# hgweb/hgweb_mod.py - Web interface for a repository.

#

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

# Copyright 2005-2007 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 contextlib

import os

from .common import (

    ErrorResponse,

    HTTP_BAD_REQUEST,

    cspvalues,

    permhooks,

    statusmessage,

)

from .. import (

    encoding,

    error,

    formatter,

    hg,

    hook,

    profiling,

    pycompat,

    repoview,

    templatefilters,

    templater,

    ui as uimod,

    util,

    wireprotoserver,

)

from . import (

    request as requestmod,

    webcommands,

    webutil,

    wsgicgi,

)

archivespecs = util.sortdict((

    ('zip', ('application/zip', 'zip', '.zip', None)),

    ('gz', ('application/x-gzip', 'tgz', '.tar.gz', None)),

    ('bz2', ('application/x-bzip2', 'tbz2', '.tar.bz2', None)),

))

def getstyle(req, configfn, templatepath):

    styles = (

        req.qsparams.get('style', None),

        configfn('web', 'style'),

        'paper',

    )

    return styles, templater.stylemap(styles, templatepath)

def makebreadcrumb(url, prefix=''):

    '''Return a 'URL breadcrumb' list

    A 'URL breadcrumb' is a list of URL-name pairs,

    corresponding to each of the path items on a URL.

    This can be used to create path navigation entries.

    '''

    if url.endswith('/'):

        url = url[:-1]

    if prefix:

        url = '/' + prefix + url

    relpath = url

    if relpath.startswith('/'):

        relpath = relpath[1:]

    breadcrumb = []

    urlel = url

    pathitems = [''] + relpath.split('/')

    for pathel in reversed(pathitems):

        if not pathel or not urlel:

            break

        breadcrumb.append({'url': urlel, 'name': pathel})

        urlel = os.path.dirname(urlel)

    return reversed(breadcrumb)

class requestcontext(object):

    """Holds state/context for an individual request.

    Servers can be multi-threaded. Holding state on the WSGI application

    is prone to race conditions. Instances of this class exist to hold

    mutable and race-free state for requests.

    """

    def __init__(self, app, repo, req, res):

        self.repo = repo

        self.reponame = app.reponame

        self.req = req

        self.res = res

        self.archivespecs = archivespecs

        self.maxchanges = self.configint('web', 'maxchanges')

        self.stripecount = self.configint('web', 'stripes')

        self.maxshortchanges = self.configint('web', 'maxshortchanges')

        self.maxfiles = self.configint('web', 'maxfiles')

        self.allowpull = self.configbool('web', 'allow-pull')

        # we use untrusted=False to prevent a repo owner from using

        # web.templates in .hg/hgrc to get access to any file readable

        # by the user running the CGI script

        self.templatepath = self.config('web', 'templates', untrusted=False)

        # This object is more expensive to build than simple config values.

        # It is shared across requests. The app will replace the object

        # if it is updated. Since this is a reference and nothing should

        # modify the underlying object, it should be constant for the lifetime

        # of the request.

        self.websubtable = app.websubtable

        self.csp, self.nonce = cspvalues(self.repo.ui)

    # Trust the settings from the .hg/hgrc files by default.

    def config(self, section, name, default=uimod._unset, untrusted=True):

        return self.repo.ui.config(section, name, default,

                                   untrusted=untrusted)

    def configbool(self, section, name, default=uimod._unset, untrusted=True):

        return self.repo.ui.configbool(section, name, default,

                                       untrusted=untrusted)

    def configint(self, section, name, default=uimod._unset, untrusted=True):

        return self.repo.ui.configint(section, name, default,

                                      untrusted=untrusted)

    def configlist(self, section, name, default=uimod._unset, untrusted=True):

        return self.repo.ui.configlist(section, name, default,

                                       untrusted=untrusted)

    def archivelist(self, nodeid):

        allowed = self.configlist('web', 'allow_archive')

        for typ, spec in self.archivespecs.iteritems():

            if typ in allowed or self.configbool('web', 'allow%s' % typ):

                yield {'type': typ, 'extension': spec[2], 'node': nodeid}

    def templater(self, req):

