# copyright 2003-2011 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/>.

"""workflow related schemas

"""

from cubicweb import _

from yams.buildobjs import (EntityType, RelationType, RelationDefinition,

                            SubjectRelation,

                            RichString, String, Int)

from cubicweb.schema import RQLConstraint

from cubicweb.schemas import (PUB_SYSTEM_ENTITY_PERMS, PUB_SYSTEM_REL_PERMS,

                              RO_REL_PERMS)

class Workflow(EntityType):

    __permissions__ = PUB_SYSTEM_ENTITY_PERMS

    name = String(required=True, indexed=True, internationalizable=True,

                  maxsize=256)

    description = RichString(default_format='text/rest',

                             description=_('semantic description of this workflow'))

    workflow_of = SubjectRelation('CWEType', cardinality='+*',

                                  description=_('entity types which may use this workflow'),

                                  constraints=[RQLConstraint('O final FALSE')])

    initial_state = SubjectRelation('State', cardinality='?*',

                                   constraints=[RQLConstraint('O state_of S',

                                                              msg=_('state doesn\'t belong to this workflow'))],

                                   description=_('initial state for this workflow'))

class default_workflow(RelationType):

    """default workflow for an entity type"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    subject = 'CWEType'

    object = 'Workflow'

    cardinality = '?*'

    constraints = [RQLConstraint('S final FALSE, O workflow_of S',

                                 msg=_('workflow isn\'t a workflow for this type'))]

class State(EntityType):

    """used to associate simple states to an entity type and/or to define

    workflows

    """

    __permissions__ = PUB_SYSTEM_ENTITY_PERMS

    __unique_together__ = [('name', 'state_of')]

    name = String(required=True, indexed=True, internationalizable=True, maxsize=256)

    description = RichString(default_format='text/rest',

                             description=_('semantic description of this state'))

    # XXX should be on BaseTransition w/ AND/OR selectors when we will

    # implements #345274

    allowed_transition = SubjectRelation('BaseTransition', cardinality='**',

                                         constraints=[RQLConstraint('S state_of WF, O transition_of WF',

                                                                    msg=_('state and transition don\'t belong the the same workflow'))],

                                         description=_('allowed transitions from this state'))

    state_of = SubjectRelation('Workflow', cardinality='1*', composite='object', inlined=True,

                               description=_('workflow to which this state belongs'))

class BaseTransition(EntityType):

    """abstract base class for transitions"""

    __permissions__ = PUB_SYSTEM_ENTITY_PERMS

    __unique_together__ = [('name', 'transition_of')]

    name = String(required=True, indexed=True, internationalizable=True, maxsize=256)

    type = String(vocabulary=(_('normal'), _('auto')), default='normal')

    description = RichString(description=_('semantic description of this transition'))

    transition_of = SubjectRelation('Workflow', cardinality='1*', composite='object', inlined=True,

                                    description=_('workflow to which this transition belongs'))

class require_group(RelationDefinition):

    """group in which a user should be to be allowed to pass this transition"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    subject = 'BaseTransition'

    object = 'CWGroup'

class condition(RelationDefinition):

    """a RQL expression which should return some results, else the transition

    won't be available.

    This query may use X and U variables that will respectivly represents the

    current entity and the current user.

    """

    __permissions__ = PUB_SYSTEM_REL_PERMS

    subject = 'BaseTransition'

    object = 'RQLExpression'

    cardinality = '*?'

    composite = 'subject'

class Transition(BaseTransition):

    """use to define a transition from one or multiple states to a destination

    states in workflow's definitions. Transition without destination state will

    go back to the state from which we arrived to the current state.

    """

    __specializes_schema__ = True

    destination_state = SubjectRelation(

        'State', cardinality='?*',

        constraints=[RQLConstraint('S transition_of WF, O state_of WF',

                                   msg=_('state and transition don\'t belong the the same workflow'))],

        description=_('destination state for this transition'))

class WorkflowTransition(BaseTransition):

    """special transition allowing to go through a sub-workflow"""

    __specializes_schema__ = True

    subworkflow = SubjectRelation('Workflow', cardinality='1*',

                                  constraints=[RQLConstraint('S transition_of WF, WF workflow_of ET, O workflow_of ET',

                                                             msg=_('subworkflow isn\'t a workflow for the same types as the transition\'s workflow'))]

                                  )

    # XXX use exit_of and inline it

    subworkflow_exit = SubjectRelation('SubWorkflowExitPoint', cardinality='*1',

                                       composite='subject')

class SubWorkflowExitPoint(EntityType):

