WeatherService/src/server/WeatherServer.go

package server

import (
	"encoding/json"
	"github.com/auth0/go-jwt-middleware"
	"github.com/dgrijalva/jwt-go"
	"github.com/getsentry/sentry-go/http"
	"github.com/gorilla/mux"
	"github.com/justinas/alice"
	"github.com/justinas/nosurf"
	"github.com/throttled/throttled"
	"github.com/throttled/throttled/store/memstore"
	"github.com/victorspringer/http-cache"
	"github.com/victorspringer/http-cache/adapter/memory"
	"joethei.xyz/weather/client"
	"joethei.xyz/weather/config"
	"log"
	"net/http"
	"strconv"
	"time"
)

var conf *config.Configuration

func StartServer() {
	conf = config.LoadConfiguration()
	port := strconv.Itoa(conf.Port)
	log.Println("starting server on port " + port)

	store, err := memstore.New(65536)
	if err != nil {
		log.Fatal(err)
	}

	quota := throttled.RateQuota{
		MaxRate: throttled.PerMin(20), MaxBurst: 30,
	}
	rateLimiter, err := throttled.NewGCRARateLimiter(store, quota)
	if err != nil {
		log.Fatal(err)
	}

	httpRateLimiter := throttled.HTTPRateLimiter{
		RateLimiter: rateLimiter,
		VaryBy:      &throttled.VaryBy{Path: true},
	}

	memcached, err := memory.NewAdapter(
		memory.AdapterWithAlgorithm(memory.LRU),
		memory.AdapterWithCapacity(10000000),
	)
	if err != nil {
		log.Fatal(err)
	}

	cacheClient, err := cache.NewClient(
		cache.ClientWithAdapter(memcached),
		cache.ClientWithTTL(10*time.Minute),
		cache.ClientWithRefreshKey("opn"),
	)
	if err != nil {
		log.Fatal(err)
	}

	jwtAuth := jwtmiddleware.New(jwtmiddleware.Options{
		ValidationKeyGetter: func(token *jwt.Token) (interface{}, error) {
			return []byte(conf.JwtSecret), nil
		},
		SigningMethod: jwt.SigningMethodHS512,
	})

	chain := alice.New(jwtAuth.Handler, timeoutHandler, httpRateLimiter.RateLimit, nosurf.NewPure, cacheClient.Middleware)
	if conf.SentryDsn != "" {

		sentryHandler := sentryhttp.New(sentryhttp.Options{
			Repanic: true,
		})
		chain.Append(sentryHandler.Handle)
	}

	router := mux.NewRouter()
	router.HandleFunc("/", defaultHandler)
	router.HandleFunc("/current/{latitude},{longitude}", chain.ThenFunc(currentHandler).ServeHTTP)
	router.HandleFunc("/forecast/{latitude},{longitude}", chain.ThenFunc(forecastHandler).ServeHTTP)
	if err := http.ListenAndServe(":"+port, router); err != nil {
		panic(err)
	}
}

func defaultHandler(writer http.ResponseWriter, _ *http.Request) {
	writer.WriteHeader(http.StatusOK)
	if _, err := writer.Write([]byte("Hello World")); err != nil {
		panic(err)
	}

}

func currentHandler(writer http.ResponseWriter, req *http.Request) {
	writer.Header().Set("Content-Type", "application/json")
	vars := mux.Vars(req)

	longitude, err := strconv.ParseFloat(vars["longitude"], 32)
	if err != nil {
		panic(err)
	}
	latitude, err := strconv.ParseFloat(vars["latitude"], 32)
	if err != nil {
		panic(err)
	}
	language, units := getOptionalArgs(req)

	data := client.GetByCoordinates(longitude, latitude, language, units)
	writer.WriteHeader(http.StatusOK)
	if err := json.NewEncoder(writer).Encode(ConvertCurrent(data)); err != nil {
		panic(err)
	}
}

