# url.py - HTTP handling for mercurial
#
# Copyright 2005, 2006, 2007, 2008 Olivia Mackall <olivia@selenic.com>
# Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import annotations

import abc
import base64
import hashlib
import socket
from typing import Protocol, TYPE_CHECKING

from .i18n import _
from .node import hex
from . import (
    encoding,
    error,
    httpconnection as httpconnectionmod,
    keepalive,
    pycompat,
    sslutil,
    urllibcompat,
    util,
)
from .utils import (
    stringutil,
    urlutil,
)

httplib = util.httplib
stringio = util.stringio
urlerr = util.urlerr
urlreq = util.urlreq

if TYPE_CHECKING:
    import http.client
    import urllib.request

    HTTPResponseT = http.client.HTTPResponse
    HTTPRequestT = urllib.request.Request


def escape(s, quote=None):
    """Replace special characters "&", "<" and ">" to HTML-safe sequences.
    If the optional flag quote is true, the quotation mark character (")
    is also translated.

    This is the same as cgi.escape in Python, but always operates on
    bytes, whereas cgi.escape in Python 3 only works on unicodes.
    """
    s = s.replace(b"&", b"&amp;")
    s = s.replace(b"<", b"&lt;")
    s = s.replace(b">", b"&gt;")
    if quote:
        s = s.replace(b'"', b"&quot;")
    return s


class passwordmgr:
    def __init__(self, ui, passwddb):
        self.ui = ui
        self.passwddb = passwddb

    def add_password(self, realm, uri, user, passwd):
        return self.passwddb.add_password(realm, uri, user, passwd)

    def find_user_password(self, realm, authuri):
        assert isinstance(realm, (type(None), str))
        assert isinstance(authuri, str)
        authinfo = self.passwddb.find_user_password(realm, authuri)
        user, passwd = authinfo
        user, passwd = pycompat.bytesurl(user), pycompat.bytesurl(passwd)
        if user and passwd:
            self._writedebug(user, passwd)
            return (pycompat.strurl(user), pycompat.strurl(passwd))

        if not user or not passwd:
            res = httpconnectionmod.readauthforuri(self.ui, authuri, user)
            if res:
                group, auth = res
                user, passwd = auth.get(b'username'), auth.get(b'password')
                self.ui.debug(b"using auth.%s.* for authentication\n" % group)
        if not user or not passwd:
            u = urlutil.url(pycompat.bytesurl(authuri))
            u.query = None
            if not self.ui.interactive():
                raise error.Abort(
                    _(b'http authorization required for %s')
                    % urlutil.hidepassword(bytes(u))
                )

            self.ui.write(
                _(b"http authorization required for %s\n")
                % urlutil.hidepassword(bytes(u))
            )
            self.ui.write(_(b"realm: %s\n") % pycompat.bytesurl(realm))
            if user:
                self.ui.write(_(b"user: %s\n") % user)
            else:
                user = self.ui.prompt(_(b"user:"), default=None)

            if not passwd:
                passwd = self.ui.getpass()

        # As of Python 3.8, the default implementation of
        # AbstractBasicAuthHandler.retry_http_basic_auth() assumes the user
        # is set if pw is not None. This means (None, str) is not a valid
        # return type of find_user_password().
        if user is None:
            return None, None

        self.passwddb.add_password(realm, authuri, user, passwd)
        self._writedebug(user, passwd)
        return (pycompat.strurl(user), pycompat.strurl(passwd))

    def _writedebug(self, user: bytes, passwd: bytes) -> None:
        msg = _(b'http auth: user %s, password %s\n')
        self.ui.debug(
            msg % (user, b'*' * len(passwd) if passwd else b'not set')
        )

    def find_stored_password(self, authuri):
        return self.passwddb.find_user_password(None, authuri)


class proxyhandler(urlreq.proxyhandler):
    def __init__(self, ui):
        proxyurl = ui.config(b"http_proxy", b"host") or encoding.environ.get(
            b'http_proxy'
        )
        # XXX proxyauthinfo = None

        if proxyurl:
            # proxy can be proper url or host[:port]
            if not (
                proxyurl.startswith(b'http:') or proxyurl.startswith(b'https:')
            ):
                proxyurl = b'http://' + proxyurl + b'/'
            proxy = urlutil.url(proxyurl)
            if not proxy.user:
                proxy.user = ui.config(b"http_proxy", b"user")
                proxy.passwd = ui.config(b"http_proxy", b"passwd")

