Add geocode and reverse geocode

directions.go

@@ -178,6 +178,10 @@ type Bounds struct {
 	Southwest LatLng `json:"southwest"`
 }
 
+func (b Bounds) String() string {
+	return fmt.Sprintf("%s|%s", b.Northeast, b.Southwest)
+}
+
 type Duration struct {
 	Value int64  `json:"value"`
 	Text  string `json:"text"`

elevation.go

@@ -68,6 +68,6 @@ type ElevationResponse struct {
 		Elevation  float64 `json:"elevation"`
 		Location   LatLng  `json:"location"`
 		Resolution float64 `json:"resolution"`
-	}
+	} `json:"results"`
 	Status string `json:"status"`
 }

geocode.go

@@ -0,0 +1,134 @@
+package maps
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+const (
+	ComponentRoute              = "route"
+	ComponentLocality           = "locality"
+	ComponentAdministrativeArea = "administrative_area"
+	ComponentPostalCode         = "postal_code"
+	ComponentCountry            = "country"
+
+	LocationTypeRooftop           = "ROOFTOP"
+	LocationTypeRangeInterpolated = "RANGE_INTERPOLATED"
+	LocationTypeGeometricCenter   = "GEOMETRIC_CENTER"
+	LocationTypeApproximate       = "APPROXIMATE"
+
+	// TODO: enums for https://developers.google.com/maps/documentation/geocoding/#Types
+)
+
+func (c Client) Geocode(opts *GeocodeOpts) (*GeocodeResponse, error) {
+	var r GeocodeResponse
+	if err := c.doDecode(baseURL+geocode(opts), &r); err != nil {
+		return nil, err
+	}
+	return &r, nil
+}
+
+func geocode(opts *GeocodeOpts) string {
+	p := url.Values{}
+	opts.update(p)
+	return "geocode/json?" + p.Encode()
+}
+
+type GeocodeOpts struct {
+	Address          Address
+	Components       []Component
+	Language, Region string
+	Bounds           *Bounds
+}
+
+type Component struct {
+	Key, Value string
+}
+
+func (c Component) encode() string {
+	return fmt.Sprintf("%s:%s", c.Key, c.Value)
+}
+
+func encodeComponents(cs []Component) string {
+	s := make([]string, len(cs))
+	for i, c := range cs {
+		s[i] = c.encode()
+	}
+	return strings.Join(s, "|")
+}
+
+func (g *GeocodeOpts) update(p url.Values) {
+	if g == nil {
+		return
+	}
+	if string(g.Address) != "" {
+		p.Set("address", g.Address.Location())
+	}
+	if g.Components != nil {
+		p.Set("components", encodeComponents(g.Components))
+	}
+	if g.Language != "" {
+		p.Set("language", g.Language)
+	}
+	if g.Region != "" {
+		p.Set("region", g.Region)
+	}
+	if g.Bounds != nil {
+		p.Set("bounds", g.Bounds.String())
+	}
+}
+
+type GeocodeResponse struct {
+	Results []struct {
+		AddressComponents []struct {
+			LongName  string   `json:"long_name"`
+			ShortName string   `json:"short_name"`
+			Types     []string `json:"types"`
+		} `json:"address_components"`
+		PostcodeLocalities []string `json:"postcode_localities"`
+		FormattedAddress   string   `json:"formatted_address"`
+		Geometry           struct {
+			Location     LatLng `json:"location"`
+			LocationType string `json:"location_type"`
+			Viewport     Bounds `json:"viewport"`
+			Bounds       Bounds `json:"bounds"`
+		} `json:"geometry"`
+		Types        []string `json:"types"`
+		PartialMatch string   `json:"partial_match"`
+	} `json:"results"`
+	Status string `json:"status"`
+}
+
+func (c Client) ReverseGeocode(ll LatLng, opts *ReverseGeocodeOpts) (*GeocodeResponse, error) {
+	var r GeocodeResponse
+	if err := c.doDecode(baseURL+reversegeocode(ll, opts), &r); err != nil {
+		return nil, err
+	}
+	return &r, nil
+}
+
+type ReverseGeocodeOpts struct {
+	Language      string
+	ResultTypes   []string
+	LocationTypes []string
+}
+
+func (r *ReverseGeocodeOpts) update(p url.Values) {
+	if r == nil {
+		return
+	}
+	if r.ResultTypes != nil {
+		p.Set("result_type", strings.Join(r.ResultTypes, "|"))
+	}
+	if r.LocationTypes != nil {
+		p.Set("location_type", strings.Join(r.LocationTypes, "|"))
+	}
+}
+
+func reversegeocode(ll LatLng, opts *ReverseGeocodeOpts) string {
+	p := url.Values{}
+	p.Set("latlng", ll.String())
+	opts.update(p)
+	return "geocode/json?" + p.Encode()
+}

maps_test.go

@@ -138,3 +138,24 @@ func TestElevation(t *testing.T) {
 	}
 	t.Logf("%v", r)
 }
+
+func TestGeocode(t *testing.T) {
+	c := NewClient("")
+	opts := &GeocodeOpts{
+		Address: Address("1600 Amphitheatre Parkway, Mountain View, CA"),
+	}
+	t.Logf("%s", baseURL+geocode(opts))
+	r, err := c.Geocode(opts)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	t.Logf("%v", r)
+
+	ll := LatLng{40.714224, -73.961452}
+	t.Logf("%s", baseURL+reversegeocode(ll, nil))
+	r, err = c.ReverseGeocode(ll, nil)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	t.Logf("%v", r)
+}