"""twisted server for CubicWeb web instances

:organization: Logilab

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

import sys

import os

import select

import hotshot

from time import mktime

from datetime import date, timedelta

from urlparse import urlsplit, urlunsplit

from twisted.application import strports

from twisted.internet import reactor, task, threads

from twisted.internet.defer import maybeDeferred

from twisted.web2 import channel, http, server, iweb

from twisted.web2 import static, resource, responsecode

from cubicweb import ObjectNotFound, CW_EVENT_MANAGER

from cubicweb.web import (AuthenticationError, NotFound, Redirect,

                          RemoteCallFailed, DirectResponse, StatusResponse,

                          ExplicitLogin)

from cubicweb.web.application import CubicWebPublisher

from cubicweb.etwist.request import CubicWebTwistedRequestAdapter

def daemonize():

    # XXX unix specific

    # XXX factorize w/ code in cw.server.server and cw.server.serverctl

    # (start-repository command)

    # See http://www.erlenstar.demon.co.uk/unix/faq_toc.html#TOC16

    if os.fork():   # launch child and...

        return 1

    os.setsid()

    if os.fork():   # launch child again.

        return 1

    # move to the root to avoit mount pb

    os.chdir('/')

    # set paranoid umask

    os.umask(077)

    null = os.open('/dev/null', os.O_RDWR)

    for i in range(3):

        try:

            os.dup2(null, i)

        except OSError, e:

            if e.errno != errno.EBADF:

                raise

    os.close(null)

    return None

def start_task(interval, func):

    lc = task.LoopingCall(func)

    # wait until interval has expired to actually start the task, else we have

    # to wait all task to be finished for the server to be actually started

    lc.start(interval, now=False)

def host_prefixed_baseurl(baseurl, host):

    scheme, netloc, url, query, fragment = urlsplit(baseurl)

    netloc_domain = '.' + '.'.join(netloc.split('.')[-2:])

    if host.endswith(netloc_domain):

        netloc = host

    baseurl = urlunsplit((scheme, netloc, url, query, fragment))

    return baseurl

class LongTimeExpiringFile(static.File):

    """overrides static.File and sets a far futre ``Expires`` date

    on the resouce.

    versions handling is done by serving static files by different

    URLs for each version. For instance::

      http://localhost:8080/data-2.48.2/cubicweb.css

      http://localhost:8080/data-2.49.0/cubicweb.css

      etc.

    """

    def renderHTTP(self, request):

        def setExpireHeader(response):

            response = iweb.IResponse(response)

            # Don't provide additional resource information to error responses

            if response.code < 400:

                # the HTTP RFC recommands not going further than 1 year ahead

                expires = date.today() + timedelta(days=6*30)

                response.headers.setHeader('Expires', mktime(expires.timetuple()))

            return response

        d = maybeDeferred(super(LongTimeExpiringFile, self).renderHTTP, request)

        return d.addCallback(setExpireHeader)

class CubicWebRootResource(resource.PostableResource):

    addSlash = False

    def __init__(self, config, debug=None):

        self.debugmode = debug

        self.config = config

        self.base_url = config['base-url'] or config.default_base_url()

        if self.base_url[-1] != '/':

            self.base_url += '/'

        self.https_url = config['https-url']

        if self.https_url and self.https_url[-1] != '/':

            self.https_url += '/'

        # instantiate publisher here and not in init_publisher to get some

        # checks done before daemonization (eg versions consistency)

        self.appli = CubicWebPublisher(config, debug=self.debugmode)

        self.versioned_datadir = 'data%s' % config.instance_md5_version()

    def init_publisher(self):

        config = self.config

        # when we have an in-memory repository, clean unused sessions every XX

        # seconds and properly shutdown the server

        if config.repo_method == 'inmemory':

            reactor.addSystemEventTrigger('before', 'shutdown',

                                          self.shutdown_event)

            # monkey patch start_looping_task to get proper reactor integration

            #self.appli.repo.__class__.start_looping_tasks = start_looping_tasks

            if config.pyro_enabled():

                # if pyro is enabled, we have to register to the pyro name

                # server, create a pyro daemon, and create a task to handle pyro

                # requests

                self.pyro_daemon = self.appli.repo.pyro_register()

                self.pyro_listen_timeout = 0.02

                self.appli.repo.looping_task(1, self.pyro_loop_event)

            self.appli.repo.start_looping_tasks()

        self.set_url_rewriter()

