1 files changed, 102 insertions, 5 deletions

diff --git a/strava/sync.go b/strava/sync.go
index b8fa428..4630a1d 100644
--- a/strava/sync.go
+++ b/strava/sync.go
@@ -1,12 +1,15 @@
 package strava
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"net/url"
 	"strconv"
 	"time"
 
+	"github.com/jftuga/geodist"
+	"github.com/martinlehoux/biking_home/ride"
 	"github.com/martinlehoux/kagamigo/kcore"
 	"github.com/tkrajina/gpxgo/gpx"
 )
@@ -68,20 +71,24 @@ func (c *Client) list(from, to time.Time, types ...string) ([]Activity, error) {
 	return all, nil
 }
 
-func (c *Client) Get(id int64) (Activity, []byte, error) {
+func (c *Client) Get(id int64) (Activity, []byte, []byte, error) {
 	var activity Activity
 	if err := c.GetJSON(fmt.Sprintf("/activities/%d", id), &activity); err != nil {
-		return Activity{}, nil, kcore.Wrap(err, "failed to get Strava activity")
+		return Activity{}, nil, nil, kcore.Wrap(err, "failed to get Strava activity")
 	}
 	streams, err := c.activityStreams(id)
 	if err != nil {
-		return Activity{}, nil, err
+		return Activity{}, nil, nil, err
 	}
 	gpxData, err := activityGPX(activity, streams)
 	if err != nil {
-		return activity, nil, err
+		return activity, nil, nil, err
 	}
-	return activity, gpxData, nil
+	fitData, err := activityFIT(activity, streams)
+	if err != nil {
+		return activity, nil, nil, err
+	}
+	return activity, gpxData, fitData, nil
 }
 
 type activityStreams struct {
@@ -139,6 +146,96 @@ func (c *Client) activityStreams(id int64) (activityStreams, error) {
 	return result, nil
 }
 
+func activityFIT(activity Activity, streams activityStreams) ([]byte, error) {
+	if len(streams.LatLng) == 0 {
+		return nil, ErrNoTrackPoints
+	}
+	n := len(streams.LatLng)
+	distances := make([]float64, 0, n)
+	elevations := make([]float64, 0, n)
+	coords := make([]geodist.Coord, 0, n)
+	timestamps := make([]time.Time, 0, n)
+	heartRates := make([]float64, 0, n)
+	cadences := make([]float64, 0, n)
+	powers := make([]float64, 0, n)
+	heartRateComplete := true
+	cadenceComplete := true
+	powerComplete := true
+
+	distance := 0.0
+	var previous *geodist.Coord
+	for i := 0; i < n; i++ {
+		coord := geodist.Coord{Lat: streams.LatLng[i][0], Lon: streams.LatLng[i][1]}
+		if previous != nil {
+			_, km := geodist.HaversineDistance(*previous, coord)
+			d := km * 1000
+			if d == 0 {
+				continue
+			}
+			distance += d
+		} else {
+			distance = 0
+		}
+		previous = &coord
+
+		var elev float64
+		if i < len(streams.Altitude) {
+			elev = streams.Altitude[i]
+		}
+		// If altitude missing and we have no value, use 0 to keep ride valid.
+		// The GPX path requires elevation; this mirrors that requirement.
+		distances = append(distances, distance)
+		elevations = append(elevations, elev)
+		coords = append(coords, coord)
+		var ts time.Time
+		if i < len(streams.Seconds) {
+			ts = activity.StartDate.Add(time.Duration(streams.Seconds[i]) * time.Second)
+		} else {
+			ts = activity.StartDate.Add(time.Duration(i) * time.Second)
+		}
+		timestamps = append(timestamps, ts)
+
+		if hr := streamValue(streams.HeartRate, i); hr == nil {
+			heartRateComplete = false
+			heartRates = append(heartRates, 0)
+		} else {
+			heartRates = append(heartRates, *hr)
+		}
+		if cad := streamValue(streams.Cadence, i); cad == nil {
+			cadenceComplete = false
+			cadences = append(cadences, 0)
+		} else {
+			cadences = append(cadences, *cad)
+		}
+		if pow := streamValue(streams.Power, i); pow == nil {
+			powerComplete = false
+			powers = append(powers, 0)
+		} else {
+			powers = append(powers, *pow)
+		}
+	}
+	if len(distances) < 2 {
+		return nil, errors.New("zero distance")
+	}
+	var hrCol, cadCol, powCol []float64
+	if heartRateComplete {
+		hrCol = heartRates
+	}
+	if cadenceComplete {
+		cadCol = cadences
+	}
+	if powerComplete {
+		powCol = powers
+	}
+	r := ride.FromColumnsWithMetrics(distances, elevations, coords, timestamps, hrCol, cadCol, powCol)
+
+	var buf bytes.Buffer
+	if err := ride.EncodeFIT(r, &buf); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
 func activityGPX(activity Activity, streams activityStreams) ([]byte, error) {
 	if len(streams.LatLng) == 0 {
 		return nil, ErrNoTrackPoints