From 8bc0b068ae073f3d6ade352fe32240ece949088d Mon Sep 17 00:00:00 2001
From: Timo Stollenwerk <timo@zmag.de>
Date: Mon, 13 Jul 2009 20:22:37 +0000
Subject: [PATCH] delete old replies and talkbacks during the migration.

svn path=/plone.app.discussion/trunk/; revision=28052
---
 plone/app/discussion/browser/migration.py    | 58 ++++++++++++++------
 plone/app/discussion/tests/test_migration.py |  1 +
 2 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/plone/app/discussion/browser/migration.py b/plone/app/discussion/browser/migration.py
index 2910092..08e0a65 100644
--- a/plone/app/discussion/browser/migration.py
+++ b/plone/app/discussion/browser/migration.py
@@ -29,14 +29,22 @@ class View(BrowserView):
         context = aq_inner(self.context)
         out = []
         self.total_comments_migrated = 0
+        self.total_comments_deleted = 0
+
+        catalog = getToolByName(context, 'portal_catalog')
+        dtool = context.portal_discussion
+        comment_brains = catalog.searchResults(Type='Discussion Item')
 
         def log(msg):
             context.plone_log(msg)
             out.append(msg)
 
         def migrate_replies(context, in_reply_to, replies, depth=0):
-            # recursive function to migrate all direct replies
-            # of a comment
+            # Recursive function to migrate all direct replies
+            # of a comment. Returns True if there are no replies to
+            # this comment left, and therefore the comment can be removed.
+            if len(replies) == 0:
+                return True
 
             for reply in replies:
 
@@ -52,8 +60,6 @@ class View(BrowserView):
                 comment.text = reply.text
                 comment.creator = reply.Creator()
 
-                #comment.creation_date = datetime.fromtimestamp(reply.creation_date)
-
                 comment.creation_date = datetime.fromtimestamp(reply.creation_date)
                 comment.modification_date = datetime.fromtimestamp(reply.modification_date)
 
@@ -64,32 +70,50 @@ class View(BrowserView):
 
                 # migrate all talkbacks of the reply
                 talkback = getattr( reply, 'talkback', None )
-                migrate_replies(context, new_in_reply_to, talkback.getReplies(), depth=depth+1)
+                no_replies_left = migrate_replies(context, new_in_reply_to, talkback.getReplies(), depth=depth+1)
+                if no_replies_left:
+                    # remove reply and talkback
+                    talkback.deleteReply(reply.id)
+                    obj = aq_parent(talkback)
+                    obj.talkback = None
+                    log("remove %s" % reply.id)
+                    self.total_comments_deleted += 1
 
         log("Comment migration started.")
 
         # Find content
-        catalog = getToolByName(context, 'portal_catalog')
-        dtool = context.portal_discussion
         brains = catalog.searchResults(
                     object_provides='Products.CMFCore.interfaces._content.IContentish')
-        comment_brains = catalog.searchResults(Type='Discussion Item')
         total_comment_brains = len(comment_brains)
         log("Found %s content objects." % len(brains))
         log("Found %s Discussion Item objects." % total_comment_brains)
 
+        # This loop is necessary to get all contentish objects, but not
+        # the Discussion Items. This wouldn't be necessary if the
+        # zcatalog would support NOT expressions.
+        new_brains = []
         for brain in brains:
             if brain.portal_type != 'Discussion Item':
-                obj = brain.getObject()
-                talkback = getattr( obj, 'talkback', None )
-                if talkback:
-                    replies = talkback.getReplies()
-                    if replies:
-                        conversation = IConversation(obj)
-                        log("Create conversation for: '%s'" % obj.Title())
-                    log("%s: Found talkback" % obj.absolute_url(relative=1))
-                    migrate_replies(context, 0, replies)
+                new_brains.append(brain)
 
+        # Recursively run through the comment tree and migrate all comments.
+        for brain in new_brains:
+            obj = brain.getObject()
+            talkback = getattr( obj, 'talkback', None )
+            if talkback:
+                replies = talkback.getReplies()
+                if replies:
+                    conversation = IConversation(obj)
+                    log("Create conversation for: '%s'" % obj.Title())
+                log("%s: Found talkback" % obj.absolute_url(relative=1))
+                migrate_replies(context, 0, replies)
+                obj = aq_parent(talkback)
+                obj.talkback = None
+
+        if self.total_comments_deleted != self.total_comments_migrated:
+            log("Something went wrong during migration. The number of migrated comments (%s)\
+                 differs from the number of deleted comments (%s)."
+                 % (self.total_comments_migrated, self.total_comments_deleted))
         log("Comment migration finished.")
         log("%s of %s comments migrated."
             % (self.total_comments_migrated, total_comment_brains))
diff --git a/plone/app/discussion/tests/test_migration.py b/plone/app/discussion/tests/test_migration.py
index 4e64e11..ad44bf1 100644
--- a/plone/app/discussion/tests/test_migration.py
+++ b/plone/app/discussion/tests/test_migration.py
@@ -70,6 +70,7 @@ class MigrationTest(PloneTestCase):
         self.assertEquals(
             [{'comment': comment1,     'depth': 0, 'id': long(comment1.id)},]
             , list(conversation.getThreads()))
+        self.failIf(self.doc.talkback)
 
     def test_migrate_nested_comments(self):
         # Create some nested comments and migrate them