            # see if we should use a proxy for this url
            no_list = [b"localhost", b"127.0.0.1"]
            no_list.extend(
                [p.lower() for p in ui.configlist(b"http_proxy", b"no")]
            )
            no_list.extend(
                [
                    p.strip().lower()
                    for p in encoding.environ.get(b"no_proxy", b'').split(b',')
                    if p.strip()
                ]
            )
            # "http_proxy.always" config is for running tests on localhost
            if ui.configbool(b"http_proxy", b"always"):
                self.no_list = []
            else:
                self.no_list = no_list

            # Keys and values need to be str because the standard library
            # expects them to be.
            proxyurl = str(proxy)
            proxies = {'http': proxyurl, 'https': proxyurl}
            ui.debug(
                b'proxying through %s\n' % urlutil.hidepassword(bytes(proxy))
            )
        else:
            proxies = {}

        urlreq.proxyhandler.__init__(self, proxies)
        self.ui = ui

    def proxy_open(self, req, proxy, type_):
        host = pycompat.bytesurl(urllibcompat.gethost(req)).split(b':')[0]
        for e in self.no_list:
            if host == e:
                return None
            if e.startswith(b'*.') and host.endswith(e[2:]):
                return None
            if e.startswith(b'.') and host.endswith(e[1:]):
                return None

        return urlreq.proxyhandler.proxy_open(self, req, proxy, type_)


def _gen_sendfile(orgsend):
    def _sendfile(self, data):
        # send a file
        if isinstance(data, httpconnectionmod.httpsendfile):
            # if auth required, some data sent twice, so rewind here
            data.seek(0)
            for chunk in util.filechunkiter(data):
                orgsend(self, chunk)
        else:
            orgsend(self, data)

    return _sendfile


has_https = hasattr(urlreq, 'httpshandler')


class httpconnection(keepalive.HTTPConnection):
    # must be able to send big bundle as stream.
    send = _gen_sendfile(keepalive.HTTPConnection.send)


# Large parts of this function have their origin from before Python 2.6
# and could potentially be removed.
def _generic_start_transaction(handler, h, req):
    tunnel_host = req._tunnel_host
    if tunnel_host:
        if tunnel_host[:7] not in ['http://', 'https:/']:
            tunnel_host = 'https://' + tunnel_host
        new_tunnel = True
    else:
        tunnel_host = urllibcompat.getselector(req)
        new_tunnel = False

    if new_tunnel or tunnel_host == urllibcompat.getfullurl(req):  # has proxy
        u = urlutil.url(pycompat.bytesurl(tunnel_host))
        if new_tunnel or u.scheme == b'https':  # only use CONNECT for HTTPS
            h.realhostport = b':'.join([u.host, (u.port or b'443')])
            h.headers = req.headers.copy()
            h.headers.update(handler.parent.addheaders)
            return

    h.realhostport = None
    h.headers = None


class httphandler(keepalive.HTTPHandler):
    def http_open(self, req):
        return self.do_open(httpconnection, req)

    def _start_transaction(self, h, req):
        _generic_start_transaction(self, h, req)
        return keepalive.HTTPHandler._start_transaction(self, h, req)


class logginghttphandler(httphandler):
    """HTTP(S) handler that logs socket I/O."""

