# copyright 2010-2011 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/>.

"""datafeed parser for xml generated by cubicweb

Example of mapping for CWEntityXMLParser::

  {u'CWUser': {                                        # EntityType

      (u'in_group', u'subject', u'link'): [            # (rtype, role, action)

          (u'CWGroup', {u'linkattr': u'name'})],       #   -> rules = [(EntityType, options), ...]

      (u'tags', u'object', u'link-or-create'): [       # (...)

          (u'Tag', {u'linkattr': u'name'})],           #   -> ...

      (u'use_email', u'subject', u'copy'): [           # (...)

          (u'EmailAddress', {})]                       #   -> ...

      }

   }

"""

import os.path as osp

from datetime import datetime, timedelta

from logilab.common.date import todate, totime

from logilab.common.textutils import splitstrip, text_to_dict

from yams.constraints import BASE_CONVERTERS

from yams.schema import role_name as rn

from cubicweb import ValidationError, typed_eid

from cubicweb.server.sources import datafeed

def ensure_str_keys(dic):

    for key in dic:

        dic[str(key)] = dic.pop(key)

# XXX see cubicweb.cwvreg.YAMS_TO_PY

# XXX see cubicweb.web.views.xmlrss.SERIALIZERS

DEFAULT_CONVERTERS = BASE_CONVERTERS.copy()

DEFAULT_CONVERTERS['String'] = unicode

DEFAULT_CONVERTERS['Password'] = lambda x: x.encode('utf8')

def convert_date(ustr):

    return todate(datetime.strptime(ustr, '%Y-%m-%d'))

DEFAULT_CONVERTERS['Date'] = convert_date

def convert_datetime(ustr):

    if '.' in ustr: # assume %Y-%m-%d %H:%M:%S.mmmmmm

        ustr = ustr.split('.',1)[0]

    return datetime.strptime(ustr, '%Y-%m-%d %H:%M:%S')

DEFAULT_CONVERTERS['Datetime'] = convert_datetime

def convert_time(ustr):

    return totime(datetime.strptime(ustr, '%H:%M:%S'))

DEFAULT_CONVERTERS['Time'] = convert_time

def convert_interval(ustr):

    return time(seconds=int(ustr))

DEFAULT_CONVERTERS['Interval'] = convert_interval

def extract_typed_attrs(eschema, stringdict, converters=DEFAULT_CONVERTERS):

    typeddict = {}

    for rschema in eschema.subject_relations():

        if rschema.final and rschema in stringdict:

            if rschema == 'eid':

                continue

            attrtype = eschema.destination(rschema)

            typeddict[rschema.type] = converters[attrtype](stringdict[rschema])

    return typeddict

def _parse_entity_etree(parent):

    for node in list(parent):

        try:

            item = {'cwtype': unicode(node.tag),

                    'cwuri': node.attrib['cwuri'],

                    'eid': typed_eid(node.attrib['eid']),

                    }

        except KeyError:

            # cw < 3.11 compat mode XXX

            item = {'cwtype': unicode(node.tag),

                    'cwuri': node.find('cwuri').text,

                    'eid': typed_eid(node.find('eid').text),

                    }

        rels = {}

        for child in node:

            role = child.get('role')

            if role:

                # relation

                related = rels.setdefault(role, {}).setdefault(child.tag, [])

                related += [ritem for ritem, _ in _parse_entity_etree(child)]

            else:

                # attribute

                item[child.tag] = unicode(child.text)

        yield item, rels

def build_search_rql(etype, attrs):

    restrictions = ['X %(attr)s %%(%(attr)s)s'%{'attr': attr} for attr in attrs]

    return 'Any X WHERE X is %s, %s' % (etype, ', '.join(restrictions))

def rtype_role_rql(rtype, role):

    if role == 'object':

        return 'Y %s X WHERE X eid %%(x)s' % rtype

    else:

        return 'X %s Y WHERE X eid %%(x)s' % rtype

def _check_no_option(action, options, eid, _):

    if options:

        msg = _("'%s' action doesn't take any options") % action

        raise ValidationError(eid, {rn('options', 'subject'): msg})

def _check_linkattr_option(action, options, eid, _):

    if not 'linkattr' in options:

        msg = _("'%s' action requires 'linkattr' option") % action

        raise ValidationError(eid, {rn('options', 'subject'): msg})

class CWEntityXMLParser(datafeed.DataFeedXMLParser):

