#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# SAT plugin for Pubsub Schemas
# Copyright (C) 2009-2018 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from sat.core.i18n import _
from sat.core import exceptions
from sat.core.constants import Const as C
from sat.tools import xml_tools
from sat.tools import utils
from twisted.words.protocols.jabber import jid
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from twisted.internet import defer
from sat.core.log import getLogger
log = getLogger(__name__)
from wokkel import disco, iwokkel
from wokkel import data_form
from wokkel import generic
from zope.interface import implements
from collections import Iterable
import copy
import itertools

NS_SCHEMA = 'https://salut-a-toi/protocol/schema:0'

PLUGIN_INFO = {
    C.PI_NAME: "PubSub Schema",
    C.PI_IMPORT_NAME: "PUBSUB_SCHEMA",
    C.PI_TYPE: "EXP",
    C.PI_PROTOCOLS: [],
    C.PI_DEPENDENCIES: ["XEP-0060", "IDENTITY"],
    C.PI_MAIN: "PubsubSchema",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Handle Pubsub data schemas""")
}


class PubsubSchema(object):

    def __init__(self, host):
        log.info(_(u"PubSub Schema initialization"))
        self.host = host
        self._p = self.host.plugins["XEP-0060"]
        self._i = self.host.plugins["IDENTITY"]
        host.bridge.addMethod("psSchemaGet", ".plugin",
                              in_sign='sss', out_sign='s',
                              method=self._getSchema,
                              async=True
                              )
        host.bridge.addMethod("psSchemaSet", ".plugin",
                              in_sign='ssss', out_sign='',
                              method=self._setSchema,
                              async=True
                              )
        host.bridge.addMethod("psSchemaUIGet", ".plugin",
                              in_sign='sss', out_sign='s',
                              method=utils.partial(self._getUISchema, default_node=None),
                              async=True
                              )
        host.bridge.addMethod("psItemsFormGet", ".plugin",
                              in_sign='ssssiassa{ss}s', out_sign='(asa{ss})',
                              method=self._getDataFormItems,
                              async=True)
        host.bridge.addMethod("psItemFormSend", ".plugin",
                              in_sign='ssa{sas}ssa{ss}s', out_sign='s',
                              method=self._sendDataFormItem,
                              async=True)

    def getHandler(self, client):
        return SchemaHandler()

    def _getSchemaBridgeCb(self, schema_elt):
        if schema_elt is None:
            return u''
        return schema_elt.toXml()

    def _getSchema(self, service, nodeIdentifier, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        d = self.getSchema(client, service, nodeIdentifier)
        d.addCallback(self._getSchemaBridgeCb)
        return d

    def _getSchemaCb(self, iq_elt):
        try:
            schema_elt = next(iq_elt.elements(NS_SCHEMA, 'schema'))
        except StopIteration:
            raise exceptions.DataError('missing <schema> element')
        try:
            x_elt = next(schema_elt.elements((data_form.NS_X_DATA, 'x')))
        except StopIteration:
            # there is not schema on this node
            return None
        return x_elt

    def getSchema(self, client, service, nodeIdentifier):
        """retrieve PubSub node schema

        @param service(jid.JID, None): jid of PubSub service
            None to use our PEP
        @param nodeIdentifier(unicode): node to get schema from
        @return (domish.Element, None): schema (<x> element)
            None if not schema has been set on this node
        """
        iq_elt = client.IQ(u'get')
        if service is not None:
            iq_elt['to'] = service.full()
        pubsub_elt = iq_elt.addElement((NS_SCHEMA, 'pubsub'))
        schema_elt = pubsub_elt.addElement((NS_SCHEMA, 'schema'))
        schema_elt['node'] = nodeIdentifier
        d = iq_elt.send()
        d.addCallback(self._getSchemaCb)
        return d

    @defer.inlineCallbacks
    def getSchemaForm(self, client, service, nodeIdentifier, schema=None, form_type='form', copy_form=True):
        """get data form from node's schema

