import os

import re

from Cookie import SimpleCookie, CookieError

from pprint import pformat

from urllib import urlencode

from urlparse import urljoin

try:

    # The mod_python version is more efficient, so try importing it first.

    from mod_python.util import parse_qsl

except ImportError:

    from cgi import parse_qsl

from django.utils.datastructures import MultiValueDict, ImmutableList

from django.utils.encoding import smart_str, iri_to_uri, force_unicode

from django.http.multipartparser import MultiPartParser

from django.conf import settings

from django.core.files import uploadhandler

from utils import *

RESERVED_CHARS="!*'();:@&=+$,/?%#[]"

absolute_http_url_re = re.compile(r"^https?://", re.I)

class Http404(Exception):

    pass

class HttpRequest(object):

    """A basic HTTP request."""

    # The encoding used in GET/POST dicts. None means use default setting.

    _encoding = None

    _upload_handlers = []

    def __init__(self):

        self.GET, self.POST, self.COOKIES, self.META, self.FILES = {}, {}, {}, {}, {}

        self.path = ''

        self.path_info = ''

        self.method = None

    def __repr__(self):

        return '<HttpRequest\nGET:%s,\nPOST:%s,\nCOOKIES:%s,\nMETA:%s>' % \

            (pformat(self.GET), pformat(self.POST), pformat(self.COOKIES),

            pformat(self.META))

    def get_host(self):

        """Returns the HTTP host using the environment or request headers."""

        # We try three options, in order of decreasing preference.

        if 'HTTP_X_FORWARDED_HOST' in self.META:

            host = self.META['HTTP_X_FORWARDED_HOST']

        elif 'HTTP_HOST' in self.META:

            host = self.META['HTTP_HOST']

        else:

            # Reconstruct the host using the algorithm from PEP 333.

            host = self.META['SERVER_NAME']

            server_port = str(self.META['SERVER_PORT'])

            if server_port != (self.is_secure() and '443' or '80'):

                host = '%s:%s' % (host, server_port)

        return host

    def get_full_path(self):

        return ''

    def build_absolute_uri(self, location=None):

        """

        Builds an absolute URI from the location and the variables available in

        this request. If no location is specified, the absolute URI is built on

        ``request.get_full_path()``.

        """

        if not location:

            location = self.get_full_path()

        if not absolute_http_url_re.match(location):

            current_uri = '%s://%s%s' % (self.is_secure() and 'https' or 'http',

                                         self.get_host(), self.path)

            location = urljoin(current_uri, location)

        return location

    def is_secure(self):

        return os.environ.get("HTTPS") == "on"

    def is_ajax(self):

        return self.META.get('HTTP_X_REQUESTED_WITH') == 'XMLHttpRequest'

    def _set_encoding(self, val):

        """

        Sets the encoding used for GET/POST accesses. If the GET or POST

        dictionary has already been created, it is removed and recreated on the

        next access (so that it is decoded correctly).

        """

        self._encoding = val

        if hasattr(self, '_get'):

            del self._get

        if hasattr(self, '_post'):

            del self._post

    def _get_encoding(self):

        return self._encoding

    encoding = property(_get_encoding, _set_encoding)

    def _initialize_handlers(self):

        self._upload_handlers = [uploadhandler.load_handler(handler, self)

                                 for handler in settings.FILE_UPLOAD_HANDLERS]

    def _set_upload_handlers(self, upload_handlers):

        if hasattr(self, '_files'):

            raise AttributeError("You cannot set the upload handlers after the upload has been processed.")

        self._upload_handlers = upload_handlers

    def _get_upload_handlers(self):

        if not self._upload_handlers:

            # If thre are no upload handlers defined, initialize them from settings.

            self._initialize_handlers()

        return self._upload_handlers

    upload_handlers = property(_get_upload_handlers, _set_upload_handlers)

    def parse_file_upload(self, META, post_data):

        """Returns a tuple of (POST QueryDict, FILES MultiValueDict)."""

        self.upload_handlers = ImmutableList(

            self.upload_handlers,

            warning = "You cannot alter upload handlers after the upload has been processed."

        )

        parser = MultiPartParser(META, post_data, self.upload_handlers, self.encoding)

        return parser.parse()

class QueryDict(MultiValueDict):

    """

    A specialized MultiValueDict that takes a query string when initialized.

    This is immutable unless you create a copy of it.

    Values retrieved from this class are converted from the given encoding

    (DEFAULT_CHARSET by default) to unicode.

