added admin verification for updating and creating functions

controllers/idManager.go

@@ -0,0 +1,47 @@
+package controllers
+
+import (
+	"context"
+	"crypto/rand"
+	"io"
+	"school-management/database"
+	"school-management/models"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+var idCollection *mongo.Collection = database.OpenCollection(database.Client, "cids")
+
+var table = [...]byte{'1', '2', '3', '4', '5', '6', '7', '8', '9', '0'}
+
+func ValidateID(id string) bool { // true: valid id, false: id already in use
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	err := idCollection.FindOne(ctx, bson.M{"cid": id})
+	cancel()
+	if err != nil && err.Err() == mongo.ErrNoDocuments {
+		var newID models.Id
+		newID.CID = id
+		newID.ID = primitive.NewObjectID()
+		_, insertErr := idCollection.InsertOne(ctx, newID)
+		if insertErr != nil {
+			return false
+		}
+		return true
+	}
+	return false
+}
+
+func GenerateID() string {
+	b := make([]byte, 6)
+	n, err := io.ReadAtLeast(rand.Reader, b, 6)
+	if n != 6 {
+		panic(err)
+	}
+	for i := 0; i < len(b); i++ {
+		b[i] = table[int(b[i])%len(table)]
+	}
+	return string(b)
+}