wrappers.py

"""Request/Response Wrappers

This module implements the Request and Response objects.
"""


from time import time
from io import BytesIO
from functools import partial

try:
    from Cookie import SimpleCookie
except ImportError:
    from http.cookies import SimpleCookie  # NOQA

from .url import parse_url
from .headers import Headers
from ..six import binary_type
from .errors import httperror
from circuits.net.sockets import BUFSIZE
from .constants import HTTP_STATUS_CODES, SERVER_VERSION

try:
    unicode
except NameError:
    unicode = str

try:
    from email.utils import formatdate
    formatdate = partial(formatdate, usegmt=True)
except ImportError:
    from rfc822 import formatdate as HTTPDate  # NOQA


def file_generator(input, chunkSize=BUFSIZE):
    chunk = input.read(chunkSize)
    while chunk:
        yield chunk
        chunk = input.read(chunkSize)
    input.close()


class Host(object):

    """An internet address.

    name should be the client's host name. If not available (because no DNS
    lookup is performed), the IP address should be used instead.
    """

    ip = "0.0.0.0"
    port = 80
    name = "unknown.tld"

    def __init__(self, ip, port, name=None):
        self.ip = ip
        self.port = port
        if name is None:
            name = ip
        self.name = name

    def __repr__(self):
        return "Host(%r, %r, %r)" % (self.ip, self.port, self.name)


class HTTPStatus(object):

    __slots__ = ("_reason", "_status",)

    def __init__(self, status=200, reason=None):
        self._status = status
        self._reason = reason or HTTP_STATUS_CODES.get(status, "")

    def __int__(self):
        return self._status

    def __lt__(self, other):
        if isinstance(other, int):
            return self._status < other
        return super(HTTPStatus, self).__lt__(other)

    def __gt__(self, other):
        if isinstance(other, int):
            return self._status > other
        return super(HTTPStatus, self).__gt__(other)

    def __le__(self, other):
        if isinstance(other, int):
            return self._status <= other
        return super(HTTPStatus, self).__le__(other)

    def __ge__(self, other):
        if isinstance(other, int):
            return self._status >= other
        return super(HTTPStatus, self).__ge__(other)

    def __eq__(self, other):
        if isinstance(other, int):
            return self._status == other
        return super(HTTPStatus, self).__eq__(other)

    def __str__(self):
        return "{0:d} {1:s}".format(self._status, self._reason)

    def __repr__(self):
        return "<Status (status={0:d} reason={1:s}>".format(
            self._status, self._reason
        )

    def __format__(self, format_spec):
        return format(str(self), format_spec)

    @property
    def status(self):
        return self._status

    @property
    def reason(self):
        return self._reason


class Request(object):

    """Creates a new Request object to hold information about a request.

    :param sock: The socket object of the request.
    :type  sock: socket.socket

    :param method: The requested method.
    :type  method: str

    :param scheme: The requested scheme.
    :type  scheme: str

    :param path: The requested path.
    :type  path: str

    :param protocol: The requested protocol.
    :type  protocol: str

    :param qs: The query string of the request.
    :type  qs: str
    """

    server = None
    """:cvar: A reference to the underlying server"""

    scheme = "http"
    protocol = (1, 1)
    host = ""
    local = Host("127.0.0.1", 80)
    remote = Host("", 0)

    index = None
    script_name = ""

    login = None
    handled = False

    def __init__(self, sock, method="GET", scheme="http", path="/",
                 protocol=(1, 1), qs="", headers=None, server=None):
        "initializes x; see x.__class__.__doc__ for signature"

        self.sock = sock
        self.method = method
        self.scheme = scheme or Request.scheme
        self.path = path
        self.protocol = protocol
        self.qs = qs
        self.print_debug = getattr(server, "display_banner", False)

        self.headers = headers or Headers()
        self.server = server

        self.cookie = SimpleCookie()

        if sock is not None:
            try:
                name = sock.getpeername()
            except OSError:
                name = None

            if name is not None:
                self.remote = Host(*name)
            else:
                try:
                    name = sock.getsockname()
                except OSError:
                    name = 'unknown'

                self.remote = Host(name, "", name)

        cookie = self.headers.get("Cookie")
        if cookie is not None:
            self.cookie.load(cookie)

        self.body = BytesIO()

        if self.server is not None:
            self.local = Host(self.server.host, self.server.port)

