fix handling of relative roots

csharp/App/Backend/DataTypes/Methods/Folder.cs

@@ -68,36 +68,17 @@ public static class FolderMethods
 
     public static Folder? Parent(this Folder folder)
     {
-        return IsAbsoluteRoot(folder)    
+        return IsRoot(folder)    
              ? null 
              : Db.GetFolderById(folder.ParentId);
     }
 
-    public static Boolean IsAbsoluteRoot(this Folder folder)
+    public static Boolean IsRoot(this Folder folder)
     { 
-        return folder.ParentId == 0; // root has ParentId 0 by definition
+        return folder.ParentId <= 0
+            && Db.GetFolderById(folder.Id)?.Id == 0; // might have been 0 because it is a relative root 
     }
     
-    public static Boolean IsRelativeRoot(this Folder folder)
-    { 
-        return folder.ParentId < 0;  // TODO
-    }
-
-    public static Boolean WasMoved(this Folder folder)
-    {
-        if (folder.IsRelativeRoot())
-            return false;
-
-        var existingFolder = Db.GetFolderById(folder.Id);
-        
-        return existingFolder is not null 
-            && existingFolder.ParentId != folder.ParentId;
-    }
-
-    public static Boolean Exists(this Folder folder)
-    {
-        return Db.Folders.Any(f => f.Id == folder.Id);
-    }
    
 }
 

csharp/App/Backend/DataTypes/Methods/Installation.cs

@@ -76,21 +76,20 @@ public static class InstallationMethods
     
     public static Folder? Parent(this Installation installation)
     {
-        return installation.IsRelativeRoot() 
+        if (installation.ParentId <= 0) // relative root
-             ? null 
+        {
-             : Db.GetFolderById(installation.ParentId);
+            var i = Db.GetInstallationById(installation.Id);
-    }
+            if (i is null)
+                return null;
 
-    public static Boolean IsRelativeRoot(this Installation i)
+            installation = i;
-    { 
+        }
-        return i.ParentId < 0; 
+        
+        return Db.GetFolderById(installation.ParentId);
     }
     
     public static Boolean WasMoved(this Installation installation)
     {
-        if (installation.IsRelativeRoot())
-            return false;
-
         var existingInstallation = Db.GetInstallationById(installation.Id);
 
         return existingInstallation is not null

csharp/App/Backend/DataTypes/Methods/Session.cs

@@ -1,5 +1,6 @@
 using InnovEnergy.App.Backend.Database;
 using InnovEnergy.App.Backend.Relations;
+using InnovEnergy.Lib.Utils;
 
 namespace InnovEnergy.App.Backend.DataTypes.Methods;
 
@@ -13,20 +14,23 @@ public static class SessionMethods
             && folder is not null 
             && user.HasWriteAccess
             && user.HasAccessTo(folder.Parent()) 
-            && Db.Create(folder)               
+            && Db.Create(folder)                // TODO: these two in a transaction
             && Db.Create(new FolderAccess { UserId = user.Id, FolderId = folder.Id });
     }
 
     public static Boolean Update(this Session? session, Folder? folder)
     {
-        var user = session?.User;
+        var user     = session?.User;
+        var original = Db.GetFolderById(folder?.Id);
         
         return user is not null
             && folder is not null 
+            && original is not null
             && user.HasWriteAccess 
             && user.HasAccessTo(folder)
-            && (folder.IsRelativeRoot() || user.HasAccessTo(folder.Parent())) 
+            && folder
-            && Db.Update(folder);
+              .WithParentOf(original)   // prevent moving
+              .Apply(Db.Update);
     }
    
     public static Boolean Delete(this Session? session, Folder? folder)
@@ -49,24 +53,27 @@ public static class SessionMethods
             && installation is not null
             && user.HasWriteAccess
             && user.HasAccessTo(installation.Parent())
-            && Db.Create(installation)
+            && Db.Create(installation)           // TODO: these two in a transaction
             && Db.Create(new InstallationAccess { UserId = user.Id, InstallationId = installation.Id })
             && await installation.CreateBucket() 
             && await installation.RenewS3BucketUrl();   // generation of access _after_ generation of  
-                                                          // bucket to prevent "zombie" access-rights.   
+                                                        // bucket to prevent "zombie" access-rights.   
     }
 
     public static Boolean Update(this Session? session, Installation? installation)
     {
         var user = session?.User;
 
