First stage of the storage schema rewrite.

* Separates between flags, docs, body and attachment docs.

* Implement IMessageCopier interface: move and have fun!
  This little change is known to push forward our beloved architect
  emotional rollercoster.

* Message deduplication.

* It also fixes a hidden bug that was rendering the multipart mime
  interface useless
  (yes, the "True" parameter in the parsestr method).

* Does not handle well nested attachs, includes dirty workaround that
  flattens them.

* Includes chiiph's patch for rc2:

 * return deferred from addMessage
 * convert StringIO types to string
 * remove unneeded yields from the chain of deferreds in fetcher

7 files changed, 808 insertions, 216 deletions

diff --git a/mail/changes/feature_split_message_docs b/mail/changes/feature_split_message_docs
new file mode 100644
index 0000000..231c36e
--- /dev/null
+++ b/mail/changes/feature_split_message_docs
@@ -0,0 +1,6 @@
+  o Defer costly operations to a pool of threads.
+  o Split the internal representation of messages into four distinct documents:
+    1) Flags 2) Headers 3) Body 4) Attachments.
+  o Add deduplication ability to the save operation, for body and attachments.
+  o Add IMessageCopier interface to mailbox implementation, so bulk moves
+    are costless. Closes: #4654
diff --git a/mail/src/leap/mail/imap/fetch.py b/mail/src/leap/mail/imap/fetch.py
index 0b31c3b..fdf1412 100644
--- a/mail/src/leap/mail/imap/fetch.py
+++ b/mail/src/leap/mail/imap/fetch.py
@@ -412,13 +412,13 @@ class LeapIncomingMail(object):
 
         # decrypt or fail gracefully
         try:
-            decrdata, valid_sig = yield self._decrypt_and_verify_data(
+            decrdata, valid_sig = self._decrypt_and_verify_data(
                 encdata, senderPubkey)
         except keymanager_errors.DecryptError as e:
             logger.warning('Failed to decrypt encrypted message (%s). '
                            'Storing message without modifications.' % str(e))
             # Bailing out!
-            yield (msg, False)
+            return (msg, False)
 
         # decrypted successully, now fix encoding and parse
         try:
@@ -441,7 +441,7 @@ class LeapIncomingMail(object):
 
         # all ok, replace payload by unencrypted payload
         msg.set_payload(decrmsg.get_payload())
-        yield (msg, valid_sig)
+        return (msg, valid_sig)
 
     def _maybe_decrypt_inline_encrypted_msg(self, origmsg, encoding,
                                             senderPubkey):
@@ -527,6 +527,7 @@ class LeapIncomingMail(object):
         """
         log.msg('adding message to local db')
         doc, data = msgtuple
+
         if isinstance(data, list):
             data = data[0]
 
diff --git a/mail/src/leap/mail/imap/fields.py b/mail/src/leap/mail/imap/fields.py
index 96b937e..40817cd 100644
--- a/mail/src/leap/mail/imap/fields.py
+++ b/mail/src/leap/mail/imap/fields.py
@@ -25,18 +25,35 @@ class WithMsgFields(object):
     Container class for class-attributes to be shared by
     several message-related classes.
     """
-    # Internal representation of Message
-    DATE_KEY = "date"
-    HEADERS_KEY = "headers"
-    FLAGS_KEY = "flags"
-    MBOX_KEY = "mbox"
+    # indexing
     CONTENT_HASH_KEY = "chash"
-    RAW_KEY = "raw"
-    SUBJECT_KEY = "subject"
+    PAYLOAD_HASH_KEY = "phash"
+
+    # Internal representation of Message
+
+    # flags doc
     UID_KEY = "uid"
+    MBOX_KEY = "mbox"
+    SEEN_KEY = "seen"
+    RECENT_KEY = "recent"
+    FLAGS_KEY = "flags"
     MULTIPART_KEY = "multi"
     SIZE_KEY = "size"
 
+    # headers
+    HEADERS_KEY = "headers"
+    NUM_PARTS_KEY = "numparts"
+    PARTS_MAP_KEY = "partmap"
+    DATE_KEY = "date"
+    SUBJECT_KEY = "subject"
+
+    # attachment
+    PART_NUMBER_KEY = "part"
+    RAW_KEY = "raw"
+
+    # content
+    BODY_KEY = "body"
+
     # Mailbox specific keys
     CLOSED_KEY = "closed"
     CREATED_KEY = "created"
@@ -55,10 +72,6 @@ class WithMsgFields(object):
 
     INBOX_VAL = "inbox"
 
-    # Flags for SoledadDocument for indexing.
-    SEEN_KEY = "seen"
-    RECENT_KEY = "recent"
-
     # Flags in Mailbox and Message
     SEEN_FLAG = "\\Seen"
     RECENT_FLAG = "\\Recent"
@@ -82,7 +95,9 @@ class WithMsgFields(object):
     TYPE_SUBS_IDX = 'by-type-and-subscribed'
     TYPE_MBOX_SEEN_IDX = 'by-type-and-mbox-and-seen'
     TYPE_MBOX_RECT_IDX = 'by-type-and-mbox-and-recent'
-    TYPE_HASH_IDX = 'by-type-and-hash'
+    TYPE_C_HASH_IDX = 'by-type-and-contenthash'
+    TYPE_C_HASH_PART_IDX = 'by-type-and-contenthash-and-partnumber'
+    TYPE_P_HASH_IDX = 'by-type-and-payloadhash'
 
     # Tomas created the `recent and seen index`, but the semantic is not too
     # correct since the recent flag is volatile.
@@ -90,7 +105,9 @@ class WithMsgFields(object):
 
     KTYPE = TYPE_KEY
     MBOX_VAL = TYPE_MBOX_VAL
-    HASH_VAL = CONTENT_HASH_KEY
+    CHASH_VAL = CONTENT_HASH_KEY
+    PHASH_VAL = PAYLOAD_HASH_KEY
+    PART_VAL = PART_NUMBER_KEY
 
     INDEXES = {
         # generic
@@ -102,7 +119,11 @@ class WithMsgFields(object):
         TYPE_SUBS_IDX: [KTYPE, 'bool(subscribed)'],
 
         # content, headers doc
-        TYPE_HASH_IDX: [KTYPE, HASH_VAL],
+        TYPE_C_HASH_IDX: [KTYPE, CHASH_VAL],
+        # attachment docs
+        TYPE_C_HASH_PART_IDX: [KTYPE, CHASH_VAL, PART_VAL],
+        # attachment payload dedup
+        TYPE_P_HASH_IDX: [KTYPE, PHASH_VAL],
 
