8 files changed, 98 insertions, 45 deletions

diff --git a/src/mailman/app/subscriptions.py b/src/mailman/app/subscriptions.py
index 0d8176ffb..dace9ccb6 100644
--- a/src/mailman/app/subscriptions.py
+++ b/src/mailman/app/subscriptions.py
@@ -24,7 +24,6 @@ from datetime import timedelta
 from email.utils import formataddr
 from enum import Enum
 from mailman.app.membership import delete_member
-from mailman.app.workflow import Workflow
 from mailman.core.i18n import _
 from mailman.database.transaction import flush
 from mailman.email.message import UserNotification
@@ -43,9 +42,10 @@ from mailman.interfaces.subscriptions import (
 from mailman.interfaces.template import ITemplateLoader
 from mailman.interfaces.user import IUser
 from mailman.interfaces.usermanager import IUserManager
-from mailman.interfaces.workflow import IWorkflowStateManager
+from mailman.interfaces.workflows import IWorkflowStateManager
 from mailman.utilities.datetime import now
 from mailman.utilities.string import expand, wrap
+from mailman.workflows.base import Workflow
 from public import public
 from zope.component import getUtility
 from zope.event import notify
diff --git a/src/mailman/app/tests/test_workflow.py b/src/mailman/app/tests/test_workflow.py
index e82001540..f242a73ec 100644
--- a/src/mailman/app/tests/test_workflow.py
+++ b/src/mailman/app/tests/test_workflow.py
@@ -20,15 +20,15 @@
 import json
 import unittest
 
-from mailman.app.workflow import Workflow
-from mailman.interfaces.workflow import IWorkflowStateManager
+from mailman.interfaces.workflows import IWorkflowStateManager
 from mailman.testing.layers import ConfigLayer
+from mailman.workflows.base import Workflow
 from zope.component import getUtility
 
 
 class MyWorkflow(Workflow):
-    INITIAL_STATE = 'first'
-    SAVE_ATTRIBUTES = ('ant', 'bee', 'cat')
+    initial_state = 'first'
+    save_attributes = ('ant', 'bee', 'cat')
 
     def __init__(self):
         super().__init__()
@@ -51,7 +51,7 @@ class MyWorkflow(Workflow):
 
 
 class DependentWorkflow(MyWorkflow):
-    SAVE_ATTRIBUTES = ('ant', 'bee', 'cat', 'elf')
+    save_attributes = ('ant', 'bee', 'cat', 'elf')
 
     def __init__(self):
         super().__init__()
@@ -136,7 +136,7 @@ class TestWorkflow(unittest.TestCase):
 
     def test_save_and_restore_dependant_attributes(self):
         # Attributes must be restored in the order they are declared in
-        # SAVE_ATTRIBUTES.
+        # save_attributes.
         workflow = iter(DependentWorkflow())
         workflow.elf = 6
         workflow.save()
diff --git a/src/mailman/config/configure.zcml b/src/mailman/config/configure.zcml
index 2fd0c8788..da4eb36b6 100644
--- a/src/mailman/config/configure.zcml
+++ b/src/mailman/config/configure.zcml
@@ -135,8 +135,8 @@
    />
 
   <utility
-    provides="mailman.interfaces.workflow.IWorkflowStateManager"
-    factory="mailman.model.workflow.WorkflowStateManager"
+    provides="mailman.interfaces.workflows.IWorkflowStateManager"
+    factory="mailman.model.workflows.WorkflowStateManager"
     />
 
 </configure>
diff --git a/src/mailman/interfaces/workflow.py b/src/mailman/interfaces/workflows.py
index 5b3582b58..b110a481e 100644
--- a/src/mailman/interfaces/workflow.py
+++ b/src/mailman/interfaces/workflows.py
@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License along with
 # GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
 
-"""Interfaces describing the state of a workflow."""
+"""Interfaces describing the a workflow, it's state and it's state manager."""
 
 from public import public
 from zope.interface import Attribute, Interface
@@ -65,3 +65,64 @@ class IWorkflowStateManager(Interface):
         """
 
     count = Attribute('The number of saved workflows in the database.')
+
+
+@public
+class IWorkflow(Interface):
+    """A workflow."""
+
+    name = Attribute('The name of the workflow, must be unique.')
+    description = Attribute('A brief description of the workflow.')
+    initial_state = Attribute('The state in which the workflow starts.')
+    save_attributes = Attribute('The sequence of attributes of the workflow, '
+                                'which are saved.')
+
+    def __iter__():
+        """Return an iterator over the steps."""
+
+    def __next__():
+        """Run the next step from the queue.
+
+        :return: The result of the step run.
+        """
+
+    def push(step):
+        """Push a step to this workflows queue."""
+
+    def run_thru(stop_after):
+        """Run the state machine through and including the given step.
+
+        :param stop_after: Name of method, sans prefix to run the
+            state machine through.  In other words, the state machine runs
+            until the named method completes.
+        """
+
+    def run_until(stop_before):
+        """Run the state machine until (not including) the given step.
+
+        :param stop_before: Name of method, sans prefix that the
+            state machine is run until the method is reached.  Unlike
+            `run_thru()` the named method is not run.
+        """
+
+    def save():
+        """Save the workflow in it's current state.
+
+        Needs to have the `token` attribute set.
+        """
+
+    def restore():
+        """Restore the workflow from the database.
+
+        Needs to have the `token` attribute set.
+        """
+
+
+@public
+class ISubscriptionWorkflow(IWorkflow):
+    """A workflow used for subscription."""
+
+
+@public
+class IUnsubscriptionWorkflow(IWorkflow):
+    """A workflow used for unsubscription."""
diff --git a/src/mailman/model/tests/test_workflow.py b/src/mailman/model/tests/test_workflow.py
index 9cc5446b7..41c00efc0 100644
--- a/src/mailman/model/tests/test_workflow.py
+++ b/src/mailman/model/tests/test_workflow.py
@@ -19,7 +19,7 @@
 
