test_offroute.py

@@ -312,7 +312,9 @@ def _typed_all(monkeypatch):
                         lambda self, cat: ALL_MODES)
 
 
-def test_route_auto_first_probe_ok_returns_vehicle(monkeypatch):
+def test_route_auto_equal_times_keep_priority(monkeypatch):
+    # All candidates succeed with no recorded time -> tie -> highest priority wins,
+    # and every candidate is probed (no early return under min-time selection).
     _typed_all(monkeypatch)
     calls = []
     monkeypatch.setattr(OffrouteRouter, "route", _stub_route(_all_ok(), calls))
@@ -321,7 +323,7 @@ def test_route_auto_first_probe_ok_returns_vehicle(monkeypatch):
     assert out["status"] == "ok"
     assert out["selected_mode"] == "vehicle"
     assert out["selected_mode_set"] == sorted(ALL_MODES)
-    assert calls == ["vehicle"]
+    assert calls == ["vehicle", "4w", "2w", "foot"]
 
 
 def test_route_auto_falls_through_to_foot(monkeypatch):
@@ -359,15 +361,15 @@ def test_route_auto_selected_mode_present_in_ok_response(monkeypatch):
     calls = []
     per_mode = {
         "vehicle": {"status": "error", "message": "No roads found"},
-        "4w": {"status": "ok", "route": {"type": "FeatureCollection", "features": []}},
-        "2w": {"status": "ok"},
-        "foot": {"status": "ok"},
+        "4w": {"status": "ok", "summary": {"total_effort_minutes": 90.0}},
+        "2w": {"status": "ok", "summary": {"total_effort_minutes": 40.0}},
+        "foot": {"status": "ok", "summary": {"total_effort_minutes": 600.0}},
     }
     monkeypatch.setattr(OffrouteRouter, "route", _stub_route(per_mode, calls))
     r = object.__new__(OffrouteRouter)
     out = r._route_auto(42.0, -114.0, 42.5, -114.5, "pragmatic")
     assert out["status"] == "ok"
-    assert out["selected_mode"] == "4w"
+    assert out["selected_mode"] == "2w"   # fastest success wins
 
 
 # ── _route_auto with category type hints (real _eligible_modes_from_category) ──
@@ -379,7 +381,7 @@ def test_route_auto_address_to_address_picks_vehicle(monkeypatch):
     out = r._route_auto(42.0, -114.0, 42.5, -114.5, "pragmatic",
                         start_category="building:house", end_category="highway:residential")
     assert out["selected_mode"] == "vehicle"
-    assert calls == ["vehicle"]
+    assert calls == ["vehicle", "4w", "2w", "foot"]
 
 
 def test_route_auto_address_to_trailhead_picks_atv(monkeypatch):
@@ -823,3 +825,41 @@ def test_pathfind_wilderness_bbox_pad_is_1_5km(monkeypatch):
     assert abs((bounds["north"] - 44.0) - 0.015) < 1e-9
     assert abs((44.0 - bounds["south"]) - 0.015) < 1e-9
     assert abs((bounds["east"] - (-115.0)) - 0.015) < 1e-9
+
+
+# ── Auto min-time selection + per-leg breakdown (feat/auto-picks-fastest) ──
+
+def test_route_auto_picks_min_time(monkeypatch):
+    # vehicle is first in AUTO_MODE_PRIORITY but slow; 4w is fastest -> 4w wins.
+    _typed_all(monkeypatch)
+    calls = []
+    per_mode = {
+        "vehicle": {"status": "ok", "summary": {"total_effort_minutes": 200.0}},
+        "4w": {"status": "ok", "summary": {"total_effort_minutes": 50.0}},
+        "2w": {"status": "ok", "summary": {"total_effort_minutes": 120.0}},
+        "foot": {"status": "ok", "summary": {"total_effort_minutes": 800.0}},
+    }
+    monkeypatch.setattr(OffrouteRouter, "route", _stub_route(per_mode, calls))
+    r = object.__new__(OffrouteRouter)
+    out = r._route_auto(42.0, -114.0, 42.5, -114.5, "pragmatic")
+    assert out["status"] == "ok"
+    assert out["selected_mode"] == "4w"                       # fastest, not first-priority
+    assert calls == ["vehicle", "4w", "2w", "foot"]           # probed every candidate
+
+
+def test_route_auto_per_leg_breakdown():
+    # Scenario A (_build_response): foot wilderness leg + network leg -> both > 0.
+    r = object.__new__(OffrouteRouter)
+    ws = [[-116.20, 43.60], [-116.21, 43.61]]
+    ws_stats = {"effort_minutes": 12.0, "distance_km": 1.0, "elevation_gain_m": 10.0,
+                "elevation_loss_m": 5.0, "on_trail_pct": 50.0, "barrier_crossings": 0}
+    net = {"distance_km": 60.0, "duration_minutes": 45.0, "maneuvers": [],
+           "coordinates": [[-116.21, 43.61], [-116.30, 43.70]]}
+    out = r._build_response(ws, ws_stats, None, net, None, None, None,
+                            "vehicle", "pragmatic", None, None, "A", 0.0, None)
+    assert out["status"] == "ok"
+    summ = out["summary"]
+    assert summ["wilderness_minutes"] > 0
+    assert summ["network_minutes"] > 0
+    # approx adds up to total
+    assert abs((summ["wilderness_minutes"] + summ["network_minutes"]) - summ["total_effort_minutes"]) < 1e-6

frontend/src/components/DirectionsPanel.jsx

@@ -316,14 +316,18 @@ export default function DirectionsPanel({ onClose }) {
         })}
       </div>
 
-      {/* Auto mode: show which travel mode feasibility picked */}
+      {/* Auto mode: show which travel mode was picked (+ leg breakdown on transitions) */}
       {routeMode === "auto" && routeResult?.selected_mode && (
         <div
           className="flex items-center justify-center gap-1 py-1.5 text-xs rounded-lg"
           style={{ background: "var(--accent-muted)", color: "var(--accent)" }}
         >
           <Zap size={14} />
-          <span>{`Auto chose ${SELECTED_MODE_LABEL[routeResult.selected_mode] || routeResult.selected_mode}`}</span>
+          <span>{
+            (routeResult?.summary?.wilderness_minutes > 0 && routeResult.selected_mode !== "foot")
+              ? `Auto: Foot ${Math.round(routeResult.summary.wilderness_minutes)}min + ${SELECTED_MODE_LABEL[routeResult.selected_mode] || routeResult.selected_mode} ${Math.round(routeResult.summary.network_minutes)}min`
+              : `Auto chose ${SELECTED_MODE_LABEL[routeResult.selected_mode] || routeResult.selected_mode}`
+          }</span>
         </div>
       )}