Analyze all files in a directory, output JSON.

README.md

@@ -0,0 +1,3 @@
+# GPX Utils
+
+Utilities for analyzing and indexing GPX routes.

cmd/analyze-gpx/main.go

@@ -2,12 +2,17 @@ package main
 
 import (
 	"archive/zip"
+	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
+	"io/ioutil"
 	"log"
 	"math"
 	"os"
+	"path"
 	"strings"
+	"time"
 
 	"github.com/dhconnelly/rtreego"
 	"github.com/fofanov/go-osgb"
@@ -17,42 +22,84 @@ import (
 )
 
 func main() {
-	openNames := flag.String("open-names", "", "Path to Ordnance Server Open Names zip archive")
+	openNames := flag.String("opname", "", "Path to Ordnance Server Open Names zip archive")
 	gpxFile := flag.String("gpx", "", "Path to GPX file")
+	dirName := flag.String("dir", "", "Directory to scan for GPX files")
 	flag.Parse()
 	if *openNames == "" {
-		log.Fatal("--open-names is required")
+		log.Fatal("--opname is required")
 	}
-	if *gpxFile == "" {
-		log.Fatal("--gpx is required")
+	if (*gpxFile == "" && *dirName == "") || (*gpxFile != "" && *dirName != "") {
+		log.Fatal("exactly one of --dir or --gpx is required")
 	}
 	rt, err := buildIndex(*openNames)
 	if err != nil {
 		log.Fatal(err)
 	}
-	points, err := readGPX(*gpxFile)
+	trans, err := osgb.NewOSTN15Transformer()
 	if err != nil {
 		log.Fatal(err)
 	}
-	var dist float64
-	var prevPlace string
-	var prevPoint rtreego.Point
-	for i, p := range points {
-		nn := rt.NearestNeighbor(p)
-		loc, _ := nn.(*openname.Record)
-		if i == 0 {
-			fmt.Printf("%0.2f %s\n", dist, loc.Name)
-			prevPlace = loc.Name
-			prevPoint = p
+	if *gpxFile != "" {
+		err = summarizeSingleFile(rt, trans, *gpxFile)
+	} else {
+		err = summarizeDirectory(rt, trans, *dirName)
+	}
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func summarizeDirectory(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, dirName string) error {
+	files, err := ioutil.ReadDir(dirName)
+	if err != nil {
+		return err
+	}
+	for _, f := range files {
+		if f.IsDir() || path.Ext(f.Name()) != ".gpx" {
 			continue
 		}
-		dist += distance(prevPoint, p)
-		if insideLoc(p, loc) && loc.Name != prevPlace {
-			fmt.Printf("%0.2f %s\n", dist/1000, loc.Name)
-			prevPlace = loc.Name
+		filename := path.Join(dirName, f.Name())
+		log.Printf("Analyzing %s", filename)
+		summary, err := summarizeGPXTrack(rt, trans, filename)
+		if err != nil {
+			return fmt.Errorf("error creating summary of GPX track %s: %v", filename, err)
 		}
-		prevPoint = p
+		outfile := filename[:len(filename)-4] + ".json"
+		wc, err := os.OpenFile(outfile, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0644)
+		if err != nil {
+			return fmt.Errorf("error creating output file %s: %v", outfile, err)
 		}
+		err = writeSummary(summary, wc)
+		if err != nil {
+			wc.Close()
+			return fmt.Errorf("error marshalling JSON to %s: %v", outfile, err)
+		}
+		if err = wc.Close(); err != nil {
+			return fmt.Errorf("error closing file %s: %v", outfile, err)
+		}
+	}
+	return nil
+}
+
+func summarizeSingleFile(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, filename string) error {
+	summary, err := summarizeGPXTrack(rt, trans, filename)
+	if err != nil {
+		return fmt.Errorf("error creating summary of GPX track %s: %v", filename, err)
+	}
+	if err = writeSummary(summary, os.Stdout); err != nil {
+		return fmt.Errorf("error marshalling summary for %s: %v", filename, err)
+	}
+	return nil
+}
+
+func writeSummary(s *Summary, w io.Writer) error {
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "    ")
+	if err := enc.Encode(s); err != nil {
+		return err
+	}
+	return nil
 }
 
 func insideLoc(p rtreego.Point, loc *openname.Record) bool {
@@ -68,10 +115,26 @@ func distance(p1, p2 rtreego.Point) float64 {
 		d := p1[i] - p2[i]
 		s += d * d
 	}
-	return math.Sqrt(s)
+	return math.Sqrt(s) / 1000.0
 }
 
-func readGPX(filename string) ([]rtreego.Point, error) {
+type POI struct {
+	Name     string
+	Distance float64
+}
+
+type Summary struct {
+	Name             string
+	Time             time.Time
+	Link             string
+	Start            string
+	Finish           string
+	Distance         float64
+	Ascent           float64
+	PointsOfInterest []POI
+}
+
+func summarizeGPXTrack(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, filename string) (*Summary, error) {
 	r, err := os.Open(filename)
 	if err != nil {
 		return nil, err
@@ -80,11 +143,21 @@ func readGPX(filename string) ([]rtreego.Point, error) {
 	if err != nil {
 		return nil, err
 	}
-	trans, err := osgb.NewOSTN15Transformer()
-	if err != nil {
-		return nil, err
+	var s Summary
+	s.Name = g.Metadata.Name
+	s.Time = g.Metadata.Time
+	for _, l := range g.Metadata.Link {
+		if strings.HasPrefix(l.HREF, "http") {
+			s.Link = l.HREF
+			break
 		}
-	var points []rtreego.Point
+	}
+
+	var prevPlace string
+	var prevPoint rtreego.Point
+	var prevHeight float64
+
+	init := true
 	for _, trk := range g.Trk {
 		for _, seg := range trk.TrkSeg {
 			for _, p := range seg.TrkPt {
@@ -93,11 +166,33 @@ func readGPX(filename string) ([]rtreego.Point, error) {
 				if err != nil {
 					return nil, err
 				}
-				points = append(points, rtreego.Point{ngCoord.Easting, ngCoord.Northing})
+				thisPoint := rtreego.Point{ngCoord.Easting, ngCoord.Northing}
+				thisHeight := ngCoord.Height
+				nn, _ := rt.NearestNeighbor(thisPoint).(*openname.Record)
+				if init {
+					s.Start = nn.Name
+					prevPlace = nn.Name
+					prevPoint = thisPoint
+					prevHeight = thisHeight
+					s.PointsOfInterest = append(s.PointsOfInterest, POI{nn.Name, 0.0})
+					init = false
+					continue
+				}
+				s.Distance += distance(thisPoint, prevPoint)
+				if ascent := thisHeight - prevHeight; ascent > 0 {
+					s.Ascent += ascent
+				}
+				if insideLoc(thisPoint, nn) && nn.Name != prevPlace {
+					s.PointsOfInterest = append(s.PointsOfInterest, POI{nn.Name, s.Distance})
+					prevPlace = nn.Name
+				}
+				prevPoint = thisPoint
+				prevHeight = thisHeight
 			}
 		}
 	}
-	return points, nil
+	s.Finish = prevPlace
+	return &s, nil
 }
 
 func buildIndex(filename string) (*rtreego.Rtree, error) {