Initial check-in.

pkg/openname/parse.go

@@ -0,0 +1,164 @@
+package openname
+
+import (
+	"bufio"
+	"encoding/csv"
+	"errors"
+	"io"
+	"strconv"
+
+	"github.com/dhconnelly/rtreego"
+)
+
+type Record struct {
+	ID                    string
+	NamesUri              string
+	Name                  string
+	NameLang              string
+	AltName               string
+	AltNameLang           string
+	Type                  string
+	LocalType             string
+	GeomX                 float64
+	GeomY                 float64
+	MostDetailViewRes     float64
+	LeastDetailViewRes    float64
+	MbrXMin               float64
+	MbrYMin               float64
+	MbrXMax               float64
+	MbrYMax               float64
+	PostcodeDistrict      string
+	PostcodeDistrictUri   string
+	PopulatedPlace        string
+	PopulatedPlaceUri     string
+	PopulatedPlaceType    string
+	DistrictBorough       string
+	DistrictBoroughUri    string
+	DistrictBoroughType   string
+	CountyUnitary         string
+	ConutyUnitaryUri      string
+	CountyUnitaryType     string
+	Region                string
+	RegionUri             string
+	Country               string
+	CountryUri            string
+	RelativeSpatialObject string
+	SameAsDbpedia         string
+	SameAsGeonames        string
+}
+
+func (r *Record) Bounds() *rtreego.Rect {
+	p := rtreego.Point{r.MbrXMin, r.MbrYMin}
+	rect, err := rtreego.NewRect(p, []float64{r.MbrXMax - r.MbrXMin, r.MbrYMax - r.MbrYMin})
+	if err != nil {
+		panic(err)
+	}
+	return rect
+}
+
+type Scanner struct {
+	csvReader  *csv.Reader
+	nextRecord *Record
+	err        error
+}
+
+func NewScanner(r io.Reader) (*Scanner, error) {
+	br := bufio.NewReader(r)
+	err := skipBOM(br)
+	if err != nil {
+		return nil, err
+	}
+	return &Scanner{csvReader: csv.NewReader(br)}, nil
+}
+
+var BOM = [3]byte{0xef, 0xbb, 0xbf}
+
+func skipBOM(br *bufio.Reader) error {
+	xs, err := br.Peek(3)
+	if err != nil {
+		return err
+	}
+	if xs[0] == BOM[0] && xs[1] == BOM[1] && xs[2] == BOM[2] {
+		br.Discard(3)
+	}
+	return nil
+}
+
+func (s *Scanner) Scan() bool {
+	rawRecord, err := s.csvReader.Read()
+	if err != nil {
+		if errors.Is(err, io.EOF) {
+			return false
+		}
+		s.err = err
+		return false
+	}
+	s.nextRecord, err = parseRecord(rawRecord)
+	if err != nil {
+		s.err = err
+		return false
+	}
+	return true
+}
+
+func (s *Scanner) Err() error {
+	return s.err
+}
+
+func (s *Scanner) Record() *Record {
+	return s.nextRecord
+}
+
+func parseRecord(xs []string) (*Record, error) {
+	if len(xs) != 34 {
+		return nil, csv.ErrFieldCount
+	}
+	record := Record{
+		ID:                    xs[0],
+		NamesUri:              xs[1],
+		Name:                  xs[2],
+		NameLang:              xs[3],
+		AltName:               xs[4],
+		AltNameLang:           xs[5],
+		Type:                  xs[6],
+		LocalType:             xs[7],
+		GeomX:                 0,
+		GeomY:                 0,
+		MostDetailViewRes:     0,
+		LeastDetailViewRes:    0,
+		MbrXMin:               0,
+		MbrYMin:               0,
+		MbrXMax:               0,
+		MbrYMax:               0,
+		PostcodeDistrict:      xs[16],
+		PostcodeDistrictUri:   xs[17],
+		PopulatedPlace:        xs[18],
+		PopulatedPlaceUri:     xs[19],
+		PopulatedPlaceType:    xs[20],
+		DistrictBorough:       xs[21],
+		DistrictBoroughUri:    xs[22],
+		DistrictBoroughType:   xs[23],
+		CountyUnitary:         xs[24],
+		ConutyUnitaryUri:      xs[25],
+		CountyUnitaryType:     xs[26],
+		Region:                xs[27],
+		RegionUri:             xs[28],
+		Country:               xs[29],
+		CountryUri:            xs[30],
+		RelativeSpatialObject: xs[31],
+		SameAsDbpedia:         xs[32],
+		SameAsGeonames:        xs[33],
+	}
+
+	for i, p := range []*float64{&record.GeomX, &record.GeomY, &record.MostDetailViewRes, &record.LeastDetailViewRes, &record.MbrXMin, &record.MbrYMin, &record.MbrXMax, &record.MbrYMax} {
+		s := xs[i+8]
+		if s != "" {
+			var err error
+			*p, err = strconv.ParseFloat(s, 64)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	return &record, nil
+}