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

:organization: Logilab

:copyright: 2001-2010 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"

from itertools import chain

from logilab.common.decorators import cached

from cubicweb.selectors import implements

from cubicweb.interfaces import 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.cw_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 is self.e_schema, self.cw_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.__regid__.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

        _done.add(self.eid)

        yield self

        for child in self.same_type_children():

            for entity in child.prefixiter(_done):

                yield entity

    @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.__regid__.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, strict=True):

        def _uptoroot(self):

            curr = self

            while True:

                curr = curr.parent()

                if curr is None:

                    break

                yield curr

        if not strict:

            return chain([self], _uptoroot(self))

        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 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._cw.entity_from_eid(self.path()[0])

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(rschema.type

                   for rschema, attrtype in cls.e_schema.attribute_definitions()

                   if attrtype.type not in ('Password', 'Bytes'))

    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() )

"""pluggable mixins system: plug classes registered in MI_REL_TRIGGERS on entity

classes which have the relation described by the dict's key.

NOTE: pluggable mixins can't override any method of the 'explicit' user classes tree

(eg without plugged classes). This includes bases Entity and AnyEntity classes.

"""

MI_REL_TRIGGERS = {

    ('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.cw_rset.get_entity(row, col)

    if entity.eid in done:

        msg = entity._cw._('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"""

    __regid__ = '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.__regid__, relatedrset, 'null', done=done, **kwargs)

        self.close_item(entity)

    def open_item(self, entity):

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

    def close_item(self, entity):

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

class TreePathMixIn(object):

    """a recursive path view"""

    __regid__ = '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.__regid__, 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"""

    # This is an adapter isn't it ?

    @property

    def cost(self):

        return self.progress_info()['estimated']

    @property

    def revised_cost(self):

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

    @property

    def done(self):

        return self.progress_info()['done']

    @property

    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

            if self.progress_info().get('notestimated'):

                return 0.

            return 100