checkpoint 1

internal/parser/gpx_parser.go

@@ -0,0 +1,100 @@
+package parser
+
+import (
+	"encoding/xml"
+	"math"
+	"time"
+
+	"github.com/yourusername/garminsync/internal/parser/activity"
+)
+
+// GPX represents the root element of a GPX file
+type GPX struct {
+	XMLName xml.Name `xml:"gpx"`
+	Trk     Trk      `xml:"trk"`
+}
+
+// Trk represents a track in a GPX file
+type Trk struct {
+	Name   string  `xml:"name"`
+	TrkSeg []TrkSeg `xml:"trkseg"`
+}
+
+// TrkSeg represents a track segment in a GPX file
+type TrkSeg struct {
+	TrkPt []TrkPt `xml:"trkpt"`
+}
+
+// TrkPt represents a track point in a GPX file
+type TrkPt struct {
+	Lat  float64 `xml:"lat,attr"`
+	Lon  float64 `xml:"lon,attr"`
+	Ele  float64 `xml:"ele"`
+	Time string  `xml:"time"`
+}
+
+// GPXParser implements the Parser interface for GPX files
+type GPXParser struct{}
+
+func (p *GPXParser) Parse(data []byte) (*activity.Activity, error) {
+	var gpx GPX
+	if err := xml.Unmarshal(data, &gpx); err != nil {
+		return nil, err
+	}
+
+	if len(gpx.Trk.TrkSeg) == 0 || len(gpx.Trk.TrkSeg[0].TrkPt) == 0 {
+		return nil, ErrNoTrackData
+	}
+
+	// Process track points
+	points := gpx.Trk.TrkSeg[0].TrkPt
+	startTime, _ := time.Parse(time.RFC3339, points[0].Time)
+	endTime, _ := time.Parse(time.RFC3339, points[len(points)-1].Time)
+	
+	activity := &activity.Activity{
+		ActivityType:  "hiking",
+		StartTime:     startTime,
+		Duration:      int(endTime.Sub(startTime).Seconds()),
+		StartLatitude: points[0].Lat,
+		StartLongitude: points[0].Lon,
+	}
+
+	// Calculate distance and elevation
+	var totalDistance, elevationGain float64
+	prev := points[0]
+	
+	for i := 1; i < len(points); i++ {
+		curr := points[i]
+		totalDistance += haversine(prev.Lat, prev.Lon, curr.Lat, curr.Lon)
+		
+		if curr.Ele > prev.Ele {
+			elevationGain += curr.Ele - prev.Ele
+		}
+		prev = curr
+	}
+
+	activity.Distance = totalDistance
+	activity.ElevationGain = elevationGain
+
+	return activity, nil
+}
+
+// haversine calculates the distance between two points on Earth
+func haversine(lat1, lon1, lat2, lon2 float64) float64 {
+	const R = 6371000 // Earth radius in meters
+	φ1 := lat1 * math.Pi / 180
+	φ2 := lat2 * math.Pi / 180
+	Δφ := (lat2 - lat1) * math.Pi / 180
+	Δλ := (lon2 - lon1) * math.Pi / 180
+
+	a := math.Sin(Δφ/2)*math.Sin(Δφ/2) +
+		math.Cos(φ1)*math.Cos(φ2)*
+			math.Sin(Δλ/2)*math.Sin(Δλ/2)
+	c := 2 * math.Atan2(math.Sqrt(a), math.Sqrt(1-a))
+
+	return R * c
+}
+
+func init() {
+	RegisterParser(".gpx", &GPXParser{})
+}