Feature: Rundweg-Vorschläge via OpenRouteService — 2/4/6 km, 3 Varianten, Navigation+Speichern — SW by-v478, APP_VER 455

backend/routes/routen.py

@@ -2,6 +2,7 @@
 
 import json, math, os, uuid
 import httpx
+import polyline as _polyline
 from fastapi import APIRouter, Depends, HTTPException, UploadFile, File
 from pydantic import BaseModel
 from typing import Optional, List
@@ -14,6 +15,8 @@ from routes.push import send_push_to_user
 
 router = APIRouter()
 
+ORS_API_KEY = os.getenv("ORS_API_KEY")
+
 _MAX_AVG_KMH = 15.0  # Über diesem Wert wird die Route nicht für Stats/Trophäen gewertet
 
 def _check_speed(distanz_km, dauer_min) -> bool:
@@ -172,6 +175,91 @@ async def create_route(data: RouteCreate, user=Depends(get_current_user)):
     return result
 
 
+# ------------------------------------------------------------------
+# POST /api/routes/suggest — Rundweg-Vorschlag via OpenRouteService
+# ------------------------------------------------------------------
+class SuggestRequest(BaseModel):
+    lat:         float
+    lon:         float
+    distance_km: float   # Zieldistanz in km (z.B. 2.0, 4.0, 6.0)
+    seed:        int = 0  # 0-4: verschiedene Routenvarianten
+
+@router.post("/suggest")
+async def suggest_route(data: SuggestRequest, user=Depends(get_current_user)):
+    if not (0.5 <= data.distance_km <= 15):
+        raise HTTPException(400, "distance_km muss zwischen 0.5 und 15 liegen.")
+
+    if not ORS_API_KEY:
+        raise HTTPException(503, "ORS nicht konfiguriert")
+
+    payload = {
+        "coordinates": [[data.lon, data.lat]],
+        "options": {
+            "round_trip": {
+                "length": data.distance_km * 1000,
+                "points": 5,
+                "seed":   data.seed,
+            },
+            "avoid_features": ["ferries", "steps"],
+        },
+        "units":        "m",
+        "geometry":     True,
+        "instructions": False,
+    }
+
+    try:
+        async with httpx.AsyncClient(timeout=10) as client:
+            resp = await client.post(
+                "https://api.openrouteservice.org/v2/directions/foot-walking",
+                headers={
+                    "Authorization": f"Bearer {ORS_API_KEY}",
+                    "Content-Type":  "application/json",
+                },
+                json=payload,
+            )
+    except httpx.TimeoutException:
+        raise HTTPException(504, "ORS-Anfrage hat das Zeitlimit überschritten.")
+
+    if resp.status_code != 200:
+        try:
+            detail = resp.json()
+        except Exception:
+            detail = resp.text
+        raise HTTPException(502, f"ORS-Fehler: {detail}")
+
+    body = resp.json()
+    try:
+        route      = body["routes"][0]
+        geometry   = route["geometry"]
+        summary    = route["summary"]
+        distanz_m  = summary.get("distance", data.distance_km * 1000)
+        dauer_s    = summary.get("duration", 0)
+    except (KeyError, IndexError) as exc:
+        raise HTTPException(502, f"Unerwartete ORS-Antwort: {exc}")
+
+    # encoded polyline → [[lat, lon], ...]
+    points = _polyline.decode(geometry)
+    gps_track = [{"lat": p[0], "lon": p[1]} for p in points]
+
+    distanz_km = round(distanz_m / 1000, 2)
+    dauer_min  = max(1, round(dauer_s / 60))
+
+    if distanz_km < 3:
+        schwierigkeit = "leicht"
+    elif distanz_km <= 5:
+        schwierigkeit = "mittel"
+    else:
+        schwierigkeit = "anspruchsvoll"
+
+    return {
+        "name":          f"Rundweg {distanz_km:.0f} km",
+        "gps_track":     gps_track,
+        "distanz_km":    distanz_km,
+        "dauer_min":     dauer_min,
+        "schwierigkeit": schwierigkeit,
+    }
+
+
 # ------------------------------------------------------------------
 # GET /api/routes/{id} — Route mit vollem GPS-Track
 # ------------------------------------------------------------------