        # determine scheme, port and server name

        # this is needed to create absolute urls

        logourl = self.config('web', 'logourl')

        logoimg = self.config('web', 'logoimg')

        staticurl = (self.config('web', 'staticurl')

                     or req.apppath + '/static/')

        if not staticurl.endswith('/'):

            staticurl += '/'

        # some functions for the templater

        def motd(**map):

            yield self.config('web', 'motd')

        # figure out which style to use

        vars = {}

        styles, (style, mapfile) = getstyle(req, self.config,

                                            self.templatepath)

        if style == styles[0]:

            vars['style'] = style

        sessionvars = webutil.sessionvars(vars, '?')

        if not self.reponame:

            self.reponame = (self.config('web', 'name', '')

                             or req.reponame

                             or req.apppath

                             or self.repo.root)

        def websubfilter(text):

            return templatefilters.websub(text, self.websubtable)

        # create the templater

        # TODO: export all keywords: defaults = templatekw.keywords.copy()

        defaults = {

            'url': req.apppath + '/',

            'logourl': logourl,

            'logoimg': logoimg,

            'staticurl': staticurl,

            'urlbase': req.advertisedbaseurl,

            'repo': self.reponame,

            'encoding': encoding.encoding,

            'motd': motd,

            'sessionvars': sessionvars,

            'pathdef': makebreadcrumb(req.apppath),

            'style': style,

            'nonce': self.nonce,

        }

        tres = formatter.templateresources(self.repo.ui, self.repo)

        tmpl = templater.templater.frommapfile(mapfile,

                                               filters={'websub': websubfilter},

                                               defaults=defaults,

                                               resources=tres)

        return tmpl

    def sendtemplate(self, name, **kwargs):

        """Helper function to send a response generated from a template."""

        self.res.setbodygen(self.tmpl(name, **kwargs))

        return self.res.sendresponse()

class hgweb(object):

    """HTTP server for individual repositories.

    Instances of this class serve HTTP responses for a particular

    repository.

    Instances are typically used as WSGI applications.

    Some servers are multi-threaded. On these servers, there may

    be multiple active threads inside __call__.

    """

    def __init__(self, repo, name=None, baseui=None):

        if isinstance(repo, str):

            if baseui:

                u = baseui.copy()

            else:

                u = uimod.ui.load()

            r = hg.repository(u, repo)

        else:

            # we trust caller to give us a private copy

            r = repo

        r.ui.setconfig('ui', 'report_untrusted', 'off', 'hgweb')

        r.baseui.setconfig('ui', 'report_untrusted', 'off', 'hgweb')

        r.ui.setconfig('ui', 'nontty', 'true', 'hgweb')

        r.baseui.setconfig('ui', 'nontty', 'true', 'hgweb')

        # resolve file patterns relative to repo root

        r.ui.setconfig('ui', 'forcecwd', r.root, 'hgweb')

        r.baseui.setconfig('ui', 'forcecwd', r.root, 'hgweb')

        # displaying bundling progress bar while serving feel wrong and may

        # break some wsgi implementation.

        r.ui.setconfig('progress', 'disable', 'true', 'hgweb')

        r.baseui.setconfig('progress', 'disable', 'true', 'hgweb')

        self._repos = [hg.cachedlocalrepo(self._webifyrepo(r))]

        self._lastrepo = self._repos[0]

        hook.redirect(True)

        self.reponame = name

    def _webifyrepo(self, repo):

        repo = getwebview(repo)

        self.websubtable = webutil.getwebsubs(repo)

        return repo

    @contextlib.contextmanager

    def _obtainrepo(self):

        """Obtain a repo unique to the caller.

