# hgweb/request.py - An http request from either CGI or the standalone server.

#

# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net>

# Copyright 2005, 2006 Matt Mackall <mpm@selenic.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 absolute_import

import cgi

import errno

import socket

import wsgiref.headers as wsgiheaders

#import wsgiref.validate

from .common import (

    ErrorResponse,

    HTTP_NOT_MODIFIED,

    statusmessage,

)

from ..thirdparty import (

    attr,

)

from .. import (

    pycompat,

    util,

)

shortcuts = {

    'cl': [('cmd', ['changelog']), ('rev', None)],

    'sl': [('cmd', ['shortlog']), ('rev', None)],

    'cs': [('cmd', ['changeset']), ('node', None)],

    'f': [('cmd', ['file']), ('filenode', None)],

    'fl': [('cmd', ['filelog']), ('filenode', None)],

    'fd': [('cmd', ['filediff']), ('node', None)],

    'fa': [('cmd', ['annotate']), ('filenode', None)],

    'mf': [('cmd', ['manifest']), ('manifest', None)],

    'ca': [('cmd', ['archive']), ('node', None)],

    'tags': [('cmd', ['tags'])],

    'tip': [('cmd', ['changeset']), ('node', ['tip'])],

    'static': [('cmd', ['static']), ('file', None)]

}

def normalize(form):

    # first expand the shortcuts

    for k in shortcuts:

        if k in form:

            for name, value in shortcuts[k]:

                if value is None:

                    value = form[k]

                form[name] = value

            del form[k]

    # And strip the values

    bytesform = {}

    for k, v in form.iteritems():

        bytesform[pycompat.bytesurl(k)] = [

            pycompat.bytesurl(i.strip()) for i in v]

    return bytesform

@attr.s(frozen=True)

class parsedrequest(object):

    """Represents a parsed WSGI request / static HTTP request parameters."""

    # Request method.

    method = attr.ib()

    # Full URL for this request.

    url = attr.ib()

    # URL without any path components. Just <proto>://<host><port>.

    baseurl = attr.ib()

    # Advertised URL. Like ``url`` and ``baseurl`` but uses SERVER_NAME instead

    # of HTTP: Host header for hostname. This is likely what clients used.

    advertisedurl = attr.ib()

    advertisedbaseurl = attr.ib()

    # WSGI application path.

    apppath = attr.ib()

    # List of path parts to be used for dispatch.

    dispatchparts = attr.ib()

    # URL path component (no query string) used for dispatch.

    dispatchpath = attr.ib()

    # Whether there is a path component to this request. This can be true

    # when ``dispatchpath`` is empty due to REPO_NAME muckery.

    havepathinfo = attr.ib()

    # Raw query string (part after "?" in URL).

    querystring = attr.ib()

    # List of 2-tuples of query string arguments.

    querystringlist = attr.ib()

    # Dict of query string arguments. Values are lists with at least 1 item.

    querystringdict = attr.ib()

    # wsgiref.headers.Headers instance. Operates like a dict with case

    # insensitive keys.

    headers = attr.ib()

def parserequestfromenv(env):

    """Parse URL components from environment variables.

    WSGI defines request attributes via environment variables. This function

    parses the environment variables into a data structure.

    """

    # PEP-0333 defines the WSGI spec and is a useful reference for this code.

    # We first validate that the incoming object conforms with the WSGI spec.

    # We only want to be dealing with spec-conforming WSGI implementations.

    # TODO enable this once we fix internal violations.

    #wsgiref.validate.check_environ(env)

    # PEP-0333 states that environment keys and values are native strings

    # (bytes on Python 2 and str on Python 3). The code points for the Unicode

    # strings on Python 3 must be between \00000-\000FF. We deal with bytes

    # in Mercurial, so mass convert string keys and values to bytes.

    if pycompat.ispy3:

        env = {k.encode('latin-1'): v for k, v in env.iteritems()}

        env = {k: v.encode('latin-1') if isinstance(v, str) else v

               for k, v in env.iteritems()}

    # https://www.python.org/dev/peps/pep-0333/#environ-variables defines

    # the environment variables.

    # https://www.python.org/dev/peps/pep-0333/#url-reconstruction defines

    # how URLs are reconstructed.

    fullurl = env['wsgi.url_scheme'] + '://'

    advertisedfullurl = fullurl

    def addport(s):

        if env['wsgi.url_scheme'] == 'https':

