Refactoring tags functionality into TagService

1 files changed, 55 insertions, 0 deletions

diff --git a/service/pixelated/adapter/tag_service.py b/service/pixelated/adapter/tag_service.py
new file mode 100644
index 00000000..00f28b40
--- /dev/null
+++ b/service/pixelated/adapter/tag_service.py
@@ -0,0 +1,55 @@
+#
+# Copyright (c) 2014 ThoughtWorks, Inc.
+#
+# Pixelated is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pixelated is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with Pixelated. If not, see <http://www.gnu.org/licenses/>.
+from pixelated.adapter.tag import Tag
+from pixelated.adapter.tag_index import TagIndex
+
+
+class TagService:
+
+    instance = None
+    SPECIAL_TAGS = {Tag('inbox', True), Tag('sent', True), Tag('drafts', True), Tag('trash', True)}
+
+    @classmethod
+    def get_instance(cls):
+        if not cls.instance:
+            cls.instance = TagService()
+        return cls.instance
+
+    def __init__(self, tag_index=TagIndex()):
+        self.tag_index = tag_index
+
+    def load_index(self, mails):
+        if self.tag_index.empty():
+            for mail in mails:
+                self.notify_tags_updated(mail.tags, [], mail.ident)
+        for tag in self.SPECIAL_TAGS:
+            self.tag_index.add(tag)
+
+    def notify_tags_updated(self, added_tags, removed_tags, mail_ident):
+        for removed_tag in removed_tags:
+            tag = self.tag_index.get(removed_tag)
+            tag.decrement(mail_ident)
+            if tag.total == 0:
+                self.tag_index.remove(tag.name)
+            else:
+                self.tag_index.set(tag)
+        for added_tag in added_tags:
+            tag = self.tag_index.get(added_tag) or self.tag_index.add(Tag(added_tag))
+            tag.increment(mail_ident)
+            self.tag_index.set(tag)
+
+    def all_tags(self):
+        return self.tag_index.values().union(self.SPECIAL_TAGS)