From 36f0c229310a0527beaf24b4880b25f9afe437c2 Mon Sep 17 00:00:00 2001
From: Martin Kagamino Lehoux <martin@lehoux.net>
Date: Sun, 27 Sep 2026 11:41:08 +0200
Subject: Parse FIT Course files as rides

---
 ride/fit.go | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

(limited to 'ride/fit.go')

diff --git a/ride/fit.go b/ride/fit.go
index db9c0b6..61d0a7b 100644
--- a/ride/fit.go
+++ b/ride/fit.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 	"math"
 	"time"
@@ -13,8 +14,9 @@ import (
 	"github.com/tormoder/fit"
 )
 
-// FITRideParser parses FIT files into Ride values. It is the FIT counterpart
-// to GPXRideParser and keeps the same invariants.
+// FITRideParser parses FIT Activity and Course files into Ride values. Both
+// types store their track as Record messages. It is the FIT counterpart to
+// GPXRideParser and keeps the same invariants.
 type FITRideParser struct{}
 
 func (p FITRideParser) Parse(reader io.Reader) (Ride, error) {
@@ -26,17 +28,16 @@ func (p FITRideParser) Parse(reader io.Reader) (Ride, error) {
 	if err != nil {
 		return Ride{}, err
 	}
-	activity, err := file.Activity()
+	records, err := fitRecords(file)
 	if err != nil {
 		return Ride{}, err
 	}
-	if len(activity.Records) == 0 {
+	if len(records) == 0 {
 		return Ride{}, ErrNoTrackPoints
 	}
 
 	// Collect points discarding invalid positions — FIT encodes missing lat/lon
 	// as 0x7FFFFFFF (Invalid). We also require altitude.
-	records := activity.Records
 	distances := make([]float64, 0, len(records))
 	elevations := make([]float64, 0, len(records))
 	coords := make([]geodist.Coord, 0, len(records))
@@ -123,6 +124,27 @@ func (p FITRideParser) Parse(reader io.Reader) (Ride, error) {
 	return fromColumns(distances, elevations, coords, timestamps, heartRatesColumn, cadencesColumn, powersColumn), nil
 }
 
+// fitRecords returns the track points of an Activity or Course FIT file; both
+// store them as Record messages.
+func fitRecords(file *fit.File) ([]*fit.RecordMsg, error) {
+	switch file.Type() {
+	case fit.FileTypeActivity:
+		activity, err := file.Activity()
+		if err != nil {
+			return nil, err
+		}
+		return activity.Records, nil
+	case fit.FileTypeCourse:
+		course, err := file.Course()
+		if err != nil {
+			return nil, err
+		}
+		return course.Records, nil
+	default:
+		return nil, fmt.Errorf("fit file type is %v, not Activity or Course", file.Type())
+	}
+}
+
 // EncodeFIT writes the ride as a minimal FIT Activity file. It stores only the
 // fields consumed by Ride (lat/lon, altitude, time, heart rate, cadence, power)
 // as Record messages.
-- 
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