func forecastHandler(writer http.ResponseWriter, req *http.Request) {
	writer.Header().Set("Content-Type", "application/json")
	vars := mux.Vars(req)

	longitude, err := strconv.ParseFloat(vars["longitude"], 32)
	if err != nil {
		panic(err)
	}
	latitude, err := strconv.ParseFloat(vars["latitude"], 32)
	if err != nil {
		panic(err)
	}
	language, units := getOptionalArgs(req)

	data := client.GetByCoordinates(longitude, latitude, language, units)
	writer.WriteHeader(http.StatusOK)
	if err := json.NewEncoder(writer).Encode(ConvertDaily(data)); err != nil {
		panic(err)
	}
}

func timeoutHandler(h http.Handler) http.Handler {
	return http.TimeoutHandler(h, 1*time.Second, "timed out")
}

func getOptionalArgs(req *http.Request) (language string, units config.Units) {
	language = conf.Language
	units = conf.Units

	if lang := req.URL.Query().Get("language"); lang != "" {
		language = lang
	}
	if unit := req.URL.Query().Get("units"); unit != "" {
		units = config.StringToUnit(unit)
	}

	return language, units
}

func ConvertCurrent(weatherData client.WeatherResponse) Current {
	return Current{
		Sunrise:     time.Unix(weatherData.Current.Sunrise, 0),
		Sunset:      time.Unix(weatherData.Current.Sunset, 0),
		Temperature: weatherData.Current.Temperature,
		FeelsLike:   weatherData.Current.FeelsLike,
		Pressure:    weatherData.Current.Pressure,
		Humidity:    weatherData.Current.Humidity,
		DewPoint:    weatherData.Current.DewPoint,
		UVI:         weatherData.Current.UVI,
		Clouds:      weatherData.Current.Clouds,
		Visibility:  weatherData.Current.Visibility,
		WindSpeed:   weatherData.Current.WindSpeed,
		WindDegree:  weatherData.Current.WindDegree,
		Description: weatherData.Current.Weather[0].Description,
		Icon:        "https://openweathermap.org/img/wn/" + weatherData.Current.Weather[0].Icon + "@4x.png",
	}
}

func ConvertDaily(weatherData client.WeatherResponse) []Daily {
	var result []Daily

	for i := 0; i < len(weatherData.Daily); i++ {
		var daily = Daily{
			Date:                       time.Unix(weatherData.Daily[i].Date, 0),
			Sunrise:                    time.Unix(weatherData.Daily[i].Sunrise, 0),
			Sunset:                     time.Unix(weatherData.Daily[i].Sunset, 0),
			TemperatureDay:             weatherData.Daily[i].Temperature.Day,
			TemperatureNight:           weatherData.Daily[i].Temperature.Night,
			TemperatureMin:             weatherData.Daily[i].Temperature.Min,
			TemperatureMax:             weatherData.Daily[i].Temperature.Max,
			FeelsLikeDay:               weatherData.Daily[i].FeelsLike.Day,
			FeelsLikeNight:             weatherData.Daily[i].FeelsLike.Night,
			Pressure:                   weatherData.Daily[i].Pressure,
			Humidity:                   weatherData.Daily[i].Humidity,
			DewPoint:                   weatherData.Daily[i].DewPoint,
			UVI:                        weatherData.Daily[i].UVI,
			Clouds:                     weatherData.Daily[i].Clouds,
			Visibility:                 weatherData.Daily[i].Visibility,
			WindSpeed:                  weatherData.Daily[i].WindSpeed,
			WindDegree:                 weatherData.Daily[i].WindDegree,
			Description:                weatherData.Daily[i].Weather[0].Description,
			Icon:                       "https://openweathermap.org/img/wn/" + weatherData.Daily[i].Weather[0].Icon + "@4x.png",
			ProbabilityOfPrecipitation: weatherData.Daily[i].PossibilityOfPrecipitation,
		}
		result = append(result, daily)
	}

	return result
}