Add concurrency

concurrency/pkg/weather/response.go

@@ -0,0 +1,9 @@
+package weather
+
+type response struct {
+	Temperatures temperatures `json:"main"`
+}
+
+type temperatures struct {
+	Temp float64 `json:"temp"`
+}

concurrency/pkg/weather/weather.go

@@ -0,0 +1,78 @@
+package weather
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+)
+
+const (
+	baseURL = "https://api.openweathermap.org/data/2.5/weather"
+)
+
+var key = func() string {
+	key := os.Getenv("OPEN_WEATHER_MAP_API_KEY")
+
+	if key == "" {
+		panic("missing open weather map api key")
+	}
+
+	return key
+}()
+
+type Weather struct {
+	Temp float64
+}
+
+func GetCity(city string) (*Weather, error) {
+	params := fmt.Sprintf(
+		"appid=%s&q=%s&units=imperial", key, url.QueryEscape(city),
+	)
+	u := fmt.Sprintf("%s?%s", baseURL, params)
+
+	res, err := http.Get(u)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		body, _ := ioutil.ReadAll(res.Body)
+		return nil, fmt.Errorf("%s (%d)", body, res.StatusCode)
+	}
+
+	var response response
+	if err := json.NewDecoder(res.Body).Decode(&response); err != nil {
+		return nil, err
+	}
+
+	return &Weather{Temp: response.Temperatures.Temp}, nil
+}
+
+func GetGeo(lat, lng string) (*Weather, error) {
+	params := fmt.Sprintf(
+		"appid=%s&lat=%s&lon=%s&units=imperial", key, lat, lng,
+	)
+	url := fmt.Sprintf("%s?%s", baseURL, params)
+
+	res, err := http.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		body, _ := ioutil.ReadAll(res.Body)
+		return nil, fmt.Errorf("%s (%d)", body, res.StatusCode)
+	}
+
+	var response response
+	if err := json.NewDecoder(res.Body).Decode(&response); err != nil {
+		return nil, err
+	}
+
+	return &Weather{Temp: response.Temperatures.Temp}, nil
+}