            if env['SERVER_PORT'] != '443':

                s += ':' + env['SERVER_PORT']

        else:

            if env['SERVER_PORT'] != '80':

                s += ':' + env['SERVER_PORT']

        return s

    if env.get('HTTP_HOST'):

        fullurl += env['HTTP_HOST']

    else:

        fullurl += env['SERVER_NAME']

        fullurl = addport(fullurl)

    advertisedfullurl += env['SERVER_NAME']

    advertisedfullurl = addport(advertisedfullurl)

    baseurl = fullurl

    advertisedbaseurl = advertisedfullurl

    fullurl += util.urlreq.quote(env.get('SCRIPT_NAME', ''))

    advertisedfullurl += util.urlreq.quote(env.get('SCRIPT_NAME', ''))

    fullurl += util.urlreq.quote(env.get('PATH_INFO', ''))

    advertisedfullurl += util.urlreq.quote(env.get('PATH_INFO', ''))

    if env.get('QUERY_STRING'):

        fullurl += '?' + env['QUERY_STRING']

        advertisedfullurl += '?' + env['QUERY_STRING']

    # When dispatching requests, we look at the URL components (PATH_INFO

    # and QUERY_STRING) after the application root (SCRIPT_NAME). But hgwebdir

    # has the concept of "virtual" repositories. This is defined via REPO_NAME.

    # If REPO_NAME is defined, we append it to SCRIPT_NAME to form a new app

    # root. We also exclude its path components from PATH_INFO when resolving

    # the dispatch path.

    apppath = env['SCRIPT_NAME']

    if env.get('REPO_NAME'):

        if not apppath.endswith('/'):

            apppath += '/'

        apppath += env.get('REPO_NAME')

    if 'PATH_INFO' in env:

        dispatchparts = env['PATH_INFO'].strip('/').split('/')

        # Strip out repo parts.

        repoparts = env.get('REPO_NAME', '').split('/')

        if dispatchparts[:len(repoparts)] == repoparts:

            dispatchparts = dispatchparts[len(repoparts):]

    else:

        dispatchparts = []

    dispatchpath = '/'.join(dispatchparts)

    querystring = env.get('QUERY_STRING', '')

    # We store as a list so we have ordering information. We also store as

    # a dict to facilitate fast lookup.

    querystringlist = util.urlreq.parseqsl(querystring, keep_blank_values=True)

    querystringdict = {}

    for k, v in querystringlist:

        if k in querystringdict:

            querystringdict[k].append(v)

        else:

            querystringdict[k] = [v]

    # HTTP_* keys contain HTTP request headers. The Headers structure should

    # perform case normalization for us. We just rewrite underscore to dash

    # so keys match what likely went over the wire.

    headers = []

    for k, v in env.iteritems():

        if k.startswith('HTTP_'):

            headers.append((k[len('HTTP_'):].replace('_', '-'), v))

    headers = wsgiheaders.Headers(headers)

    # This is kind of a lie because the HTTP header wasn't explicitly

    # sent. But for all intents and purposes it should be OK to lie about

    # this, since a consumer will either either value to determine how many

    # bytes are available to read.

    if 'CONTENT_LENGTH' in env and 'HTTP_CONTENT_LENGTH' not in env:

        headers['Content-Length'] = env['CONTENT_LENGTH']

    return parsedrequest(method=env['REQUEST_METHOD'],

                         url=fullurl, baseurl=baseurl,

                         advertisedurl=advertisedfullurl,

                         advertisedbaseurl=advertisedbaseurl,

                         apppath=apppath,

                         dispatchparts=dispatchparts, dispatchpath=dispatchpath,

                         havepathinfo='PATH_INFO' in env,

                         querystring=querystring,

                         querystringlist=querystringlist,

                         querystringdict=querystringdict,

                         headers=headers)

class wsgirequest(object):

    """Higher-level API for a WSGI request.

    WSGI applications are invoked with 2 arguments. They are used to

    instantiate instances of this class, which provides higher-level APIs

    for obtaining request parameters, writing HTTP output, etc.