    def __init__(self, logfh, name, observeropts, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self._logfh = logfh
        self._logname = name
        self._observeropts = observeropts

    def do_open(self, http_class, *args, **kwargs):
        _logfh = self._logfh
        _logname = self._logname
        _observeropts = self._observeropts

        class logginghttpconnection(http_class):
            def connect(self):
                super().connect()
                self.sock = util.makeloggingsocket(
                    _logfh, self.sock, _logname, **_observeropts
                )

        return super().do_open(logginghttpconnection, *args, **kwargs)


if has_https:

    def _generic_proxytunnel(self: httpsconnection):
        headers = self.headers  # pytype: disable=attribute-error
        proxyheaders = {
            pycompat.bytestr(x): pycompat.bytestr(headers[x])
            for x in headers
            if x.lower().startswith('proxy-')
        }
        realhostport = self.realhostport  # pytype: disable=attribute-error
        self.send(b'CONNECT %s HTTP/1.0\r\n' % realhostport)

        for header in proxyheaders.items():
            self.send(b'%s: %s\r\n' % header)
        self.send(b'\r\n')

        # majority of the following code is duplicated from
        # httplib.HTTPConnection as there are no adequate places to
        # override functions to provide the needed functionality.

        # pytype: disable=attribute-error
        res = self.response_class(self.sock, method=self._method)
        # pytype: enable=attribute-error

        while True:
            # pytype: disable=attribute-error
            version, status, reason = res._read_status()
            # pytype: enable=attribute-error
            if status != httplib.CONTINUE:
                break
            # skip lines that are all whitespace
            list(iter(lambda: res.fp.readline().strip(), b''))

        if status == 200:
            # skip lines until we find a blank line
            list(iter(res.fp.readline, b'\r\n'))
        else:
            self.close()
            raise OSError(
                "Tunnel connection failed: %d %s" % (status, reason.strip())
            )

    class httpsconnection(keepalive.HTTPConnection):
        response_class = keepalive.HTTPResponse
        default_port = httplib.HTTPS_PORT
        # must be able to send big bundle as stream.
        send = _gen_sendfile(keepalive.safesend)
        getresponse = keepalive.wrapgetresponse(httplib.HTTPConnection)

        def __init__(
            self,
            host,
            port=None,
            key_file=None,
            cert_file=None,
            *args,
            **kwargs,
        ):
            keepalive.HTTPConnection.__init__(self, host, port, *args, **kwargs)
            self.key_file = key_file
            self.cert_file = cert_file

        def connect(self):
            self.sock = socket.create_connection(
                (self.host, self.port), self.timeout
            )

            host = self.host
            realhostport = self.realhostport  # pytype: disable=attribute-error
            if realhostport:  # use CONNECT proxy
                _generic_proxytunnel(self)
                host = realhostport.rsplit(b':', 1)[0]
            self.sock = sslutil.wrapsocket(
                self.sock,
                self.key_file,
                self.cert_file,
                ui=self.ui,  # pytype: disable=attribute-error
                serverhostname=host,
            )
            sslutil.validatesocket(self.sock)

    class httpshandler(keepalive.KeepAliveHandler, urlreq.httpshandler):
        def __init__(self, ui, timeout=None):
            keepalive.KeepAliveHandler.__init__(self, timeout=timeout)
            urlreq.httpshandler.__init__(self)
            self.ui = ui
            self.pwmgr = passwordmgr(self.ui, self.ui.httppasswordmgrdb)

        def _start_transaction(self, h, req):
            _generic_start_transaction(self, h, req)
            return keepalive.KeepAliveHandler._start_transaction(self, h, req)

        def https_open(self, req):
            # urllibcompat.getfullurl() does not contain credentials
            # and we may need them to match the certificates.
            url = urllibcompat.getfullurl(req)
            user, password = self.pwmgr.find_stored_password(url)
            res = httpconnectionmod.readauthforuri(self.ui, url, user)
            if res:
                group, auth = res
                self.auth = auth
                self.ui.debug(b"using auth.%s.* for authentication\n" % group)
            else:
                self.auth = None
            return self.do_open(self._makeconnection, req)

        def _makeconnection(self, host, port=None, *args, **kwargs):
            keyfile = None
            certfile = None

            if len(args) >= 1:  # key_file
                keyfile = args[0]
            if len(args) >= 2:  # cert_file
                certfile = args[1]
            args = args[2:]

