path: root/python/werkzeug/_internal.py

# -*- coding: utf-8 -*-
"""
    werkzeug._internal
    ~~~~~~~~~~~~~~~~~~

    This module provides internally used helpers and constants.

    :copyright: 2007 Pallets
    :license: BSD-3-Clause
"""
import inspect
import logging
import re
import string
from datetime import date
from datetime import datetime
from itertools import chain
from weakref import WeakKeyDictionary

from ._compat import int_to_byte
from ._compat import integer_types
from ._compat import iter_bytes
from ._compat import range_type
from ._compat import text_type


_logger = None
_signature_cache = WeakKeyDictionary()
_epoch_ord = date(1970, 1, 1).toordinal()
_cookie_params = {
    b"expires",
    b"path",
    b"comment",
    b"max-age",
    b"secure",
    b"httponly",
    b"version",
}
_legal_cookie_chars = (
    string.ascii_letters + string.digits + u"/=!#$%&'*+-.^_`|~:"
).encode("ascii")

_cookie_quoting_map = {b",": b"\\054", b";": b"\\073", b'"': b'\\"', b"\\": b"\\\\"}
for _i in chain(range_type(32), range_type(127, 256)):
    _cookie_quoting_map[int_to_byte(_i)] = ("\\%03o" % _i).encode("latin1")

_octal_re = re.compile(br"\\[0-3][0-7][0-7]")
_quote_re = re.compile(br"[\\].")
_legal_cookie_chars_re = br"[\w\d!#%&\'~_`><@,:/\$\*\+\-\.\^\|\)\(\?\}\{\=]"
_cookie_re = re.compile(
    br"""
    (?P<key>[^=;]+)
    (?:\s*=\s*
        (?P<val>
            "(?:[^\\"]|\\.)*" |
             (?:.*?)
        )
    )?
    \s*;
""",
    flags=re.VERBOSE,
)


class _Missing(object):
    def __repr__(self):
        return "no value"

    def __reduce__(self):
        return "_missing"


_missing = _Missing()


def _get_environ(obj):
    env = getattr(obj, "environ", obj)
    assert isinstance(env, dict), (
        "%r is not a WSGI environment (has to be a dict)" % type(obj).__name__
    )
    return env


def _has_level_handler(logger):
    """Check if there is a handler in the logging chain that will handle
    the given logger's effective level.
    """
    level = logger.getEffectiveLevel()
    current = logger

    while current:
        if any(handler.level <= level for handler in current.handlers):
            return True

        if not current.propagate:
            break

        current = current.parent

    return False


def _log(type, message, *args, **kwargs):
    """Log a message to the 'werkzeug' logger.

    The logger is created the first time it is needed. If there is no
    level set, it is set to :data:`logging.INFO`. If there is no handler
    for the logger's effective level, a :class:`logging.StreamHandler`
    is added.
    """
    global _logger

    if _logger is None:
        _logger = logging.getLogger("werkzeug")

        if _logger.level == logging.NOTSET:
            _logger.setLevel(logging.INFO)

        if not _has_level_handler(_logger):
            _logger.addHandler(logging.StreamHandler())

    getattr(_logger, type)(message.rstrip(), *args, **kwargs)


def _parse_signature(func):
    """Return a signature object for the function."""
    if hasattr(func, "im_func"):
        func = func.im_func

    # if we have a cached validator for this function, return it
    parse = _signature_cache.get(func)
    if parse is not None:
        return parse

    # inspect the function signature and collect all the information
    if hasattr(inspect, "getfullargspec"):
        tup = inspect.getfullargspec(func)
    else:
        tup = inspect.getargspec(func)
    positional, vararg_var, kwarg_var, defaults = tup[:4]
    defaults = defaults or ()
    arg_count = len(positional)
    arguments = []
    for idx, name in enumerate(positional):
        if isinstance(name, list):
            raise TypeError(
                "cannot parse functions that unpack tuples in the function signature"
            )
        try:
            default = defaults[idx - arg_count]
        except IndexError:
            param = (name, False, None)
        else:
            param = (name, True, default)
        arguments.append(param)
    arguments = tuple(arguments)

    def parse(args, kwargs):
        new_args = []
        missing = []
        extra = {}

