# copyright 2003-2013 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/>.

#

# (disable pylint msg for client obj access to protected member as in obj._cw)

# pylint: disable=W0212

"""The ``ajaxcontroller`` module defines the :class:`AjaxController`

controller and the ``ajax-func`` cubicweb registry.

.. autoclass:: cubicweb.web.views.ajaxcontroller.AjaxController

   :members:

``ajax-funcs`` registry hosts exposed remote functions, that is

functions that can be called from the javascript world.

To register a new remote function, either decorate your function

with the :func:`~cubicweb.web.views.ajaxcontroller.ajaxfunc` decorator:

.. sourcecode:: python

    from cubicweb.predicates import mactch_user_groups

    from cubicweb.web.views.ajaxcontroller import ajaxfunc

    @ajaxfunc(output_type='json', selector=match_user_groups('managers'))

    def list_users(self):

        return [u for (u,) in self._cw.execute('Any L WHERE U login L')]

or inherit from :class:`~cubicweb.web.views.ajaxcontroller.AjaxFunction` and

implement the ``__call__`` method:

.. sourcecode:: python

    from cubicweb.web.views.ajaxcontroller import AjaxFunction

    class ListUser(AjaxFunction):

        __regid__ = 'list_users' # __regid__ is the name of the exposed function

        __select__ = match_user_groups('managers')

        output_type = 'json'

        def __call__(self):

            return [u for (u, ) in self._cw.execute('Any L WHERE U login L')]

.. autoclass:: cubicweb.web.views.ajaxcontroller.AjaxFunction

   :members:

.. autofunction:: cubicweb.web.views.ajaxcontroller.ajaxfunc

"""

import http.client as http_client

from functools import partial

from logilab.common.date import strptime

from logilab.common.registry import yes

from cubicweb import ObjectNotFound, NoSelectableObject, ValidationError

from cubicweb.appobject import AppObject

from cubicweb.utils import json, json_dumps, UStringIO

from cubicweb.uilib import exc_message

from cubicweb.web import RemoteCallFailed, DirectResponse

from cubicweb.web.controller import Controller

from cubicweb.web.views import vid_from_rset

from cubicweb.web.views import basecontrollers

def optional_kwargs(extraargs):

    if extraargs is None:

        return {}

    # we receive unicode keys which is not supported by the **syntax

    return dict((str(key), value) for key, value in extraargs.items())

class AjaxController(Controller):

    """AjaxController handles ajax remote calls from javascript

    The following javascript function call:

    .. sourcecode:: javascript

      var d = asyncRemoteExec('foo', 12, "hello");

      d.addCallback(function(result) {

          alert('server response is: ' + result);

      });

    will generate an ajax HTTP GET on the following url::

        BASE_URL/ajax?fname=foo&arg=12&arg="hello"

    The AjaxController controller will therefore be selected to handle those URLs

    and will itself select the :class:`cubicweb.web.views.ajaxcontroller.AjaxFunction`

    matching the *fname* parameter.

    """

    __regid__ = 'ajax'

    def publish(self, rset=None):

        self._cw.ajax_request = True

        try:

            fname = self._cw.form['fname']

        except KeyError:

            raise RemoteCallFailed('no method specified',

                                   status=http_client.BAD_REQUEST)

        try:

            func = self._cw.vreg['ajax-func'].select(fname, self._cw)

        except ObjectNotFound:

            raise RemoteCallFailed('no %s method' % fname,

                                   status=http_client.BAD_REQUEST)

        debug_mode = self._cw.vreg.config.debugmode

        # no <arg> attribute means the callback takes no argument

        args = self._cw.form.get('arg', ())

        if not isinstance(args, (list, tuple)):

            args = (args,)

        try:

            args = [json.loads(arg) for arg in args]

        except ValueError as exc:

            if debug_mode:

                self.exception('error while decoding json arguments for '

                               'js_%s: %s (err: %s)', fname, args, exc)

            raise RemoteCallFailed(exc_message(exc, self._cw.encoding),

                                   status=http_client.BAD_REQUEST)

        try:

            result = func(*args)

        except (RemoteCallFailed, DirectResponse):

            raise

        except ValidationError as exc:

            raise RemoteCallFailed(exc_message(exc, self._cw.encoding),

                                   status=http_client.BAD_REQUEST)

        except Exception as exc:

            if debug_mode:

                self.exception(

                    'an exception occurred while calling js_%s(%s): %s',

                    fname, args, exc)

            raise RemoteCallFailed(exc_message(exc, self._cw.encoding))

        if result is None:

            return b''