            # if the user has specified different key/cert files in
            # hgrc, we prefer these
            if self.auth and b'key' in self.auth and b'cert' in self.auth:
                keyfile = self.auth[b'key']
                certfile = self.auth[b'cert']

            conn = httpsconnection(
                host, port, keyfile, certfile, *args, **kwargs
            )
            conn.ui = self.ui
            return conn


class httpdigestauthhandler(urlreq.httpdigestauthhandler):
    def __init__(self, *args, **kwargs):
        urlreq.httpdigestauthhandler.__init__(self, *args, **kwargs)
        self.retried_req = None

    def reset_retry_count(self):
        # Python 2.6.5 will call this on 401 or 407 errors and thus loop
        # forever. We disable reset_retry_count completely and reset in
        # http_error_auth_reqed instead.
        pass

    def http_error_auth_reqed(self, auth_header, host, req, headers):
        # Reset the retry counter once for each request.
        if req is not self.retried_req:
            self.retried_req = req
            self.retried = 0
        return urlreq.httpdigestauthhandler.http_error_auth_reqed(
            self, auth_header, host, req, headers
        )


class httpbasicauthhandler(urlreq.httpbasicauthhandler):
    def __init__(self, *args, **kwargs):
        self.auth = None
        urlreq.httpbasicauthhandler.__init__(self, *args, **kwargs)
        self.retried_req = None

    def http_request(self, request):
        if self.auth:
            request.add_unredirected_header(self.auth_header, self.auth)

        return request

    def https_request(self, request):
        if self.auth:
            request.add_unredirected_header(self.auth_header, self.auth)

        return request

    def reset_retry_count(self):
        # Python 2.6.5 will call this on 401 or 407 errors and thus loop
        # forever. We disable reset_retry_count completely and reset in
        # http_error_auth_reqed instead.
        pass

    def http_error_auth_reqed(self, auth_header, host, req, headers):
        # Reset the retry counter once for each request.
        if req is not self.retried_req:
            self.retried_req = req
            self.retried = 0
        return urlreq.httpbasicauthhandler.http_error_auth_reqed(
            self, auth_header, host, req, headers
        )

    def retry_http_basic_auth(self, host, req, realm):
        user, pw = self.passwd.find_user_password(
            realm, urllibcompat.getfullurl(req)
        )
        if pw is not None:
            raw = b"%s:%s" % (pycompat.bytesurl(user), pycompat.bytesurl(pw))
            auth = 'Basic %s' % pycompat.strurl(base64.b64encode(raw).strip())
            if req.get_header(self.auth_header, None) == auth:
                return None
            self.auth = auth
            req.add_unredirected_header(self.auth_header, auth)
            return self.parent.open(req)
        else:
            return None


def load_cookiejar(ui):
    cookiefile = ui.config(b'auth', b'cookiefile')
    if not cookiefile:
        return
    cookiefile = util.expandpath(cookiefile)
    try:
        cookiejar = util.cookielib.MozillaCookieJar(
            pycompat.fsdecode(cookiefile)
        )
        cookiejar.load()
        return cookiejar
    except util.cookielib.LoadError as e:
        ui.warn(
            _(
                b'(error loading cookie file %s: %s; continuing without '
                b'cookies)\n'
            )
            % (cookiefile, stringutil.forcebytestr(e))
        )


class readlinehandler(urlreq.basehandler):
    def http_response(self, request, response):
        class readlineresponse(response.__class__):
            def readlines(self, sizehint=0):
                total = 0
                list = []
                while True:
                    line = self.readline()
                    if not line:
                        break
                    list.append(line)
                    total += len(line)
                    if sizehint and total >= sizehint:
                        break
                return list

        response.__class__ = readlineresponse
        return response

    https_response = http_response


class digesthandler(urlreq.basehandler):
    # exchange.py assumes the algorithms are listed in order of preference,
    # earlier entries are prefered.
    digest_algorithms = {
        b'sha256': hashlib.sha256,
        b'sha512': hashlib.sha512,
    }

