"""mixins of entity/views organized somewhat in a graph or tree structure

:organization: Logilab

:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from logilab.common.decorators import cached

from cubicweb.selectors import implements

from cubicweb.interfaces import IWorkflowable, IEmailable, ITree

class TreeMixIn(object):

    """base tree-mixin providing the tree interface

    This mixin has to be inherited explicitly and configured using the

    tree_attribute, parent_target and children_target class attribute to

    benefit from this default implementation

    """

    tree_attribute = None

    # XXX misnamed

    parent_target = 'subject'

    children_target = 'object'

    def different_type_children(self, entities=True):

        """return children entities of different type as this entity.

        according to the `entities` parameter, return entity objects or the

        equivalent result set

        """

        res = self.related(self.tree_attribute, self.children_target,

                           entities=entities)

        if entities:

            return [e for e in res if e.e_schema != self.e_schema]

        return res.filtered_rset(lambda x: x.e_schema != self.e_schema, self.col)

    def same_type_children(self, entities=True):

        """return children entities of the same type as this entity.

        according to the `entities` parameter, return entity objects or the

        equivalent result set

        """

        res = self.related(self.tree_attribute, self.children_target,

                           entities=entities)

        if entities:

            return [e for e in res if e.e_schema == self.e_schema]

        return res.filtered_rset(lambda x: x.e_schema == self.e_schema, self.col)

    def iterchildren(self, _done=None):

        if _done is None:

            _done = set()

        for child in self.children():

            if child.eid in _done:

                self.error('loop in %s tree', self.id.lower())

                continue

            yield child

            _done.add(child.eid)

    def prefixiter(self, _done=None):

        if _done is None:

            _done = set()

        if self.eid in _done:

            return

        yield self

        _done.add(self.eid)

        for child in self.iterchildren(_done):

            try:

                for entity in child.prefixiter(_done):

                    yield entity

            except AttributeError:

                pass

    @cached

    def path(self):

        """returns the list of eids from the root object to this object"""

        path = []

        parent = self

        while parent:

            if parent.eid in path:

                self.error('loop in %s tree', self.id.lower())

                break

            path.append(parent.eid)

            try:

                # check we are not leaving the tree

                if (parent.tree_attribute != self.tree_attribute or

                    parent.parent_target != self.parent_target):

                    break

                parent = parent.parent()

            except AttributeError:

                break

        path.reverse()

        return path

    def iterparents(self):

        def _uptoroot(self):

            curr = self

            while True:

                curr = curr.parent()

                if curr is None:

                    break

                yield curr

        return _uptoroot(self)

    def notification_references(self, view):

        """used to control References field of email send on notification

        for this entity. `view` is the notification view.

        Should return a list of eids which can be used to generate message ids

        of previously sent email

        """

        return self.path()[:-1]

    ## ITree interface ########################################################

    def parent(self):

        """return the parent entity if any, else None (e.g. if we are on the

        root

        """

        try:

            return self.related(self.tree_attribute, self.parent_target,

                                entities=True)[0]

        except (KeyError, IndexError):

            return None

    def children(self, entities=True, sametype=False):

        """return children entities

        according to the `entities` parameter, return entity objects or the

        equivalent result set

        """

        if sametype:

            return self.same_type_children(entities)

        else:

            return self.related(self.tree_attribute, self.children_target,

                                entities=entities)

    def children_rql(self):

        return self.related_rql(self.tree_attribute, self.children_target)

    def __iter__(self):

        return self.iterchildren()

    def is_leaf(self):

        return len(self.children()) == 0

    def is_root(self):

        return self.parent() is None

    def root(self):

        """return the root object"""

        return self.req.eid_rset(self.path()[0]).get_entity(0, 0)

class WorkflowableMixIn(object):

    """base mixin providing workflow helper methods for workflowable entities.

    This mixin will be automatically set on class supporting the 'in_state'

    relation (which implies supporting 'wf_info_for' as well)

    """

    __implements__ = (IWorkflowable,)

    @property

    def state(self):

        try:

            return self.in_state[0].name

        except IndexError:

            self.warning('entity %s has no state', self)

            return None

    @property

    def displayable_state(self):

        return self.req._(self.state)

    def wf_state(self, statename):

        rset = self.req.execute('Any S, SN WHERE S name %(n)s, S state_of E, E name %(e)s',

                                {'n': statename, 'e': str(self.e_schema)})

        if rset:

            return rset.get_entity(0, 0)

        return None

    def wf_transition(self, trname):

        rset = self.req.execute('Any T, TN WHERE T name %(n)s, T transition_of E, E name %(e)s',

                                {'n': trname, 'e': str(self.e_schema)})

        if rset:

            return rset.get_entity(0, 0)

        return None

    def change_state(self, stateeid, trcomment=None, trcommentformat=None):

        """change the entity's state according to a state defined in given

        parameters

        """

        if trcomment:

            self.req.set_shared_data('trcomment', trcomment)

        if trcommentformat:

            self.req.set_shared_data('trcommentformat', trcommentformat)

        self.req.execute('SET X in_state S WHERE X eid %(x)s, S eid %(s)s',

                         {'x': self.eid, 's': stateeid}, 'x')

    def can_pass_transition(self, trname):

        """return the Transition instance if the current user can pass the

        transition with the given name, else None

        """

        stateeid = self.in_state[0].eid

        rset = self.req.execute('Any T,N,DS WHERE S allowed_transition T,'

                                'S eid %(x)s,T name %(trname)s,ET name %(et)s,'

