# copyright 2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb 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 Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

__docformat__ = "restructuredtext en"

_ = unicode

from logilab.common.registry import Predicate

from cubicweb import UnknownEid, tags, transaction as tx

from cubicweb.view import View, StartupView

from cubicweb.predicates import match_kwargs, ExpectedValuePredicate

from cubicweb.schema import display_name

class undoable_action(Predicate):

    """Select only undoable actions depending on filters provided. Undo Action

    is expected to be specified by the `tx_action` argument.

    Currently the only implemented filter is:

    :param action_type: chars among CUDAR (standing for Create, Update, Delete,

                        Add, Remove)

    """

    # XXX FIXME : this selector should be completed to allow selection on the

    # entity or relation types and public / private.

    def __init__(self, action_type='CUDAR'):

        assert not set(action_type) - set('CUDAR')

        self.action_type = action_type

    def __str__(self):

        return '%s(%s)' % (self.__class__.__name__, ', '.join(

            "%s=%v" % (str(k), str(v)) for k, v in kwargs.iteritems() ))

    def __call__(self, cls, req, tx_action=None, **kwargs):

        # tx_action is expected to be a transaction.AbstractAction

        if not isinstance(tx_action, tx.AbstractAction):

            return 0

        # Filter according to action type

        return int(tx_action.action in self.action_type)

class UndoHistoryView(StartupView):

    __regid__ = 'undohistory'

    title = _('Undoing')

    item_vid = 'undoable-transaction-view'

    cache_max_age = 0

    redirect_path = 'view' #TODO

    redirect_params = dict(vid='undohistory') #TODO

    public_actions_only = True

    # TODO Allow to choose if if want all actions or only the public ones

    # (default)

    def call(self, **kwargs):

        txs = self._cw.cnx.undoable_transactions()

        if txs :

            self.w(u"<ul class='undo-transactions'>")

            for tx in txs:

                self.cell_call(tx)

            self.w(u"</ul>")

    def cell_call(self, tx):

        self.w(u'<li>')

        self.wview(self.item_vid, None, txuuid=tx.uuid,

                   public=self.public_actions_only,

                   redirect_path=self.redirect_path,

                   redirect_params=self.redirect_params)

        self.w(u'</li>\n')

class UndoableTransactionView(View):

    __regid__ = 'undoable-transaction-view'

    __select__ = View.__select__ & match_kwargs('txuuid')

    item_vid = 'undoable-action-list-view'

    cache_max_age = 0

    def build_undo_link(self, txuuid,

                        redirect_path=None, redirect_params=None):

        """ the kwargs are passed to build_url"""

        _ = self._cw._

        redirect = {}

        if redirect_path:

            redirect['__redirectpath'] = redirect_path

        if redirect_params:

            if isinstance(redirect_params, dict):

                redirect['__redirectparams'] = self._cw.build_url_params(**redirect_params)

            else:

                redirect['__redirectparams'] = redirect_params

        link_url = self._cw.build_url('undo', txuuid=txuuid, **redirect)

        msg = u"<span class='undo'>%s</span>" % tags.a( _('undo'), href=link_url)

        return msg

    def call(self, txuuid, public=True,

             redirect_path=None, redirect_params=None):

        _ = self._cw._

        txinfo = self._cw.cnx.transaction_info(txuuid)

        try:

            #XXX Under some unknown circumstances txinfo.user_eid=-1

            user = self._cw.entity_from_eid(txinfo.user_eid)

        except UnknownEid:

            user = None

        undo_url = self.build_undo_link(txuuid,

                                        redirect_path=redirect_path,

                                        redirect_params=redirect_params)

        txinfo_dict = dict( dt = self._cw.format_date(txinfo.datetime, time=True),

                            user_eid = txinfo.user_eid,

                            user = user and user.view('outofcontext') or _("undefined user"),

                            txuuid = txuuid,

                            undo_link = undo_url)

        self.w( _("By %(user)s on %(dt)s [%(undo_link)s]") % txinfo_dict)

        tx_actions = txinfo.actions_list(public=public)

        if tx_actions :

            self.wview(self.item_vid, None, tx_actions=tx_actions)

class UndoableActionListView(View):

    __regid__ = 'undoable-action-list-view'

    __select__ = View.__select__ & match_kwargs('tx_actions')

    title = _('Undoable actions')

    item_vid = 'undoable-action-view'

    cache_max_age = 0

    def call(self, tx_actions):

        if tx_actions :

            self.w(u"<ol class='undo-actions'>")

            for action in tx_actions:

                self.cell_call(action)

            self.w(u"</ol>")

    def cell_call(self, action):

        self.w(u'<li>')

        self.wview(self.item_vid, None, tx_action=action)

        self.w(u'</li>\n')

class UndoableActionBaseView(View):

    __regid__ = 'undoable-action-view'

    __abstract__ = True

    def call(self, tx_action):

        raise NotImplementedError(self)

    def _build_entity_link(self, eid):

        try:

            entity = self._cw.entity_from_eid(eid)

            return entity.view('outofcontext')

        except UnknownEid:

            return _("(suppressed) entity #%d") % eid

    def _build_relation_info(self, rtype, eid_from,  eid_to):

        return dict( rtype=display_name(self._cw, rtype),

                     entity_from=self._build_entity_link(eid_from),

                     entity_to=self._build_entity_link(eid_to) )

    def _build_entity_info(self, etype, eid, changes):

        return dict( etype=display_name(self._cw, etype),

                     entity=self._build_entity_link(eid),

                     eid=eid,

                     changes=changes)

class UndoableAddActionView(UndoableActionBaseView):

    __select__ = UndoableActionBaseView.__select__ & undoable_action(action_type='A')

    def call(self, tx_action):

        _ = self._cw._

        self.w(_("Added relation : %(entity_from)s %(rtype)s %(entity_to)s") %

               self._build_relation_info(tx_action.rtype, tx_action.eid_from, tx_action.eid_to))

class UndoableRemoveActionView(UndoableActionBaseView):

    __select__ = UndoableActionBaseView.__select__ & undoable_action(action_type='R')

    def call(self, tx_action):

        _ = self._cw._

        self.w(_("Delete relation : %(entity_from)s %(rtype)s %(entity_to)s") %

               self._build_relation_info(tx_action.rtype, tx_action.eid_from, tx_action.eid_to))

class UndoableCreateActionView(UndoableActionBaseView):

    __select__ = UndoableActionBaseView.__select__ & undoable_action(action_type='C')

    def call(self, tx_action):

        _ = self._cw._

        self.w(_("Created %(etype)s : %(entity)s") % #  : %(changes)s

               self._build_entity_info( tx_action.etype, tx_action.eid, tx_action.changes) )

class UndoableDeleteActionView(UndoableActionBaseView):

    __select__ = UndoableActionBaseView.__select__ & undoable_action(action_type='D')

    def call(self, tx_action):

        _ = self._cw._

        self.w(_("Deleted %(etype)s : %(entity)s") %

               self._build_entity_info( tx_action.etype, tx_action.eid, tx_action.changes))

class UndoableUpdateActionView(UndoableActionBaseView):

    __select__ = UndoableActionBaseView.__select__ & undoable_action(action_type='U')

    def call(self, tx_action):

        _ = self._cw._

        self.w(_("Updated %(etype)s : %(entity)s") %

               self._build_entity_info( tx_action.etype, tx_action.eid, tx_action.changes))