From c93e88b2fe0b465b87a0620951329f8ef92c7fbb Mon Sep 17 00:00:00 2001
From: syrell <syrell@syyrell.com>
Date: Mon, 14 Oct 2024 23:00:46 +0200
Subject: [PATCH] feat: Added chapter 2

---
 main.go    | 13 +++++++++++--
 metrics.go | 18 ++++++++++++++++++
 reset.go   |  9 +++++++++
 3 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 metrics.go
 create mode 100644 reset.go

diff --git a/main.go b/main.go
index 1913d4b..10112ee 100644
--- a/main.go
+++ b/main.go
@@ -2,18 +2,27 @@ package main
 
 import (
 	"net/http"
+	"sync/atomic"
 )
 
+type apiConfig struct {
+	fileserverHits atomic.Int32
+}
+
 func main() {
+	apiCfg := &apiConfig{}
 	mux := http.NewServeMux()
 	fileServer := http.FileServer(http.Dir("."))
-	mux.Handle("/app", http.StripPrefix("/app", fileServer))
+	mux.Handle("/app", apiCfg.middlewareMetricsInc(http.StripPrefix("/app", fileServer)))
 	mux.Handle("/app/assets/", http.StripPrefix("/app/assets/", http.FileServer(http.Dir("./assets/"))))
-	mux.HandleFunc("/healthz", func(w http.ResponseWriter, req *http.Request) {
+	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, req *http.Request) {
 		req.Header.Set("Content-Type", "text/plain; charset=utf-8")
 		w.WriteHeader(http.StatusOK)
 		w.Write([]byte("OK"))
 	})
+	mux.Handle("GET /metrics", http.HandlerFunc(apiCfg.serveMetrics))
+	mux.Handle("POST /reset", http.HandlerFunc(apiCfg.serveReset))
+
 	server := &http.Server{
 		Addr:    ":8080",
 		Handler: mux,
diff --git a/metrics.go b/metrics.go
new file mode 100644
index 0000000..961d6d1
--- /dev/null
+++ b/metrics.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func (cfg *apiConfig) middlewareMetricsInc(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		cfg.fileserverHits.Add(1)
+		next.ServeHTTP(w, req)
+	})
+}
+
+func (cfg *apiConfig) serveMetrics(w http.ResponseWriter, r *http.Request) {
+	hits := cfg.fileserverHits.Load()
+	fmt.Fprintf(w, "Hits: %d", hits)
+}
diff --git a/reset.go b/reset.go
new file mode 100644
index 0000000..4513334
--- /dev/null
+++ b/reset.go
@@ -0,0 +1,9 @@
+package main
+
+import (
+	"net/http"
+)
+
+func (cfg *apiConfig) serveReset(w http.ResponseWriter, r *http.Request) {
+	cfg.fileserverHits.Store(0)
+}