init commit

Backend/main.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"Backend/models"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+
+	_ "github.com/lib/pq"
+)
+
+var DB *sql.DB
+
+func main() {
+	var err error
+	dbConnStr := getDBConn()
+	DB, err = sql.Open("postgres", dbConnStr)
+	if err!= nil {
+        log.Fatal(err)
+    }
+	defer DB.Close()
+
+	http.HandleFunc("/time", timeHandler)
+
+	fmt.Println("Server is running at http://localhost:8080")
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}
+
+func timeHandler(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "PUT":
+		createBooking(w, r)
+	default:
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+func createBooking(w http.ResponseWriter, r *http.Request) {
+
+	booking := getBooking(r.URL.Query())
+	if models.VerifyBooking(booking) {
+		err := models.InsertBooking(booking, DB)
+		if err == fmt.Errorf("the same booking already exists") {
+			http.Error(w, "Booking already exists", http.StatusConflict)
+            return
+		}
+		if err != nil {
+            log.Println("Error inserting booking: ", err)
+            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+            return
+        }
+		w.WriteHeader(http.StatusAccepted)
+		json.NewEncoder(w).Encode(booking)
+	}
+	w.WriteHeader(http.StatusBadRequest)
+}
+
+func getBooking(query_params url.Values) models.Booking {
+	bookingType, err := strconv.Atoi(query_params.Get("bookingType"))
+	if err!= nil {
+        log.Println("Error parsing bookingType: ", err)
+        return models.Booking{}
+    }
+	return models.Booking{
+		CradID:      query_params.Get("cardID"),
+		ReaderID:    query_params.Get("readerID"),
+		BookingType: bookingType,
+	}
+}
+
+func getDBConn() string {
+	dbHost := getEnv("POSTGRES_HOST", "localhost")
+	dbName := getEnv("POSTGRES_DB", "arbeitszeitmessung")
+	dbUser := getEnv("POSTGRES_USER", "arbeit_zeit")
+	dbPassword := getEnv("POSTGRES_PASS", "password")
+
+	return fmt.Sprintf("postgres://%s:%s@%s:5432/%s?sslmode=disable", dbUser, dbPassword, dbHost, dbName)
+}
+
+func getEnv(key, fallback string) string {
+    if value, ok := os.LookupEnv(key); ok {
+        return value
+    }
+    return fallback
+}