    """

    def __init__(self, wsgienv, start_response):

        version = wsgienv[r'wsgi.version']

        if (version < (1, 0)) or (version >= (2, 0)):

            raise RuntimeError("Unknown and unsupported WSGI version %d.%d"

                               % version)

        self.inp = wsgienv[r'wsgi.input']

        if r'HTTP_CONTENT_LENGTH' in wsgienv:

            self.inp = util.cappedreader(self.inp,

                                         int(wsgienv[r'HTTP_CONTENT_LENGTH']))

        elif r'CONTENT_LENGTH' in wsgienv:

            self.inp = util.cappedreader(self.inp,

                                         int(wsgienv[r'CONTENT_LENGTH']))

        self.err = wsgienv[r'wsgi.errors']

        self.threaded = wsgienv[r'wsgi.multithread']

        self.multiprocess = wsgienv[r'wsgi.multiprocess']

        self.run_once = wsgienv[r'wsgi.run_once']

        self.env = wsgienv

        self.form = normalize(cgi.parse(self.inp,

                                        self.env,

                                        keep_blank_values=1))

        self._start_response = start_response

        self.server_write = None

        self.headers = []

    def respond(self, status, type, filename=None, body=None):

        if not isinstance(type, str):

            type = pycompat.sysstr(type)

        if self._start_response is not None:

            self.headers.append((r'Content-Type', type))

            if filename:

                filename = (filename.rpartition('/')[-1]

                            .replace('\\', '\\\\').replace('"', '\\"'))

                self.headers.append(('Content-Disposition',

                                     'inline; filename="%s"' % filename))

            if body is not None:

                self.headers.append((r'Content-Length', str(len(body))))

            for k, v in self.headers:

                if not isinstance(v, str):

                    raise TypeError('header value must be string: %r' % (v,))

            if isinstance(status, ErrorResponse):

                self.headers.extend(status.headers)

                if status.code == HTTP_NOT_MODIFIED:

                    # RFC 2616 Section 10.3.5: 304 Not Modified has cases where

                    # it MUST NOT include any headers other than these and no

                    # body

                    self.headers = [(k, v) for (k, v) in self.headers if

                                    k in ('Date', 'ETag', 'Expires',

                                          'Cache-Control', 'Vary')]

                status = statusmessage(status.code, pycompat.bytestr(status))

            elif status == 200:

                status = '200 Script output follows'

            elif isinstance(status, int):

                status = statusmessage(status)

            # Various HTTP clients (notably httplib) won't read the HTTP

            # response until the HTTP request has been sent in full. If servers

            # (us) send a response before the HTTP request has been fully sent,

            # the connection may deadlock because neither end is reading.

            #

            # We work around this by "draining" the request data before

            # sending any response in some conditions.

            drain = False

            close = False

            # If the client sent Expect: 100-continue, we assume it is smart

            # enough to deal with the server sending a response before reading

            # the request. (httplib doesn't do this.)

            if self.env.get(r'HTTP_EXPECT', r'').lower() == r'100-continue':

                pass

            # Only tend to request methods that have bodies. Strictly speaking,

            # we should sniff for a body. But this is fine for our existing

            # WSGI applications.

            elif self.env[r'REQUEST_METHOD'] not in (r'POST', r'PUT'):

                pass

            else:

                # If we don't know how much data to read, there's no guarantee

                # that we can drain the request responsibly. The WSGI

                # specification only says that servers *should* ensure the

                # input stream doesn't overrun the actual request. So there's

                # no guarantee that reading until EOF won't corrupt the stream

                # state.

                if not isinstance(self.inp, util.cappedreader):

                    close = True

                else:

                    # We /could/ only drain certain HTTP response codes. But 200

                    # and non-200 wire protocol responses both require draining.

                    # Since we have a capped reader in place for all situations

                    # where we drain, it is safe to read from that stream. We'll

                    # either do a drain or no-op if we're already at EOF.

                    drain = True

            if close:

                self.headers.append((r'Connection', r'Close'))

            if drain:

                assert isinstance(self.inp, util.cappedreader)

                while True:

                    chunk = self.inp.read(32768)

                    if not chunk:

                        break

            self.server_write = self._start_response(

                pycompat.sysstr(status), self.headers)

            self._start_response = None

            self.headers = []

        if body is not None:

            self.write(body)

            self.server_write = None

    def write(self, thing):

        if thing:

            try:

                self.server_write(thing)

            except socket.error as inst:

                if inst[0] != errno.ECONNRESET:

                    raise

    def flush(self):

        return None

def wsgiapplication(app_maker):

    '''For compatibility with old CGI scripts. A plain hgweb() or hgwebdir()

    can and should now be used as a WSGI application.'''

    application = app_maker()

    def run_wsgi(env, respond):

        return application(env, respond)

    return run_wsgi