                                'T name N,T destination_state DS,T transition_of ET',

                                {'x': stateeid, 'et': str(self.e_schema),

                                 'trname': trname}, 'x')

        for tr in rset.entities():

            if tr.may_be_passed(self.eid, stateeid):

                return tr

    def latest_trinfo(self):

        """return the latest transition information for this entity"""

        return self.reverse_wf_info_for[-1]

    # specific vocabulary methods #############################################

    def subject_in_state_vocabulary(self, rschema, limit=None):

        """vocabulary method for the in_state relation, looking for

        relation's object entities (i.e. self is the subject) according

        to initial_state, state_of and next_state relation

        """

        if not self.has_eid() or not self.in_state:

            # get the initial state

            rql = 'Any S where S state_of ET, ET name %(etype)s, ET initial_state S'

            rset = self.req.execute(rql, {'etype': str(self.e_schema)})

            if rset:

                return [(rset.get_entity(0, 0).view('combobox'), rset[0][0])]

            return []

        results = []

        for tr in self.in_state[0].transitions(self):

            state = tr.destination_state[0]

            results.append((state.view('combobox'), state.eid))

        return sorted(results)

    # __method methods ########################################################

    def set_state(self, params=None):

        """change the entity's state according to a state defined in given

        parameters, used to be called using __method controler facility

        """

        params = params or self.req.form

        self.change_state(int(params.pop('state')), params.get('trcomment'),

                          params.get('trcommentformat'))

        self.req.set_message(self.req._('__msg state changed'))

class EmailableMixIn(object):

    """base mixin providing the default get_email() method used by

    the massmailing view

    NOTE: The default implementation is based on the

    primary_email / use_email scheme

    """

    __implements__ = (IEmailable,)

    def get_email(self):

        if getattr(self, 'primary_email', None):

            return self.primary_email[0].address

        if getattr(self, 'use_email', None):

            return self.use_email[0].address

        return None

    @classmethod

    def allowed_massmail_keys(cls):

        """returns a set of allowed email substitution keys

        The default is to return the entity's attribute list but an

        entity class might override this method to allow extra keys.

        For instance, the Person class might want to return a `companyname`

        key.

        """

        return set(rs.type for rs, _ in cls.e_schema.attribute_definitions())

    def as_email_context(self):

        """returns the dictionary as used by the sendmail controller to

        build email bodies.

        NOTE: the dictionary keys should match the list returned by the

        `allowed_massmail_keys` method.

        """

        return dict( (attr, getattr(self, attr)) for attr in self.allowed_massmail_keys() )

MI_REL_TRIGGERS = {

    ('in_state',    'subject'): WorkflowableMixIn,

    ('primary_email',   'subject'): EmailableMixIn,

    ('use_email',   'subject'): EmailableMixIn,

    }

def _done_init(done, view, row, col):

    """handle an infinite recursion safety belt"""

    if done is None:

        done = set()

    entity = view.entity(row, col)

    if entity.eid in done:

        msg = entity.req._('loop in %(rel)s relation (%(eid)s)') % {

            'rel': entity.tree_attribute,

            'eid': entity.eid

            }

        return None, msg

    done.add(entity.eid)

    return done, entity

class TreeViewMixIn(object):

    """a recursive tree view"""

    id = 'tree'

    item_vid = 'treeitem'

    __select__ = implements(ITree)

    def call(self, done=None, **kwargs):

        if done is None:

            done = set()

        super(TreeViewMixIn, self).call(done=done, **kwargs)

    def cell_call(self, row, col=0, vid=None, done=None, **kwargs):

        done, entity = _done_init(done, self, row, col)

        if done is None:

            # entity is actually an error message

            self.w(u'<li class="badcontent">%s</li>' % entity)

            return

        self.open_item(entity)

        entity.view(vid or self.item_vid, w=self.w, **kwargs)

        relatedrset = entity.children(entities=False)

        self.wview(self.id, relatedrset, 'null', done=done, **kwargs)

        self.close_item(entity)

    def open_item(self, entity):

        self.w(u'<li class="%s">\n' % entity.id.lower())

    def close_item(self, entity):

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

class TreePathMixIn(object):

    """a recursive path view"""

    id = 'path'

    item_vid = 'oneline'

    separator = u' > '

    def call(self, **kwargs):

        self.w(u'<div class="pathbar">')

        super(TreePathMixIn, self).call(**kwargs)

        self.w(u'</div>')

    def cell_call(self, row, col=0, vid=None, done=None, **kwargs):

        done, entity = _done_init(done, self, row, col)

        if done is None:

            # entity is actually an error message

            self.w(u'<span class="badcontent">%s</span>' % entity)

            return

        parent = entity.parent()

        if parent:

            parent.view(self.id, w=self.w, done=done)

            self.w(self.separator)

        entity.view(vid or self.item_vid, w=self.w)

class ProgressMixIn(object):

    """provide default implementations for IProgress interface methods"""

    @property

    @cached

    def cost(self):

        return self.progress_info()['estimated']

    @property

    @cached

    def revised_cost(self):

        return self.progress_info().get('estimatedcorrected', self.cost)

    @property

    @cached

    def done(self):

        return self.progress_info()['done']

    @property

    @cached

    def todo(self):

        return self.progress_info()['todo']

    @cached

    def progress_info(self):

        raise NotImplementedError()

    def finished(self):

        return not self.in_progress()

    def in_progress(self):

        raise NotImplementedError()

    def progress(self):

        try:

            return 100. * self.done / self.revised_cost

        except ZeroDivisionError:

            # total cost is 0 : if everything was estimated, task is completed