frostfs-node/pkg/util/locode/db/point.go
Pavel Karpy 501c78f327 [#902] util/locode: Fix parsing minutes
Convert minutes of received coordinates
to decimal parts of degree, and do not
use decimal part of float as storage for
minutes: "5915N 01806E" is
59.25N 18.10E, not 59°15'N 18°06'E.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
2021-10-12 22:25:01 +03:00

93 lines
1.8 KiB
Go

package locodedb
import (
"fmt"
"strconv"
locodecolumn "github.com/nspcc-dev/neofs-node/pkg/util/locode/column"
)
// Point represents 2D geographic point.
type Point struct {
lat, lng float64
}
// NewPoint creates, initializes and returns new Point.
func NewPoint(lat, lng float64) *Point {
return &Point{
lat: lat,
lng: lng,
}
}
// Latitude returns Point's latitude.
func (p Point) Latitude() float64 {
return p.lat
}
// Longitude returns Point's longitude.
func (p Point) Longitude() float64 {
return p.lng
}
// PointFromCoordinates converts UN/LOCODE coordinates to Point.
func PointFromCoordinates(crd *locodecolumn.Coordinates) (*Point, error) {
if crd == nil {
return nil, nil
}
cLat := crd.Latitude()
cLatDeg := cLat.Degrees()
cLatMnt := cLat.Minutes()
lat, err := toDecimal(cLatDeg[:], cLatMnt[:])
if err != nil {
return nil, fmt.Errorf("could not parse latitude: %w", err)
}
if !cLat.Hemisphere().North() {
lat = -lat
}
cLng := crd.Longitude()
cLngDeg := cLng.Degrees()
cLngMnt := cLng.Minutes()
lng, err := toDecimal(cLngDeg[:], cLngMnt[:])
if err != nil {
return nil, fmt.Errorf("could not parse longitude: %w", err)
}
if !cLng.Hemisphere().East() {
lng = -lng
}
return &Point{
lat: lat,
lng: lng,
}, nil
}
func toDecimal(intRaw, minutesRaw []byte) (float64, error) {
integer, err := strconv.ParseFloat(string(intRaw), 64)
if err != nil {
return 0, fmt.Errorf("could not parse integer part: %w", err)
}
decimal, err := minutesToDegrees(minutesRaw)
if err != nil {
return 0, fmt.Errorf("could not parse decimal part: %w", err)
}
return integer + decimal, nil
}
// minutesToDegrees converts minutes to decimal part of a degree
func minutesToDegrees(raw []byte) (float64, error) {
minutes, err := strconv.ParseFloat(string(raw), 64)
if err != nil {
return 0, err
}
return minutes / 60, nil
}