    """datafeed parser for the 'xml' entity view"""

    __regid__ = 'cw.entityxml'

    action_options = {

        'copy': _check_no_option,

        'link-or-create': _check_linkattr_option,

        'link': _check_linkattr_option,

        }

    parse_etree = staticmethod(_parse_entity_etree)

    def __init__(self, *args, **kwargs):

        super(CWEntityXMLParser, self).__init__(*args, **kwargs)

        self.action_methods = {

            'copy': self.related_copy,

            'link-or-create': self.related_link_or_create,

            'link': self.related_link,

            }

    # mapping handling #########################################################

    def add_schema_config(self, schemacfg, checkonly=False):

        """added CWSourceSchemaConfig, modify mapping accordingly"""

        _ = self._cw._

        try:

            rtype = schemacfg.schema.rtype.name

        except AttributeError:

            msg = _("entity and relation types can't be mapped, only attributes "

                    "or relations")

            raise ValidationError(schemacfg.eid, {rn('cw_for_schema', 'subject'): msg})

        if schemacfg.options:

            options = text_to_dict(schemacfg.options)

        else:

            options = {}

        try:

            role = options.pop('role')

            if role not in ('subject', 'object'):

                raise KeyError

        except KeyError:

            msg = _('"role=subject" or "role=object" must be specified in options')

            raise ValidationError(schemacfg.eid, {rn('options', 'subject'): msg})

        try:

            action = options.pop('action')

            self.action_options[action](action, options, schemacfg.eid, _)

        except KeyError:

            msg = _('"action" must be specified in options; allowed values are '

                    '%s') % ', '.join(self.action_methods)

            raise ValidationError(schemacfg.eid, {rn('options', 'subject'): msg})

        if not checkonly:

            if role == 'subject':

                etype = schemacfg.schema.stype.name

                ttype = schemacfg.schema.otype.name

            else:

                etype = schemacfg.schema.otype.name

                ttype = schemacfg.schema.stype.name

            etyperules = self.source.mapping.setdefault(etype, {})

            etyperules.setdefault((rtype, role, action), []).append(

                (ttype, options) )

            self.source.mapping_idx[schemacfg.eid] = (

                etype, rtype, role, action, ttype)

    def del_schema_config(self, schemacfg, checkonly=False):

        """deleted CWSourceSchemaConfig, modify mapping accordingly"""

        etype, rtype, role, action, ttype = self.source.mapping_idx[schemacfg.eid]

        rules = self.source.mapping[etype][(rtype, role, action)]

        rules = [x for x in rules if not x[0] == ttype]

        if not rules:

            del self.source.mapping[etype][(rtype, role, action)]

    # import handling ##########################################################

    # XXX suppression support according to source configuration. If set, get all

    # cwuri of entities from this source, and compare with newly imported ones

    def process_item(self, item, rels):

        entity = self.extid2entity(str(item.pop('cwuri')),  item.pop('cwtype'),

                                   item=item)

        if not (self.created_during_pull(entity) or self.updated_during_pull(entity)):

            self.notify_updated(entity)

            item.pop('eid')

            # XXX check modification date

            attrs = extract_typed_attrs(entity.e_schema, item)

            entity.set_attributes(**attrs)

        for (rtype, role, action), rules in self.source.mapping.get(entity.__regid__, {}).iteritems():

            try:

                related_items = rels[role][rtype]

            except KeyError:

                self.source.error('relation %s-%s not found in xml export of %s',

                                  rtype, role, entity.__regid__)

                continue

            try:

                actionmethod = self.action_methods[action]

            except KeyError:

                raise Exception('Unknown action %s' % action)

            actionmethod(entity, rtype, role, related_items, rules)

        return entity

    def before_entity_copy(self, entity, sourceparams):

        """IDataFeedParser callback"""

        attrs = extract_typed_attrs(entity.e_schema, sourceparams['item'])

        entity.cw_edited.update(attrs)

    def related_copy(self, entity, rtype, role, others, rules):

        """implementation of 'copy' action

        Takes no option.

