:author: marcink

    :copyright: (C) 2011-2012 Marcin Kuzminski <marcin@python-works.com>

    :license: GPLv3, see COPYING for more details.

"""

# This program is free software; you can redistribute it and/or

# modify it under the terms of the GNU General Public License

# as published by the Free Software Foundation; version 2

# of the License or (at your opinion) any later version of the license.

#

# 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 General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

# MA  02110-1301, USA.

import inspect

import logging

import types

import urllib

import traceback

from rhodecode.lib.compat import izip_longest, json

from paste.response import replace_header

from pylons.controllers import WSGIController

from webob.exc import HTTPNotFound, HTTPForbidden, HTTPInternalServerError, \

HTTPBadRequest, HTTPError

from rhodecode.model.db import User

from rhodecode.lib.auth import AuthUser

log = logging.getLogger('JSONRPC')

class JSONRPCError(BaseException):

    def __init__(self, message):

        self.message = message

        super(JSONRPCError, self).__init__()

    def __str__(self):

        return str(self.message)

def jsonrpc_error(message, retid=None, code=None):

    """

    Generate a Response object with a JSON-RPC error body

    """

    from pylons.controllers.util import Response

    return Response(

            body=json.dumps(dict(id=retid, result=None, error=message)),

            status=code,

            content_type='application/json'

    )

     A WSGI-speaking JSON-RPC controller class

     See the specification:

     <http://json-rpc.org/wiki/specification>`.

     Valid controller return values should be json-serializable objects.

     Sub-classes should catch their exceptions and raise JSONRPCError

     if they want to pass meaningful errors to the client.

     """

    def _get_method_args(self):

        """

        Return `self._rpc_args` to dispatched controller method

        chosen by __call__

        """

        return self._rpc_args

    def __call__(self, environ, start_response):

        """

        Parse the request body as JSON, look up the method on the

        controller and if it exists, dispatch to it.

        """

        self._req_id = None

        if 'CONTENT_LENGTH' not in environ:

            log.debug("No Content-Length")

            return jsonrpc_error(retid=self._req_id,

                                 message="No Content-Length in request")

        else:

            length = environ['CONTENT_LENGTH'] or 0

            length = int(environ['CONTENT_LENGTH'])

            log.debug('Content-Length: %s' % length)

        if length == 0:

            log.debug("Content-Length is 0")

            return jsonrpc_error(retid=self._req_id,

                                 message="Content-Length is 0")

        raw_body = environ['wsgi.input'].read(length)

        try:

            json_body = json.loads(urllib.unquote_plus(raw_body))

        except ValueError, e:

            # catch JSON errors Here

            return jsonrpc_error(retid=self._req_id,

                                 message="JSON parse error ERR:%s RAW:%r" \

                                 % (e, urllib.unquote_plus(raw_body)))

                    )

                )

        self._rpc_args = {USER_SESSION_ATTR: u}

        self._rpc_args.update(self._request_params)

        self._rpc_args['action'] = self._req_method

        self._rpc_args['environ'] = environ

        self._rpc_args['start_response'] = start_response

        status = []

        headers = []

        exc_info = []

        def change_content(new_status, new_headers, new_exc_info=None):

            status.append(new_status)

            headers.extend(new_headers)

            exc_info.append(new_exc_info)

        output = WSGIController.__call__(self, environ, change_content)

        output = list(output)

        headers.append(('Content-Length', str(len(output[0]))))

        replace_header(headers, 'Content-Type', 'application/json')

        start_response(status[0], headers, exc_info[0])

        return output

    def _dispatch_call(self):

        """

        Implement dispatch interface specified by WSGIController

        """

        try:

            raw_response = self._inspect_call(self._func)

            if isinstance(raw_response, HTTPError):

                self._error = str(raw_response)

        except JSONRPCError, e:

            self._error = str(e)

        except Exception, e:

            log.error('Encountered unhandled exception: %s' \

                      % traceback.format_exc())

            json_exc = JSONRPCError('Internal server error')

            self._error = str(json_exc)

        if self._error is not None:

            raw_response = None

        response = dict(id=self._req_id, result=raw_response,

                        error=self._error)