backend: initial commit

bincio/extract/parsers/tcx.py

@@ -0,0 +1,89 @@
+"""TCX (Training Center XML) file parser."""
+
+from datetime import datetime, timezone
+from pathlib import Path
+
+from lxml import etree
+
+from bincio.extract.models import DataPoint, ParsedActivity
+from bincio.extract.sport import normalise_sport
+
+_NS = {
+    "tcx": "http://www.garmin.com/xmlschemas/TrainingCenterDatabase/v2",
+    "ext": "http://www.garmin.com/xmlschemas/ActivityExtension/v2",
+}
+
+
+class TcxParser:
+    def parse(self, path: Path, raw_bytes: bytes) -> ParsedActivity:
+        # Some exporters (e.g. Garmin) prepend whitespace before the XML
+        # declaration, which is technically invalid. Strip it.
+        root = etree.fromstring(raw_bytes.lstrip())
+
+        activities = root.findall(".//tcx:Activity", _NS)
+        if not activities:
+            raise ValueError(f"No Activity elements found in {path.name}")
+
+        # Use the first activity
+        act = activities[0]
+        sport_attr = act.get("Sport", "Biking")
+        sport = normalise_sport(sport_attr)
+
+        points: list[DataPoint] = []
+        for tp in act.findall(".//tcx:Trackpoint", _NS):
+            ts_el = tp.find("tcx:Time", _NS)
+            if ts_el is None or not ts_el.text:
+                continue
+            ts = _parse_ts(ts_el.text)
+
+            lat, lon = None, None
+            pos = tp.find("tcx:Position", _NS)
+            if pos is not None:
+                lat_el = pos.find("tcx:LatitudeDegrees", _NS)
+                lon_el = pos.find("tcx:LongitudeDegrees", _NS)
+                lat = float(lat_el.text) if lat_el is not None and lat_el.text else None
+                lon = float(lon_el.text) if lon_el is not None and lon_el.text else None
+
+            ele_el = tp.find("tcx:AltitudeMeters", _NS)
+            hr_el = tp.find(".//tcx:HeartRateBpm/tcx:Value", _NS)
+            cad_el = tp.find("tcx:Cadence", _NS)
+            dist_el = tp.find("tcx:DistanceMeters", _NS)
+
+            # Extensions (speed, watts)
+            speed_el = tp.find(".//ext:Speed", _NS)
+            power_el = tp.find(".//ext:Watts", _NS)
+
+            dp = DataPoint(
+                timestamp=ts,
+                lat=lat,
+                lon=lon,
+                elevation_m=float(ele_el.text) if ele_el is not None and ele_el.text else None,
+                hr_bpm=int(float(hr_el.text)) if hr_el is not None and hr_el.text else None,
+                cadence_rpm=int(float(cad_el.text)) if cad_el is not None and cad_el.text else None,
+                distance_m=float(dist_el.text) if dist_el is not None and dist_el.text else None,
+                speed_kmh=float(speed_el.text) * 3.6 if speed_el is not None and speed_el.text else None,
+                power_w=int(float(power_el.text)) if power_el is not None and power_el.text else None,
+            )
+            points.append(dp)
+
+        if not points:
+            raise ValueError(f"No trackpoints found in {path.name}")
+
+        return ParsedActivity(
+            points=points,
+            sport=sport,
+            started_at=points[0].timestamp,
+            source_file=path.name,
+            source_hash="",
+        )
+
+
+def _parse_ts(s: str) -> datetime:
+    # ISO 8601 with or without fractional seconds
+    s = s.rstrip("Z")
+    for fmt in ("%Y-%m-%dT%H:%M:%S.%f", "%Y-%m-%dT%H:%M:%S"):
+        try:
+            return datetime.strptime(s, fmt).replace(tzinfo=timezone.utc)
+        except ValueError:
+            continue
+    raise ValueError(f"Cannot parse timestamp: {s!r}")