package locodecolumn import ( "fmt" "strings" "github.com/TrueCloudLab/frostfs-node/pkg/util/locode" ) const ( minutesDigits = 2 hemisphereSymbols = 1 ) const ( latDegDigits = 2 lngDegDigits = 3 ) type coordinateCode struct { degDigits int value []uint8 } // LongitudeCode represents the value of the longitude // of the location conforming to UN/LOCODE specification. type LongitudeCode coordinateCode // LongitudeHemisphere represents the hemisphere of the earth // // along the Greenwich meridian. type LongitudeHemisphere [hemisphereSymbols]uint8 // LatitudeCode represents the value of the latitude // of the location conforming to UN/LOCODE specification. type LatitudeCode coordinateCode // LatitudeHemisphere represents the hemisphere of the earth // along the equator. type LatitudeHemisphere [hemisphereSymbols]uint8 func coordinateFromString(s string, degDigits int, hemisphereAlphabet []uint8) (*coordinateCode, error) { if len(s) != degDigits+minutesDigits+hemisphereSymbols { return nil, locode.ErrInvalidString } for i := range s[:degDigits+minutesDigits] { if !isDigit(s[i]) { return nil, locode.ErrInvalidString } } loop: for _, sym := range s[degDigits+minutesDigits:] { for j := range hemisphereAlphabet { if hemisphereAlphabet[j] == uint8(sym) { continue loop } } return nil, locode.ErrInvalidString } return &coordinateCode{ degDigits: degDigits, value: []uint8(s), }, nil } // LongitudeFromString parses a string and returns the location's longitude. func LongitudeFromString(s string) (*LongitudeCode, error) { cc, err := coordinateFromString(s, lngDegDigits, []uint8{'W', 'E'}) if err != nil { return nil, err } return (*LongitudeCode)(cc), nil } // LatitudeFromString parses a string and returns the location's latitude. func LatitudeFromString(s string) (*LatitudeCode, error) { cc, err := coordinateFromString(s, latDegDigits, []uint8{'N', 'S'}) if err != nil { return nil, err } return (*LatitudeCode)(cc), nil } func (cc *coordinateCode) degrees() []uint8 { return cc.value[:cc.degDigits] } // Degrees returns the longitude's degrees. func (lc *LongitudeCode) Degrees() (l [lngDegDigits]uint8) { copy(l[:], (*coordinateCode)(lc).degrees()) return } // Degrees returns the latitude's degrees. func (lc *LatitudeCode) Degrees() (l [latDegDigits]uint8) { copy(l[:], (*coordinateCode)(lc).degrees()) return } func (cc *coordinateCode) minutes() (mnt [minutesDigits]uint8) { for i := 0; i < minutesDigits; i++ { mnt[i] = cc.value[cc.degDigits+i] } return } // Minutes returns the longitude's minutes. func (lc *LongitudeCode) Minutes() [minutesDigits]uint8 { return (*coordinateCode)(lc).minutes() } // Minutes returns the latitude's minutes. func (lc *LatitudeCode) Minutes() [minutesDigits]uint8 { return (*coordinateCode)(lc).minutes() } // Hemisphere returns the longitude's hemisphere code. func (lc *LongitudeCode) Hemisphere() LongitudeHemisphere { return (*coordinateCode)(lc).hemisphere() } // Hemisphere returns the latitude's hemisphere code. func (lc *LatitudeCode) Hemisphere() LatitudeHemisphere { return (*coordinateCode)(lc).hemisphere() } func (cc *coordinateCode) hemisphere() (h [hemisphereSymbols]uint8) { for i := 0; i < hemisphereSymbols; i++ { h[i] = cc.value[cc.degDigits+minutesDigits+i] } return h } // North returns true for the northern hemisphere. func (h LatitudeHemisphere) North() bool { return h[0] == 'N' } // East returns true for the eastern hemisphere. func (h LongitudeHemisphere) East() bool { return h[0] == 'E' } // Coordinates represents the coordinates of the location from UN/LOCODE table. type Coordinates struct { lat *LatitudeCode lng *LongitudeCode } // Latitude returns the location's latitude. func (c *Coordinates) Latitude() *LatitudeCode { return c.lat } // Longitude returns the location's longitude. func (c *Coordinates) Longitude() *LongitudeCode { return c.lng } // CoordinatesFromString parses a string and returns the location's coordinates. func CoordinatesFromString(s string) (*Coordinates, error) { if len(s) == 0 { return nil, nil } strs := strings.Split(s, " ") if len(strs) != 2 { return nil, locode.ErrInvalidString } lat, err := LatitudeFromString(strs[0]) if err != nil { return nil, fmt.Errorf("could not parse latitude: %w", err) } lng, err := LongitudeFromString(strs[1]) if err != nil { return nil, fmt.Errorf("could not parse longitude: %w", err) } return &Coordinates{ lat: lat, lng: lng, }, nil }