    def __init__(self, digest):
        if b':' not in digest:
            raise error.Abort(_(b'invalid digest specification'))
        algo, checksum = digest.split(b':')
        if algo not in self.digest_algorithms:
            raise error.Abort(_(b'unsupported digest algorithm: %s') % algo)
        self._digest = checksum
        self._hasher = self.digest_algorithms[algo]()

    def http_response(self, request, response):
        class digestresponse(response.__class__):
            def _digest_input(self, data):
                self._hasher.update(data)
                self._digest_consumed += len(data)
                if self._digest_finished:
                    digest = hex(self._hasher.digest())
                    if digest != self._digest:
                        raise error.SecurityError(
                            _(
                                b'file with digest %s expected, but %s found for %d bytes'
                            )
                            % (
                                pycompat.bytestr(self._digest),
                                pycompat.bytestr(digest),
                                self._digest_consumed,
                            )
                        )

            def read(self, amt=None):
                self._digest_recursion_level += 1
                data = super().read(amt)
                self._digest_recursion_level -= 1
                if self._digest_recursion_level == 0:
                    self._digest_input(data)
                return data

            def readline(self):
                self._digest_recursion_level += 1
                data = super().readline()
                self._digest_recursion_level -= 1
                if self._digest_recursion_level == 0:
                    self._digest_input(data)
                return data

            def readinto(self, dest):
                self._digest_recursion_level += 1
                got = super().readinto(dest)
                self._digest_recursion_level -= 1
                if self._digest_recursion_level == 0:
                    self._digest_input(dest[:got])
                return got

            def _close_conn(self):
                self._digest_finished = True
                return super().close()

        response.__class__ = digestresponse
        response._digest = self._digest
        response._digest_consumed = 0
        response._hasher = self._hasher.copy()
        # Python 3.8 / 3.9 recurses internally between read/readinto.
        response._digest_recursion_level = 0
        response._digest_finished = False
        return response

    https_response = http_response


handlerfuncs = []


class _Stream(Protocol):
    """Simple protocol class to help typing `UrlOpenerT`"""

    @abc.abstractmethod
    def read(self, size: int = -1, /) -> bytes:
        ...


class UrlOpenerT(Protocol):
    handlers: list
    requestscount: int
    sentbytescount: int
    receivedbytescount: int

    def open(
        self,
        x: HTTPRequestT | str,
        data: bytes | _Stream | None = None,
        timeout: float | None = None,
    ) -> HTTPResponseT:
        ...

    def add_handler(self, handler: urllib.request.BaseHandler):
        ...


def opener(
    ui,
    authinfo=None,
    useragent=None,
    loggingfh=None,
    loggingname=b's',
    loggingopts=None,
    sendaccept=True,
    digest=None,
) -> UrlOpenerT:
    """
    construct an opener suitable for urllib2
    authinfo will be added to the password manager

    The opener can be configured to log socket events if the various
    ``logging*`` arguments are specified.

    ``loggingfh`` denotes a file object to log events to.
    ``loggingname`` denotes the name of the to print when logging.
    ``loggingopts`` is a dict of keyword arguments to pass to the constructed
    ``util.socketobserver`` instance.

    ``sendaccept`` allows controlling whether the ``Accept`` request header
    is sent. The header is sent by default.
    """
    timeout = ui.configwith(float, b'http', b'timeout')
    handlers = []

    if loggingfh:
        handlers.append(
            logginghttphandler(
                loggingfh, loggingname, loggingopts or {}, timeout=timeout
            )
        )
    else:
        handlers.append(httphandler(timeout=timeout))
    if has_https:
        # pytype get confused about the conditional existence for httpshandler here.
        handlers.append(
            # pytype: disable=name-error
            httpshandler(ui, timeout=timeout)
            # pytype: enable=name-error
        )

    handlers.append(proxyhandler(ui))

