# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os

import logging

import traceback

from dulwich import server as dulserver

class SimpleGitUploadPackHandler(dulserver.UploadPackHandler):

    def handle(self):

        write = lambda x: self.proto.write_sideband(1, x)

        graph_walker = dulserver.ProtocolGraphWalker(self,

                                                     self.repo.object_store,

                                                     self.repo.get_peeled)

        objects_iter = self.repo.fetch_objects(

          graph_walker.determine_wants, graph_walker, self.progress,

          get_tagged=self.get_tagged)

        # Do they want any objects?

        if objects_iter is None or len(objects_iter) == 0:

            return

        self.progress("counting objects: %d, done.\n" % len(objects_iter))

        dulserver.write_pack_objects(dulserver.ProtocolFile(None, write),

                                  objects_iter, len(objects_iter))

        messages = []

        messages.append('thank you for using rhodecode')

        for msg in messages:

            self.progress(msg + "\n")

        # we are done

        self.proto.write("0000")

dulserver.DEFAULT_HANDLERS = {

  'git-upload-pack': SimpleGitUploadPackHandler,

  'git-receive-pack': dulserver.ReceivePackHandler,

}

from dulwich.repo import Repo

from dulwich.web import HTTPGitApplication

from paste.auth.basic import AuthBasicAuthenticator

from paste.httpheaders import REMOTE_USER, AUTH_TYPE

from rhodecode.lib import safe_str

from rhodecode.lib.utils import invalidate_cache, is_valid_repo

from rhodecode.model.db import User

from webob.exc import HTTPNotFound, HTTPForbidden, HTTPInternalServerError

log = logging.getLogger(__name__)

def is_git(environ):

    """Returns True if request's target is git server.

    ``HTTP_USER_AGENT`` would then have git client version given.

    :param environ:

    """

    http_user_agent = environ.get('HTTP_USER_AGENT')

    if http_user_agent and http_user_agent.startswith('git'):

        return True

    return False

class SimpleGit(object):

    def __init__(self, application, config):

        self.application = application

        self.config = config

        # base path of repo locations

        self.basepath = self.config['base_path']

        #authenticate this mercurial request using authfunc

        self.authenticate = AuthBasicAuthenticator('', authfunc)

    def __call__(self, environ, start_response):

        if not is_git(environ):

            return self.application(environ, start_response)

        proxy_key = 'HTTP_X_REAL_IP'

        def_key = 'REMOTE_ADDR'

        ipaddr = environ.get(proxy_key, environ.get(def_key, '0.0.0.0'))

        username = None

        # skip passing error to error controller

        environ['pylons.status_code_redirect'] = True

        #======================================================================

        # EXTRACT REPOSITORY NAME FROM ENV

        #======================================================================

        try:

            repo_name = self.__get_repository(environ)

            log.debug('Extracted repo name is %s' % repo_name)

        except:

            return HTTPInternalServerError()(environ, start_response)

        #======================================================================

        # GET ACTION PULL or PUSH

        #======================================================================

        action = self.__get_action(environ)

        #======================================================================

        # CHECK ANONYMOUS PERMISSION

        #======================================================================

        if action in ['pull', 'push']:

            anonymous_user = self.__get_user('default')

            username = anonymous_user.username

            anonymous_perm = self.__check_permission(action,

                                                     anonymous_user,

                                                     repo_name)

            if anonymous_perm is not True or anonymous_user.active is False:

                if anonymous_perm is not True:

                    log.debug('Not enough credentials to access this '

                              'repository as anonymous user')

                if anonymous_user.active is False:

                    log.debug('Anonymous access is disabled, running '

                              'authentication')

                #==============================================================

                # DEFAULT PERM FAILED OR ANONYMOUS ACCESS IS DISABLED SO WE

                # NEED TO AUTHENTICATE AND ASK FOR AUTH USER PERMISSIONS

                #==============================================================

                    self.authenticate.realm = \

                        safe_str(self.config['rhodecode_realm'])

                    result = self.authenticate(environ)

                    if isinstance(result, str):

                        AUTH_TYPE.update(environ, 'basic')

                        REMOTE_USER.update(environ, result)

                    else:

                        return result.wsgi_application(environ, start_response)

                #==============================================================

                # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME FROM

                # BASIC AUTH

                #==============================================================

                if action in ['pull', 'push']:

                    try:

                        user = self.__get_user(username)

                        if user is None:

                            return HTTPForbidden()(environ, start_response)                        

                        username = user.username

                    except:

                        log.error(traceback.format_exc())

                        return HTTPInternalServerError()(environ,

                                                         start_response)

                    #check permissions for this repository

                    perm = self.__check_permission(action, user,

                                                   repo_name)

                    if perm is not True:

                        return HTTPForbidden()(environ, start_response)

        extras = {'ip': ipaddr,

                  'username': username,

                  'action': action,

                  'repository': repo_name}

        #===================================================================

        # GIT REQUEST HANDLING

        #===================================================================

        repo_path = safe_str(os.path.join(self.basepath, repo_name))

        log.debug('Repository path is %s' % repo_path)

        # quick check if that dir exists...

        if is_valid_repo(repo_name, self.basepath) is False:

            return HTTPNotFound()(environ, start_response)

        try:

            #invalidate cache on push

            if action == 'push':

                self.__invalidate_cache(repo_name)

            app = self.__make_app(repo_name, repo_path)

            return app(environ, start_response)

        except Exception:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

    def __make_app(self, repo_name, repo_path):

        """

        Make an wsgi application using dulserver

        :param repo_name: name of the repository