# copyright 2003-2011 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/>.
"""WSGI request adapter for cubicweb

NOTE: each docstring tagged with ``COME FROM DJANGO`` means that
the code has been taken (or adapted) from Djanco source code :
  http://www.djangoproject.com/

"""

__docformat__ = "restructuredtext en"

import tempfile

from StringIO import StringIO
from urllib import quote
from urlparse import parse_qs
from warnings import warn

from cubicweb.multipart import (
    copy_file, parse_form_data, MultipartError, parse_options_header)
from cubicweb.web import RequestError
from cubicweb.web.request import CubicWebRequestBase
from cubicweb.wsgi import pformat, normalize_header


class CubicWebWsgiRequest(CubicWebRequestBase):
    """most of this code COMES FROM DJANGO
    """

    def __init__(self, environ, vreg):
        # self.vreg is used in get_posted_data, which is called before the
        # parent constructor.
        self.vreg = vreg

        self.environ = environ
        self.path = environ['PATH_INFO']
        self.method = environ['REQUEST_METHOD'].upper()

        # content_length "may be empty or absent"
        try:
            length = int(environ['CONTENT_LENGTH'])
        except (KeyError, ValueError):
            length = 0
        # wsgi.input is not seekable, so copy the request contents to a temporary file
        if length < 100000:
            self.content = StringIO()
        else:
            self.content = tempfile.TemporaryFile()
        copy_file(environ['wsgi.input'], self.content, maxread=length)
        self.content.seek(0, 0)
        environ['wsgi.input'] = self.content

        headers_in = dict((normalize_header(k[5:]), v) for k, v in self.environ.items()
                          if k.startswith('HTTP_'))
        if 'CONTENT_TYPE' in environ:
            headers_in['Content-Type'] = environ['CONTENT_TYPE']
        https = self.is_secure()
        if self.path.startswith('/https/'):
            self.path = self.path[6:]
            self.environ['PATH_INFO'] = self.path
            https = True

        post, files = self.get_posted_data()

        super(CubicWebWsgiRequest, self).__init__(vreg, https, post,
                                                  headers= headers_in)
        self.content = environ['wsgi.input']
        if files is not None:
            for key, part in files.iteritems():
                self.form[key] = (part.filename, part.file)

    def __repr__(self):
        # Since this is called as part of error handling, we need to be very
        # robust against potentially malformed input.
        form = pformat(self.form)
        meta = pformat(self.environ)
        return '<CubicWebWsgiRequest\FORM:%s,\nMETA:%s>' % \
            (form, meta)

    ## cubicweb request interface ################################################

    def http_method(self):
        """returns 'POST', 'GET', 'HEAD', etc."""
        return self.method

    def relative_path(self, includeparams=True):
        """return the normalized path of the request (ie at least relative
        to the instance's root, but some other normalization may be needed
        so that the returned path may be used to compare to generated urls

        :param includeparams:
           boolean indicating if GET form parameters should be kept in the path
        """
        path = self.environ['PATH_INFO']
        path = path[1:] # remove leading '/'
        if includeparams:
            qs = self.environ.get('QUERY_STRING')
            if qs:
                return '%s?%s' % (path, qs)

        return path

    ## wsgi request helpers ###################################################

    def is_secure(self):
        return self.environ['wsgi.url_scheme'] == 'https'

    def get_posted_data(self):
        # The WSGI spec says 'QUERY_STRING' may be absent.
        post = parse_qs(self.environ.get('QUERY_STRING', ''))
        files = None
        if self.method == 'POST':
            content_type = self.environ.get('CONTENT_TYPE')
            if not content_type:
                raise RequestError("Missing Content-Type")
            content_type, options = parse_options_header(content_type)
            if content_type in (
                    'multipart/form-data',
                    'application/x-www-form-urlencoded',
                    'application/x-url-encoded'):
                forms, files = parse_form_data(
                    self.environ, strict=True,
                    mem_limit=self.vreg.config['max-post-length'])
                post.update(forms.dict)
        self.content.seek(0, 0)
        return post, files

    def setup_params(self, params):
        # This is a copy of CubicWebRequestBase.setup_params, but without
        # converting unicode strings because it is partially done by
        # get_posted_data
        self.form = {}
        if params is None:
            return
        encoding = self.encoding
        for param, val in params.iteritems():
            if isinstance(val, (tuple, list)):
                val = [
                    unicode(x, encoding) if isinstance(x, str) else x
                    for x in val]
                if len(val) == 1:
                    val = val[0]
            elif isinstance(val, str):
                val = unicode(val, encoding)
            if param in self.no_script_form_params and val:
                val = self.no_script_form_param(param, val)
            if param == '_cwmsgid':
                self.set_message_id(val)
            elif param == '__message':
                warn('[3.13] __message in request parameter is deprecated (may '
                     'only be given to .build_url). Seeing this message usualy '
                     'means your application hold some <form> where you should '
                     'replace use of __message hidden input by form.set_message, '
                     'so new _cwmsgid mechanism is properly used',
                     DeprecationWarning)
                self.set_message(val)
            else:
                self.form[param] = val