Added weather route and embedded cache system

controller/controller.go

@@ -0,0 +1,81 @@
+package controller
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/ceticamarco/zephyr/model"
+	"github.com/ceticamarco/zephyr/types"
+)
+
+func jsonError(res http.ResponseWriter, key string, value string, status int) {
+	res.Header().Set("Content-Type", "application/json")
+	res.WriteHeader(status)
+	json.NewEncoder(res).Encode(map[string]string{key: value})
+}
+
+func jsonValue(res http.ResponseWriter, val any) {
+	res.Header().Set("Content-Type", "application/json")
+	res.WriteHeader(http.StatusOK)
+	json.NewEncoder(res).Encode(val)
+}
+
+func fmtTemperature(temp string, isImperial bool) string {
+	parsedTemp, _ := strconv.ParseFloat(temp, 64)
+
+	if isImperial {
+		return fmt.Sprintf("%d°F", int(math.Round(parsedTemp*(9/5)+32)))
+	}
+
+	return fmt.Sprintf("%d°C", int(math.Round(parsedTemp)))
+}
+
+func GetWeather(res http.ResponseWriter, req *http.Request, cache *types.Cache[types.Weather], vars *types.Variables) {
+	if req.Method != http.MethodGet {
+		jsonError(res, "error", "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	// Extract city name from '/weather/:city'
+	path := strings.TrimPrefix(req.URL.Path, "/weather/")
+	cityName := strings.Trim(path, "/") // Remove trailing slash if present
+
+	// Check whether the 'i' parameter(imperial mode) is specified
+	isImperial := req.URL.Query().Has("i")
+
+	weather, found := cache.GetCache(cityName, vars.TimeToLive)
+	if found {
+		// Format weather values and then return it
+		weather.Temperature = fmtTemperature(weather.Temperature, isImperial)
+		weather.FeelsLike = fmtTemperature(weather.FeelsLike, isImperial)
+
+		jsonValue(res, weather)
+	} else {
+		// Get city coordinates
+		city, err := model.GetCoordinates(cityName, vars.Token)
+		if err != nil {
+			jsonError(res, "error", err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		// Get city weather
+		weather, err := model.GetWeather(&city, vars.Token)
+		if err != nil {
+			jsonError(res, "error", err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		// Add result to cache
+		cache.AddEntry(weather, cityName)
+
+		// Format weather values and then return it
+		weather.Temperature = fmtTemperature(weather.Temperature, isImperial)
+		weather.FeelsLike = fmtTemperature(weather.FeelsLike, isImperial)
+
+		jsonValue(res, weather)
+	}
+}