Implemented a way to re-import from an .apkg file and update the existing notes.

AnkiServer/importer.py

@@ -6,6 +6,8 @@ from anki.importing.supermemo_xml import SupermemoXmlImporter
 from anki.importing.mnemo import MnemosyneImporter
 from anki.importing.pauker import PaukerImporter
 
+__all__ = ['get_importer_class', 'import_file']
+
 importers = {
   'text': TextImporter,
   'apkg': AnkiPackageImporter,
@@ -19,11 +21,80 @@ def get_importer_class(type):
     global importers
     return importers.get(type)
 
-def import_file(importer_class, col, path):
+def import_file(importer_class, col, path, allow_update = False):
     importer = importer_class(col, path)
 
+    if allow_update:
+        importer.allowUpdate = True
+
     if importer.needMapper:
         importer.open()
 
     importer.run()
 
+#
+# Monkey patch anki.importing.anki2 to support updating existing notes.
+# TODO: submit a patch to Anki!
+#
+
+def _importNotes(self):
+    # build guid -> (id,mod,mid) hash & map of existing note ids
+    self._notes = {}
+    existing = {}
+    for id, guid, mod, mid in self.dst.db.execute(
+        "select id, guid, mod, mid from notes"):
+        self._notes[guid] = (id, mod, mid)
+        existing[id] = True
+    # we may need to rewrite the guid if the model schemas don't match,
+    # so we need to keep track of the changes for the card import stage
+    self._changedGuids = {}
+    # iterate over source collection
+    add = []
+    dirty = []
+    usn = self.dst.usn()
+    dupes = 0
+    for note in self.src.db.execute(
+        "select * from notes"):
+        # turn the db result into a mutable list
+        note = list(note)
+        shouldAdd = self._uniquifyNote(note)
+        if shouldAdd:
+            # ensure id is unique
+            while note[0] in existing:
+                note[0] += 999
+            existing[note[0]] = True
+            # bump usn
+            note[4] = usn
+            # update media references in case of dupes
+            note[6] = self._mungeMedia(note[MID], note[6])
+            add.append(note)
+            dirty.append(note[0])
+            # note we have the added the guid
+            self._notes[note[GUID]] = (note[0], note[3], note[MID])
+        else:
+            # update existing note
+            newer = note[3] > mod
+            if self.allowUpdate and self._mid(mid) == mid and newer:
+                localNid = self._notes[guid][0]
+                note[0] = localNid
+                note[4] = usn
+                add.append(note)
+                dirty.append(note[0])
+            else:
+                dupes += 1
+
+    if dupes:
+        self.log.append(_("Already in collection: %s.") % (ngettext(
+            "%d note", "%d notes", dupes) % dupes))
+    # add to col
+    self.dst.db.executemany(
+        "insert or replace into notes values (?,?,?,?,?,?,?,?,?,?,?)",
+        add)
+    self.dst.updateFieldCache(dirty)
+    self.dst.tags.registerNotes(dirty)
+
+from anki.importing.anki2 import Anki2Importer, MID, GUID
+from anki.lang import _, ngettext
+Anki2Importer._importNotes = _importNotes
+Anki2Importer.allowUpdate = False
+