         # messages
         TYPE_MBOX_SEEN_IDX: [KTYPE, MBOX_VAL, 'bool(seen)'],
diff --git a/mail/src/leap/mail/imap/index.py b/mail/src/leap/mail/imap/index.py
index 2280d86..5f0919a 100644
--- a/mail/src/leap/mail/imap/index.py
+++ b/mail/src/leap/mail/imap/index.py
@@ -21,7 +21,7 @@ import logging
 
 from leap.common.check import leap_assert, leap_assert_type
 
-from leap.mail.imap.account import SoledadBackedAccount
+from leap.mail.imap.fields import fields
 
 
 logger = logging.getLogger(__name__)
@@ -54,7 +54,7 @@ class IndexedDB(object):
         db_indexes = dict()
         if self._soledad is not None:
             db_indexes = dict(self._soledad.list_indexes())
-        for name, expression in SoledadBackedAccount.INDEXES.items():
+        for name, expression in fields.INDEXES.items():
             if name not in db_indexes:
                 # The index does not yet exist.
                 self._soledad.create_index(name, *expression)
diff --git a/mail/src/leap/mail/imap/mailbox.py b/mail/src/leap/mail/imap/mailbox.py
index 09c06a2..5ea6f55 100644
--- a/mail/src/leap/mail/imap/mailbox.py
+++ b/mail/src/leap/mail/imap/mailbox.py
@@ -17,7 +17,13 @@
 """
 Soledad Mailbox.
 """
+import copy
+import threading
 import logging
+import time
+import StringIO
+import cStringIO
+
 from collections import defaultdict
 
 from twisted.internet import defer
@@ -45,9 +51,14 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
     The low-level database methods are contained in MessageCollection class,
     which we instantiate and make accessible in the `messages` attribute.
     """
-    implements(imap4.IMailboxInfo, imap4.IMailbox, imap4.ICloseableMailbox)
+    implements(
+        imap4.IMailbox,
+        imap4.IMailboxInfo,
+        imap4.ICloseableMailbox,
+        imap4.IMessageCopier)
+
     # XXX should finish the implementation of IMailboxListener
-    # XXX should implement IMessageCopier too
+    # XXX should implement ISearchableMailbox too
 
     messages = None
     _closed = False
@@ -65,6 +76,7 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
     CMD_UNSEEN = "UNSEEN"
 
     _listeners = defaultdict(set)
+    next_uid_lock = threading.Lock()
 
     def __init__(self, mbox, soledad=None, rw=1):
         """
@@ -284,8 +296,9 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
 
         :rtype: int
         """
-        self.last_uid += 1
-        return self.last_uid
+        with self.next_uid_lock:
+            self.last_uid += 1
+            return self.last_uid
 
     def getMessageCount(self):
         """
@@ -366,6 +379,8 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
 
         :return: a deferred that evals to None
         """
+        if isinstance(message, (cStringIO.OutputType, StringIO.StringIO)):
+            message = message.getvalue()
         # XXX we should treat the message as an IMessage from here
         leap_assert_type(message, basestring)
         uid_next = self.getUIDNext()
@@ -375,11 +390,12 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
         else:
             flags = tuple(str(flag) for flag in flags)
 
-        d = self._do_add_messages(message, flags, date, uid_next)
+        d = self._do_add_message(message, flags, date, uid_next)
         d.addCallback(self._notify_new)
+        return d
 
     @deferred
-    def _do_add_messages(self, message, flags, date, uid_next):
+    def _do_add_message(self, message, flags, date, uid_next):
         """
         Calls to the messageCollection add_msg method (deferred to thread).
         Invoked from addMessage.
@@ -420,28 +436,21 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
         # we should postpone the removal
         self._soledad.delete_doc(self._get_mbox())
 
+    @deferred
     def expunge(self):
         """
         Remove all messages flagged \\Deleted
         """
         if not self.isWriteable():
             raise imap4.ReadOnlyMailbox
-        delete = []
         deleted = []
-
-        for m in self.messages.get_all_docs():
-            # XXX should operate with LeapMessages instead,
-            # so we don't expose the implementation.
-            # (so, iterate for m in self.messages)
-            if self.DELETED_FLAG in m.content[self.FLAGS_KEY]:
-                delete.append(m)
-        for m in delete:
-            deleted.append(m.content)
-            self.messages.remove(m)
-
-        # XXX should return the UIDs of the deleted messages
-        # more generically
-        return [x for x in range(len(deleted))]
+        for m in self.messages:
+            if self.DELETED_FLAG in m.getFlags():
+                self.messages.remove(m)
+                # XXX this would ve more efficient if we can just pass
+                # a sequence of uids.
+                deleted.append(m.getUID())
+        return deleted
 
     @deferred
     def fetch(self, messages, uid):
@@ -510,6 +519,17 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
         session is the first session to be notified about a message,
         then that message SHOULD be considered recent.
         """
+        # TODO this fucker, for the sake of correctness, is messing with
+        # the whole collection of flag docs.
+
+        # Possible ways of action:
+        # 1. Ignore it, we want fun.
+        # 2. Trigger it with a delay
+        # 3. Route it through a queue with lesser priority than the
+        #    regularar writer.
+
+        # hmm let's try 2. in a quickndirty way...
+        time.sleep(1)
         log.msg('unsetting recent flags...')
         for msg in self.messages.get_recent():
             msg.removeFlags((fields.RECENT_FLAG,))
@@ -570,6 +590,8 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
         for msg_id in messages:
             log.msg("MSG ID = %s" % msg_id)
             msg = self.messages.get_msg_by_uid(msg_id)
+            if not msg:
+                return result
             if mode == 1:
                 msg.addFlags(flags)
             elif mode == -1:
@@ -589,15 +611,36 @@ class SoledadMailbox(WithMsgFields, MBoxParser):
         self.expunge()
         self.closed = True
 
-    #@deferred
-    #def copy(self, messageObject):
-        #"""
-        #Copy the given message object into this mailbox.
-        #"""
-        # XXX should just:
-        # 1. Get the message._fdoc
-        # 2. Change the UID to UIDNext for this mailbox
-        # 3. Add implements IMessageCopier
+    # IMessageCopier
+
+    @deferred
+    def copy(self, messageObject):
+        """
+        Copy the given message object into this mailbox.
+        """
+        uid_next = self.getUIDNext()
+        msg = messageObject
+
+        # XXX should use a public api instead
+        fdoc = msg._fdoc
+        if not fdoc:
+            logger.debug("Tried to copy a MSG with no fdoc")
+            return
+
+        new_fdoc = copy.deepcopy(fdoc.content)
+        new_fdoc[self.UID_KEY] = uid_next
+        new_fdoc[self.MBOX_KEY] = self.mbox
+
+        d = self._do_add_doc(new_fdoc)
+        d.addCallback(self._notify_new)
+
+    @deferred
+    def _do_add_doc(self, doc):
+        """
+        Defers the adding of a new doc.
+        :param doc: document to be created in soledad.
+        """
+        self._soledad.create_doc(doc)
 