 import unittest
 
-from mailman.interfaces.workflow import IWorkflowStateManager
+from mailman.interfaces.workflows import IWorkflowStateManager
 from mailman.testing.layers import ConfigLayer
 from zope.component import getUtility
 
diff --git a/src/mailman/model/workflow.py b/src/mailman/model/workflows.py
index 3ca3412a6..587d3375e 100644
--- a/src/mailman/model/workflow.py
+++ b/src/mailman/model/workflows.py
@@ -20,7 +20,7 @@
 from mailman.database.model import Model
 from mailman.database.transaction import dbconnection
 from mailman.database.types import SAUnicode
-from mailman.interfaces.workflow import IWorkflowState, IWorkflowStateManager
+from mailman.interfaces.workflows import IWorkflowState, IWorkflowStateManager
 from public import public
 from sqlalchemy import Column
 from zope.interface import implementer
diff --git a/src/mailman/workflows/__init__.py b/src/mailman/workflows/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/mailman/workflows/__init__.py
diff --git a/src/mailman/app/workflow.py b/src/mailman/workflows/base.py
index 92b78c184..5988dfa43 100644
--- a/src/mailman/app/workflow.py
+++ b/src/mailman/workflows/base.py
@@ -22,7 +22,8 @@ import json
 import logging
 
 from collections import deque
-from mailman.interfaces.workflow import IWorkflowStateManager
+
+from mailman.interfaces.workflows import IWorkflowStateManager
 from public import public
 from zope.component import getUtility
 
@@ -35,24 +36,33 @@ log = logging.getLogger('mailman.error')
 class Workflow:
     """Generic workflow."""
 
-    SAVE_ATTRIBUTES = ()
-    INITIAL_STATE = None
+    initial_state = None
+    save_attributes = ()
 
     def __init__(self):
         self.token = None
         self._next = deque()
-        self.push(self.INITIAL_STATE)
+        self.push(self.initial_state)
         self.debug = False
         self._count = 0
 
-    @property
-    def name(self):
-        return self.__class__.__name__
-
     def __iter__(self):
+        """See `IWorkflow`."""
         return self
 
+    def __next__(self):
+        """See `IWorkflow`."""
+        try:
+            name, step = self._pop()
+            return step()
+        except IndexError:
+            raise StopIteration
+        except:
+            log.exception('deque: {}'.format(COMMASPACE.join(self._next)))
+            raise
+
     def push(self, step):
+        """See `IWorkflow`."""
         self._next.append(step)
 
     def _pop(self):
@@ -63,23 +73,8 @@ class Workflow:
             print('[{:02d}] -> {}'.format(self._count, name), file=sys.stderr)
         return name, step
 
-    def __next__(self):
-        try:
-            name, step = self._pop()
-            return step()
-        except IndexError:
-            raise StopIteration
-        except:
-            log.exception('deque: {}'.format(COMMASPACE.join(self._next)))
-            raise
-
     def run_thru(self, stop_after):
-        """Run the state machine through and including the given step.
-
-        :param stop_after: Name of method, sans prefix to run the
-            state machine through.  In other words, the state machine runs
-            until the named method completes.
-        """
+        """See `IWorkflow`."""
         results = []
         while True:
             try:
@@ -93,12 +88,7 @@ class Workflow:
         return results
 
     def run_until(self, stop_before):
-        """Trun the state machine until (not including) the given step.
-
-        :param stop_before: Name of method, sans prefix that the
-            state machine is run until the method is reached.  Unlike
-            `run_thru()` the named method is not run.
-        """
+        """See `IWorkflow`."""
         results = []
         while True:
             try:
@@ -116,9 +106,10 @@ class Workflow:
         return results
 
     def save(self):
+        """See `IWorkflow`."""
         assert self.token, 'Workflow token must be set'
         state_manager = getUtility(IWorkflowStateManager)
-        data = {attr: getattr(self, attr) for attr in self.SAVE_ATTRIBUTES}
+        data = {attr: getattr(self, attr) for attr in self.save_attributes}
         # Note: only the next step is saved, not the whole stack.  This is not
         # an issue in practice, since there's never more than a single step in
         # the queue anyway.  If we want to support more than a single step in
@@ -135,6 +126,7 @@ class Workflow:
         state_manager.save(self.token, step, json.dumps(data))
 
     def restore(self):
+        """See `IWorkflow`."""
         state_manager = getUtility(IWorkflowStateManager)
         state = state_manager.restore(self.token)
         if state is None:
@@ -144,7 +136,7 @@ class Workflow:
         if state.step:
             self._next.append(state.step)
         data = json.loads(state.data)
-        for attr in self.SAVE_ATTRIBUTES:
+        for attr in self.save_attributes:
             try:
                 setattr(self, attr, data[attr])
             except KeyError: