WIP on baclog fetcher

[loctrkd.git] / gps303 / backlog.py

diff --git a/gps303/backlog.py b/gps303/backlog.py
new file mode 100644 (file)
index 0000000..39dfcbc
--- /dev/null
+++ b/gps303/backlog.py
@@ -0,0 +1,26 @@
+""" Get backlog from evstore """
+
+from .opencellid import qry_cell
+from .evstore import initdb, fetch
+from .gps303proto import GPS_POSITIONING, WIFI_POSITIONING, parse_message
+from .zmsg import LocEvt
+
+OCDB = None
+
+def blinit(evdb, ocdb):
+    global OCDB
+    OCDB = ocdb
+    initdb(evdb)
+
+def backlog(imei, backlog):
+    result = []
+    for packet in fetch(imei, (GPS_POSITIONING.PROTO, WIFI_POSITIONING.PROTO), backlog):
+        msg = parse_message(packet)
+        if isinstance(msg, GPS_POSITIONING):
+            result.append(LocEvt(devtime=msg.devtime, lon=msg.longitude,
+                lat=msg.latitude, is_gps=True, imei=imei))
+        elif isinstance(msg, WIFI_POSITIONING):
+            lat, lon = qry_cell(OCDB, msg.mcc, msg.gsm_cells)
+            result.append(LocEvt(devtime=msg.devtime, lon=lon,
+                lat=lat, is_gps=False, imei=imei))
+    return reversed(result)