        Internally we maintain a stack of cachedlocalrepo instances

        to be handed out. If one is available, we pop it and return it,

        ensuring it is up to date in the process. If one is not available,

        we clone the most recently used repo instance and return it.

        It is currently possible for the stack to grow without bounds

        if the server allows infinite threads. However, servers should

        have a thread limit, thus establishing our limit.

        """

        if self._repos:

            cached = self._repos.pop()

            r, created = cached.fetch()

        else:

            cached = self._lastrepo.copy()

            r, created = cached.fetch()

        if created:

            r = self._webifyrepo(r)

        self._lastrepo = cached

        self.mtime = cached.mtime

        try:

            yield r

        finally:

            self._repos.append(cached)

    def run(self):

        """Start a server from CGI environment.

        Modern servers should be using WSGI and should avoid this

        method, if possible.

        """

        if not encoding.environ.get('GATEWAY_INTERFACE',

                                    '').startswith("CGI/1."):

            raise RuntimeError("This function is only intended to be "

                               "called while running as a CGI script.")

        wsgicgi.launch(self)

    def __call__(self, env, respond):

        """Run the WSGI application.

        This may be called by multiple threads.

        """

        req = requestmod.parserequestfromenv(env)

        res = requestmod.wsgiresponse(req, respond)

        return self.run_wsgi(req, res)

    def run_wsgi(self, req, res):

        """Internal method to run the WSGI application.

        This is typically only called by Mercurial. External consumers

        should be using instances of this class as the WSGI application.

        """

        with self._obtainrepo() as repo:

            profile = repo.ui.configbool('profiling', 'enabled')

            with profiling.profile(repo.ui, enabled=profile):

                for r in self._runwsgi(req, res, repo):

                    yield r

    def _runwsgi(self, req, res, repo):

        rctx = requestcontext(self, repo, req, res)

        # This state is global across all threads.

        encoding.encoding = rctx.config('web', 'encoding')

        rctx.repo.ui.environ = req.rawenv

        if rctx.csp:

            # hgwebdir may have added CSP header. Since we generate our own,

            # replace it.

            res.headers['Content-Security-Policy'] = rctx.csp

        handled = wireprotoserver.handlewsgirequest(

            rctx, req, res, self.check_perm)

        if handled:

            return res.sendresponse()

        # Old implementations of hgweb supported dispatching the request via

        # the initial query string parameter instead of using PATH_INFO.

        # If PATH_INFO is present (signaled by ``req.dispatchpath`` having

        # a value), we use it. Otherwise fall back to the query string.

        if req.dispatchpath is not None:

            query = req.dispatchpath

        else:

            query = req.querystring.partition('&')[0].partition(';')[0]

        # translate user-visible url structure to internal structure

        args = query.split('/', 2)

        if 'cmd' not in req.qsparams and args and args[0]:

            cmd = args.pop(0)

            style = cmd.rfind('-')

            if style != -1:

                req.qsparams['style'] = cmd[:style]

                cmd = cmd[style + 1:]

            # avoid accepting e.g. style parameter as command

            if util.safehasattr(webcommands, cmd):

                req.qsparams['cmd'] = cmd

            if cmd == 'static':

                req.qsparams['file'] = '/'.join(args)

            else:

                if args and args[0]:

                    node = args.pop(0).replace('%2F', '/')

                    req.qsparams['node'] = node

                if args:

                    if 'file' in req.qsparams:

                        del req.qsparams['file']

                    for a in args:

                        req.qsparams.add('file', a)

            ua = req.headers.get('User-Agent', '')

            if cmd == 'rev' and 'mercurial' in ua:

                req.qsparams['style'] = 'raw'

            if cmd == 'archive':

                fn = req.qsparams['node']

                for type_, spec in rctx.archivespecs.iteritems():

                    ext = spec[2]

                    if fn.endswith(ext):

                        req.qsparams['node'] = fn[:-len(ext)]