CHANGE: go debug working + seperated database and renam,ed module

Backend/main.go

@@ -1,15 +1,14 @@
 package main
 
 import (
-	"Backend/models"
+	"arbeitszeitmessung/models"
 	"database/sql"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
 	"net/http"
-	"net/url"
 	"os"
-	"strconv"
 
 	_ "github.com/lib/pq"
 )
@@ -18,11 +17,10 @@ var DB *sql.DB
 
 func main() {
 	var err error
-	dbConnStr := getDBConn()
-	DB, err = sql.Open("postgres", dbConnStr)
-	if err!= nil {
-        log.Fatal(err)
-    }
+	DB, err = OpenDatabase()
+	if err != nil {
+		log.Fatal(err)
+	}
 	defer DB.Close()
 
 	http.HandleFunc("/time", timeHandler)
@@ -41,50 +39,27 @@ func timeHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 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") {
+	booking := (*models.Booking).FromUrlParams(nil, r.URL.Query())
+	if booking.Verify() {
+		err := booking.Insert(DB)
+		if errors.Is(models.SameBookingError{}, err) {
 			http.Error(w, "Booking already exists", http.StatusConflict)
-            return
+			return
 		}
 		if err != nil {
-            log.Println("Error inserting booking: ", err)
-            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-            return
-        }
+			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
+	if value, ok := os.LookupEnv(key); ok {
+		return value
+	}
+	return fallback
 }