        # get unicode on @htmlize methods, encoded string on @jsonize methods

        elif isinstance(result, str):

            return result.encode(self._cw.encoding)

        return result

class AjaxFunction(AppObject):

    """

    Attributes on this base class are:

    :attr: `check_pageid`: make sure the pageid received is valid before proceeding

    :attr: `output_type`:

           - *None*: no processing, no change on content-type

           - *json*: serialize with `json_dumps` and set *application/json*

                     content-type

           - *xhtml*: wrap result in an XML node and forces HTML / XHTML

                      content-type (use ``_cw.html_content_type()``)

    """

    __registry__ = 'ajax-func'

    __select__ = yes()

    __abstract__ = True

    check_pageid = False

    output_type = None

    @staticmethod

    def _rebuild_posted_form(names, values, action=None):

        form = {}

        for name, value in zip(names, values):

            # remove possible __action_xxx inputs

            if name.startswith('__action'):

                if action is None:

                    # strip '__action_' to get the actual action name

                    action = name[9:]

                continue

            # form.setdefault(name, []).append(value)

            if name in form:

                curvalue = form[name]

                if isinstance(curvalue, list):

                    curvalue.append(value)

                else:

                    form[name] = [curvalue, value]

            else:

                form[name] = value

        # simulate click on __action_%s button to help the controller

        if action:

            form['__action_%s' % action] = u'whatever'

        return form

    def validate_form(self, action, names, values):

        self._cw.form = self._rebuild_posted_form(names, values, action)

        return basecontrollers._validate_form(self._cw, self._cw.vreg)

    def _exec(self, rql, args=None, rocheck=True):

        """json mode: execute RQL and return resultset as json"""

        rql = rql.strip()

        if rql.startswith('rql:'):

            rql = rql[4:]

        if rocheck:

            self._cw.ensure_ro_rql(rql)

        try:

            return self._cw.execute(rql, args)

        except Exception as ex:

            if self._cw.vreg.config.debugmode:

                self.exception("error in _exec(rql=%s): %s", rql, ex)

            return None

        return None

    def _call_view(self, view, paginate=False, **kwargs):

        divid = self._cw.form.get('divid')

        # we need to call pagination before with the stream set

        try:

            stream = view.set_stream()

        except AttributeError:

            stream = UStringIO()

            kwargs['w'] = stream.write

            assert not paginate

        if divid == 'contentmain':

            # ensure divid isn't reused by the view (e.g. table view)

            del self._cw.form['divid']

            paginate = True

        if divid == 'contentmain':

            stream.write(u'<div id="contentmain">')

        nav_html = UStringIO()

        if paginate and not view.handle_pagination:

            view.paginate(w=nav_html.write)

        stream.write(nav_html.getvalue())

        view.render(**kwargs)

        stream.write(nav_html.getvalue())

        if divid == 'contentmain':

            stream.write(u'</div>')

        extresources = self._cw.html_headers.getvalue(skiphead=True)

        if extresources:

            stream.write(u'<div class="ajaxHtmlHead">\n') # XXX use a widget?

            stream.write(extresources)

            stream.write(u'</div>\n')

        return stream.getvalue()

def _ajaxfunc_factory(implementation, selector=yes(), _output_type=None,

                      _check_pageid=False, regid=None):

    """converts a standard python function into an AjaxFunction appobject"""

    class AnAjaxFunc(AjaxFunction):

        __regid__ = regid or implementation.__name__

        __select__ = selector

        output_type = _output_type

        check_pageid = _check_pageid

        def serialize(self, content):

            if self.output_type is None:

                return content

            elif self.output_type == 'xhtml':

                self._cw.set_content_type(self._cw.html_content_type())

                return ''.join((u'<div>',

                                content.strip(), u'</div>'))

            elif self.output_type == 'json':

                self._cw.set_content_type('application/json')

                return json_dumps(content)

            raise RemoteCallFailed('no serializer found for output type %s'

                                   % self.output_type)

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

            if self.check_pageid:

                data = self._cw.session.data.get(self._cw.pageid)

                if data is None:

                    raise RemoteCallFailed(self._cw._('pageid-not-found'))

            return self.serialize(implementation(self, *args, **kwargs))

    AnAjaxFunc.__name__ = implementation.__name__

    # make sure __module__ refers to the original module otherwise

    # vreg.register(obj) will ignore ``obj``.

    AnAjaxFunc.__module__ = implementation.__module__

    # relate the ``implementation`` object to its wrapper appobject

    # will be used by e.g.:

    #   import base_module

    #   @ajaxfunc

    #   def foo(self):

    #       return 42

    #   assert foo(object) == 42

    #   vreg.register_and_replace(foo, base_module.older_foo)

    implementation.__appobject__ = AnAjaxFunc

    return implementation

def ajaxfunc(implementation=None, selector=yes(), output_type=None,

             check_pageid=False, regid=None):

    """promote a standard function to an ``AjaxFunction`` appobject.

