From 7acdbfa9ae461f6f0e2ac5c2cfeffea64ac54de8 Mon Sep 17 00:00:00 2001
From: Damien Elmes <git@ichi2.net>
Date: Thu, 21 Apr 2011 09:34:33 +0900
Subject: [PATCH] support for shifting

---
 anki/sched.py       | 13 ++++++++++++-
 tests/test_sched.py | 25 +++++++++++++++++++++----
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/anki/sched.py b/anki/sched.py
index 10d698ff2..2abd66d48 100644
--- a/anki/sched.py
+++ b/anki/sched.py
@@ -790,7 +790,7 @@ where id = :id""", vals)
     # Random<->ordered new cards
     ##########################################################################
 
-    def sortCards(self, cids, start=1, step=1, shuffle=False):
+    def sortCards(self, cids, start=1, step=1, shuffle=False, shift=False):
         scids = ids2str(cids)
         now = intTime()
         fids = self.deck.db.list(
@@ -802,6 +802,17 @@ where id = :id""", vals)
             random.shuffle(fids)
         for c, fid in enumerate(fids):
             due[fid] = start+c*step
+        high = start+c*step
+        # shift?
+        if shift:
+            low = self.deck.db.scalar(
+                "select min(due) from cards where due >= ? and type = 0 "
+                "and id not in %s" % scids,
+                start)
+            shiftby = high - low + 1
+            self.deck.db.execute("""
+update cards set mod=?, due=due+? where id not in %s
+and due >= ?""" % scids, now, shiftby, low)
         # reorder cards
         d = []
         for id, fid in self.deck.db.execute(
diff --git a/tests/test_sched.py b/tests/test_sched.py
index 8b97b31db..833193060 100644
--- a/tests/test_sched.py
+++ b/tests/test_sched.py
@@ -693,10 +693,10 @@ def test_reorder():
     f = d.newFact()
     f['Front'] = u"one"
     d.addFact(f)
-    f = d.newFact()
-    f['Front'] = u"two"
-    d.addFact(f)
-    assert f.cards()[0].due == f.id
+    f2 = d.newFact()
+    f2['Front'] = u"two"
+    d.addFact(f2)
+    assert f2.cards()[0].due == f2.id
     found=False
     # 50/50 chance of being reordered
     for i in range(20):
@@ -707,6 +707,23 @@ def test_reorder():
     assert found
     d.sched.orderCards()
     assert f.cards()[0].due == f.id
+    # shifting
+    f3 = d.newFact()
+    f3['Front'] = u"three"
+    d.addFact(f3)
+    f4 = d.newFact()
+    f4['Front'] = u"four"
+    d.addFact(f4)
+    assert f.cards()[0].due == 1
+    assert f2.cards()[0].due == 2
+    assert f3.cards()[0].due == 3
+    assert f4.cards()[0].due == 4
+    d.sched.sortCards([
+        f3.cards()[0].id, f4.cards()[0].id], start=1, shift=True)
+    assert f.cards()[0].due == 3
+    assert f2.cards()[0].due == 4
+    assert f3.cards()[0].due == 1
+    assert f4.cards()[0].due == 2
 
 def test_forget():
     d = getEmptyDeck()