from paste.httpheaders import REMOTE_USER, AUTH_TYPE

from rhodecode.lib.utils2 import safe_str

from rhodecode.lib.base import BaseVCSController

from rhodecode.lib.auth import get_container_username

from rhodecode.lib.utils import make_ui, is_valid_repo, ui_sections

from rhodecode.model.db import User

from webob.exc import HTTPNotFound, HTTPForbidden, HTTPInternalServerError

log = logging.getLogger(__name__)

def is_mercurial(environ):

    """

    Returns True if request's target is mercurial server - header

    ``HTTP_ACCEPT`` of such request would start with ``application/mercurial``.

    """

    http_accept = environ.get('HTTP_ACCEPT')

    path_info = environ['PATH_INFO']

    if http_accept and http_accept.startswith('application/mercurial'):

        ishg_path = True

    else:

        ishg_path = False

    log.debug('pathinfo: %s detected as HG %s' % (

        path_info, ishg_path)

    )

    return ishg_path

class SimpleHg(BaseVCSController):

    def _handle_request(self, environ, start_response):

        if not is_mercurial(environ):

            return self.application(environ, start_response)

        ipaddr = self._get_ip_addr(environ)

        username = None 

        # skip passing error to error controller

        environ['pylons.status_code_redirect'] = True

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

        # EXTRACT REPOSITORY NAME FROM ENV

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

        try:

            repo_name = environ['REPO_NAME'] = self.__get_repository(environ)

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

        except:

            return HTTPInternalServerError()(environ, start_response)

        # quick check if that dir exists...

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

            return HTTPNotFound()(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

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

                # Attempting to retrieve username from the container

                username = get_container_username(environ, self.config)

                # If not authenticated by the container, running basic auth

                if not username:

                    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)

                        username = result

                    else:

                        return result.wsgi_application(environ, start_response)

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

                # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME

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

                try:

                    user = self.__get_user(username)

                    if user is None or not user.active:

                        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 are injected into mercurial UI object and later available

        # in hg hooks executed by rhodecode

        extras = {

            'ip': ipaddr,

            'username': username,

            'action': action,

            'repository': repo_name,

            'scm': 'hg',

        }

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

        # MERCURIAL REQUEST HANDLING

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

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

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

        baseui = make_ui('db')

        self.__inject_extras(repo_path, baseui, extras)

        try:

            # invalidate cache on push

            if action == 'push':

                self._invalidate_cache(repo_name)

            log.info('%s action on HG repo "%s"' % (action, repo_name))

            app = self.__make_app(repo_path, baseui, extras)

            return app(environ, start_response)

        except RepoError, e:

            if str(e).find('not found') != -1:

                return HTTPNotFound()(environ, start_response)

        except Exception:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

    def __make_app(self, repo_name, baseui, extras):

        """

        Make an wsgi application using hgweb, and inject generated baseui

        instance, additionally inject some extras into ui object

        """

        return hgweb_mod.hgweb(repo_name, name=repo_name, baseui=baseui)

    def __get_repository(self, environ):

        """

        Get's repository name out of PATH_INFO header

        :param environ: environ where PATH_INFO is stored

        """

        try:

            environ['PATH_INFO'] = self._get_by_id(environ['PATH_INFO'])

            repo_name = '/'.join(environ['PATH_INFO'].split('/')[1:])

            if repo_name.endswith('/'):

                repo_name = repo_name.rstrip('/')

        except:

            log.error(traceback.format_exc())

            raise

        return repo_name

    def __get_user(self, username):

        return User.get_by_username(username)

    def __get_action(self, environ):

        """

        Maps mercurial request commands into a clone,pull or push command.

        This should always return a valid command string

        :param environ:

        """

        mapping = {'changegroup': 'pull',

                   'changegroupsubset': 'pull',

                   'stream_out': 'pull',

                   'listkeys': 'pull',

                   'unbundle': 'push',

                   'pushkey': 'push', }

        for qry in environ['QUERY_STRING'].split('&'):

            if qry.startswith('cmd'):

                cmd = qry.split('=')[-1]

                if cmd in mapping:

                    return mapping[cmd]

                    return 'pull'

    def __inject_extras(self, repo_path, baseui, extras={}):

        """

        Injects some extra params into baseui instance

        also overwrites global settings with those takes from local hgrc file

        :param baseui: baseui instance

        :param extras: dict with extra params to put into baseui

        """

        hgrc = os.path.join(repo_path, '.hg', 'hgrc')

        # make our hgweb quiet so it doesn't print output

        baseui.setconfig('ui', 'quiet', 'true')

        #inject some additional parameters that will be available in ui

        #for hooks

        for k, v in extras.items():

            baseui.setconfig('rhodecode_extras', k, v)

        repoui = make_ui('file', hgrc, False)

        if repoui:

            #overwrite our ui instance with the section from hgrc file

            for section in ui_sections:

                for k, v in repoui.configitems(section):

                    baseui.setconfig(section, k, v)