        # consume as many arguments as positional as possible
        for idx, (name, has_default, default) in enumerate(arguments):
            try:
                new_args.append(args[idx])
            except IndexError:
                try:
                    new_args.append(kwargs.pop(name))
                except KeyError:
                    if has_default:
                        new_args.append(default)
                    else:
                        missing.append(name)
            else:
                if name in kwargs:
                    extra[name] = kwargs.pop(name)

        # handle extra arguments
        extra_positional = args[arg_count:]
        if vararg_var is not None:
            new_args.extend(extra_positional)
            extra_positional = ()
        if kwargs and kwarg_var is None:
            extra.update(kwargs)
            kwargs = {}

        return (
            new_args,
            kwargs,
            missing,
            extra,
            extra_positional,
            arguments,
            vararg_var,
            kwarg_var,
        )

    _signature_cache[func] = parse
    return parse


def _date_to_unix(arg):
    """Converts a timetuple, integer or datetime object into the seconds from
    epoch in utc.
    """
    if isinstance(arg, datetime):
        arg = arg.utctimetuple()
    elif isinstance(arg, integer_types + (float,)):
        return int(arg)
    year, month, day, hour, minute, second = arg[:6]
    days = date(year, month, 1).toordinal() - _epoch_ord + day - 1
    hours = days * 24 + hour
    minutes = hours * 60 + minute
    seconds = minutes * 60 + second
    return seconds


class _DictAccessorProperty(object):
    """Baseclass for `environ_property` and `header_property`."""

    read_only = False

    def __init__(
        self,
        name,
        default=None,
        load_func=None,
        dump_func=None,
        read_only=None,
        doc=None,
    ):
        self.name = name
        self.default = default
        self.load_func = load_func
        self.dump_func = dump_func
        if read_only is not None:
            self.read_only = read_only
        self.__doc__ = doc

    def __get__(self, obj, type=None):
        if obj is None:
            return self
        storage = self.lookup(obj)
        if self.name not in storage:
            return self.default
        rv = storage[self.name]
        if self.load_func is not None:
            try:
                rv = self.load_func(rv)
            except (ValueError, TypeError):
                rv = self.default
        return rv

    def __set__(self, obj, value):
        if self.read_only:
            raise AttributeError("read only property")
        if self.dump_func is not None:
            value = self.dump_func(value)
        self.lookup(obj)[self.name] = value

    def __delete__(self, obj):
        if self.read_only:
            raise AttributeError("read only property")
        self.lookup(obj).pop(self.name, None)

    def __repr__(self):
        return "<%s %s>" % (self.__class__.__name__, self.name)


def _cookie_quote(b):
    buf = bytearray()
    all_legal = True
    _lookup = _cookie_quoting_map.get
    _push = buf.extend

    for char in iter_bytes(b):
        if char not in _legal_cookie_chars:
            all_legal = False
            char = _lookup(char, char)
        _push(char)

    if all_legal:
        return bytes(buf)
    return bytes(b'"' + buf + b'"')


def _cookie_unquote(b):
    if len(b) < 2:
        return b
    if b[:1] != b'"' or b[-1:] != b'"':
        return b

    b = b[1:-1]

    i = 0
    n = len(b)
    rv = bytearray()
    _push = rv.extend

    while 0 <= i < n:
        o_match = _octal_re.search(b, i)
        q_match = _quote_re.search(b, i)
        if not o_match and not q_match:
            rv.extend(b[i:])
            break
        j = k = -1
        if o_match:
            j = o_match.start(0)
        if q_match:
            k = q_match.start(0)
        if q_match and (not o_match or k < j):
            _push(b[i:k])
            _push(b[k + 1 : k + 2])
            i = k + 2
        else:
            _push(b[i:j])
            rv.append(int(b[j + 1 : j + 4], 8))
            i = j + 4

    return bytes(rv)


def _cookie_parse_impl(b):
    """Lowlevel cookie parsing facility that operates on bytes."""
    i = 0
    n = len(b)

    while i < n:
        match = _cookie_re.search(b + b";", i)
        if not match:
            break

        key = match.group("key").strip()
        value = match.group("val") or b""
        i = match.end(0)