        @param service(None, jid.JID): PubSub service
        @param nodeIdentifier(unicode): node
        @param schema(domish.Element, data_form.Form, None): node schema
            if domish.Element, will be converted to data form
            if data_form.Form it will be returned without modification
            if None, it will be retrieved from node (imply one additional XMPP request)
        @param form_type(unicode): type of the form
        @param copy_form(bool): if True and if schema is already a data_form.Form, will deep copy it before returning
            needed when the form is reused and it will be modified (e.g. in sendDataFormItem)
        @return(data_form.Form): data form
            the form should not be modified if copy_form is not set
        """
        if schema is None:
            log.debug(_(u"unspecified schema, we need to request it"))
            schema = yield self.getSchema(client, service, nodeIdentifier)
            if schema is None:
                raise exceptions.DataError(_(u"no schema specified, and this node has no schema either, we can't construct the data form"))
        elif isinstance(schema, data_form.Form):
            if copy_form:
                schema = copy.deepcopy(schema)
            defer.returnValue(schema)

        try:
            form = data_form.Form.fromElement(schema)
        except data_form.Error as e:
            raise exceptions.DataError(_(u"Invalid Schema: {msg}").format(
                msg = e))
        form.formType = form_type
        defer.returnValue(form)

    def schema2XMLUI(self, schema_elt):
        form = data_form.Form.fromElement(schema_elt)
        xmlui = xml_tools.dataForm2XMLUI(form, '')
        return xmlui

    def _getUISchema(self, service, nodeIdentifier, default_node=None, profile_key=C.PROF_KEY_NONE):
        if not nodeIdentifier:
            if not default_node:
                raise ValueError(_(u"nodeIndentifier needs to be set"))
            nodeIdentifier = default_node
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        d = self.getUISchema(client, service, nodeIdentifier)
        d.addCallback(lambda xmlui: xmlui.toXml())
        return d

    def getUISchema(self, client, service, nodeIdentifier):
        d = self.getSchema(client, service, nodeIdentifier)
        d.addCallback(self.schema2XMLUI)
        return d

    def _setSchema(self, service, nodeIdentifier, schema, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        schema = generic.parseXml(schema.encode('utf-8'))
        return self.setSchema(client, service, nodeIdentifier, schema)

    def setSchema(self, client, service, nodeIdentifier, schema):
        """set or replace PubSub node schema

        @param schema(domish.Element, None): schema to set
            None if schema need to be removed
        """
        iq_elt = client.IQ()
        if service is not None:
            iq_elt['to'] = service.full()
        pubsub_elt = iq_elt.addElement((NS_SCHEMA, 'pubsub'))
        schema_elt = pubsub_elt.addElement((NS_SCHEMA, 'schema'))
        schema_elt['node'] = nodeIdentifier
        if schema is not None:
            schema_elt.addChild(schema)
        return iq_elt.send()

    def _getDataFormItems(self, form_ns='', service='', node='', schema='', max_items=10, item_ids=None, sub_id=None, extra_dict=None, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = jid.JID(service) if service else None
        if not node:
            raise exceptions.DataError(_(u'empty node is not allowed'))
        if schema:
            schema = generic.parseXml(schema.encode('utf-8'))
        else:
            schema = None
        max_items = None if max_items == C.NO_LIMIT else max_items
        extra = self._p.parseExtra(extra_dict)
        d = self.getDataFormItems(client, service, node, schema, max_items or None, item_ids, sub_id or None, extra.rsm_request, extra.extra, form_ns=form_ns or None)
        d.addCallback(self._p.serItemsData)
        return d

    @defer.inlineCallbacks
    def getDataFormItems(self, client, service, nodeIdentifier, schema=None, max_items=None, item_ids=None, sub_id=None, rsm_request=None, extra=None, default_node=None, form_ns=None, filters=None):
        """Get items known as being data forms, and convert them to XMLUI