        """

        assert not any(x[1] for x in rules), "'copy' action takes no option"

        eids = [] # local eids

            self._clear_relation(entity, rtype, role, ttypes)

    def related_link(self, entity, rtype, role, others, rules):

        """implementation of 'link' action

        requires an options to control search of the linked entity.

        """

        for ttype, options in rules:

            assert 'linkattr' in options, (

                "'link' action requires a list of attributes used to "

                "search if the entity already exists")

            self._related_link(entity, rtype, role, ttype, others, [options['linkattr']],

                               create_when_not_found=False)

    def related_link_or_create(self, entity, rtype, role, others, rules):

        """implementation of 'link-or-create' action

        requires an options to control search of the linked entity.

        """

        for ttype, options in rules:

            assert 'linkattr' in options, (

                "'link-or-create' action requires a list of attributes used to "

                "search if the entity already exists")

            self._related_link(entity, rtype, role, ttype, others, [options['linkattr']],

                               create_when_not_found=True)

    def _related_link(self, entity, rtype, role, ttype, others, searchattrs,

                      create_when_not_found):

        def issubset(x,y):

            return all(z in y for z in x)

        eids = [] # local eids

        for item in others:

            if item['cwtype'] != ttype:

                continue

            if not issubset(searchattrs, item):

                item, _rels = self._complete_item(item, False)

                if not issubset(searchattrs, item):

                    self.source.error('missing attribute, got %s expected keys %s'

                                      % item, searchattrs)

                    continue

            kwargs = dict((attr, item[attr]) for attr in searchattrs)

            rql = build_search_rql(item['cwtype'], kwargs)

            rset = self._cw.execute(rql, kwargs)

            if len(rset) > 1:

                self.source.error('ambiguous link: found %s entity %s with attributes %s',

                                  len(rset), item['cwtype'], kwargs)

            elif len(rset) == 1:

                eids.append(rset[0][0])

            elif create_when_not_found:

                ensure_str_keys(kwargs) # XXX necessary with python < 2.6

                eids.append(self._cw.create_entity(item['cwtype'], **kwargs).eid)

            else:

                self.source.error('can not find %s entity with attributes %s',

                                  item['cwtype'], kwargs)

            self._clear_relation(entity, rtype, role, (ttype,))

    def _complete_item(self, item, add_relations=True):

        itemurl = item['cwuri'] + '?vid=xml'

        if add_relations:

            for rtype, role, _ in self.source.mapping.get(item['cwtype'], ()):

                itemurl += '&relation=%s_%s' % (rtype, role)

        item_rels = list(self.parse(itemurl))

        assert len(item_rels) == 1

        return item_rels[0]

    def _clear_relation(self, entity, rtype, role, ttypes):

        if entity.eid not in self.stats['created']:

            if len(ttypes) > 1:

                typerestr = ', Y is IN(%s)' % ','.join(ttypes)

            else:

                typerestr = ', Y is %s' % ','.join(ttypes)

            self._cw.execute('DELETE ' + rtype_role_rql(rtype, role) + typerestr,

                             {'x': entity.eid})

    def _set_relation(self, entity, rtype, role, eids):

        rqlbase = rtype_role_rql(rtype, role)

        self._cw.execute(rql, {'x': entity.eid})

def registration_callback(vreg):

    vreg.register_all(globals().values(), __name__)

    global HOST_MAPPING

    HOST_MAPPING = {}

    if vreg.config.apphome:

        host_mapping_file = osp.join(vreg.config.apphome, 'hostmapping.py')

        if osp.exists(host_mapping_file):

            HOST_MAPPING = eval(file(host_mapping_file).read())

            vreg.info('using host mapping %s from %s', HOST_MAPPING, host_mapping_file)