    All parameters are optional:

    :param selector: a custom selector object if needed, default is ``yes()``

    :param output_type: either None, 'json' or 'xhtml' to customize output

                        content-type. Default is None

    :param check_pageid: whether the function requires a valid `pageid` or not

                         to proceed. Default is False.

    :param regid: a custom __regid__ for the created ``AjaxFunction`` object. Default

                  is to keep the wrapped function name.

    ``ajaxfunc`` can be used both as a standalone decorator:

    .. sourcecode:: python

        @ajaxfunc

        def my_function(self):

            return 42

    or as a parametrizable decorator:

    .. sourcecode:: python

        @ajaxfunc(output_type='json')

        def my_function(self):

            return 42

    """

    # if used as a parametrized decorator (e.g. @ajaxfunc(output_type='json'))

    if implementation is None:

        def _decorator(func):

            return _ajaxfunc_factory(func, selector=selector,

                                     _output_type=output_type,

                                     _check_pageid=check_pageid,

                                     regid=regid)

        return _decorator

    # else, used as a standalone decorator (i.e. @ajaxfunc)

    return _ajaxfunc_factory(implementation, selector=selector,

                             _output_type=output_type,

                             _check_pageid=check_pageid, regid=regid)

###############################################################################

#  Cubicweb remote functions for :                                            #

#  - appobject rendering                                                      #

#  - user / page session data management                                      #

###############################################################################

@ajaxfunc(output_type='xhtml')

def view(self):

    # XXX try to use the page-content template

    req = self._cw

    rql = req.form.get('rql')

    if rql:

        rset = self._exec(rql)

    elif 'eid' in req.form:

        rset = self._cw.eid_rset(req.form['eid'])

    else:

        rset = None

    vid = req.form.get('vid') or vid_from_rset(req, rset, self._cw.vreg.schema)

    try:

        viewobj = self._cw.vreg['views'].select(vid, req, rset=rset)

    except NoSelectableObject:

        vid = req.form.get('fallbackvid', 'noresult')

        viewobj = self._cw.vreg['views'].select(vid, req, rset=rset)

    viewobj.set_http_cache_headers()

    if req.is_client_cache_valid():

        return ''

    return self._call_view(viewobj, paginate=req.form.pop('paginate', False))

@ajaxfunc(output_type='xhtml')

def component(self, compid, rql, registry='components', extraargs=None):

    if rql:

        rset = self._exec(rql)

    else:

        rset = None

    # XXX while it sounds good, addition of the try/except below cause pb:

    # when filtering using facets return an empty rset, the edition box

    # isn't anymore selectable, as expected. The pb is that with the

    # try/except below, we see a "an error occurred" message in the ui, while

    # we don't see it without it. Proper fix would probably be to deal with

    # this by allowing facet handling code to tell to js_component that such

    # error is expected and should'nt be reported.

    #try:

    comp = self._cw.vreg[registry].select(compid, self._cw, rset=rset,

                                          **optional_kwargs(extraargs))

    #except NoSelectableObject:

    #    raise RemoteCallFailed('unselectable')

    return self._call_view(comp, **optional_kwargs(extraargs))

@ajaxfunc(output_type='xhtml')

def render(self, registry, oid, eid=None,

              selectargs=None, renderargs=None):

    if eid is not None:

        rset = self._cw.eid_rset(eid)

        # XXX set row=0

    elif self._cw.form.get('rql'):

        rset = self._cw.execute(self._cw.form['rql'])

    else:

        rset = None

    viewobj = self._cw.vreg[registry].select(oid, self._cw, rset=rset,

                                             **optional_kwargs(selectargs))

    return self._call_view(viewobj, **optional_kwargs(renderargs))

@ajaxfunc(output_type='json')

def i18n(self, msgids):

    """returns the translation of `msgid`"""

    return [self._cw._(msgid) for msgid in msgids]