    """

    # These are both reset in __init__, but is specified here at the class

    # level so that unpickling will have valid values

    _mutable = True

    _encoding = None

    def __init__(self, query_string, mutable=False, encoding=None):

        MultiValueDict.__init__(self)

        if not encoding:

            # *Important*: do not import settings any earlier because of note

            # in core.handlers.modpython.

            from django.conf import settings

            encoding = settings.DEFAULT_CHARSET

        self.encoding = encoding

        for key, value in parse_qsl((query_string or ''), True): # keep_blank_values=True

            self.appendlist(force_unicode(key, encoding, errors='replace'),

                            force_unicode(value, encoding, errors='replace'))

        self._mutable = mutable

    def _get_encoding(self):

        if self._encoding is None:

            # *Important*: do not import settings at the module level because

            # of the note in core.handlers.modpython.

            from django.conf import settings

            self._encoding = settings.DEFAULT_CHARSET

        return self._encoding

    def _set_encoding(self, value):

        self._encoding = value

    encoding = property(_get_encoding, _set_encoding)

    def _assert_mutable(self):

        if not self._mutable:

            raise AttributeError("This QueryDict instance is immutable")

    def __setitem__(self, key, value):

        self._assert_mutable()

        key = str_to_unicode(key, self.encoding)

        value = str_to_unicode(value, self.encoding)

        MultiValueDict.__setitem__(self, key, value)

    def __delitem__(self, key):

        self._assert_mutable()

        super(QueryDict, self).__delitem__(key)

    def __copy__(self):

        result = self.__class__('', mutable=True)

        for key, value in dict.items(self):

            dict.__setitem__(result, key, value)

        return result

    def __deepcopy__(self, memo):

        import copy

        result = self.__class__('', mutable=True)

        memo[id(self)] = result

        for key, value in dict.items(self):

            dict.__setitem__(result, copy.deepcopy(key, memo), copy.deepcopy(value, memo))

        return result

    def setlist(self, key, list_):

        self._assert_mutable()

        key = str_to_unicode(key, self.encoding)

        list_ = [str_to_unicode(elt, self.encoding) for elt in list_]

        MultiValueDict.setlist(self, key, list_)

    def setlistdefault(self, key, default_list=()):

        self._assert_mutable()

        if key not in self:

            self.setlist(key, default_list)

        return MultiValueDict.getlist(self, key)

    def appendlist(self, key, value):

        self._assert_mutable()

        key = str_to_unicode(key, self.encoding)

        value = str_to_unicode(value, self.encoding)

        MultiValueDict.appendlist(self, key, value)

    def update(self, other_dict):

        self._assert_mutable()

        f = lambda s: str_to_unicode(s, self.encoding)

        if hasattr(other_dict, 'lists'):

            for key, valuelist in other_dict.lists():

                for value in valuelist:

                    MultiValueDict.update(self, {f(key): f(value)})

        else:

            d = dict([(f(k), f(v)) for k, v in other_dict.items()])

            MultiValueDict.update(self, d)

    def pop(self, key, *args):

        self._assert_mutable()

        return MultiValueDict.pop(self, key, *args)

    def popitem(self):

        self._assert_mutable()

        return MultiValueDict.popitem(self)

    def clear(self):

        self._assert_mutable()

        MultiValueDict.clear(self)

    def setdefault(self, key, default=None):

        self._assert_mutable()

        key = str_to_unicode(key, self.encoding)

        default = str_to_unicode(default, self.encoding)

        return MultiValueDict.setdefault(self, key, default)

    def copy(self):

        """Returns a mutable copy of this object."""

        return self.__deepcopy__({})

    def urlencode(self):

        output = []

        for k, list_ in self.lists():

            k = smart_str(k, self.encoding)

            output.extend([urlencode({k: smart_str(v, self.encoding)}) for v in list_])

        return '&'.join(output)

def parse_cookie(cookie):

    if cookie == '':

        return {}

    try:

        c = SimpleCookie()

        c.load(cookie)

    except CookieError:

        # Invalid cookie

        return {}

    cookiedict = {}

    for key in c.keys():

        cookiedict[key] = c.get(key).value

    return cookiedict

class HttpResponse(object):

    """A basic HTTP response, with content and dictionary-accessed headers."""

    status_code = 200

    def __init__(self, content='', mimetype=None, status=None,

            content_type=None):

        from django.conf import settings

        self._charset = settings.DEFAULT_CHARSET

        if mimetype:

            content_type = mimetype     # For backwards compatibility

        if not content_type:

            content_type = "%s; charset=%s" % (settings.DEFAULT_CONTENT_TYPE,

                    settings.DEFAULT_CHARSET)

        if not isinstance(content, basestring) and hasattr(content, '__iter__'):

            self._container = content

            self._is_string = False

        else:

            self._container = [content]

            self._is_string = True

        self.cookies = SimpleCookie()

        if status:

            self.status_code = status

        # _headers is a mapping of the lower-case name to the original case of

        # the header (required for working with legacy systems) and the header

        # value.

        self._headers = {'content-type': ('Content-Type', content_type)}

    def __str__(self):

