Refactor to pull useful functionailty into a package.

.gitignore

@@ -1 +1,2 @@
 /data/
+/bin/

cmd/analyze-gpx/main.go

@@ -1,22 +1,14 @@
 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"
-	"github.com/twpayne/go-gpx"
 
 	"github.com/ray1729/gpx-utils/pkg/openname"
 )
@@ -32,25 +24,25 @@ func main() {
 	if (*gpxFile == "" && *dirName == "") || (*gpxFile != "" && *dirName != "") {
 		log.Fatal("exactly one of --dir or --gpx is required")
 	}
-	rt, err := buildIndex(*openNames)
+	rt, err := openname.BuildIndex(*openNames)
 	if err != nil {
 		log.Fatal(err)
 	}
-	trans, err := osgb.NewOSTN15Transformer()
+	gs, err := openname.NewGPXSummarizer(rt)
 	if err != nil {
 		log.Fatal(err)
 	}
 	if *gpxFile != "" {
-		err = summarizeSingleFile(rt, trans, *gpxFile)
+		err = summarizeSingleFile(gs, *gpxFile)
 	} else {
-		err = summarizeDirectory(rt, trans, *dirName)
+		err = summarizeDirectory(gs, *dirName)
 	}
 	if err != nil {
 		log.Fatal(err)
 	}
 }
 
-func summarizeDirectory(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, dirName string) error {
+func summarizeDirectory(gs *openname.GPXSummarizer, dirName string) error {
 	files, err := ioutil.ReadDir(dirName)
 	if err != nil {
 		return err
@@ -61,7 +53,7 @@ func summarizeDirectory(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, dir
 		}
 		filename := path.Join(dirName, f.Name())
 		log.Printf("Analyzing %s", filename)
-		summary, err := summarizeGPXTrack(rt, trans, filename)
+		summary, err := gs.SummarizeTrack(filename)
 		if err != nil {
 			return fmt.Errorf("error creating summary of GPX track %s: %v", filename, err)
 		}
@@ -82,8 +74,8 @@ func summarizeDirectory(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, dir
 	return nil
 }
 
-func summarizeSingleFile(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, filename string) error {
+func summarizeSingleFile(gs *openname.GPXSummarizer, filename string) error {
-	summary, err := summarizeGPXTrack(rt, trans, filename)
+	summary, err := gs.SummarizeTrack(filename)
 	if err != nil {
 		return fmt.Errorf("error creating summary of GPX track %s: %v", filename, err)
 	}
@@ -93,7 +85,7 @@ func summarizeSingleFile(rt *rtreego.Rtree, trans osgb.CoordinateTransformer, fi
 	return nil
 }
 
-func writeSummary(s *Summary, w io.Writer) error {
+func writeSummary(s *openname.TrackSummary, w io.Writer) error {
 	enc := json.NewEncoder(w)
 	enc.SetIndent("", "    ")
 	if err := enc.Encode(s); err != nil {
@@ -101,129 +93,3 @@ func writeSummary(s *Summary, w io.Writer) error {
 	}
 	return nil
 }
-
-func insideLoc(p rtreego.Point, loc *openname.Record) bool {
-	return p[0] >= loc.MbrXMin && p[0] <= loc.MbrXMax && p[1] >= loc.MbrYMin && p[1] <= loc.MbrYMax
-}
-
-func distance(p1, p2 rtreego.Point) float64 {
-	if len(p1) != len(p2) {
-		panic("Length mismatch")
-	}
-	var s float64
-	for i := range p1 {
-		d := p1[i] - p2[i]
-		s += d * d
-	}
-	return math.Sqrt(s) / 1000.0
-}
-
-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
-	}
-	g, err := gpx.Read(r)
-	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 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 {
-				gpsCoord := osgb.NewETRS89Coord(p.Lon, p.Lat, p.Ele)
-				ngCoord, err := trans.ToNationalGrid(gpsCoord)
-				if err != nil {
-					return nil, err
-				}
-				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
-			}
-		}
-	}
-	s.Finish = prevPlace
-	return &s, nil
-}
-
-func buildIndex(filename string) (*rtreego.Rtree, error) {
-	r, err := zip.OpenReader(filename)
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer r.Close()
-	rt := rtreego.NewTree(2, 25, 50)
-	for _, f := range r.File {
-		if !(strings.HasPrefix(f.Name, "DATA/") && strings.HasSuffix(f.Name, ".csv")) {
-			continue
-		}
-		rc, err := f.Open()
-		if err != nil {
-			log.Fatal(err)
-		}
-		defer rc.Close()
-		s, err := openname.NewScanner(rc)
-		if err != nil {
-			log.Fatalf("Error reading %s: %v", f.Name, err)
-		}
-		for s.Scan() {
-			r := s.Record()
-			if r.Type == "populatedPlace" && r.MbrXMax != r.MbrXMin && r.MbrYMax != r.MbrYMin {
-				rt.Insert(r)
-			}
-		}
-		if err = s.Err(); err != nil {
-			log.Fatalf("Error parsing %s: %v", f.Name, err)
-		}
-	}
-	return rt, nil
-}

