Initial commit: LoraTester Android + server

server/core/elevation.py

@@ -0,0 +1,40 @@
+"""Terrain elevation via Open-Meteo (cached per coordinate)."""
+
+from __future__ import annotations
+
+import logging
+from typing import Optional
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+_CACHE: dict[tuple[float, float], Optional[float]] = {}
+_TIMEOUT = 3.0
+
+
+def _cache_key(lat: float, lon: float) -> tuple[float, float]:
+    return (round(lat, 4), round(lon, 4))
+
+
+def fetch_elevation_m(lat: float, lon: float) -> Optional[float]:
+    key = _cache_key(lat, lon)
+    if key in _CACHE:
+        return _CACHE[key]
+    try:
+        with httpx.Client(timeout=_TIMEOUT) as client:
+            r = client.get(
+                "https://api.open-meteo.com/v1/elevation",
+                params={"latitude": lat, "longitude": lon},
+            )
+            r.raise_for_status()
+            data = r.json()
+            elevations = data.get("elevation") or []
+            if elevations:
+                val = float(elevations[0])
+                _CACHE[key] = val
+                return val
+    except Exception as e:
+        logger.warning("open-meteo elevation failed for %s,%s: %s", lat, lon, e)
+    _CACHE[key] = None
+    return None