query/GeoLocation.go
raw ยท 1388 bytes
package query
import (
"github.com/tidwall/geodesic"
"sort"
)
type GeoLocation struct {
Latitude float64
Longitude float64
}
func (b GeoLocation) HasGeoLocation() bool { return true }
func (b GeoLocation) Lat() float64 { return b.Latitude }
func (b GeoLocation) Lon() float64 { return b.Longitude }
func (b GeoLocation) Dist(lat float64, lon float64) float64 {
var dist float64
geodesic.WGS84.Inverse(
lat, lon,
b.Latitude, b.Longitude,
&dist, nil, nil,
)
return dist
}
type NoGeoLocation struct{}
func (b NoGeoLocation) HasGeoLocation() bool { return false }
func (b NoGeoLocation) Lat() float64 { return 0 }
func (b NoGeoLocation) Lon() float64 { return 0 }
func (b NoGeoLocation) Dist(lat, lon float64) float64 { return 0 }
func (b NoGeoLocation) Register(map[string]struct{}) bool {
return false
}
type GeoLocations []ISearchable
func (m GeoLocations) SortByNearest(p GeoLocation) {
sort.Slice(m, func(i, j int) bool {
return m[i].Dist(p.Lat(), p.Lon()) < m[j].Dist(p.Lat(), p.Lon())
})
}
func (b GeoLocation) Register(map[string]struct{}) bool {
return false
}
func (m GeoLocations) Clean() *GeoLocations {
registers := map[string]struct{}{}
items := &GeoLocations{}
for _, item := range m {
if item.HasGeoLocation() && item.Register(registers) {
*items = append(*items, item)
}
}
return items
}