# Copyright (C) 2007-2011 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Directory lookup that uses Launchpad."""

from __future__ import absolute_import

try:
    from urllib.parse import urlsplit
except ImportError:  # python < 3
    from urlparse import urlsplit
try:
    from xmlrpc.client import Fault
except ImportError:  # Python < 3
    from xmlrpclib import Fault

from ... import (
    debug,
    errors,
    trace,
    transport,
    )
from ...i18n import gettext

from .uris import (
    DEFAULT_INSTANCE,
    LAUNCHPAD_DOMAINS,
    )
from .lp_registration import (
    InvalidURL,
    LaunchpadService,
    ResolveLaunchpadPathRequest,
    )
from .account import get_lp_login


# As breezy.transport.remote may not be loaded yet, make sure bzr+ssh
# is counted as a netloc protocol.
transport.register_urlparse_netloc_protocol('bzr+ssh')
transport.register_urlparse_netloc_protocol('lp')
transport.register_urlparse_netloc_protocol('lp+bzr')


def _requires_launchpad_login(scheme, netloc, path, query,
                              fragment):
    """Does the URL require a Launchpad login in order to be reached?

    The URL is specified by its parsed components, as returned from
    urlsplit.
    """
    return (scheme in ('bzr+ssh', 'sftp')
            and (netloc.endswith('launchpad.net') or
                 netloc.endswith('launchpad.test')))


def _expand_user(path, url, lp_login):
    if path.startswith('~/'):
        if lp_login is None:
            raise InvalidURL(path=url,
                             extra='Cannot resolve "~" to your username.'
                             ' See "bzr help launchpad-login"')
        path = '~' + lp_login + path[1:]
    return path


def _update_url_scheme(url):
    # Do ubuntu: and debianlp: expansions.
    scheme, netloc, path, query, fragment = urlsplit(url)
    if scheme in ('ubuntu', 'debianlp'):
        if scheme == 'ubuntu':
            distro = 'ubuntu'
        elif scheme == 'debianlp':
            distro = 'debian'
            # No shortcuts for Debian distroseries.
        else:
            raise AssertionError('scheme should be ubuntu: or debianlp:')
        # Split the path.  It's either going to be 'project' or
        # 'series/project', but recognize that it may be a series we don't
        # know about.
        path_parts = path.split('/')
        if len(path_parts) == 1:
            # It's just a project name.
            lp_url_template = 'lp:%(distro)s/%(project)s'
            project = path_parts[0]
            series = None
        elif len(path_parts) == 2:
            # It's a series and project.
            lp_url_template = 'lp:%(distro)s/%(series)s/%(project)s'
            series, project = path_parts
        else:
            # There are either 0 or > 2 path parts, neither of which is
            # supported for these schemes.
            raise InvalidURL('Bad path: %s' % url)
        # Hack the url and let the following do the final resolution.
        url = lp_url_template % dict(
            distro=distro,
            series=series,
            project=project)
        scheme, netloc, path, query, fragment = urlsplit(url)
    elif scheme == 'lp+bzr':
        scheme = 'lp'
    return url, path


class LaunchpadDirectory(object):

    def look_up(self, name, url, purpose=None):
        """See DirectoryService.look_up"""
        return self._resolve(url)

    def _resolve_locally(self, path, url, _request_factory):
        # This is the best I could work out about XMLRPC. If an lp: url
        # includes ~user, then it is specially validated. Otherwise, it is just
        # sent to +branch/$path.
        _, netloc, _, _, _ = urlsplit(url)
        if netloc == '':
            netloc = DEFAULT_INSTANCE
        base_url = LAUNCHPAD_DOMAINS[netloc]
        base = 'bzr+ssh://bazaar.%s/' % (base_url,)
        maybe_invalid = False
        if path.startswith('~'):
            # A ~user style path, validate it a bit.
            # If a path looks fishy, fall back to asking XMLRPC to
            # resolve it for us. That way we still get their nicer error
            # messages.
            parts = path.split('/')
            if (len(parts) < 3
                    or (parts[1] in ('ubuntu', 'debian') and len(parts) < 5)):
                # This special case requires 5-parts to be valid.
                maybe_invalid = True
        else:
            base += '+branch/'
        if maybe_invalid:
            return self._resolve_via_xmlrpc(path, url, _request_factory)
        return {'urls': [base + path]}

    def _resolve_via_xmlrpc(self, path, url, _request_factory):
        service = LaunchpadService.for_url(url)
        resolve = _request_factory(path)
        try:
            result = resolve.submit(service)
        except Fault as fault:
            raise InvalidURL(
                path=url, extra=fault.faultString)
        return result

    def _resolve(self, url,
                 _request_factory=ResolveLaunchpadPathRequest,
                 _lp_login=None):
        """Resolve the base URL for this transport."""
        url, path = _update_url_scheme(url)
        if _lp_login is None:
            _lp_login = get_lp_login()
        path = path.strip('/')
        path = _expand_user(path, url, _lp_login)
        if _lp_login is not None:
            result = self._resolve_locally(path, url, _request_factory)
            if 'launchpad' in debug.debug_flags:
                local_res = result
                result = self._resolve_via_xmlrpc(path, url, _request_factory)
                trace.note(gettext(
                    'resolution for {0}\n  local: {1}\n remote: {2}').format(
                    url, local_res['urls'], result['urls']))
        else:
            result = self._resolve_via_xmlrpc(path, url, _request_factory)

        if 'launchpad' in debug.debug_flags:
            trace.mutter("resolve_lp_path(%r) == %r", url, result)

        _warned_login = False
        for url in result['urls']:
            scheme, netloc, path, query, fragment = urlsplit(url)
            if _requires_launchpad_login(scheme, netloc, path, query,
                                         fragment):
                # Only accept launchpad.net bzr+ssh URLs if we know
                # the user's Launchpad login:
                if _lp_login is not None:
                    break
                if _lp_login is None:
                    if not _warned_login:
                        trace.warning(
                            'You have not informed bzr of your Launchpad ID, and you must do this to\n'
                            'write to Launchpad or access private data.  See "bzr help launchpad-login".')
                        _warned_login = True
            else:
                # Use the URL if we can create a transport for it.
                try:
                    transport.get_transport(url)
                except (errors.PathError, errors.TransportError):
                    pass
                else:
                    break
        else:
            raise InvalidURL(path=url, extra='no supported schemes')
        return url


def get_test_permutations():
    # Since this transport doesn't do anything once opened, it's not subjected
    # to the usual transport tests.
    return []