     # convenience fun
 
diff --git a/mail/src/leap/mail/imap/messages.py b/mail/src/leap/mail/imap/messages.py
index b0d5da2..c69c023 100644
--- a/mail/src/leap/mail/imap/messages.py
+++ b/mail/src/leap/mail/imap/messages.py
@@ -29,9 +29,9 @@ from zope.interface import implements
 from zope.proxy import sameProxiedObjects
 
 from leap.common.check import leap_assert, leap_assert_type
+from leap.common.decorators import memoized_method
 from leap.common.mail import get_email_charset
 from leap.mail.decorators import deferred
-from leap.mail.imap.account import SoledadBackedAccount
 from leap.mail.imap.index import IndexedDB
 from leap.mail.imap.fields import fields, WithMsgFields
 from leap.mail.imap.parser import MailParser, MBoxParser
@@ -40,6 +40,181 @@ from leap.mail.messageflow import IMessageConsumer, MessageProducer
 logger = logging.getLogger(__name__)
 
 
+def first(things):
+    """
+    Return the head of a collection.
+    """
+    try:
+        return things[0]
+    except (IndexError, TypeError):
+        return None
+
+
+class MessageBody(object):
+    """
+    IMessagePart implementor for the main
+    body of a multipart message.
+
+    Excusatio non petita: see the interface documentation.
+    """
+
+    implements(imap4.IMessagePart)
+
+    def __init__(self, fdoc, bdoc):
+        self._fdoc = fdoc
+        self._bdoc = bdoc
+
+    def getSize(self):
+        return len(self._bdoc.content[fields.BODY_KEY])
+
+    def getBodyFile(self):
+        fd = StringIO.StringIO()
+
+        if self._bdoc:
+            body = self._bdoc.content[fields.BODY_KEY]
+        else:
+            body = ""
+        charset = self._get_charset(body)
+        try:
+            body = body.encode(charset)
+        except (UnicodeEncodeError, UnicodeDecodeError) as e:
+            logger.error("Unicode error {0}".format(e))
+            body = body.encode(charset, 'replace')
+        fd.write(body)
+        fd.seek(0)
+        return fd
+
+    @memoized_method
+    def _get_charset(self, stuff):
+        return get_email_charset(unicode(stuff))
+
+    def getHeaders(self, negate, *names):
+        return {}
+
+    def isMultipart(self):
+        return False
+
+    def getSubPart(self, part):
+        return None
+
+
+class MessageAttachment(object):
+
+    implements(imap4.IMessagePart)
+
+    def __init__(self, msg):
+        """
+        Initializes the messagepart with a Message instance.
+        :param msg: a message instance
+        :type msg: Message
+        """
+        self._msg = msg
+
+    def getSize(self):
+        """
+        Return the total size, in octets, of this message part.
+
+        :return: size of the message, in octets
+        :rtype: int
+        """
+        if not self._msg:
+            return 0
+        return len(self._msg.as_string())
+
+    def getBodyFile(self):
+        """
+        Retrieve a file object containing only the body of this message.
+
+        :return: file-like object opened for reading
+        :rtype: StringIO
+        """
+        fd = StringIO.StringIO()
+        if self._msg:
+            body = self._msg.get_payload()
+        else:
+            logger.debug("Empty message!")
+            body = ""
+
+        # XXX should only do the dance if we're sure it's
+        # content/text-plain!!!
+        #charset = self._get_charset(body)
+        #try:
+            #body = body.encode(charset)
+        #except (UnicodeEncodeError, UnicodeDecodeError) as e:
+            #logger.error("Unicode error {0}".format(e))
+            #body = body.encode(charset, 'replace')
+        fd.write(body)
+        fd.seek(0)
+        return fd
+
+    @memoized_method
+    def _get_charset(self, stuff):
+        # TODO put in a common class with LeapMessage
+        """
+        Gets (guesses?) the charset of a payload.
+
+        :param stuff: the stuff to guess about.
+        :type stuff: basestring
+        :returns: charset
+        """
+        # XXX existential doubt 1. wouldn't be smarter to
+        # peek into the mail headers?
+        # XXX existential doubt 2. shouldn't we make the scope
+        # of the decorator somewhat more persistent?
+        # ah! yes! and put memory bounds.
+        return get_email_charset(unicode(stuff))
+
+    def getHeaders(self, negate, *names):
+        """
+        Retrieve a group of message headers.
+
+        :param names: The names of the headers to retrieve or omit.
+        :type names: tuple of str
+
+        :param negate: If True, indicates that the headers listed in names
+                       should be omitted from the return value, rather
+                       than included.
+        :type negate: bool
+
+        :return: A mapping of header field names to header field values
+        :rtype: dict
+        """
+        if not self._msg:
+            return {}
+        headers = dict(self._msg.items())
+        names = map(lambda s: s.upper(), names)
+        if negate:
+            cond = lambda key: key.upper() not in names
+        else:
+            cond = lambda key: key.upper() in names
+
+        # unpack and filter original dict by negate-condition
+        filter_by_cond = [
+            map(str, (key, val)) for
+            key, val in headers.items()
+            if cond(key)]
+        return dict(filter_by_cond)
+
+    def isMultipart(self):
+        """
+        Return True if this message is multipart.
+        """
+        return self._msg.is_multipart()
+
+    def getSubPart(self, part):
+        """
+        Retrieve a MIME submessage
+
+        :type part: C{int}
+        :param part: The number of the part to retrieve, indexed from 0.
+        :raise IndexError: Raised if the specified part does not exist.
+        :raise TypeError: Raised if this message is not multipart.
+        :rtype: Any object implementing C{IMessagePart}.
+        :return: The specified sub-part.
+        """
+        return self._msg.get_payload()
+
+
 class LeapMessage(fields, MailParser, MBoxParser):
 
     implements(imap4.IMessage)
@@ -59,25 +234,21 @@ class LeapMessage(fields, MailParser, MBoxParser):
         self._soledad = soledad
         self._uid = int(uid)
         self._mbox = self._parse_mailbox_name(mbox)
-        self._chash = None
 
