add: added projectsHEADmain

1 files changed, 128 insertions, 0 deletions

diff --git a/idvoc-2025/CommentsEngine/main.go b/idvoc-2025/CommentsEngine/main.go
new file mode 100644
index 0000000..9fb8105
--- /dev/null
+++ b/idvoc-2025/CommentsEngine/main.go
@@ -0,0 +1,128 @@
+package main
+
+import (
+	"CommentsEngine/redisc"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/gorilla/handlers"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/redis/go-redis/v9"
+	"io"
+	"log"
+	"net/http"
+	"os"
+)
+
+func getenv(key, fallback string) string {
+	value := os.Getenv(key)
+	if len(value) == 0 {
+		return fallback
+	}
+	return value
+}
+
+var (
+	httpHits = promauto.NewCounterVec(prometheus.CounterOpts{
+		Name: "comments_engine_http_hits_total",
+		Help: "The total number of hits on a given route",
+	}, []string{"route", "method"})
+	commentsReceived = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "comments_engine_comments_received_total",
+		Help: "The total number of comments received",
+	})
+	errorsSent = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "comments_interactor_errors_sent_total",
+		Help: "The total number of errors returned",
+	})
+)
+
+func getRoot(w http.ResponseWriter, r *http.Request) {
+	httpHits.With(prometheus.Labels{"route": "/", "method": r.Method}).Inc()
+	io.WriteString(w, "CommentsEngine answering here !\n")
+}
+
+func sendError(w http.ResponseWriter, err error, additionalInfo string) {
+	errorsSent.Inc()
+	w.WriteHeader(http.StatusInternalServerError)
+	resp := make(map[string]string)
+	resp["message"] = fmt.Sprint(err)
+	resp["additionalInfo"] = additionalInfo
+	jsonResp, err := json.Marshal(resp)
+	if err != nil {
+		log.Fatalf("Error happened in JSON marshal. Err: %s", err)
+	}
+	w.Write(jsonResp)
+}
+
+func sendMessage(w http.ResponseWriter, message string) {
+	commentsReceived.Inc()
+	resp := make(map[string]string)
+	resp["message"] = message
+	jsonResp, err := json.Marshal(resp)
+	if err != nil {
+		log.Fatalf("Error happened in JSON marshal. Err: %s", err)
+	}
+	w.Write(jsonResp)
+}
+
+func getLatestComments(w http.ResponseWriter, r *http.Request) {
+	httpHits.With(prometheus.Labels{"route": "/latest", "method": r.Method}).Inc()
+	w.Header().Set("Content-Type", "application/json")
+	messages, err := redisc.GetLatestComments()
+	if err == nil {
+		io.WriteString(w, messages)
+	} else {
+		sendError(w, err, "Maybe there is a problem with redis backend ?")
+	}
+}
+
+type Comment struct {
+	Comment string `json:"comment"`
+}
+
+func sendComment(w http.ResponseWriter, r *http.Request) {
+	httpHits.With(prometheus.Labels{"route": "/comment", "method": r.Method}).Inc()
+	w.Header().Set("Content-Type", "application/json")
+	if r.Method != http.MethodPost {
+		sendError(w, errors.New("POST not used"), "HTTP method was not POST")
+		return
+	}
+	comment := &Comment{}
+	err := json.NewDecoder(r.Body).Decode(comment)
+	if err != nil {
+		sendError(w, err, "The data sent was likely incorrect")
+		return
+	}
+	_, err = redisc.StoreComment(comment.Comment)
+	if err != nil {
+		sendError(w, err, "Problem with redis maybe ?")
+		return
+	}
+	sendMessage(w, "stored !")
+}
+
+func main() {
+	http.HandleFunc("/", getRoot)
+	http.HandleFunc("/latest", getLatestComments)
+	http.HandleFunc("/comment", sendComment)
+	http.Handle("/metrics", promhttp.Handler())
+
+	redisc.Client = redis.NewClient(&redis.Options{
+		Addr:     getenv("REDIS_ENDPOINT", "localhost:6379"),
+		Password: "", // no password set
+		DB:       0,  // use default DB
+	})
+
+	listeningHostPort := getenv("HOST", "127.0.0.1") + ":" + getenv("PORT", "8000")
+	fmt.Printf("Starting the server on %s\n", listeningHostPort)
+	err := http.ListenAndServe(listeningHostPort, handlers.LoggingHandler(os.Stdout, http.DefaultServeMux))
+	if errors.Is(err, http.ErrServerClosed) {
+		fmt.Printf("server closed\n")
+	} else if err != nil {
+		fmt.Printf("error starting server: %s\n", err)
+		os.Exit(1)
+	}
+}