"""workflow related schemas

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

_ = unicode

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

                            ObjectRelation, RichString, String)

from cubicweb.schema import RQLConstraint

class State(EntityType):

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

    workflows

    """

    permissions = META_ETYPE_PERMS

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

                  maxsize=256)

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

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

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

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

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

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

                                         constraints=[RQLConstraint('S state_of ET, O transition_of ET')],

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

    initial_state = ObjectRelation('CWEType', cardinality='?*',

                                   # S initial_state O, O state_of S

                                   constraints=[RQLConstraint('O state_of S')],

                                   description=_('initial state for entities of this type'))

class Transition(EntityType):

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

    states in workflow's definitions.

    """

    permissions = META_ETYPE_PERMS

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

                  maxsize=256)

    description = RichString(fulltextindexed=True,

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

    condition = SubjectRelation('RQLExpression', cardinality='*?', composite='subject',

                                description=_('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'))

    require_group = SubjectRelation('CWGroup', cardinality='**',

                                    description=_('group in which a user should be to be '

                                                  'allowed to pass this transition'))

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

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

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

    destination_state = SubjectRelation('State', cardinality='1*',

                                        constraints=[RQLConstraint('S transition_of ET, O state_of ET')],

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

class TrInfo(EntityType):

    permissions = META_ETYPE_PERMS

    from_state = SubjectRelation('State', cardinality='?*')

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

    comment = RichString(fulltextindexed=True)

    # get actor and date time using owned_by and creation_date

class from_state(RelationType):

    inlined = True

class to_state(RelationType):

    inlined = True

class wf_info_for(RelationType):

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

    permissions = {

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

        'add':    (), # handled automatically, no one should add one explicitly

        'delete': ('managers',), # RRQLExpression('U has_delete_permission O')

        }

    inlined = True

    composite = 'object'

    fulltext_container = composite

class state_of(RelationType):

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

    permissions = META_RTYPE_PERMS

class transition_of(RelationType):

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

    permissions = META_RTYPE_PERMS

class initial_state(RelationType):

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

    states is created

    """

    permissions = META_RTYPE_PERMS

    inlined = True

class destination_state(RelationType):

    """destination state of a transition"""

    permissions = META_RTYPE_PERMS

    inlined = True

class allowed_transition(RelationType):

    """allowed transition from this state"""

    permissions = META_RTYPE_PERMS

class in_state(RelationType):

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

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

    # has to be stored outside the CWUser table

    # add/delete perms given to managers/users, after what most of the job

    # is done by workflow enforcment

    permissions = {

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

        'add':    ('managers', 'users',), # XXX has_update_perm

        'delete': ('managers', 'users',),

        }