        # Ignore parameters.  We have no interest in them.
        if key.lower() not in _cookie_params:
            yield _cookie_unquote(key), _cookie_unquote(value)


def _encode_idna(domain):
    # If we're given bytes, make sure they fit into ASCII
    if not isinstance(domain, text_type):
        domain.decode("ascii")
        return domain

    # Otherwise check if it's already ascii, then return
    try:
        return domain.encode("ascii")
    except UnicodeError:
        pass

    # Otherwise encode each part separately
    parts = domain.split(".")
    for idx, part in enumerate(parts):
        parts[idx] = part.encode("idna")
    return b".".join(parts)


def _decode_idna(domain):
    # If the input is a string try to encode it to ascii to
    # do the idna decoding.  if that fails because of an
    # unicode error, then we already have a decoded idna domain
    if isinstance(domain, text_type):
        try:
            domain = domain.encode("ascii")
        except UnicodeError:
            return domain

    # Decode each part separately.  If a part fails, try to
    # decode it with ascii and silently ignore errors.  This makes
    # most sense because the idna codec does not have error handling
    parts = domain.split(b".")
    for idx, part in enumerate(parts):
        try:
            parts[idx] = part.decode("idna")
        except UnicodeError:
            parts[idx] = part.decode("ascii", "ignore")

    return ".".join(parts)


def _make_cookie_domain(domain):
    if domain is None:
        return None
    domain = _encode_idna(domain)
    if b":" in domain:
        domain = domain.split(b":", 1)[0]
    if b"." in domain:
        return domain
    raise ValueError(
        "Setting 'domain' for a cookie on a server running locally (ex: "
        "localhost) is not supported by complying browsers. You should "
        "have something like: '127.0.0.1 localhost dev.localhost' on "
        "your hosts file and then point your server to run on "
        "'dev.localhost' and also set 'domain' for 'dev.localhost'"
    )


def _easteregg(app=None):
    """Like the name says.  But who knows how it works?"""

    def bzzzzzzz(gyver):
        import base64
        import zlib

        return zlib.decompress(base64.b64decode(gyver)).decode("ascii")

    gyver = u"\n".join(
        [
            x + (77 - len(x)) * u" "
            for x in bzzzzzzz(
                b"""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"""
            ).splitlines()
        ]
    )

    def easteregged(environ, start_response):
        def injecting_start_response(status, headers, exc_info=None):
            headers.append(("X-Powered-By", "Werkzeug"))
            return start_response(status, headers, exc_info)

        if app is not None and environ.get("QUERY_STRING") != "macgybarchakku":
            return app(environ, injecting_start_response)
        injecting_start_response("200 OK", [("Content-Type", "text/html")])
        return [
            (
                u"""
<!DOCTYPE html>
<html>
<head>
<title>About Werkzeug</title>
<style type="text/css">
  body { font: 15px Georgia, serif; text-align: center; }
  a { color: #333; text-decoration: none; }
  h1 { font-size: 30px; margin: 20px 0 10px 0; }
  p { margin: 0 0 30px 0; }
  pre { font: 11px 'Consolas', 'Monaco', monospace; line-height: 0.95; }
</style>
</head>
<body>
<h1><a href="http://werkzeug.pocoo.org/">Werkzeug</a></h1>
<p>the Swiss Army knife of Python web development.</p>
<pre>%s\n\n\n</pre>
</body>
</html>"""
                % gyver
            ).encode("latin1")
        ]

    return easteregged