2 files changed, 193 insertions, 0 deletions
diff --git a/photon/photon.go b/photon/photon.go
new file mode 100644
index 0000000..7dee4c5
--- /dev/null
+++ b/photon/photon.go
@@ -0,0 +1,126 @@
+// Copyright © 2022 siddharth ravikumar <s@ricketyspace.net>
+// SPDX-License-Identifier: ISC
+
+package photon
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"strings"
+
+	"ricketyspace.net/peach/client"
+)
+
+// Coordinates.
+type Coordinates struct {
+	Lat  float32
+	Lng  float32
+	Name string
+}
+
+// Represents a response from the Photon API.
+type Response struct {
+	Features []Feature
+}
+
+// Represents features object in the Response.
+type Feature struct {
+	Geometry   Geometry
+	Properties Properties
+}
+
+// Represents geometry object in the Response.
+type Geometry struct {
+	Coordinates []float32
+}
+
+// Represents properties object in the Response.
+type Properties struct {
+	CountryCode string
+	Name        string
+	State       string
+}
+
+// Returns true of geocoding is possible.
+func Enabled() bool {
+	return len(os.Getenv("PEACH_PHOTON_URL")) > 0
+}
+
+func Url() (*url.URL, error) {
+	if !Enabled() {
+		return nil, fmt.Errorf("geocoding not enabled")
+	}
+
+	pu, err := url.Parse(os.Getenv("PEACH_PHOTON_URL"))
+	if err != nil {
+		return nil, err
+	}
+	if len(pu.Path) < 1 || pu.Path == "/" {
+		pu.Path = "/api"
+	}
+	return pu, nil
+}
+
+// Returns a list of matching Coordinates for a given location.
+func Geocode(location string) ([]Coordinates, error) {
+	mCoords := []Coordinates{} // Matching coordinates
+	location = strings.TrimSpace(location)
+	if len(location) < 2 {
+		return mCoords, fmt.Errorf("geocode: location invalid")
+	}
+
+	// Construct request.
+	u, err := Url()
+	if err != nil {
+		return mCoords, fmt.Errorf("geocode: %v", err)
+	}
+	q := url.Values{}
+	q.Add("q", location)
+	q.Add("osm_tag", "place:city")
+	q.Add("limit", "5")
+	u.RawQuery = q.Encode()
+
+	// Make request.
+	resp, err := client.Get(u.String())
+	if err != nil {
+		return mCoords, fmt.Errorf("geocode: get: %v", err)
+	}
+
+	// Parse response body.
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return mCoords, fmt.Errorf("geocode: body: %v", err)
+	}
+
+	// Check if the request failed.
+	if resp.StatusCode != 200 {
+		return mCoords, fmt.Errorf("geocode: %s", body)
+	}
+
+	// Unmarshal
+	r := new(Response)
+	err = json.Unmarshal(body, r)
+	if err != nil {
+		return mCoords, fmt.Errorf("geocode: decode: %v", err)
+	}
+
+	// Make matching coordinates list.
+	for _, feature := range r.Features {
+		if feature.Properties.CountryCode != "US" {
+			continue // skip
+		}
+
+		c := Coordinates{}
+		c.Lat = feature.Geometry.Coordinates[1]
+		c.Lng = feature.Geometry.Coordinates[0]
+		c.Name = fmt.Sprintf("%s, %s",
+			feature.Properties.Name,
+			feature.Properties.State,
+		)
+		mCoords = append(mCoords, c)
+	}
+	return mCoords, nil
+}
diff --git a/photon/photon_test.go b/photon/photon_test.go
new file mode 100644
index 0000000..3a87bc8
--- /dev/null
+++ b/photon/photon_test.go
@@ -0,0 +1,67 @@
+// Copyright © 2022 siddharth ravikumar <s@ricketyspace.net>
+// SPDX-License-Identifier: ISC
+
+package photon
+
+import (
+	"os"
+	"testing"
+)
+
+func TestEnabled(t *testing.T) {
+	if Enabled() {
+		t.Errorf("geo is enabled")
+		return
+	}
+
+	os.Setenv("PEACH_PHOTON_URL", "https://photon.komoot.io")
+	if !Enabled() {
+		t.Errorf("geo is not enabled")
+		return
+	}
+}
+
+func TestPhotonUrl(t *testing.T) {
+	os.Setenv("PEACH_PHOTON_URL", "")
+	pUrl, err := Url()
+	if err == nil {
+		t.Errorf("url: %v", pUrl)
+		return
+	}
+
+	os.Setenv("PEACH_PHOTON_URL", "https://photon.komoot.io")
+	pUrl, err = Url()
+	if err != nil {
+		t.Errorf("url: %v", err)
+		return
+	}
+	if pUrl.String() != "https://photon.komoot.io/api" {
+		t.Errorf("url: %v", pUrl)
+		return
+	}
+}
+
+func TestGeocode(t *testing.T) {
+	os.Setenv("PEACH_PHOTON_URL", "https://photon.komoot.io")
+	mCoords, err := Geocode("Tiffin,OH")
+	if err != nil {
+		t.Errorf("%v", err)
+		return
+	}
+	if len(mCoords) < 0 {
+		t.Errorf("no matching coordinates")
+		return
+	}
+	if mCoords[0].Lat != 41.114485 {
+		t.Errorf("lat: %v", mCoords[0].Lat)
+		return
+	}
+	if mCoords[0].Lng != -83.1779537 {
+		t.Errorf("lng: %v", mCoords[0].Lat)
+		return
+	}
+	if mCoords[0].Name != "Tiffin, Ohio" {
+		t.Errorf("name: %v", mCoords[0].Name)
+		return
+	}
+}