+        var original = Db.GetInstallationById(installation?.Id);
+        
         return user is not null
             && installation is not null
+            && original is not null
             && user.HasWriteAccess
-            && installation.Exists()
             && user.HasAccessTo(installation)
-            && (installation.IsRelativeRoot() || user.HasAccessTo(installation.Parent()))  // TODO: triple check this
+            && installation
-            && Db.Update(installation);
+              .WithParentOf(original)  // prevent moving
+              .Apply(Db.Update); 
     }
 
     public static Boolean Delete(this Session? session, Installation? installation)
@@ -77,7 +84,7 @@ public static class SessionMethods
             && installation is not null
             && user.HasWriteAccess
             && user.HasAccessTo(installation)
-       //   && installation.DeleteBucket().Result  // TODO: await?
+       //   && installation.DeleteBucket().Result  // TODO
             && Db.Delete(installation);
     }
     
@@ -85,29 +92,29 @@ public static class SessionMethods
     {
         var sessionUser = session?.User;
         
-        if (sessionUser is null || newUser is null || !sessionUser.HasWriteAccess)
+        return sessionUser is not null 
-            return false;
+            && newUser is not null 
-        
+            && sessionUser.HasWriteAccess 
-        newUser.ParentId = sessionUser.Id; // Important!
+            && newUser
-
+              .WithParent(sessionUser)
-        return Db.Create(newUser);
+              .Do(() => newUser.Password = newUser.SaltAndHashPassword(newUser.Password))
+              .Apply(Db.Create);
     }
 
     public static Boolean Update(this Session? session, User? editedUser)
     {
         var sessionUser = session?.User;
-        if (editedUser == null || sessionUser == null) return false;
+        var originalUser = Db.GetUserById(editedUser?.Id);
         
-        // TODO: make specific method for changing user account settings like pwd   
+        return editedUser is not null 
-        // Password change is only allowed for oneself
+            && sessionUser is not null
-        editedUser.Password = editedUser.Id != sessionUser.Id 
+            && originalUser is not null
-                            ? sessionUser.Password 
+            && sessionUser.HasWriteAccess 
-                            : sessionUser.SaltAndHashPassword(editedUser.Password);
+            && sessionUser.HasAccessTo(editedUser)
-
+            && editedUser
-        return sessionUser.HasWriteAccess 
+              .WithParentOf(originalUser)     // prevent moving
-               && sessionUser.HasAccessTo(editedUser)
+              .WithPasswordOf(originalUser)   
-               && (editedUser.IsRelativeRoot() || sessionUser.HasAccessTo(editedUser.Parent()) || editedUser.Id == sessionUser.Id) // TODO: triple check this
+              .Apply(Db.Update);
-               && Db.Update(editedUser);
     }
    
     public static Boolean Delete(this Session? session, User? userToDelete)
@@ -117,7 +124,7 @@ public static class SessionMethods
         return sessionUser is not null
             && userToDelete is not null
             && sessionUser.HasWriteAccess
-            && sessionUser.HasAccessTo(userToDelete)   //   TODO: && user.HasAccessTo(installation.Parent()) ??? 
+            && sessionUser.HasAccessTo(userToDelete)    
             && Db.Delete(userToDelete);
     }
 
@@ -127,8 +134,8 @@ public static class SessionMethods
         var sessionUser = session?.User;
 
         return sessionUser is not null
-            && user is not null
             && installation is not null
+            && user is not null
             && user.IsDescendantOf(sessionUser)
             && sessionUser.HasAccessTo(installation)
             && !user.HasAccessTo(installation)
@@ -140,8 +147,8 @@ public static class SessionMethods
         var sessionUser = session?.User;
 
         return sessionUser is not null
-            && user is not null
             && folder is not null
+            && user is not null
             && user.IsDescendantOf(sessionUser)
             && sessionUser.HasAccessTo(folder)
             && !user.HasAccessTo(folder)
@@ -153,8 +160,8 @@ public static class SessionMethods
         var sessionUser = session?.User;
         
         return sessionUser is not null
-            && user is not null
             && installation is not null
+            && user is not null
             && user.IsDescendantOf(sessionUser)
             && sessionUser.HasAccessTo(installation)
             && user.HasAccessTo(installation)
@@ -166,8 +173,8 @@ public static class SessionMethods
         var sessionUser = session?.User;
         
         return sessionUser is not null
-            && user is not null
             && folder is not null
+            && user is not null
             && user.IsDescendantOf(sessionUser)
             && sessionUser.HasAccessTo(folder)
             && user.HasAccessTo(folder)

