# copyright 2003-2010 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/>.

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

__docformat__ = "restructuredtext en"

from itertools import chain

from logilab.common.decorators import cached

from cubicweb.selectors import implements

class TreeMixIn(object):

    """base tree-mixin implementing 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)

    ## 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

    """

    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

"""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,

    }

class TreeViewMixIn(object):

    """a recursive tree view"""

    __regid__ = 'tree'

    item_vid = 'treeitem'

    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 a default implementations for IProgress interface methods"""

    @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