        CW_EVENT_MANAGER.bind('after-registry-reload', self.set_url_rewriter)

    def start_service(self):

        config = self.config

        interval = min(config['cleanup-session-time'] or 120,

                       config['cleanup-anonymous-session-time'] or 720) / 2.

        start_task(interval, self.appli.session_handler.clean_sessions)

    def set_url_rewriter(self):

        self.url_rewriter = self.appli.vreg['components'].select_object('urlrewriter')

    def shutdown_event(self):

        """callback fired when the server is shutting down to properly

        clean opened sessions

        """

        self.appli.repo.shutdown()

    def pyro_loop_event(self):

        """listen for pyro events"""

        try:

            self.pyro_daemon.handleRequests(self.pyro_listen_timeout)

        except select.error:

            return

    def locateChild(self, request, segments):

        """Indicate which resource to use to process down the URL's path"""

        if segments:

            if segments[0] == 'https':

                segments = segments[1:]

            if len(segments) >= 2:

                if segments[0] in (self.versioned_datadir, 'data', 'static'):

                    # Anything in data/, static/ is treated as static files

                    if segments[0] == 'static':

                        # instance static directory

                        datadir = self.config.static_directory

                    elif segments[1] == 'fckeditor':

                        fckeditordir = self.config.ext_resources['FCKEDITOR_PATH']

                        return static.File(fckeditordir), segments[2:]

                    else:

                        # cube static data file

                        datadir = self.config.locate_resource(segments[1])

                        if datadir is None:

                            return None, []

                    self.info('static file %s from %s', segments[-1], datadir)

                    if segments[0] == 'data':

                        return static.File(str(datadir)), segments[1:]

                    else:

                        return LongTimeExpiringFile(datadir), segments[1:]

                elif segments[0] == 'fckeditor':

                    fckeditordir = self.config.ext_resources['FCKEDITOR_PATH']

                    return static.File(fckeditordir), segments[1:]

        # Otherwise we use this single resource

        return self, ()

    def render(self, request):

        """Render a page from the root resource"""

        # reload modified files in debug mode

        if self.debugmode:

            self.appli.vreg.register_objects(self.config.vregistry_path())

        if self.config['profile']: # default profiler don't trace threads

            return self.render_request(request)

        else:

            return threads.deferToThread(self.render_request, request)

    def render_request(self, request):

        origpath = request.path

        host = request.host

        # dual http/https access handling: expect a rewrite rule to prepend

        # 'https' to the path to detect https access

        if origpath.split('/', 2)[1] == 'https':

            origpath = origpath[6:]

            request.uri = request.uri[6:]

            https = True

            baseurl = self.https_url or self.base_url

        else:

            https = False

            baseurl = self.base_url

        if self.config['use-request-subdomain']:

            baseurl = host_prefixed_baseurl(baseurl, host)

            self.warning('used baseurl is %s for this request', baseurl)

        req = CubicWebTwistedRequestAdapter(request, self.appli.vreg, https, baseurl)

        if req.authmode == 'http':

            # activate realm-based auth

            realm = self.config['realm']

            req.set_header('WWW-Authenticate', [('Basic', {'realm' : realm })], raw=False)

        try:

            self.appli.connect(req)

        except AuthenticationError:

            return self.request_auth(req)

        except Redirect, ex:

            return self.redirect(req, ex.location)

        if https and req.cnx.anonymous_connection:

            # don't allow anonymous on https connection

            return self.request_auth(req)

        if self.url_rewriter is not None:

            # XXX should occur before authentication?

            try:

                path = self.url_rewriter.rewrite(host, origpath, req)

            except Redirect, ex:

                return self.redirect(req, ex.location)

            request.uri.replace(origpath, path, 1)

        else:

            path = origpath

        if not path or path == "/":

            path = 'view'

        try:

            result = self.appli.publish(path, req)

        except DirectResponse, ex:

            return ex.response

        except StatusResponse, ex:

            return http.Response(stream=ex.content, code=ex.status,

                                 headers=req.headers_out or None)

        except RemoteCallFailed, ex:

            req.set_header('content-type', 'application/json')

            return http.Response(stream=ex.dumps(),

                                 code=responsecode.INTERNAL_SERVER_ERROR)

        except NotFound:

            result = self.appli.notfound_content(req)

            return http.Response(stream=result, code=responsecode.NOT_FOUND,

                                 headers=req.headers_out or None)

        except ExplicitLogin:  # must be before AuthenticationError

            return self.request_auth(req)

        except AuthenticationError:

            if self.config['auth-mode'] == 'cookie':