csharp/App/Backend/DataTypes/Methods/TreeNode.cs

@@ -0,0 +1,24 @@
+namespace InnovEnergy.App.Backend.DataTypes.Methods;
+
+public static class TreeNodeMethods
+{
+    
+    public static T WithParentOf<T>(this T treeNode, T other) where T: TreeNode
+    {
+        treeNode.ParentId = other.ParentId;
+        return treeNode;
+    }
+    
+    public static T WithParent<T>(this T treeNode, T other) where T: TreeNode
+    {
+        treeNode.ParentId = other.Id;
+        return treeNode;
+    }
+    
+    public static T HideParent<T>(this T treeNode) where T: TreeNode
+    {
+        treeNode.ParentId = 0;
+        return treeNode;
+    }
+    
+}

csharp/App/Backend/DataTypes/Methods/User.cs

@@ -34,7 +34,7 @@ public static class UserMethods
         // to a child folder of a folder he has already access to
         // TODO shouldn't we prevent doubling permissions? -K"
         // TODO yes we should -ig (still TODO)
-        // however we should leave the distinct, defensive programming...
+        // however we should still leave the distinct, defensive programming...
     }
 
     public static IEnumerable<TreeNode> AccessibleFoldersAndInstallations(this User user)
@@ -51,9 +51,9 @@ public static class UserMethods
               .InstallationAccess
               .Where(r => r.UserId == user.Id)
               .Select(r => r.InstallationId)
-              .Select(Db.GetInstallationById)
+              .Select(i => Db.GetInstallationById(i))
               .NotNull()
-              .Do(i => i.ParentId = 0); // hide inaccessible parents from calling user
+              .Do(i => i.HideParent()); // hide inaccessible parents from calling user
     }
 
     public static IEnumerable<Folder> DirectlyAccessibleFolders(this User user)
@@ -62,9 +62,9 @@ public static class UserMethods
               .FolderAccess
               .Where(r => r.UserId == user.Id)
               .Select(r => r.FolderId)
-              .Select(Db.GetFolderById)
+              .Select(i => Db.GetFolderById(i))
               .NotNull()
-              .Do(i => i.ParentId = 0); // hide inaccessible parents from calling user;
+              .Do(f => f.HideParent()); // hide inaccessible parents from calling user;
     }
 
     public static IEnumerable<User> ChildUsers(this User parent)
@@ -112,19 +112,15 @@ public static class UserMethods
     
     public static User? Parent(this User u)
     {
-        return u.IsAbsoluteRoot()
+        return u.IsRoot()
              ? null
              : Db.GetUserById(u.ParentId);
     }
 
-    public static Boolean IsAbsoluteRoot(this User u)
+    public static Boolean IsRoot(this User user)
     { 
-        return u.ParentId == 0; 
+        return user.ParentId <= 0
-    }
+            && Db.GetUserById(user.Id)?.Id == 0; // might have been 0 because it is a relative root 
-    
-    public static Boolean IsRelativeRoot(this User u)
-    {
-        return u.ParentId < 0; 
     }
     
     public static Boolean HasDirectAccessTo(this User user, Folder folder)
@@ -174,12 +170,6 @@ public static class UserMethods
               .Contains(user);
     }
     
-    public static Boolean IsRelativeRoot(this User user,  Installation i)
-    { 
-        // TODO: determine not by id but by accessibility
-        return i.ParentId < 0; 
-    }
-
     public static String Salt(this User user)
     {
         // + id          => salt unique per user
@@ -188,6 +178,14 @@ public static class UserMethods
         return $"{user.Id}InnovEnergy";   
     }
     
+    public static User WithPasswordOf(this User user, User other)
+    {
+        user.Password = other.Password;
+        return user;
+    }
+
+    
+    
     
     // TODO?
     private static Boolean IsValidEmail(String email)

csharp/App/Backend/Program.cs

@@ -4,6 +4,9 @@ namespace InnovEnergy.App.Backend;
 
 public static class Program
 {
+    
+    // TODO: Trash    
+    
     public static void Main(String[] args)
     {
         //Db.CreateFakeRelations();

csharp/App/Backend/Relations/Session.cs

@@ -1,6 +1,5 @@
 using InnovEnergy.App.Backend.Database;
 using InnovEnergy.App.Backend.DataTypes;
-using InnovEnergy.Lib.Utils;
 using SQLite;
 
 namespace InnovEnergy.App.Backend.Relations;
@@ -13,8 +12,8 @@ public class Session : Relation<String, Int64>
     [Indexed] public Int64    UserId   { get => Right; init => Right = value;}
     [Indexed] public DateTime LastSeen { get; set; }
 
-    [Ignore] public Boolean Valid => DateTime.Now - LastSeen < MaxAge 
+    [Ignore]  public Boolean Valid => DateTime.Now - LastSeen < MaxAge
-                                  && !User.Email.IsNullOrEmpty();
+                                   && (User) is not null;
 
     [Ignore] public User User => _User ??= Db.GetUserById(UserId)!;