-        self.__cdoc = None
+        self.__chash = None
+        self.__bdoc = None
 
     @property
     def _fdoc(self):
         """
         An accessor to the flags document.
         """
-        return self._get_flags_doc()
-
-    @property
-    def _cdoc(self):
-        """
-        An accessor to the content document.
-        """
-        if not self.__cdoc:
-            self.__cdoc = self._get_content_doc()
-        return self.__cdoc
+        if all(map(bool, (self._uid, self._mbox))):
+            fdoc = self._get_flags_doc()
+            if fdoc:
+                self.__chash = fdoc.content.get(
+                    fields.CONTENT_HASH_KEY, None)
+            return fdoc
 
     @property
     def _chash(self):
@@ -86,7 +257,26 @@ class LeapMessage(fields, MailParser, MBoxParser):
         """
         if not self._fdoc:
             return None
-        return self._fdoc.content.get(fields.CONTENT_HASH_KEY, None)
+        if not self.__chash and self._fdoc:
+            self.__chash = self._fdoc.content.get(
+                fields.CONTENT_HASH_KEY, None)
+        return self.__chash
+
+    @property
+    def _hdoc(self):
+        """
+        An accessor to the headers document.
+        """
+        return self._get_headers_doc()
+
+    @property
+    def _bdoc(self):
+        """
+        An accessor to the body document.
+        """
+        if not self.__bdoc:
+            self.__bdoc = self._get_body_doc()
+        return self.__bdoc
 
     # IMessage implementation
 
@@ -110,9 +300,9 @@ class LeapMessage(fields, MailParser, MBoxParser):
             return []
 
         flags = []
-        flag_doc = self._fdoc
-        if flag_doc:
-            flags = flag_doc.content.get(self.FLAGS_KEY, None)
+        fdoc = self._fdoc
+        if fdoc:
+            flags = fdoc.content.get(self.FLAGS_KEY, None)
         if flags:
             flags = map(str, flags)
         return tuple(flags)
@@ -180,7 +370,7 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :rtype: C{str}
         :return: An RFC822-formatted date string.
         """
-        return str(self._cdoc.content.get(self.DATE_KEY, ''))
+        return str(self._hdoc.content.get(self.DATE_KEY, ''))
 
     #
     # IMessagePart
@@ -197,25 +387,38 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :rtype: StringIO
         """
         fd = StringIO.StringIO()
+        bdoc = self._bdoc
+        if bdoc:
+            body = self._bdoc.content.get(self.BODY_KEY, "")
+        else:
+            body = ""
 
-        cdoc = self._cdoc
-        content = cdoc.content.get(self.RAW_KEY, '')
-        charset = get_email_charset(
-            unicode(cdoc.content.get(self.RAW_KEY, '')))
+        charset = self._get_charset(body)
         try:
-            content = content.encode(charset)
+            body = body.encode(charset)
         except (UnicodeEncodeError, UnicodeDecodeError) as e:
             logger.error("Unicode error {0}".format(e))
-            content = content.encode(charset, 'replace')
-
-        raw = self._get_raw_msg()
-        msg = self._get_parsed_msg(raw)
-        body = msg.get_payload()
+            body = body.encode(charset, 'replace')
         fd.write(body)
-        # XXX SHOULD use a separate BODY FIELD ...
         fd.seek(0)
         return fd
 
+    @memoized_method
+    def _get_charset(self, stuff):
+        """
+        Gets (guesses?) the charset of a payload.
+
+        :param stuff: the stuff to guess about.
+        :type stuff: basestring
+        :returns: charset
+        """
+        # XXX existential doubt 1. wouldn't be smarter to
+        # peek into the mail headers?
+        # XXX existential doubt 2. shouldn't we make the scope
+        # of the decorator somewhat more persistent?
+        # ah! yes! and put memory bounds.
+        return get_email_charset(unicode(stuff))
+
     def getSize(self):
         """
         Return the total size, in octets, of this message.
@@ -223,19 +426,17 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :return: size of the message, in octets
         :rtype: int
         """
-        size = self._cdoc.content.get(self.SIZE_KEY, False)
+        size = None
+        if self._fdoc:
+            size = self._fdoc.content.get(self.SIZE_KEY, False)
+        else:
+            logger.warning("No FLAGS doc for %s:%s" % (self._mbox,
+                                                       self._uid))
         if not size:
             # XXX fallback, should remove when all migrated.
             size = self.getBodyFile().len
         return size
 
-    def _get_headers(self):
-        """
-        Return the headers dict stored in this message document.
-        """
-        # XXX get from the headers doc
-        return self._cdoc.content.get(self.HEADERS_KEY, {})
-
     def getHeaders(self, negate, *names):
         """
         Retrieve a group of message headers.
@@ -252,26 +453,49 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :rtype: dict
         """
         headers = self._get_headers()
+        if not headers:
+            return {'content-type': ''}
         names = map(lambda s: s.upper(), names)
         if negate:
             cond = lambda key: key.upper() not in names
         else:
             cond = lambda key: key.upper() in names
 
+        head = copy.deepcopy(dict(headers.items()))
+
+            # twisted imap server expects headers to be lowercase
+        head = dict(
+            map(str, (key, value)) if key.lower() != "content-type"
+            else map(str, (key.lower(), value))
+            for (key, value) in head.items())
+
         # unpack and filter original dict by negate-condition
-        filter_by_cond = [
-            map(str, (key, val)) for
-            key, val in headers.items()
-            if cond(key)]
+        filter_by_cond = [(key, val) for key, val in head.items() if cond(key)]
         return dict(filter_by_cond)
 
+    def _get_headers(self):
+        """
+        Return the headers dict for this message.
+        """
+        if self._hdoc is not None:
+            return self._hdoc.content.get(self.HEADERS_KEY, {})
+        else:
+            logger.warning(
+                "No HEADERS doc for msg %s:%s" % (
+                    self._mbox,
+                    self._uid))
+
     def isMultipart(self):
         """
         Return True if this message is multipart.
         """
-        if self._cdoc:
-            retval = self._fdoc.content.get(self.MULTIPART_KEY, False)
-            return retval
+        if self._fdoc:
+            return self._fdoc.content.get(self.MULTIPART_KEY, False)
+        else:
+            logger.warning(
+                "No FLAGS doc for msg %s:%s" % (
+                    self.mbox,
+                    self.uid))
 
     def getSubPart(self, part):
         """
@@ -284,12 +508,22 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :rtype: Any object implementing C{IMessagePart}.
         :return: The specified sub-part.
         """
+        logger.debug("Getting subpart: %s" % part)
         if not self.isMultipart():
             raise TypeError
 
