ADD: added database connection for players data handling and started login funtion with database

backend/internal/tournament/handler.go

@@ -4,6 +4,8 @@ import (
 	"net/http"
 	"volleyball/internal/common"
 
+	"slices"
+
 	"github.com/gin-gonic/gin"
 )
 
@@ -17,7 +19,7 @@ var tournaments = []Tournament{
 			{ID: "t1", Name: "Smasher"},
 			{ID: "t2", Name: "Blockbuster"},
 		},
-		OrganizerId: "system-user-id",
+		OrganizerId: []string{"example-user"},
 	},
 	{
 		ID:              "2",
@@ -25,7 +27,7 @@ var tournaments = []Tournament{
 		Location:        "Hamburg",
 		MaxParticipants: 10,
 		Teams:           []Team{},
-		OrganizerId:     "other-user",
+		OrganizerId:     []string{"example-user"},
 	},
 }
 
@@ -74,7 +76,8 @@ func UpdateTournament(c *gin.Context) {
 
 	for i, t := range tournaments {
 		if t.ID == id {
-			if t.OrganizerId != userId {
+			isOrganizer := slices.Contains(t.OrganizerId, userId)
+			if !isOrganizer {
 				c.JSON(http.StatusForbidden, gin.H{"error": "No permission"})
 				return
 			}