From 1b66888bd7aeb170932eaedfa2fbeece85da26ba Mon Sep 17 00:00:00 2001
From: Xavier Bustamante Talavera <xavier@bustawin.com>
Date: Fri, 10 Aug 2018 00:52:01 +0200
Subject: [PATCH] Add roots() method in lots

---
 ereuse_devicehub/resources/inventory.py  |  3 ++-
 ereuse_devicehub/resources/lot/models.py |  5 +++++
 tests/test_lot.py                        | 13 +++++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/ereuse_devicehub/resources/inventory.py b/ereuse_devicehub/resources/inventory.py
index 087e56c6..10171804 100644
--- a/ereuse_devicehub/resources/inventory.py
+++ b/ereuse_devicehub/resources/inventory.py
@@ -7,6 +7,7 @@ from sqlalchemy import Column
 
 from ereuse_devicehub.resources.device.models import Device
 from ereuse_devicehub.resources.event.models import Rate
+from ereuse_devicehub.resources.lot.models import Lot
 from ereuse_devicehub.resources.schemas import Thing
 from ereuse_devicehub.resources.tag import Tag
 from teal.query import Between, FullTextSearch, ILike, Join, Or, Query, Sort, SortField
@@ -97,7 +98,7 @@ class InventoryView(View):
             .paginate(page=args['page'], per_page=30)  # type: Pagination
         inventory = {
             'devices': app.resources[Device.t].schema.dump(devices.items, many=True, nested=1),
-            'groups': [],
+            'lots': Lot.roots(),
             'widgets': {},
             'pagination': {
                 'page': devices.page,
diff --git a/ereuse_devicehub/resources/lot/models.py b/ereuse_devicehub/resources/lot/models.py
index c442be42..a264183c 100644
--- a/ereuse_devicehub/resources/lot/models.py
+++ b/ereuse_devicehub/resources/lot/models.py
@@ -48,6 +48,11 @@ class Lot(Thing):
     def __contains__(self, child: 'Lot'):
         return Edge.has_lot(self.id, child.id)
 
+    @classmethod
+    def roots(cls):
+        """Gets the lots that are not under any other lot."""
+        return set(cls.query.join(cls.edges).filter(db.func.nlevel(Edge.path) == 1).all())
+
     def __repr__(self) -> str:
         return '<Lot {0.name} devices={0.devices!r}>'.format(self)
 
diff --git a/tests/test_lot.py b/tests/test_lot.py
index e6b9a4d7..97edb752 100644
--- a/tests/test_lot.py
+++ b/tests/test_lot.py
@@ -168,3 +168,16 @@ def test_lot_unite_graphs():
     l2.remove_child(l4)
     assert l4 not in l2 and l5 not in l2 and l6 not in l2 and l7 not in l2 and l8 not in l2
     assert l4 not in l3 and l5 not in l3 and l6 not in l3 and l7 not in l3 and l8 not in l3
+
+
+@pytest.mark.usefixtures(conftest.auth_app_context.__name__)
+def test_lot_roots():
+    """Tests getting the method Lot.roots."""
+    lots = Lot('1'), Lot('2'), Lot('3')
+    l1, l2, l3 = lots
+    db.session.add_all(lots)
+    db.session.flush()
+
+    assert Lot.roots() == {l1, l2, l3}
+    l1.add_child(l2)
+    assert Lot.roots() == {l1, l3}