        @param schema(domish.Element, data_form.Form, None): schema of the node if known
            if None, it will be retrieved from node
        @param default_node(unicode): node to use if nodeIdentifier is None or empty
        @param form_ns (unicode, None): namespace of the form
            None to accept everything, even if form has no namespace
        @param filters(dict, None): same as for xml_tools.dataFormResult2XMLUI
        other parameters as the same as for [getItems]
        @return (list[unicode]): XMLUI of the forms
            if an item is invalid (not corresponding to form_ns or not a data_form)
            it will be skipped
        @raise ValueError: one argument is invalid
        """
        if not nodeIdentifier:
            if not default_node:
                raise ValueError(_(u"default_node must be set if nodeIdentifier is not set"))
            nodeIdentifier = default_node
        # we need the initial form to get options of fields when suitable
        schema_form = yield self.getSchemaForm(client, service, nodeIdentifier, schema, form_type='result', copy_form=False)
        items_data = yield self._p.getItems(client, service, nodeIdentifier, max_items, item_ids, sub_id, rsm_request, extra)
        items, metadata = items_data
        items_xmlui = []
        for item_elt in items:
            for x_elt in item_elt.elements((data_form.NS_X_DATA, u'x')):
                form = data_form.Form.fromElement(x_elt)
                if form_ns and form.formNamespace != form_ns:
                    continue
                xmlui = xml_tools.dataFormResult2XMLUI(
                    form,
                    schema_form,
                    # FIXME: conflicts with schema (i.e. if "id" or "publisher" already exists)
                    #        are not checked
                    prepend = (('label', 'id'),('text', item_elt['id'], u'id'),
                               ('label', 'publisher'),('text', item_elt.getAttribute('publisher',''), u'publisher')),
                    filters = filters,
                    )
                items_xmlui.append(xmlui)
                break
        defer.returnValue((items_xmlui, metadata))


    def _sendDataFormItem(self, service, nodeIdentifier, values, schema=None, item_id=None, extra=None, profile_key=C.PROF_KEY_NONE):
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        if schema:
            schema = generic.parseXml(schema.encode('utf-8'))
        else:
            schema = None
        d = self.sendDataFormItem(client, service, nodeIdentifier, values, schema, item_id or None, extra, deserialise=True)
        d.addCallback(lambda ret: ret or u'')
        return d

    @defer.inlineCallbacks
    def sendDataFormItem(self, client, service, nodeIdentifier, values, schema=None, item_id=None, extra=None, deserialise=False):
        """Publish an item as a dataform when we know that there is a schema

        @param values(dict[key(unicode), [iterable[object], object]]): values set for the form
            if not iterable, will be put in a list
        @param schema(domish.Element, data_form.Form, None): data schema
            None to retrieve data schema from node (need to do a additional XMPP call)
            Schema is needed to construct data form to publish
        @param deserialise(bool): if True, data are list of unicode and must be deserialized according to expected type
            This is done in this method and not directly in _sendDataFormItem because we need to know the data type
            which is in the form, not availablable in _sendDataFormItem
        other parameters as the same as for [self._p.sendItem]
        @return (unicode): id of the created item
        """
        form = yield self.getSchemaForm(client, service, nodeIdentifier, schema, form_type='submit')

        for name, values_list in values.iteritems():
            try:
                field = form.fields[name]
            except KeyError:
                log.warning(_(u"field {name} doesn't exist, ignoring it").format(name=name))
                continue
            if isinstance(values_list, basestring) or not isinstance(values_list, Iterable):
                values_list = [values_list]
            if deserialise:
                if field.fieldType == 'boolean':
                    values_list = [C.bool(v) for v in values_list]
                elif field.fieldType == 'text-multi':
                    # for text-multi, lines must be put on separate values
                    values_list = list(itertools.chain(*[v.splitlines() for v in values_list]))

                elif 'jid' in field.fieldType:
                    values_list = [jid.JID(v) for v in values_list]
            if 'list' in field.fieldType:
                # for lists, we check that given values are allowed in form
                allowed_values = [o.value for o in field.options]
                values_list = [v for v in values_list if v in allowed_values]
                if not values_list:
                    # if values don't map to allowed values, we use default ones
                    values_list = field.values
            field.values = values_list

        yield self._p.sendItem(client, service, nodeIdentifier, form.toElement(), item_id, extra)