    passmgr = passwordmgr(ui, ui.httppasswordmgrdb)
    if authinfo is not None:
        realm, uris, user, passwd = authinfo
        saveduser, savedpass = passmgr.find_stored_password(uris[0])
        if user != saveduser or passwd:
            passmgr.add_password(realm, uris, user, passwd)
        ui.debug(
            b'http auth: user %s, password %s\n'
            % (user, b'*' * len(passwd) if passwd else b'not set')
        )

    handlers.extend(
        (httpbasicauthhandler(passmgr), httpdigestauthhandler(passmgr))
    )
    handlers.extend([h(ui, passmgr) for h in handlerfuncs])
    handlers.append(urlreq.httpcookieprocessor(cookiejar=load_cookiejar(ui)))
    handlers.append(readlinehandler())
    if digest:
        handlers.append(digesthandler(digest))
    opener = urlreq.buildopener(*handlers)

    # keepalive.py's handlers will populate these attributes if they exist.
    opener.requestscount = 0
    opener.sentbytescount = 0
    opener.receivedbytescount = 0

    # The user agent should should *NOT* be used by servers for e.g.
    # protocol detection or feature negotiation: there are other
    # facilities for that.
    #
    # "mercurial/proto-1.0" was the original user agent string and
    # exists for backwards compatibility reasons.
    #
    # The "(Mercurial %s)" string contains the distribution
    # name and version. Other client implementations should choose their
    # own distribution name. Since servers should not be using the user
    # agent string for anything, clients should be able to define whatever
    # user agent they deem appropriate.
    #
    # The custom user agent is for lfs, because unfortunately some servers
    # do look at this value.
    if not useragent:
        agent = b'mercurial/proto-1.0 (Mercurial %s)' % util.version()
        opener.addheaders = [('User-agent', pycompat.sysstr(agent))]
    else:
        opener.addheaders = [('User-agent', pycompat.sysstr(useragent))]

    # This header should only be needed by wire protocol requests. But it has
    # been sent on all requests since forever. We keep sending it for backwards
    # compatibility reasons. Modern versions of the wire protocol use
    # X-HgProto-<N> for advertising client support.
    if sendaccept:
        opener.addheaders.append(('Accept', 'application/mercurial-0.1'))

    return opener


def open(ui, url_, data=None, sendaccept=True, digest=None) -> HTTPResponseT:
    u = urlutil.url(url_)
    if u.scheme:
        u.scheme = u.scheme.lower()
        url_, authinfo = u.authinfo()
    else:
        path = util.normpath(util.abspath(url_))
        url_ = b'file://' + pycompat.bytesurl(
            urlreq.pathname2url(pycompat.fsdecode(path))
        )
        authinfo = None
    return opener(ui, authinfo, sendaccept=sendaccept, digest=digest).open(
        pycompat.strurl(url_), data
    )


def wrapresponse(resp):
    """Wrap a response object with common error handlers.

    This ensures that any I/O from any consumer raises the appropriate
    error and messaging.
    """
    origread = resp.read

    class readerproxy(resp.__class__):
        def read(self, size=None):
            try:
                return origread(size)
            except httplib.IncompleteRead as e:
                # e.expected is an integer if length known or None otherwise.
                if e.expected:
                    got = len(e.partial)
                    total = e.expected + got
                    msg = _(
                        b'HTTP request error (incomplete response; '
                        b'expected %d bytes got %d)'
                    ) % (total, got)
                else:
                    msg = _(b'HTTP request error (incomplete response)')

                raise error.PeerTransportError(
                    msg,
                    hint=_(
                        b'this may be an intermittent network failure; '
                        b'if the error persists, consider contacting the '
                        b'network or server operator'
                    ),
                )
            except httplib.HTTPException as e:
                raise error.PeerTransportError(
                    _(b'HTTP request error (%s)') % e,
                    hint=_(
                        b'this may be an intermittent network failure; '
                        b'if the error persists, consider contacting the '
                        b'network or server operator'
                    ),
                )

    resp.__class__ = readerproxy