                # in cookie mode redirecting to the index view is enough :

                # either anonymous connection is allowed and the page will

                # be displayed or we'll be redirected to the login form

                msg = req._('you have been logged out')

                if req.https:

                    req._base_url =  self.base_url

                    req.https = False

                url = req.build_url('view', vid='index', __message=msg)

                return self.redirect(req, url)

            else:

                # in http we have to request auth to flush current http auth

                # information

                return self.request_auth(req, loggedout=True)

        except Redirect, ex:

            return self.redirect(req, ex.location)

        # request may be referenced by "onetime callback", so clear its entity

        # cache to avoid memory usage

        req.drop_entity_cache()

        return http.Response(stream=result, code=responsecode.OK,

                             headers=req.headers_out or None)

    def redirect(self, req, location):

        req.headers_out.setHeader('location', str(location))

        self.debug('redirecting to %s', location)

        # 303 See other

        return http.Response(code=303, headers=req.headers_out)

    def request_auth(self, req, loggedout=False):

        if self.https_url and req.base_url() != self.https_url:

            req.headers_out.setHeader('location', self.https_url + 'login')

            return http.Response(code=303, headers=req.headers_out)

        if self.config['auth-mode'] == 'http':

            code = responsecode.UNAUTHORIZED

        else:

            code = responsecode.FORBIDDEN

        if loggedout:

            if req.https:

                req._base_url =  self.base_url

                req.https = False

            content = self.appli.loggedout_content(req)

        else:

            content = self.appli.need_login_content(req)

        return http.Response(code, req.headers_out, content)

from twisted.python import failure

from twisted.internet import defer

from twisted.web2 import fileupload

# XXX set max file size to 100Mo: put max upload size in the configuration

# line below for twisted >= 8.0, default param value for earlier version

resource.PostableResource.maxSize = 100*1024*1024

def parsePOSTData(request, maxMem=100*1024, maxFields=1024,

                  maxSize=100*1024*1024):

    if request.stream.length == 0:

        return defer.succeed(None)

    ctype = request.headers.getHeader('content-type')

    if ctype is None:

        return defer.succeed(None)

    def updateArgs(data):

        args = data

        request.args.update(args)

    def updateArgsAndFiles(data):

        args, files = data

        request.args.update(args)

        request.files.update(files)

    def error(f):

        f.trap(fileupload.MimeFormatError)

        raise http.HTTPError(responsecode.BAD_REQUEST)

    if ctype.mediaType == 'application' and ctype.mediaSubtype == 'x-www-form-urlencoded':

        d = fileupload.parse_urlencoded(request.stream, keep_blank_values=True)

        d.addCallbacks(updateArgs, error)

        return d

    elif ctype.mediaType == 'multipart' and ctype.mediaSubtype == 'form-data':

        boundary = ctype.params.get('boundary')

        if boundary is None:

            return defer.fail(http.HTTPError(

                http.StatusResponse(responsecode.BAD_REQUEST,

                                    "Boundary not specified in Content-Type.")))

        d = fileupload.parseMultipartFormData(request.stream, boundary,

                                              maxMem, maxFields, maxSize)

        d.addCallbacks(updateArgsAndFiles, error)

        return d

    else:

        raise http.HTTPError(responsecode.BAD_REQUEST)

server.parsePOSTData = parsePOSTData

from logging import getLogger

from cubicweb import set_log_methods

set_log_methods(CubicWebRootResource, getLogger('cubicweb.twisted'))

def _gc_debug():

    import gc

    from pprint import pprint

    from cubicweb.appobject import AppObject

    gc.collect()

    count = 0

    acount = 0

    ocount = {}

    for obj in gc.get_objects():

        if isinstance(obj, CubicWebTwistedRequestAdapter):

            count += 1

        elif isinstance(obj, AppObject):

            acount += 1

        else:

            try:

                ocount[obj.__class__] += 1

            except KeyError:

                ocount[obj.__class__] = 1

            except AttributeError:

                pass

    print 'IN MEM REQUESTS', count

    print 'IN MEM APPOBJECTS', acount

    ocount = sorted(ocount.items(), key=lambda x: x[1], reverse=True)[:20]