backend: initial commit

2026-03-28 13:57:12 +01:00
commit 38c5423aeb
36 changed files with 2463 additions and 0 deletions
@@ -0,0 +1,133 @@
+"""FIT file parser (Garmin binary format)."""
+
+from datetime import timezone
+from pathlib import Path
+from typing import Any
+
+import fitdecode
+
+from bincio.extract.models import DataPoint, LapData, ParsedActivity
+from bincio.extract.sport import normalise_sport
+
+
+class FitParser:
+    def parse(self, path: Path, raw_bytes: bytes) -> ParsedActivity:
+        import io
+
+        points: list[DataPoint] = []
+        laps: list[LapData] = []
+        sport: str = "cycling"
+        sub_sport: str | None = None
+        device: str | None = None
+
+        with fitdecode.FitReader(io.BytesIO(raw_bytes)) as fit:
+            for frame in fit:
+                if not isinstance(frame, fitdecode.FitDataMessage):
+                    continue
+
+                if frame.name == "sport":
+                    sport = normalise_sport(_get(frame, "sport", "cycling"))
+                    sub_sport = _normalise_sub_sport(_get(frame, "sub_sport"))
+
+                elif frame.name == "device_info":
+                    mfr = _get(frame, "manufacturer")
+                    prod = _get(frame, "product_name") or _get(frame, "garmin_product")
+                    if mfr and prod:
+                        device = f"{mfr} {prod}"
+                    elif prod:
+                        device = str(prod)
+
+                elif frame.name == "record":
+                    ts = _get(frame, "timestamp")
+                    if ts is None:
+                        continue
+                    if hasattr(ts, "tzinfo") and ts.tzinfo is None:
+                        ts = ts.replace(tzinfo=timezone.utc)
+
+                    lat = _semicircles_to_deg(_get(frame, "position_lat"))
+                    lon = _semicircles_to_deg(_get(frame, "position_long"))
+                    speed_raw = _get(frame, "speed")  # m/s
+
+                    dp = DataPoint(
+                        timestamp=ts,
+                        lat=lat,
+                        lon=lon,
+                        elevation_m=_get(frame, "altitude"),
+                        hr_bpm=_get(frame, "heart_rate"),
+                        cadence_rpm=_get(frame, "cadence"),
+                        speed_kmh=speed_raw * 3.6 if speed_raw is not None else None,
+                        power_w=_get(frame, "power"),
+                        temperature_c=_get(frame, "temperature"),
+                        distance_m=_get(frame, "distance"),
+                    )
+                    points.append(dp)
+
+                elif frame.name == "lap":
+                    ts = _get(frame, "start_time")
+                    if ts is not None:
+                        if hasattr(ts, "tzinfo") and ts.tzinfo is None:
+                            ts = ts.replace(tzinfo=timezone.utc)
+                        elapsed = _get(frame, "total_elapsed_time")
+                        speed_raw = _get(frame, "avg_speed")
+                        laps.append(
+                            LapData(
+                                index=len(laps),
+                                started_at=ts,
+                                duration_s=int(elapsed) if elapsed else None,
+                                distance_m=_get(frame, "total_distance"),
+                                elevation_gain_m=_get(frame, "total_ascent"),
+                                avg_speed_kmh=speed_raw * 3.6 if speed_raw else None,
+                                avg_hr_bpm=_get(frame, "avg_heart_rate"),
+                                avg_power_w=_get(frame, "avg_power"),
+                            )
+                        )
+
+        if not points:
+            raise ValueError(f"No record messages found in {path.name}")
+
+        return ParsedActivity(
+            points=points,
+            sport=sport,
+            sub_sport=sub_sport,
+            started_at=points[0].timestamp,
+            device=device,
+            laps=laps,
+            source_file=path.name,
+            source_hash="",
+        )
+
+
+def _get(frame: fitdecode.FitDataMessage, field: str, default: Any = None) -> Any:
+    try:
+        return frame.get_value(field)
+    except KeyError:
+        return default
+
+
+def _semicircles_to_deg(value: Any) -> float | None:
+    if value is None:
+        return None
+    try:
+        deg = float(value) * (180.0 / 2**31)
+        # Sanity check: invalid semicircle values often come out as ±180+
+        if abs(deg) > 180:
+            return None
+        return deg
+    except (TypeError, ValueError):
+        return None
+
+
+def _normalise_sub_sport(value: Any) -> str | None:
+    if value is None:
+        return None
+    s = str(value).lower().replace(" ", "_")
+    mapping = {
+        "road": "road",
+        "mountain": "mountain",
+        "gravel_cycling": "gravel",
+        "cyclocross": "gravel",
+        "indoor_cycling": "indoor",
+        "trail": "trail",
+        "track": "track",
+    }
+    return mapping.get(s, s) or None