        try:
            host = self.headers["Host"]
            if ":" in host:
                parts = host.split(":", 1)
                host = parts[0]
                port = int(parts[1])
            else:
                port = 443 if self.scheme == "https" else 80
        except KeyError:
            host = self.local.name or self.local.ip
            port = getattr(self.server, "port")

        self.host = host
        self.port = port

        base = "{0:s}://{1:s}{2:s}/".format(
            self.scheme,
            self.host,
            ":{0:d}".format(self.port) if self.port not in (80, 443) else ""
        )
        self.base = parse_url(base)

        url = "{0:s}{1:s}{2:s}".format(
            base,
            self.path,
            "?{0:s}".format(self.qs) if self.qs else ""
        )
        self.uri = parse_url(url)
        self.uri.sanitize()

    def __repr__(self):
        protocol = "HTTP/%d.%d" % self.protocol
        return "<Request %s %s %s>" % (self.method, self.path, protocol)


class Body(object):

    """Response Body"""

    def __get__(self, response, cls=None):
        if response is None:
            return self
        else:
            return response._body

    def __set__(self, response, value):
        if response == value:
            return

        if isinstance(value, binary_type):
            if value:
                value = [value]
            else:
                value = []
        elif hasattr(value, "read"):
            response.stream = True
            value = file_generator(value)
        elif isinstance(value, httperror):
            value = [str(value)]
        elif value is None:
            value = []

        response._body = value


class Status(object):

    """Response Status"""

    def __get__(self, response, cls=None):
        if response is None:
            return self
        else:
            return response._status

    def __set__(self, response, value):
        value = HTTPStatus(value) if isinstance(value, int) else value

        response._status = value


class Response(object):

    """Response(sock, request) -> new Response object

    A Response object that holds the response to
    send back to the client. This ensure that the correct data
    is sent in the correct order.
    """

    body = Body()
    status = Status()

    done = False
    close = False
    stream = False
    chunked = False

    def __init__(self, request, encoding='utf-8', status=None):
        "initializes x; see x.__class__.__doc__ for signature"

        self.request = request
        self.encoding = encoding

        self._body = []
        self._status = HTTPStatus(status if status is not None else 200)

        self.time = time()

        self.headers = Headers()
        self.headers["Date"] = formatdate()

        if getattr(self.request.server, "display_banner", False):
            if self.request.server is not None:
                self.headers.add_header("Server", request.server.http.version)
            else:
                self.headers.add_header("X-Powered-By", SERVER_VERSION)

        self.cookie = self.request.cookie

        self.protocol = "HTTP/%d.%d" % self.request.protocol

    def __repr__(self):
        return "<Response %s %s (%d)>" % (
            self.status,
            self.headers.get("Content-Type"),
            (len(self.body) if isinstance(self.body, str) else 0)
        )

    def __str__(self):
        self.prepare()
        protocol = self.protocol
        status = "{0:s}".format(self.status)
        return "{0:s} {1:s}\r\n".format(protocol, status)

    def __bytes__(self):
        return str(self).encode(self.encoding)

    def prepare(self):
        # Set a default content-Type if we don't have one.
        self.headers.setdefault(
            "Content-Type", "text/html; charset={0:s}".format(self.encoding)
        )

        cLength = None
        if self.body is not None:
            if isinstance(self.body, bytes):
                cLength = len(self.body)
            elif isinstance(self.body, unicode):
                cLength = len(self.body.encode(self.encoding))
            elif isinstance(self.body, list):
                cLength = sum(
                    [
                        len(s.encode(self.encoding))
                        if not isinstance(s, bytes)
                        else len(s) for s in self.body
                        if s is not None
                    ]
                )

        if cLength is not None:
            self.headers["Content-Length"] = str(cLength)

        for k, v in self.cookie.items():
            self.headers.add_header("Set-Cookie", v.OutputString())

        status = self.status

        if status == 413:
            self.close = True
        elif "Content-Length" not in self.headers:
            if status < 200 or status in (204, 205, 304):
                pass
            else:
                if self.protocol == "HTTP/1.1" \
                        and self.request.method != "HEAD" \
                        and self.request.server is not None \
                        and not cLength == 0:
                    self.chunked = True
                    self.headers.add_header("Transfer-Encoding", "chunked")
                else:
                    self.close = True

        if (self.request.server is not None
                and "Connection" not in self.headers):
            if self.protocol == "HTTP/1.1":
                if self.close:
                    self.headers.add_header("Connection", "close")
            else:
                if not self.close:
                    self.headers.add_header("Connection", "Keep-Alive")

        if self.headers.get("Transfer-Encoding", "") == "chunked":
            self.chunked = True