fix(dashboard): Remove duplicated rows when dataset shared Publicly in the hub page

Author: Mrudhulraj

amber/src/main/scala/org/apache/texera/web/resource/dashboard/DatasetSearchQueryBuilder.scala

@@ -66,28 +66,38 @@ object DatasetSearchQueryBuilder extends SearchQueryBuilder with LazyLogging {
       params: DashboardResource.SearchQueryParams,
       includePublic: Boolean = false
   ): TableLike[_] = {
-    // Select datasets that any `uid` has access to
-    // if `uid` is null the left join operation on USER_ACCESS is skipped
-    // if `uid` is not null find tables of specific `uid` filtered
+    // Case 1: if `uid` is (set) and `includePublic` is false
+    // -> return ONLY datasets that given `uid` has explicit access to.
+    // Case 2: if `uid` is (null) and `includePublic` is true
+    // -> return ONLY datasets that are public
+    // Case 3 (DUPLICATE ROWS): if `uid` is (set) and `includePublic` is true
+    // -> Intersection of datasets that are public and explicitly shared with user is returned
+    // Case 4: if `uid` is (null) and `includePublic` is false
+    // -> return public datasets by default as user might not be logged in
     val baseJoin = DATASET
        .leftJoin(DATASET_USER_ACCESS)
        .on(DATASET_USER_ACCESS.DID.eq(DATASET.DID))
        .and(if (uid == null) DSL.falseCondition() else DATASET_USER_ACCESS.UID.eq(uid))
        .leftJoin(USER)
        .on(USER.UID.eq(DATASET.OWNER_UID))
 
-    // Set the `condition` where clause here    
+    // Set the `condition` where clause here
     val condition: Condition =
-       if (uid == null) {
+      if (uid == null) {
+        // Case 2 and 4
         // Get all the public datasets by default
-         DATASET.IS_PUBLIC.eq(true)
-       } else if (includePublic) {
-        // Get all the datasets that `uid` has access to and the publio datasets
-         DATASET.IS_PUBLIC.eq(true).or(DATASET_USER_ACCESS.UID.isNotNull)
-       } else {
-        // If `includePublic`` is false get only user accessible datasets
-         DATASET_USER_ACCESS.UID.isNotNull
-       }
+          DATASET.IS_PUBLIC.eq(true)
+      } else { 
+          if(includePublic) {
+          // Case 3
+          // Get all the datasets that `uid` has access to and the public datasets
+            DATASET.IS_PUBLIC.eq(true).or(DATASET_USER_ACCESS.UID.isNotNull)
+          } else{
+          // Case 1
+          // If `includePublic` is false get only user accessible datasets
+            DATASET_USER_ACCESS.UID.isNotNull
+          }
+      }
      baseJoin.where(condition)
   }
 
@@ -138,7 +148,9 @@ object DatasetSearchQueryBuilder extends SearchQueryBuilder with LazyLogging {
     val dd = DashboardDataset(
       dataset,
       owner.getEmail,
-      record.get(DATASET_USER_ACCESS.PRIVILEGE, classOf[PrivilegeEnum]),
+      Option(record.get(
+        DATASET_USER_ACCESS.PRIVILEGE, classOf[PrivilegeEnum]
+      )).getOrElse(PrivilegeEnum.NONE),
       dataset.getOwnerUid == uid,
       size
     )