added config via viper

main.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/mmcdole/gofeed"
+	"github.com/spf13/viper"
 )
 
 type Update struct {
@@ -21,7 +22,7 @@ var (
 	cacheMu       sync.Mutex
 	cachedUpdates []Update
 	cacheExpiry   time.Time
-	cacheDuration = 5 * time.Minute // adjust as needed
+	cacheDuration time.Duration
 )
 
 func fetchUpdates(feedURL string) ([]Update, error) {
@@ -86,7 +87,7 @@ func invalidateCache(w http.ResponseWriter, r *http.Request) {
 	defer cacheMu.Unlock()
 
 	cachedUpdates = nil
-	cacheExpiry = time.Time{} // zero time to force refresh on next request
+	cacheExpiry = time.Time{}
 
 	w.WriteHeader(http.StatusOK)
 	w.Write([]byte("Cache invalidated\n"))
@@ -108,10 +109,37 @@ func updatesHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
+	// Setup Viper
+	viper.SetDefault("port", "8080")
+	viper.SetDefault("cache_duration", "5m") // 5 minutes
+
+	viper.SetConfigName("config") // config file name (without extension)
+	viper.SetConfigType("yaml")   // or json, toml, etc.
+	viper.AddConfigPath(".")      // look for config in working directory
+
+	// Read config file (if exists)
+	err := viper.ReadInConfig()
+	if err != nil {
+		log.Println("No config file found or error reading config, continuing with defaults/env")
+	}
+
+	// Allow environment variables to override config
+	viper.AutomaticEnv() // read env variables matching keys (e.g., PORT, CACHE_DURATION)
+
+	// Parse cache duration
+	cacheDurationStr := viper.GetString("cache_duration")
+	dur, err := time.ParseDuration(cacheDurationStr)
+	if err != nil {
+		log.Fatalf("Invalid cache_duration: %v", err)
+	}
+	cacheDuration = dur
+
+	port := viper.GetString("port")
+
 	http.HandleFunc("/updates", updatesHandler)
 	http.HandleFunc("/invalidate-cache", invalidateCache)
 
-	log.Println("Listening on http://localhost:8080/")
-	log.Fatal(http.ListenAndServe(":8080", nil))
+	log.Printf("Listening on http://localhost:%s/", port)
+	log.Fatal(http.ListenAndServe(":"+port, nil))
 }