    ## filters ##
    # filters useful for data form to XMLUI conversion #

    def valueOrPublisherFilter(self, form_xmlui, widget_type, args, kwargs):
        """Replace missing value by publisher's user part"""
        if not args[0]:
            # value is not filled: we use user part of publisher (if we have it)
            try:
                publisher = jid.JID(form_xmlui.named_widgets['publisher'].value)
            except (KeyError, RuntimeError):
                pass
            else:
                args[0] = publisher.user.capitalize()
        return widget_type, args, kwargs

    def textbox2ListFilter(self, form_xmlui, widget_type, args, kwargs):
        """Split lines of a textbox in a list

        main use case is using a textbox for labels
        """
        if widget_type != u'textbox':
            return widget_type, args, kwargs
        widget_type = u'list'
        options = [o for o in args.pop(0).split(u'\n') if o]
        kwargs = {'options': options,
                  'name': kwargs.get('name'),
                  'styles': (u'noselect', u'extensible', u'reducible')}
        return widget_type, args, kwargs

    def dateFilter(self, form_xmlui, widget_type, args, kwargs):
        """Convert a string with a date to a unix timestamp"""
        if widget_type != u'string' or not args[0]:
            return widget_type, args, kwargs
        # we convert XMPP date to timestamp
        try:
            args[0] = unicode(utils.date_parse(args[0]))
        except Exception as e:
            log.warning(_(u"Can't parse date field: {msg}").format(msg=e))
        return widget_type, args, kwargs

    ## Helper methods ##

    def prepareBridgeGet(self, service, node, max_items, sub_id, extra_dict, profile_key):
        """Parse arguments received from bridge *Get methods and return higher level data

        @return (tuple): (client, service, node, max_items, extra, sub_id) usable for internal methods
        """
        client = self.host.getClient(profile_key)
        service = jid.JID(service) if service else None
        if not node:
            node = None
        max_items = None if max_items == C.NO_LIMIT else max_items
        if not sub_id:
            sub_id = None
        extra = self._p.parseExtra(extra_dict)

        return client, service, node, max_items, extra, sub_id

    def _get(self, service='', node='', max_items=10, item_ids=None, sub_id=None, extra=None, default_node=None, form_ns=None, filters=None, profile_key=C.PROF_KEY_NONE):
        """Bridge method to retrieve data from node with schema

        this method is a helper so dependant plugins can use it directly
        when adding *Get methods
        extra can have the key "labels_as_list" which is a hack to convert
            labels from textbox to list in XMLUI, which usually render better
            in final UI.
        """
        if filters is None:
            filters = {}
        if extra is None:
            extra = {}
        # XXX: Q&D way to get list for labels when displaying them, but text when we
        #      have to modify them
        if C.bool(extra.get('labels_as_list', C.BOOL_FALSE)):
            filters = filters.copy()
            filters[u'labels'] = self.textbox2ListFilter
        client, service, node, max_items, extra, sub_id = self.prepareBridgeGet(service, node, max_items, sub_id, extra, profile_key)
        d = self.getDataFormItems(client, service, node or None,
            max_items=max_items,
            item_ids=item_ids,
            sub_id=sub_id,
            rsm_request=extra.rsm_request,
            extra=extra.extra,
            default_node=default_node,
            form_ns=form_ns,
            filters=filters)
        d.addCallback(self._p.serItemsData)
        return d

    def prepareBridgeSet(self, service, node, schema, item_id, extra, profile_key):
        """Parse arguments received from bridge *Set methods and return higher level data

