# Copyright (C) 2015-2016 by the Free Software Foundation, Inc.
#
# This file is part of GNU Mailman.
#
# GNU Mailman is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# GNU Mailman 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 General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.

"""Model for workflow states."""

from mailman import public
from mailman.database.model import Model
from mailman.database.transaction import dbconnection
from mailman.interfaces.workflow import IWorkflowState, IWorkflowStateManager
from sqlalchemy import Column, Unicode
from zope.interface import implementer


@public
@implementer(IWorkflowState)
class WorkflowState(Model):
    """Workflow states."""

    __tablename__ = 'workflowstate'

    name = Column(Unicode, primary_key=True)
    token = Column(Unicode, primary_key=True)
    step = Column(Unicode)
    data = Column(Unicode)


@public
@implementer(IWorkflowStateManager)
class WorkflowStateManager:
    """See `IWorkflowStateManager`."""

    @dbconnection
    def save(self, store, name, token, step=None, data=None):
        """See `IWorkflowStateManager`."""
        state = WorkflowState(name=name, token=token, step=step, data=data)
        store.add(state)

    @dbconnection
    def restore(self, store, name, token):
        """See `IWorkflowStateManager`."""
        state = store.query(WorkflowState).get((name, token))
        if state is not None:
            store.delete(state)
        return state

    @dbconnection
    def discard(self, store, name, token):
        """See `IWorkflowStateManager`."""
        state = store.query(WorkflowState).get((name, token))
        if state is not None:
            store.delete(state)

    @property
    @dbconnection
    def count(self, store):
        """See `IWorkflowStateManager`."""
        return store.query(WorkflowState).count()