-        msg = self._get_parsed_msg()
-        # XXX should wrap IMessagePart
-        return msg.get_payload()[part]
+        if part == 0:
+            # Let's get the first part, which
+            # is really the body.
+            return MessageBody(self._fdoc, self._bdoc)
+
+        attach_doc = self._get_attachment_doc(part)
+        if not attach_doc:
+            # so long and thanks for all the fish
+            logger.debug("...not today")
+            raise IndexError
+        msg_part = self._get_parsed_msg(attach_doc.content[self.RAW_KEY])
+        return MessageAttachment(msg_part)
 
     #
     # accessors
@@ -301,32 +535,87 @@ class LeapMessage(fields, MailParser, MBoxParser):
         message.
         """
         flag_docs = self._soledad.get_from_index(
-            SoledadBackedAccount.TYPE_MBOX_UID_IDX,
+            fields.TYPE_MBOX_UID_IDX,
             fields.TYPE_FLAGS_VAL, self._mbox, str(self._uid))
-        flag_doc = flag_docs[0] if flag_docs else None
-        return flag_doc
+        return first(flag_docs)
 
-    def _get_content_doc(self):
+    def _get_headers_doc(self):
         """
-        Return the document that keeps the flags for this
+        Return the document that keeps the headers for this
+        message.
+        """
+        head_docs = self._soledad.get_from_index(
+            fields.TYPE_C_HASH_IDX,
+            fields.TYPE_HEADERS_VAL, str(self._chash))
+        return first(head_docs)
+
+    def _get_body_doc(self):
+        """
+        Return the document that keeps the body for this
         message.
         """
-        cont_docs = self._soledad.get_from_index(
-            SoledadBackedAccount.TYPE_HASH_IDX,
-            fields.TYPE_MESSAGE_VAL, self._content_hash, str(self._uid))
-        cont_doc = cont_docs[0] if cont_docs else None
-        return cont_doc
+        body_docs = self._soledad.get_from_index(
+            fields.TYPE_C_HASH_IDX,
+            fields.TYPE_MESSAGE_VAL, str(self._chash))
+        return first(body_docs)
+
+    def _get_num_parts(self):
+        """
+        Return the number of parts for a multipart message.
+        """
+        if not self.isMultipart():
+            raise TypeError(
+                "Tried to get num parts in a non-multipart message")
+        if not self._hdoc:
+            return None
+        return self._hdoc.content.get(fields.NUM_PARTS_KEY, 2)
+
+    def _get_attachment_doc(self, part):
+        """
+        Return the document that keeps the headers for this
+        message.
+
+        :param part: the part number for the multipart message.
+        :type part: int
+        """
+        if not self._hdoc:
+            return None
+        try:
+            phash = self._hdoc.content[self.PARTS_MAP_KEY][str(part)]
+        except KeyError:
+            # this is the remnant of a debug session until
+            # I found that the index is actually a string...
+            # It should be safe to just raise the KeyError now,
+            # but leaving it here while the blood is fresh...
+            logger.warning("We expected a phash in the "
+                           "index %s, but noone found" % (part, ))
+            logger.debug(self._hdoc.content[self.PARTS_MAP_KEY])
+            return None
+        attach_docs = self._soledad.get_from_index(
+            fields.TYPE_P_HASH_IDX,
+            fields.TYPE_ATTACHMENT_VAL, str(phash))
+
+        # The following is true for the fist owner.
+        # We could use this relationship to flag the "owner"
+        # and orphan when we delete it.
+
+        #attach_docs = self._soledad.get_from_index(
+            #fields.TYPE_C_HASH_PART_IDX,
+            #fields.TYPE_ATTACHMENT_VAL, str(self._chash), str(part))
+        return first(attach_docs)
 
     def _get_raw_msg(self):
         """
         Return the raw msg.
         :rtype: basestring
         """
-        return self._cdoc.content.get(self.RAW_KEY, '')
+        # TODO deprecate this.
+        return self._bdoc.content.get(self.RAW_KEY, '')
 
     def __getitem__(self, key):
         """
-        Return the content of the message document.
+        Return an item from the content of the flags document,
+        for convenience.
 
         :param key: The key
         :type key: str
@@ -334,14 +623,73 @@ class LeapMessage(fields, MailParser, MBoxParser):
         :return: The content value indexed by C{key} or None
         :rtype: str
         """
-        return self._cdoc.content.get(key, None)
+        return self._fdoc.content.get(key, None)
+
+    # setters
+
+    # XXX to be used in the messagecopier interface?!
+
+    def set_uid(self, uid):
+        """
+        Set new uid for this message.
+
+        :param uid: the new uid
+        :type uid: basestring
+        """
+        # XXX dangerous! lock?
+        self._uid = uid
+        d = self._fdoc
+        d.content[self.UID_KEY] = uid
+        self._soledad.put_doc(d)
+
+    def set_mbox(self, mbox):
+        """
+        Set new mbox for this message.
+
+        :param mbox: the new mbox
+        :type mbox: basestring
+        """
+        # XXX dangerous! lock?
+        self._mbox = mbox
+        d = self._fdoc
+        d.content[self.MBOX_KEY] = mbox
+        self._soledad.put_doc(d)
+
+    # destructor
+
+    @deferred
+    def remove(self):
+        """
+        Remove all docs associated with this message.
+        """
+        # XXX this would ve more efficient if we can just pass
+        # a sequence of uids.
+
+        # XXX For the moment we are only removing the flags and headers
+        # docs. The rest we leave there polluting your hard disk,
+        # until we think about a good way of deorphaning.
+        # Maybe a crawler of unreferenced docs.
+
+        fd = self._get_flags_doc()
+        hd = self._get_headers_doc()
+        #bd = self._get_body_doc()
+        #docs = [fd, hd, bd]
+
+        docs = [fd, hd]
+
+        #for pn in range(self._get_num_parts()[1:]):
+            #ad = self._get_attachment_doc(pn)
+            #docs.append(ad)
+
+        for d in filter(None, docs):
+            self._soledad.delete_doc(d)
 
     def does_exist(self):
         """
-        Return True if there is actually a message for this
+        Return True if there is actually a flags message for this
         UID and mbox.
         """
-        return bool(self._fdoc)
+        return self._fdoc is not None
 
 
 SoledadWriterPayload = namedtuple(
@@ -349,6 +697,8 @@ SoledadWriterPayload = namedtuple(
 
 SoledadWriterPayload.CREATE = 1
 SoledadWriterPayload.PUT = 2
+SoledadWriterPayload.BODY_CREATE = 3
+SoledadWriterPayload.ATTACHMENT_CREATE = 4
 
 
 class SoledadDocWriter(object):
@@ -378,20 +728,98 @@ class SoledadDocWriter(object):
         empty = queue.empty()
         while not empty:
             item = queue.get()
+            call = None
+            payload = item.payload
+
             if item.mode == SoledadWriterPayload.CREATE:
                 call = self._soledad.create_doc
+            elif item.mode == SoledadWriterPayload.BODY_CREATE:
+                if not self._body_does_exist(payload):
+                    call = self._soledad.create_doc
+            elif item.mode == SoledadWriterPayload.ATTACHMENT_CREATE:
+                if not self._attachment_does_exist(payload):
+                    call = self._soledad.create_doc
             elif item.mode == SoledadWriterPayload.PUT:
                 call = self._soledad.put_doc
 
-            # should handle errors
-            try:
-                call(item.payload)
-            except u1db_errors.RevisionConflict as exc:
-                logger.error("Error: %r" % (exc,))
-                raise exc
+            # XXX delete?
+
+            if call:
+                # should handle errors
+                try:
+                    call(item.payload)
+                except u1db_errors.RevisionConflict as exc:
+                    logger.error("Error: %r" % (exc,))
+                    raise exc
 
             empty = queue.empty()
 
+    """
+    Message deduplication.
+
+    We do a query for the content hashes before writing to our beloved
+    slcipher backend of Soledad. This means, by now, that:
+
+    1. We will not store the same attachment twice, only the hash of it.
+    2. We will not store the same message body twice, only the hash of it.
+
+    The first case is useful if you are always receiving the same old memes
+    from unwary friends that still have not discovered that 4chan is the
+    generator of the internet. The second will save your day if you have
+    initiated session with the same account in two different machines. I also
+    wonder why would you do that, but let's respect each other choices, like
+    with the religious celebrations, and assume that one day we'll be able
+    to run Bitmask in completely free phones. Yes, I mean that, the whole GSM
+    Stack.
+    """
+
+    def _body_does_exist(self, doc):
+        """
+        Check whether we already have a body payload with this hash in our
+        database.
+
+        :param doc: tentative body document
+        :type doc: dict
+        :returns: True if that happens, False otherwise.
+        """
+        if not doc:
+            return False
+        chash = doc[fields.CONTENT_HASH_KEY]
+        body_docs = self._soledad.get_from_index(
+            fields.TYPE_C_HASH_IDX,
+            fields.TYPE_MESSAGE_VAL, str(chash))
+        if not body_docs:
+            return False
+        if len(body_docs) != 1:
+            logger.warning("Found more than one copy of chash %s!"
+                           % (chash,))
+        logger.debug("Found body doc with that hash! Skipping save!")
+        return True
+
+    def _attachment_does_exist(self, doc):
+        """
+        Check whether we already have an attachment payload with this hash
+        in our database.
+
+        :param doc: tentative body document
+        :type doc: dict
+        :returns: True if that happens, False otherwise.
+        """
+        if not doc:
+            return False
+        phash = doc[fields.PAYLOAD_HASH_KEY]
+        attach_docs = self._soledad.get_from_index(
+            fields.TYPE_P_HASH_IDX,
+            fields.TYPE_ATTACHMENT_VAL, str(phash))
+        if not attach_docs:
+            return False
+
+        if len(attach_docs) != 1:
+            logger.warning("Found more than one copy of phash %s!"
+                           % (phash,))
+        logger.debug("Found attachment doc with that hash! Skipping save!")
+        return True
+
 
 class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
     """
@@ -402,35 +830,62 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
     database.
     """
     # XXX this should be able to produce a MessageSet methinks
-
-    EMPTY_MSG = {
-        fields.TYPE_KEY: fields.TYPE_MESSAGE_VAL,
-        fields.UID_KEY: 1,
-        fields.MBOX_KEY: fields.INBOX_VAL,
-
-        fields.SUBJECT_KEY: "",
-        fields.DATE_KEY: "",
-        fields.RAW_KEY: "",
-
-        # XXX should separate headers into another doc
-        fields.HEADERS_KEY: {},
+    # could validate these kinds of objects turning them
+    # into a template for the class.
+    FLAGS_DOC = "FLAGS"
+    HEADERS_DOC = "HEADERS"
+    ATTACHMENT_DOC = "ATTACHMENT"
+    BODY_DOC = "BODY"
+
+    templates = {
+
+        FLAGS_DOC: {
+            fields.TYPE_KEY: fields.TYPE_FLAGS_VAL,
+            fields.UID_KEY: 1,
+            fields.MBOX_KEY: fields.INBOX_VAL,
+
+            fields.SEEN_KEY: False,
+            fields.RECENT_KEY: True,
+            fields.FLAGS_KEY: [],
+            fields.MULTIPART_KEY: False,
+            fields.SIZE_KEY: 0
+        },
+
+        HEADERS_DOC: {
+            fields.TYPE_KEY: fields.TYPE_HEADERS_VAL,
+            fields.CONTENT_HASH_KEY: "",
+
+            fields.HEADERS_KEY: {},
+            fields.NUM_PARTS_KEY: 0,
+            fields.PARTS_MAP_KEY: {},
+            fields.DATE_KEY: "",
+            fields.SUBJECT_KEY: ""
+        },
+
+        ATTACHMENT_DOC: {
+            fields.TYPE_KEY: fields.TYPE_ATTACHMENT_VAL,
+            fields.PART_NUMBER_KEY: 0,
+            fields.CONTENT_HASH_KEY:  "",
+            fields.PAYLOAD_HASH_KEY: "",
+
+            fields.RAW_KEY: ""
+        },
+
+        BODY_DOC: {
+            fields.TYPE_KEY: fields.TYPE_MESSAGE_VAL,
+            fields.CONTENT_HASH_KEY: "",
+
+            fields.BODY_KEY: "",
+
+            # this should not be needed,
+            # but let's keep the raw msg for some time
+            # until we are sure we can reconstruct
+            # the original msg from our disection.
+            fields.RAW_KEY: "",
+
+        }
     }
 
-    EMPTY_FLAGS = {
-        fields.TYPE_KEY: fields.TYPE_FLAGS_VAL,
-        fields.UID_KEY: 1,
-        fields.MBOX_KEY: fields.INBOX_VAL,
-
-        fields.FLAGS_KEY: [],
-        fields.SEEN_KEY: False,
-        fields.RECENT_KEY: True,
-        fields.MULTIPART_KEY: False,
-    }
-
-    # get from SoledadBackedAccount the needed index-related constants
-    INDEXES = SoledadBackedAccount.INDEXES
-    TYPE_IDX = SoledadBackedAccount.TYPE_IDX
-
     def __init__(self, mbox=None, soledad=None):
         """
         Constructor for MessageCollection.
@@ -465,23 +920,16 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
             SoledadDocWriter(soledad),
             period=0.05)
 
-    def _get_empty_msg(self):
+    def _get_empty_doc(self, _type=FLAGS_DOC):
         """
-        Returns an empty message.
-
-        :return: a dict containing a default empty message
+        Returns an empty doc for storing different message parts.
+        Defaults to returning a template for a flags document.
+        :return: a dict with the template
         :rtype: dict
         """
-        return copy.deepcopy(self.EMPTY_MSG)
-
-    def _get_empty_flags_doc(self):
-        """
-        Returns an empty doc for storing flags.
-
-        :return:
-        :rtype:
-        """
-        return copy.deepcopy(self.EMPTY_FLAGS)
+        if not _type in self.templates.keys():
+            raise TypeError("Improper type passed to _get_empty_doc")
+        return copy.deepcopy(self.templates[_type])
 
     @deferred
     def add_msg(self, raw, subject=None, flags=None, date=None, uid=1):
@@ -509,52 +957,107 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
             flags = tuple()
         leap_assert_type(flags, tuple)
 
-        content_doc = self._get_empty_msg()
-        flags_doc = self._get_empty_flags_doc()
-
-        content_doc[self.MBOX_KEY] = self.mbox
-        flags_doc[self.MBOX_KEY] = self.mbox
-        # ...should get a sanity check here.
-        content_doc[self.UID_KEY] = uid
-        flags_doc[self.UID_KEY] = uid
-
-        if flags:
-            flags_doc[self.FLAGS_KEY] = map(self._stringify, flags)
-            flags_doc[self.SEEN_KEY] = self.SEEN_FLAG in flags
+        # docs for flags, headers, and body
+        fd, hd, bd = map(
+            lambda t: self._get_empty_doc(t),
+            (self.FLAGS_DOC, self.HEADERS_DOC, self.BODY_DOC))
 
         msg = self._get_parsed_msg(raw)
         headers = dict(msg)
-
-        logger.debug("adding. is multipart:%s" % msg.is_multipart())
-        flags_doc[self.MULTIPART_KEY] = msg.is_multipart()
-        # XXX get lower case for keys?
-        # XXX get headers doc
-        content_doc[self.HEADERS_KEY] = headers
-        # set subject based on message headers and eventually replace by
-        # subject given as param
-        if self.SUBJECT_FIELD in headers:
-            content_doc[self.SUBJECT_KEY] = headers[self.SUBJECT_FIELD]
-        if subject is not None:
-            content_doc[self.SUBJECT_KEY] = subject
-
-        # XXX could separate body into its own doc
-        # but should also separate multiparts
-        # that should be wrapped in MessagePart
-        content_doc[self.RAW_KEY] = self._stringify(raw)
-        content_doc[self.SIZE_KEY] = len(raw)
-
+        raw_str = msg.as_string()
+        chash = self._get_hash(msg)
+        multi = msg.is_multipart()
+
+        attaches = []
+        inner_parts = []
+
+        if multi:
+            # XXX should walk down recursively
+            # in a better way.  but fixing this quick
+            # to have an rc.
+            # XXX should pick the content-type in txt
+            body = first(msg.get_payload()).get_payload()
+            if isinstance(body, list):
+                # allowing one nesting level for now...
+                body, rest = body[0].get_payload(), body[1:]
+                for p in rest:
+                    inner_parts.append(p)
+        else:
+            body = msg.get_payload()
+        logger.debug("adding msg (multipart:%s)" % multi)
+
+        # flags doc ---------------------------------------
+        fd[self.MBOX_KEY] = self.mbox
+        fd[self.UID_KEY] = uid
+        fd[self.CONTENT_HASH_KEY] = chash
+        fd[self.MULTIPART_KEY] = multi
+        fd[self.SIZE_KEY] = len(raw_str)
+        if flags:
+            fd[self.FLAGS_KEY] = map(self._stringify, flags)
+            fd[self.SEEN_KEY] = self.SEEN_FLAG in flags
+            fd[self.RECENT_KEY] = self.RECENT_FLAG in flags
+
+        # headers doc ----------------------------------------
+        hd[self.CONTENT_HASH_KEY] = chash
+        hd[self.HEADERS_KEY] = headers
+        if not subject and self.SUBJECT_FIELD in headers:
+            hd[self.SUBJECT_KEY] = headers[self.SUBJECT_FIELD]
+        else:
+            hd[self.SUBJECT_KEY] = subject
         if not date and self.DATE_FIELD in headers:
-            content_doc[self.DATE_KEY] = headers[self.DATE_FIELD]
+            hd[self.DATE_KEY] = headers[self.DATE_FIELD]
         else:
-            content_doc[self.DATE_KEY] = date
-
-        logger.debug('enqueuing message for write')
-
+            hd[self.DATE_KEY] = date
+        if multi:
+            hd[self.NUM_PARTS_KEY] = len(msg.get_payload())
+
+        # body doc
+        bd[self.CONTENT_HASH_KEY] = chash
+        bd[self.BODY_KEY] = body
+        # in an ideal world, we would not need to save a copy of the
+        # raw message. But we'll keep it until we can be sure that
+        # we can rebuild the original message from the parts.
+        bd[self.RAW_KEY] = raw_str
+
+        docs = [fd, hd]
+
+        # attachment docs
+        if multi:
+            outer_parts = msg.get_payload()
+            parts = outer_parts + inner_parts
+
+            # skip first part, we already got it in body
+            to_attach = ((i, m) for i, m in enumerate(parts) if i > 0)
+            for index, part_msg in to_attach:
+                att_doc = self._get_empty_doc(self.ATTACHMENT_DOC)
+                att_doc[self.PART_NUMBER_KEY] = index
+                att_doc[self.CONTENT_HASH_KEY] = chash
+                phash = self._get_hash(part_msg)
+                att_doc[self.PAYLOAD_HASH_KEY] = phash
+                att_doc[self.RAW_KEY] = part_msg.as_string()
+
+                # keep a pointer to the payload hash in the
+                # headers doc, under the parts_map
+                hd[self.PARTS_MAP_KEY][str(index)] = phash
+                attaches.append(att_doc)
+
+        # Saving ... -------------------------------
+        # ok, there we go...
+        logger.debug('enqueuing message docs for write')
         ptuple = SoledadWriterPayload
+
+        # first, regular docs: flags and headers
+        for doc in docs:
+            self.soledad_writer.put(ptuple(
+                mode=ptuple.CREATE, payload=doc))
+        # second, try to create body doc.
         self.soledad_writer.put(ptuple(
-            mode=ptuple.CREATE, payload=content_doc))
-        self.soledad_writer.put(ptuple(
-            mode=ptuple.CREATE, payload=flags_doc))
+            mode=ptuple.BODY_CREATE, payload=bd))
+        # and last, but not least, try to create
+        # attachment docs if not already there.
+        for at in attaches:
+            self.soledad_writer.put(ptuple(
+                mode=ptuple.ATTACHMENT_CREATE, payload=at))
 
