Refactor of caching & data storage part 9 #118

providers/solarconditions/ionosonde_utils.py

@@ -0,0 +1,37 @@
+from core.constants import BANDS
+
+HF_BANDS = [b for b in BANDS if b.is_ham_hf]
+
+
+def _latest(d) -> float | None:
+    """Given a map where the key is a timestamp and the value is a number represented as a string, find the latest
+    timestamp and return the corresponding value as a float."""
+
+    val = str(d[max(d.keys())]) if d else None
+    return float(val) if (val is not None and val != "None") else None
+
+
+def compute_band_states(fof2_dict, muf_dict, luf_dict):
+    """Compute HF band states from the latest foF2, MUF and LUF values.
+
+    Returns a map where the keys are HF bands and the values are as follows:
+      "Closed" if band frequency is above MUF or below LUF (if known)
+      "Short" if band frequency is >= LUF and < foF2 (good for NVIS)
+      "Long" if band frequency is >= foF2 and < MUF (good for DX)
+    """
+
+    fof2 = _latest(fof2_dict)
+    muf = _latest(muf_dict)
+    luf = _latest(luf_dict) if luf_dict else None
+    if fof2 is None or muf is None:
+        return {}
+    band_states = {}
+    for band in HF_BANDS:
+        freq = band.start_freq / 1_000_000
+        if freq > muf or (luf is not None and freq < luf):
+            band_states[band.name] = "Closed"
+        elif freq < fof2:
+            band_states[band.name] = "Short"
+        else:
+            band_states[band.name] = "Long"
+    return band_states