Make sure nestedJobWhiteboard is processed in order

There was a problem where depending on the order of the hashmap
insertion, nested folders would not show up in the GUI. The issue
was caused by using childrenMap.entrySet which doesn't concern
about order.

To solve this issue the map values were encapsulated in a object
that implements the right sorting based on level, making sure
children paths are processed before their parents.

cuebot/src/main/java/com/imageworks/spcue/dao/postgres/NestedWhiteboardDaoJdbc.java

@@ -23,10 +23,10 @@
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 
 import org.springframework.jdbc.core.RowMapper;
 import org.springframework.jdbc.core.support.JdbcDaoSupport;
@@ -157,10 +157,56 @@ public CachedJobWhiteboardMapper(NestedJobWhiteboardMapper result) {
         "AND " +
             "folder.pk_dept = dept.pk_dept ";
 
-    class NestedJobWhiteboardMapper implements RowMapper<NestedGroup> {
+    private class ChildrenEntry {
+        String key;
+        int level;
+        List<String> children;
+        String name;
+
+        public ChildrenEntry(String key, int level, String name) {
+            this.key = key;
+            this.level = level;
+            this.children = new ArrayList<>();
+            this.name = name;
+        }
+
+        public List<String> getChildren() {
+            return children;
+        }
+
+        public void addChild(String child) {
+            children.add(child);
+        }
+
+        public String getKey() {
+            return key;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public int compareTo(ChildrenEntry o) {
+            // Invert order
+            return Integer.compare(o.level, this.level);
+        }
 
-        public Map<String, NestedGroup> groups = new HashMap<String,NestedGroup>(50);
-        public Map<String, List<String>> childrenMap = new HashMap<String, List<String>>();
+        @Override
+        public String toString() {
+            StringBuilder out = new StringBuilder();
+            String spacing = " ".repeat(Math.max(0, this.level + 1));
+            out.append(spacing);
+            out.append(key + "(c " + name + ")");
+            for (String id : children) {
+                out.append("\n " + spacing + id.substring(0, 4));
+            }
+            return out.toString();
+        }
+    }
+
+    class NestedJobWhiteboardMapper implements RowMapper<NestedGroup> {
+        public Map<String, NestedGroup> groups = new HashMap<String, NestedGroup>(50);
+        public Map<String, ChildrenEntry> childrenMap = new HashMap<String, ChildrenEntry>();
         public String rootGroupID;
 
         @Override
@@ -186,12 +232,16 @@ public NestedGroup mapRow(ResultSet rs, int rowNum) throws SQLException {
 
                 String parentGroupId = rs.getString("pk_parent_folder");
                 if (parentGroupId != null) {
-                    List<String> children = childrenMap.get(parentGroupId);
-                    if (children == null) {
-                        children = new ArrayList<>();
-                        childrenMap.put(parentGroupId, children);
+                    ChildrenEntry childrenEntry = childrenMap.get(parentGroupId);
+                    if (childrenEntry == null) {
+                        childrenEntry = new ChildrenEntry(
+                                parentGroupId, group.getLevel() - 1, rs.getString("group_name"));
+                        childrenEntry.addChild(groupId);
+                        childrenMap.put(parentGroupId, childrenEntry);
+                    }
+                    else {
+                        childrenEntry.addChild(groupId);
                     }
-                    children.add(groupId);
                 }
                 else {
                     rootGroupID = rs.getString("pk_folder");
@@ -223,19 +273,22 @@ public NestedGroup mapRow(ResultSet rs, int rowNum) throws SQLException {
     }
 
     private NestedJobWhiteboardMapper updateConnections(NestedJobWhiteboardMapper mapper) {
-        for (Map.Entry<String, List<String>> entry : mapper.childrenMap.entrySet()) {
-            NestedGroup group = mapper.groups.get(entry.getKey());
-            NestedGroupSeq.Builder childrenBuilder = NestedGroupSeq.newBuilder();
-            for (String childId : entry.getValue()) {
-                NestedGroup child = mapper.groups.get(childId);
-                child = child.toBuilder().setParent(group).build();
-                childrenBuilder.addNestedGroups(child);
-                mapper.groups.put(childId, child);
-            }
-            group = group.toBuilder()
-                    .setGroups(childrenBuilder.build())
-                    .build();
-            mapper.groups.put(entry.getKey(), group);
+        ArrayList<ChildrenEntry> orderedChildren = new ArrayList<>(mapper.childrenMap.values());
+        orderedChildren.sort(ChildrenEntry::compareTo);
+
+        for (ChildrenEntry entry : orderedChildren) {
+           NestedGroup group = mapper.groups.get(entry.getKey());
+           NestedGroupSeq.Builder childrenBuilder = NestedGroupSeq.newBuilder();
+           for (String childId : entry.getChildren()) {
+               NestedGroup child = mapper.groups.get(childId);
+               child = child.toBuilder().setParent(group).build();
+               childrenBuilder.addNestedGroups(child);
+               mapper.groups.put(childId, child);
+           }
+           group = group.toBuilder()
+                   .setGroups(childrenBuilder.build())
+                   .build();
+           mapper.groups.put(entry.getKey(), group);
         }
         return mapper;
     }