    """define how we get out from a sub-workflow"""

    subworkflow_state = SubjectRelation(

        'State', cardinality='1*',

        constraints=[RQLConstraint('T subworkflow_exit S, T subworkflow WF, O state_of WF',

                                   msg=_('exit state must be a subworkflow state'))],

        description=_('subworkflow state'))

    destination_state = SubjectRelation(

        'State', cardinality='?*',

        constraints=[RQLConstraint('T subworkflow_exit S, T transition_of WF, O state_of WF',

                                   msg=_('destination state must be in the same workflow as our parent transition'))],

        description=_('destination state. No destination state means that transition '

                      'should go back to the state from which we\'ve entered the '

                      'subworkflow.'))

class TrInfo(EntityType):

    """workflow history item"""

    # 'add' security actually done by hooks

    __permissions__ = {

        'read':   ('managers', 'users', 'guests',), # XXX U has_read_permission O ?

        'add':    ('managers', 'users', 'guests',),

        'delete': (), # XXX should we allow managers to delete TrInfo?

        'update': ('managers', 'owners',),

    }

    # The unique_together constraint ensures that 2 repositories

    # sharing the db won't be able to fire a transition simultaneously

    # on the same entity tr_count is filled in the FireTransitionHook

    # to the number of TrInfo attached to the entity on which we

    # attempt to fire a transition. In other word, it contains the

    # rank of the TrInfo for that entity, and the constraint says we

    # cannot have 2 TrInfo with the same rank.

    __unique_together__ = [('tr_count', 'wf_info_for')]

    from_state = SubjectRelation('State', cardinality='1*', inlined=True)

    to_state = SubjectRelation('State', cardinality='1*', inlined=True)

    # make by_transition optional because we want to allow managers to set

    # entity into an arbitrary state without having to respect wf transition

    by_transition = SubjectRelation('BaseTransition', cardinality='?*')

    comment = RichString(fulltextindexed=True, default_format='text/plain')

    tr_count = Int(description='autocomputed attribute used to ensure transition coherency')

    # get actor and date time using owned_by and creation_date

class from_state(RelationType):

    __permissions__ = RO_REL_PERMS.copy()

    inlined = True

class to_state(RelationType):

    __permissions__ = RO_REL_PERMS.copy()

    inlined = True

class by_transition(RelationType):

    # 'add' security actually done by hooks

    __permissions__ = {

        'read':   ('managers', 'users', 'guests',),

        'add':    ('managers', 'users', 'guests',),

        'delete': (),

    }

    inlined = True

class workflow_of(RelationType):

    """link a workflow to one or more entity type"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

class state_of(RelationType):

    """link a state to one or more workflow"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

class transition_of(RelationType):

    """link a transition to one or more workflow"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

class destination_state(RelationType):

    """destination state of a transition"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

class allowed_transition(RelationType):

    """allowed transitions from this state"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

class initial_state(RelationType):

    """indicate which state should be used by default when an entity using

    states is created

    """

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

class subworkflow(RelationType):

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

class exit_point(RelationType):

    __permissions__ = PUB_SYSTEM_REL_PERMS

class subworkflow_state(RelationType):

    __permissions__ = PUB_SYSTEM_REL_PERMS

    inlined = True

# "abstract" relations, set by WorkflowableEntityType ##########################

class custom_workflow(RelationType):

    """allow to set a specific workflow for an entity"""

    __permissions__ = PUB_SYSTEM_REL_PERMS

    cardinality = '?*'

    constraints = [RQLConstraint('S is ET, O workflow_of ET',

                                 msg=_('workflow isn\'t a workflow for this type'))]

    object = 'Workflow'

class wf_info_for(RelationType):

    """link a transition information to its object"""

    # 'add' security actually done by hooks

    __permissions__ = {

        'read':   ('managers', 'users', 'guests',),

        'add':    ('managers', 'users', 'guests',),

        'delete': (),

    }

    inlined = True

    cardinality = '1*'

    composite = 'object'

    fulltext_container = composite

    subject = 'TrInfo'

class in_state(RelationType):

    """indicate the current state of an entity"""

    __permissions__ = RO_REL_PERMS

    # not inlined intentionnally since when using ldap sources, user'state

    # has to be stored outside the CWUser table

    inlined = False

    cardinality = '1*'

    constraints = [RQLConstraint('S is ET, O state_of WF, WF workflow_of ET',

                                 msg=_('state doesn\'t apply to this entity\'s type'))]

    object = 'State'