72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
package cafes
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import (
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"encoding/json"
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"fmt"
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"io"
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"io/ioutil"
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"log"
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"net/http"
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"github.com/dhconnelly/rtreego"
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"github.com/fofanov/go-osgb"
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)
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const cyclingMapsCafesUrl = "https://cafes.cyclingmaps.net/data/cafes.json"
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type CyclingMapsCafe struct {
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Name string
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Website string
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Lat float64
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Lng float64
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}
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func BuildCyclingMapsIndex(r io.Reader) (*rtreego.Rtree, error) {
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var cafes []CyclingMapsCafe
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data, err := ioutil.ReadAll(r)
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if err != nil {
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return nil, err
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}
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err = json.Unmarshal(data, &cafes)
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if err != nil {
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return nil, err
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}
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trans, err := osgb.NewOSTN15Transformer()
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if err != nil {
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return nil, err
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}
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stops := make([]rtreego.Spatial, 0, len(cafes))
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for _, c := range cafes {
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gpsCoord := osgb.NewETRS89Coord(c.Lng, c.Lat, 0)
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ngCoord, err := trans.ToNationalGrid(gpsCoord)
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if err != nil {
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log.Printf("Error translating coordinates %v: %v", gpsCoord, err)
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continue
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}
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stops = append(stops, &RefreshmentStop{
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Name: c.Name,
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Url: c.Website,
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Easting: ngCoord.Easting,
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Northing: ngCoord.Northing,
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})
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}
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return rtreego.NewTree(2, 25, 50, stops...), nil
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}
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func FetchCyclingMapsIndex() (*rtreego.Rtree, error) {
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log.Printf("Fetching %s", cyclingMapsCafesUrl)
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res, err := http.Get(cyclingMapsCafesUrl)
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if err != nil {
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return nil, fmt.Errorf("error getting %s: %v", cyclingMapsCafesUrl, err)
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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return nil, fmt.Errorf("unexpected status fetching %s: %s", cyclingMapsCafesUrl, res.Status)
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}
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index, err := BuildCyclingMapsIndex(res.Body)
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if err != nil {
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return nil, fmt.Errorf("error building cyclingmaps.net cafe stops index: %v", err)
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}
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log.Printf("Loaded %d cyclingmaps.net stops", index.Size())
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return index, nil
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}
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