pkg/openname/index.go

@@ -0,0 +1,42 @@
+package openname
+
+import (
+	"archive/zip"
+	"log"
+	"strings"
+
+	"github.com/dhconnelly/rtreego"
+)
+
+func BuildIndex(filename string) (*rtreego.Rtree, error) {
+	r, err := zip.OpenReader(filename)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer r.Close()
+	rt := rtreego.NewTree(2, 25, 50)
+	for _, f := range r.File {
+		if !(strings.HasPrefix(f.Name, "DATA/") && strings.HasSuffix(f.Name, ".csv")) {
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer rc.Close()
+		s, err := NewScanner(rc)
+		if err != nil {
+			log.Fatalf("Error reading %s: %v", f.Name, err)
+		}
+		for s.Scan() {
+			r := s.Record()
+			if r.Type == "populatedPlace" && r.MbrXMax != r.MbrXMin && r.MbrYMax != r.MbrYMin {
+				rt.Insert(r)
+			}
+		}
+		if err = s.Err(); err != nil {
+			log.Fatalf("Error parsing %s: %v", f.Name, err)
+		}
+	}
+	return rt, nil
+}

pkg/openname/summarize.go

@@ -0,0 +1,120 @@
+package openname
+
+import (
+	"math"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/dhconnelly/rtreego"
+	"github.com/fofanov/go-osgb"
+	"github.com/twpayne/go-gpx"
+)
+
+type GPXSummarizer struct {
+	rt    *rtreego.Rtree
+	trans osgb.CoordinateTransformer
+}
+
+func NewGPXSummarizer(rt *rtreego.Rtree) (*GPXSummarizer, error) {
+	trans, err := osgb.NewOSTN15Transformer()
+	if err != nil {
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &GPXSummarizer{rt: rt, trans: trans}, nil
+}
+
+func insideLoc(p rtreego.Point, loc *Record) bool {
+	return p[0] >= loc.MbrXMin && p[0] <= loc.MbrXMax && p[1] >= loc.MbrYMin && p[1] <= loc.MbrYMax
+}
+
+func distance(p1, p2 rtreego.Point) float64 {
+	if len(p1) != len(p2) {
+		panic("Length mismatch")
+	}
+	var s float64
+	for i := range p1 {
+		d := p1[i] - p2[i]
+		s += d * d
+	}
+	return math.Sqrt(s) / 1000.0
+}
+
+type POI struct {
+	Name     string
+	Distance float64
+}
+
+type TrackSummary struct {
+	Name             string
+	Time             time.Time
+	Link             string
+	Start            string
+	Finish           string
+	Distance         float64
+	Ascent           float64
+	PointsOfInterest []POI
+}
+
+func (gs *GPXSummarizer) SummarizeTrack(filename string) (*TrackSummary, error) {
+	r, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	g, err := gpx.Read(r)
+	if err != nil {
+		return nil, err
+	}
+	var s TrackSummary
+	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 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 {
+				gpsCoord := osgb.NewETRS89Coord(p.Lon, p.Lat, p.Ele)
+				ngCoord, err := gs.trans.ToNationalGrid(gpsCoord)
+				if err != nil {
+					return nil, err
+				}
+				thisPoint := rtreego.Point{ngCoord.Easting, ngCoord.Northing}
+				thisHeight := ngCoord.Height
+				nn, _ := gs.rt.NearestNeighbor(thisPoint).(*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
+			}
+		}
+	}
+	s.Finish = prevPlace
+	return &s, nil
+}