        """Full HTTP message, including headers."""

        return '\n'.join(['%s: %s' % (key, value)

            for key, value in self._headers.values()]) \

            + '\n\n' + self.content

    def _convert_to_ascii(self, *values):

        """Converts all values to ascii strings."""

        for value in values:

            if isinstance(value, unicode):

                try:

                    yield value.encode('us-ascii')

                except UnicodeError, e:

                    e.reason += ', HTTP response headers must be in US-ASCII format'

                    raise

            else:

                yield str(value)

    def __setitem__(self, header, value):

        header, value = self._convert_to_ascii(header, value)

        self._headers[header.lower()] = (header, value)

    def __delitem__(self, header):

        try:

            del self._headers[header.lower()]

        except KeyError:

            pass

    def __getitem__(self, header):

        return self._headers[header.lower()][1]

    def has_header(self, header):

        """Case-insensitive check for a header."""

        return self._headers.has_key(header.lower())

    __contains__ = has_header

    def items(self):

        return self._headers.values()

    def get(self, header, alternate):

        return self._headers.get(header.lower(), (None, alternate))[1]

    def set_cookie(self, key, value='', max_age=None, expires=None, path='/',

                   domain=None, secure=False):

        self.cookies[key] = value

        if max_age is not None:

            self.cookies[key]['max-age'] = max_age

        if expires is not None:

            self.cookies[key]['expires'] = expires

        if path is not None:

            self.cookies[key]['path'] = path

        if domain is not None:

            self.cookies[key]['domain'] = domain

        if secure:

            self.cookies[key]['secure'] = True

    def delete_cookie(self, key, path='/', domain=None):

        self.set_cookie(key, max_age=0, path=path, domain=domain,

                        expires='Thu, 01-Jan-1970 00:00:00 GMT')

    def _get_content(self):

        if self.has_header('Content-Encoding'):

            return ''.join(self._container)

        return smart_str(''.join(self._container), self._charset)

    def _set_content(self, value):

        self._container = [value]

        self._is_string = True

    content = property(_get_content, _set_content)

    def __iter__(self):

        self._iterator = iter(self._container)

        return self

    def next(self):

        chunk = self._iterator.next()

        if isinstance(chunk, unicode):

            chunk = chunk.encode(self._charset)

        return str(chunk)

    def close(self):

        if hasattr(self._container, 'close'):

            self._container.close()

    # The remaining methods partially implement the file-like object interface.

    # See http://docs.python.org/lib/bltin-file-objects.html

    def write(self, content):

        if not self._is_string:

            raise Exception("This %s instance is not writable" % self.__class__)

        self._container.append(content)

    def flush(self):

        pass

    def tell(self):

        if not self._is_string:

            raise Exception("This %s instance cannot tell its position" % self.__class__)

        return sum([len(chunk) for chunk in self._container])

class HttpResponseRedirect(HttpResponse):

    status_code = 302

    def __init__(self, redirect_to):

        HttpResponse.__init__(self)

        self['Location'] = iri_to_uri(redirect_to)

class HttpResponsePermanentRedirect(HttpResponse):

    status_code = 301

    def __init__(self, redirect_to):

        HttpResponse.__init__(self)

        self['Location'] = iri_to_uri(redirect_to)

class HttpResponseNotModified(HttpResponse):

    status_code = 304

class HttpResponseBadRequest(HttpResponse):

    status_code = 400

class HttpResponseNotFound(HttpResponse):

    status_code = 404

class HttpResponseForbidden(HttpResponse):

    status_code = 403

class HttpResponseNotAllowed(HttpResponse):

    status_code = 405

    def __init__(self, permitted_methods):

        HttpResponse.__init__(self)

        self['Allow'] = ', '.join(permitted_methods)

class HttpResponseGone(HttpResponse):

    status_code = 410

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

        HttpResponse.__init__(self, *args, **kwargs)

class HttpResponseServerError(HttpResponse):

    status_code = 500

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

        HttpResponse.__init__(self, *args, **kwargs)

# A backwards compatible alias for HttpRequest.get_host.

def get_host(request):

    return request.get_host()

# It's neither necessary nor appropriate to use

# django.utils.encoding.smart_unicode for parsing URLs and form inputs. Thus,

# this slightly more restricted function.

def str_to_unicode(s, encoding):

    """

    Converts basestring objects to unicode, using the given encoding. Illegally

    encoded input characters are replaced with Unicode "unknown" codepoint

    (\ufffd).

    Returns any non-basestring objects without change.

    """

    if isinstance(s, str):

        return unicode(s, encoding, 'replace')

    else:

        return s