        @return (tuple): (client, service, node, schema, item_id, extra) usable for internal methods
        """
        client = self.host.getClient(profile_key)
        service = None if not service else jid.JID(service)
        if schema:
            schema = generic.parseXml(schema.encode('utf-8'))
        else:
            schema = None
        if extra and u'update' in extra:
            extra[u'update'] = C.bool(extra[u'update'])
        return client, service, node or None, schema, item_id or None, extra

    def _set(self, service, node, values, schema=None, item_id=None, extra=None, default_node=None, form_ns=None, fill_author=True, profile_key=C.PROF_KEY_NONE):
        """Bridge method to set item in node with schema

        this method is a helper so dependant plugins can use it directly
        when adding *Set methods
        """
        client, service, node, schema, item_id, extra = self.prepareBridgeSet(service, node, schema, item_id, extra)
        d = self.set(client, service, node, values, schema, item_id, extra,
                     deserialise=True,
                     form_ns=form_ns,
                     default_node=default_node,
                     fill_author=fill_author)
        d.addCallback(lambda ret: ret or u'')
        return d

    @defer.inlineCallbacks
    def set(self, client, service, node, values, schema, item_id, extra, deserialise, form_ns, default_node=None, fill_author=True):
        """Set an item in a node with a schema

        This method can be used directly by *Set methods added by dependant plugin
        @param values(dict[key(unicode), [iterable[object]|object]]): values of the items
            if value is not iterable, it will be put in a list
            'created' and 'updated' will be forced to current time:
                - 'created' is set if item_id is None, i.e. if it's a new ticket
                - 'updated' is set everytime
        @param extra(dict, None): same as for [XEP-0060.sendItem] with additional keys:
            - update(bool): if True, get previous item data to merge with current one
                if True, item_id must be None
        @param form_ns (unicode, None): namespace of the form
            needed when an update is done
        @param default_node(unicode, None): value to use if node is not set
        other arguments are same as for [self._s.sendDataFormItem]
        @return (unicode): id of the created item
        """
        if not node:
            if default_node is None:
                raise ValueError(_(u"default_node must be set if node is not set"))
            node = default_node
        now = utils.xmpp_date()
        if not item_id:
            values['created'] = now
        elif extra.get(u'update', False):
            if item_id is None:
                raise exceptions.DataError(_(u'if extra["update"] is set, item_id must be set too'))
            try:
                # we get previous item
                items_data = yield self._p.getItems(client, service, node, item_ids=[item_id])
                item_elt = items_data[0][0]
            except Exception as e:
                log.warning(_(u"Can't get previous item, update ignored: {reason}").format(
                    reason = e))
            else:
                # and parse it
                form = data_form.findForm(item_elt, form_ns)
                if form is None:
                    log.warning(_(u"Can't parse previous item, update ignored: data form not found").format(
                        reason = e))
                else:
                    for name, field in form.fields.iteritems():
                        if name not in values:
                            values[name] = u'\n'.join(unicode(v) for v in field.values)

        values['updated'] = now
        if fill_author:
            if not values.get('author'):
                identity = yield self._i.getIdentity(client, client.jid)
                values['author'] = identity['nick']
            if not values.get('author_jid'):
                values['author_jid'] = client.jid.full()
        item_id = yield self.sendDataFormItem(client, service, node, values, schema, item_id, extra, deserialise)
        defer.returnValue(item_id)


class SchemaHandler(XMPPHandler):
    implements(iwokkel.IDisco)

    def getDiscoInfo(self, requestor, service, nodeIdentifier=''):
        return [disco.DiscoFeature(NS_SCHEMA)]

    def getDiscoItems(self, requestor, service, nodeIdentifier=''):
        return []