     def remove(self, msg):
         """
@@ -563,8 +1066,6 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         :param msg: a  Leapmessage instance
         :type msg: LeapMessage
         """
-        # XXX remove
-        #self._soledad.delete_doc(msg)
         msg.remove()
 
     # getters
@@ -596,14 +1097,14 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         :rtype: list of SoledadDocument
         """
         if _type not in fields.__dict__.values():
-            raise TypeError("Wrong type passed to get_all")
+            raise TypeError("Wrong type passed to get_all_docs")
 
         if sameProxiedObjects(self._soledad, None):
             logger.warning('Tried to get messages but soledad is None!')
             return []
 
         all_docs = [doc for doc in self._soledad.get_from_index(
-            SoledadBackedAccount.TYPE_MBOX_IDX,
+            fields.TYPE_MBOX_IDX,
             _type, self.mbox)]
 
         # inneficient, but first let's grok it and then
@@ -618,8 +1119,8 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         """
         all_uids = (doc.content[self.UID_KEY] for doc in
                     self._soledad.get_from_index(
-                        SoledadBackedAccount.TYPE_MBOX_IDX,
-                        self.TYPE_FLAGS_VAL, self.mbox))
+                        fields.TYPE_MBOX_IDX,
+                        fields.TYPE_FLAGS_VAL, self.mbox))
         return (u for u in sorted(all_uids))
 
     def count(self):
@@ -629,7 +1130,7 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         :rtype: int
         """
         count = self._soledad.get_count_from_index(
-            SoledadBackedAccount.TYPE_MBOX_IDX,
+            fields.TYPE_MBOX_IDX,
             fields.TYPE_FLAGS_VAL, self.mbox)
         return count
 
@@ -645,8 +1146,8 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         """
         return (doc.content[self.UID_KEY] for doc in
                 self._soledad.get_from_index(
-                    SoledadBackedAccount.TYPE_MBOX_SEEN_IDX,
-                    self.TYPE_FLAGS_VAL, self.mbox, '0'))
+                    fields.TYPE_MBOX_SEEN_IDX,
+                    fields.TYPE_FLAGS_VAL, self.mbox, '0'))
 
     def count_unseen(self):
         """
@@ -656,8 +1157,8 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         :rtype: int
         """
         count = self._soledad.get_count_from_index(
-            SoledadBackedAccount.TYPE_MBOX_SEEN_IDX,
-            self.TYPE_FLAGS_VAL, self.mbox, '0')
+            fields.TYPE_MBOX_SEEN_IDX,
+            fields.TYPE_FLAGS_VAL, self.mbox, '0')
         return count
 
     def get_unseen(self):
@@ -681,8 +1182,8 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         """
         return (doc.content[self.UID_KEY] for doc in
                 self._soledad.get_from_index(
-                    SoledadBackedAccount.TYPE_MBOX_RECT_IDX,
-                    self.TYPE_FLAGS_VAL, self.mbox, '1'))
+                    fields.TYPE_MBOX_RECT_IDX,
+                    fields.TYPE_FLAGS_VAL, self.mbox, '1'))
 
     def get_recent(self):
         """
@@ -702,8 +1203,8 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         :rtype: int
         """
         count = self._soledad.get_count_from_index(
-            SoledadBackedAccount.TYPE_MBOX_RECT_IDX,
-            self.TYPE_FLAGS_VAL, self.mbox, '1')
+            fields.TYPE_MBOX_RECT_IDX,
+            fields.TYPE_FLAGS_VAL, self.mbox, '1')
         return count
 
     def __len__(self):
@@ -731,5 +1232,5 @@ class MessageCollection(WithMsgFields, IndexedDB, MailParser, MBoxParser):
         return u"<MessageCollection: mbox '%s' (%s)>" % (
             self.mbox, self.count())
 
-    # XXX should implement __eq__ also !!! --- use a hash
-    # of content for that, will be used for dedup.
+    # XXX should implement __eq__ also !!!
+    # --- use the content hash for that, will be used for dedup.
diff --git a/mail/src/leap/mail/imap/parser.py b/mail/src/leap/mail/imap/parser.py
index 1ae19c0..306dcf0 100644
--- a/mail/src/leap/mail/imap/parser.py
+++ b/mail/src/leap/mail/imap/parser.py
@@ -19,10 +19,14 @@ Mail parser mixins.
 """
 import cStringIO
 import StringIO
+import hashlib
 import re
 
+from email.message import Message
 from email.parser import Parser
 
+from leap.common.check import leap_assert_type
+
 
 class MailParser(object):
     """
@@ -34,16 +38,30 @@ class MailParser(object):
         """
         self._parser = Parser()
 
-    def _get_parsed_msg(self, raw):
+    def _get_parsed_msg(self, raw, headersonly=False):
         """
         Return a parsed Message.
 
         :param raw: the raw string to parse
         :type raw: basestring, or StringIO object
+
+        :param headersonly: True for parsing only the headers.
+        :type headersonly: bool
         """
-        msg = self._get_parser_fun(raw)(raw, True)
+        msg = self._get_parser_fun(raw)(raw, headersonly=headersonly)
         return msg
 
+    def _get_hash(self, msg):
+        """
+        Returns a hash of the string representation of the raw message,
+        suitable for indexing the inmutable pieces.
+
+        :param msg: a Message object
+        :type msg: Message
+        """
+        leap_assert_type(msg, Message)
+        return hashlib.sha256(msg.as_string()).hexdigest()
+
     def _get_parser_fun(self, o):
         """
         Retunn the proper parser function for an object.
@@ -67,6 +85,8 @@ class MailParser(object):
         :param o: object
         :type o: object
         """
+        # XXX Maybe we don't need no more, we're using
+        # msg.as_string()
         if isinstance(o, (cStringIO.OutputType, StringIO.StringIO)):
             return o.getvalue()
         else: