# -*- coding: UTF-8 -*-

# Copyright (c) 2007 - 2010, Pascal Volk

# See COPYING for distribution information.

"""

   VirtualMailManager.Handler

   A wrapper class. It wraps round all other classes and does some

   dependencies checks.

   Additionally it communicates with the PostgreSQL database, creates

   or deletes directories of domains or users.

"""

import os

import re

from shutil import rmtree

from subprocess import Popen, PIPE

from pyPgSQL import PgSQL  # python-pgsql - http://pypgsql.sourceforge.net

import VirtualMailManager.constants.ERROR as ERR

from VirtualMailManager import ENCODING, set_configuration

from VirtualMailManager.Account import Account

from VirtualMailManager.Alias import Alias

from VirtualMailManager.AliasDomain import AliasDomain

from VirtualMailManager.common import exec_ok

from VirtualMailManager.Config import Config as Cfg

from VirtualMailManager.Domain import Domain, ace2idna, get_gid

from VirtualMailManager.EmailAddress import EmailAddress

from VirtualMailManager.errors import VMMError, AliasError, DomainError, \

     RelocatedError

from VirtualMailManager.Relocated import Relocated

from VirtualMailManager.Transport import Transport

from VirtualMailManager.ext.Postconf import Postconf

SALTCHARS = './0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

RE_DOMAIN_SEARCH = """^[a-z0-9-\.]+$"""

RE_MBOX_NAMES = """^[\x20-\x25\x27-\x7E]*$"""

TYPE_ACCOUNT = 0x1

TYPE_ALIAS = 0x2

TYPE_RELOCATED = 0x4

class Handler(object):

    """Wrapper class to simplify the access on all the stuff from

    VirtualMailManager"""

    __slots__ = ('_Cfg', '_cfgFileName', '_dbh', '_scheme', '__warnings',

                 '_postconf')

    def __init__(self, skip_some_checks=False):

        """Creates a new Handler instance.

        ``skip_some_checks`` : bool

            When a derived class knows how to handle all checks this

            argument may be ``True``. By default it is ``False`` and

            all checks will be performed.

        Throws a NotRootError if your uid is greater 0.

        """

        self._cfgFileName = ''

        self.__warnings = []

        self._Cfg = None

        self._dbh = None

        if os.geteuid():

            raise NotRootError(_(u"You are not root.\n\tGood bye!\n"),

                ERR.CONF_NOPERM)

        if self.__chkCfgFile():

            self._Cfg = Cfg(self._cfgFileName)

            self._Cfg.load()

        if not skip_some_checks:

            self._Cfg.check()

            self._chkenv()

            # will be moved to the new password module and Alias

            #self._scheme = self._Cfg.dget('misc.password_scheme')

            #self._postconf = Postconf(self._Cfg.dget('bin.postconf'))

        set_configuration(self._Cfg)

    def __findCfgFile(self):

        for path in ['/root', '/usr/local/etc', '/etc']:

            tmp = os.path.join(path, 'vmm.cfg')

            if os.path.isfile(tmp):

                self._cfgFileName = tmp

                break

        if not len(self._cfgFileName):

            raise VMMError(

                _(u"No “vmm.cfg” found in: /root:/usr/local/etc:/etc"),

                ERR.CONF_NOFILE)

    def __chkCfgFile(self):

        """Checks the configuration file, returns bool"""

        self.__findCfgFile()

        fstat = os.stat(self._cfgFileName)

        fmode = int(oct(fstat.st_mode & 0777))

        if fmode % 100 and fstat.st_uid != fstat.st_gid or \

            fmode % 10 and fstat.st_uid == fstat.st_gid:

                raise PermissionError(_(

                    u'fix permissions (%(perms)s) for “%(file)s”\n\

`chmod 0600 %(file)s` would be great.') % {'file':

                    self._cfgFileName, 'perms': fmode}, ERR.CONF_WRONGPERM)

        else:

            return True

    def _chkenv(self):

        """"""

        basedir = self._Cfg.dget('misc.base_directory')

        if not os.path.exists(basedir):

            old_umask = os.umask(0006)

            os.makedirs(basedir, 0771)

            os.chown(basedir, 0, 0)

            os.umask(old_umask)

        elif not os.path.isdir(basedir):

            raise VMMError(_(u'“%s” is not a directory.\n\

(vmm.cfg: section "misc", option "base_directory")') %

                                 basedir, ERR.NO_SUCH_DIRECTORY)

        for opt, val in self._Cfg.items('bin'):

            try:

                exec_ok(val)

            except VMMError, e:

                if e.code is ERR.NO_SUCH_BINARY:

                    raise VMMError(_(u'“%(binary)s” doesn\'t exist.\n\

(vmm.cfg: section "bin", option "%(option)s")') %

                                       {'binary': val, 'option': opt},

                                       ERR.NO_SUCH_BINARY)

                elif e.code is ERR.NOT_EXECUTABLE:

                    raise VMMError(_(u'“%(binary)s” is not executable.\

\n(vmm.cfg: section "bin", option "%(option)s")') %

                                       {'binary': val, 'option': opt},

                                       ERR.NOT_EXECUTABLE)

                else:

                    raise

    def __dbConnect(self):

        """Creates a pyPgSQL.PgSQL.connection instance."""

        if self._dbh is None or (isinstance(self._dbh, PgSQL.Connection) and

                                  not self._dbh._isOpen):

            try:

                self._dbh = PgSQL.connect(

                        database=self._Cfg.dget('database.name'),

                        user=self._Cfg.pget('database.user'),

                        host=self._Cfg.dget('database.host'),

                        password=self._Cfg.pget('database.pass'),

                        client_encoding='utf8', unicode_results=True)

                dbc = self._dbh.cursor()

                dbc.execute("SET NAMES 'UTF8'")

                dbc.close()

            except PgSQL.libpq.DatabaseError, e:

                raise VMMError(str(e), ERR.DATABASE_ERROR)

    def _chk_other_address_types(self, address, exclude):

        """Checks if the EmailAddress *address* is known as `TYPE_ACCOUNT`,

        `TYPE_ALIAS` or `TYPE_RELOCATED`, but not as the `TYPE_*` specified

        by *exclude*.  If the *address* is known as one of the `TYPE_*`s

        the according `TYPE_*` constant will be returned.  Otherwise 0 will

        be returned."""

        assert exclude in (TYPE_ACCOUNT, TYPE_ALIAS, TYPE_RELOCATED) and \

                isinstance(address, EmailAddress)

        if exclude is not TYPE_ACCOUNT:

            account = Account(self._dbh, address)

            if account.uid > 0:

                return TYPE_ACCOUNT

        if exclude is not TYPE_ALIAS:

            alias = Alias(self._dbh, address)

            if alias:

                return TYPE_ALIAS

        if exclude is not TYPE_RELOCATED:

            relocated = Relocated(self._dbh, address)

            if relocated:

                return TYPE_RELOCATED

        return 0

    def __getAccount(self, address, password=None):

        address = EmailAddress(address)

        if not password is None:

            password = self.__pwhash(password)

        self.__dbConnect()

        return Account(self._dbh, address, password)

    def __getAlias(self, address):

        address = EmailAddress(address)

        self.__dbConnect()

        return Alias(self._dbh, address)

    def __getRelocated(self, address):

        address = EmailAddress(address)

        self.__dbConnect()

        return Relocated(self._dbh, address)

    def __getDomain(self, domainname):

        self.__dbConnect()

        return Domain(self._dbh, domainname)

    def __getDiskUsage(self, directory):

        """Estimate file space usage for the given directory.

        Keyword arguments:

        directory -- the directory to summarize recursively disk usage for

        """

        if self.__isdir(directory):

            return Popen([self._Cfg.dget('bin.du'), "-hs", directory],

                stdout=PIPE).communicate()[0].split('\t')[0]

        else:

            return 0

    def __isdir(self, directory):

        isdir = os.path.isdir(directory)

        if not isdir:

            self.__warnings.append(_('No such directory: %s') % directory)

        return isdir

    def __makedir(self, directory, mode=None, uid=None, gid=None):

        if mode is None:

            mode = self._Cfg.dget('account.directory_mode')

        if uid is None:

            uid = 0

        if gid is None:

            gid = 0

        os.makedirs(directory, mode)

        os.chown(directory, uid, gid)

    def __domDirMake(self, domdir, gid):

        #TODO: clenaup!

        os.umask(0006)

        oldpwd = os.getcwd()

        basedir = self._Cfg.dget('misc.base_directory')

        domdirdirs = domdir.replace(basedir + '/', '').split('/')

        os.chdir(basedir)

        if not os.path.isdir(domdirdirs[0]):

            self.__makedir(domdirdirs[0], 489, 0, 0)

        os.chdir(domdirdirs[0])

        os.umask(0007)

        self.__makedir(domdirdirs[1], self._Cfg.dget('domain.directory_mode'),

                       0, gid)

        os.chdir(oldpwd)

    def __subscribe(self, folderlist, uid, gid):

        """Creates a subscriptions file with the mailboxes from `folderlist`"""

        fname = os.path.join(self._Cfg.dget('maildir.name'), 'subscriptions')

        sf = open(fname, 'w')

        sf.write('\n'.join(folderlist))

        sf.write('\n')

        sf.flush()

        sf.close()

        os.chown(fname, uid, gid)

        os.chmod(fname, 384)

    def __mailDirMake(self, domdir, uid, gid):

        """Creates maildirs and maildir subfolders.

        Keyword arguments:

        domdir -- the path to the domain directory

        uid -- user id from the account

        gid -- group id from the account

        """

        os.umask(0007)

        oldpwd = os.getcwd()

        os.chdir(domdir)

        maildir = self._Cfg.dget('maildir.name')

        folders = [maildir]

        append = folders.append

        for folder in self._Cfg.dget('maildir.folders').split(':'):

            folder = folder.strip()

            if len(folder) and not folder.count('..'):

                if re.match(RE_MBOX_NAMES, folder):

                    append('%s/.%s' % (maildir, folder))

                else:

                    self.__warnings.append(_('Skipped mailbox folder: %r') %

                                           folder)

            else:

                self.__warnings.append(_('Skipped mailbox folder: %r') %

                                       folder)

        subdirs = ['cur', 'new', 'tmp']

        mode = self._Cfg.dget('account.directory_mode')

        self.__makedir('%s' % uid, mode, uid, gid)

        os.chdir('%s' % uid)

        for folder in folders:

            self.__makedir(folder, mode, uid, gid)

            for subdir in subdirs:

                self.__makedir(os.path.join(folder, subdir), mode, uid, gid)

        self.__subscribe((f.replace(maildir + '/.', '') for f in folders[1:]),

                         uid, gid)

        os.chdir(oldpwd)

    def __userDirDelete(self, domdir, uid, gid):

        if uid > 0 and gid > 0:

            userdir = '%s' % uid

            if userdir.count('..') or domdir.count('..'):

                raise VMMError(_(u'Found ".." in home directory path.'),

                                   ERR.FOUND_DOTS_IN_PATH)

            if os.path.isdir(domdir):

                os.chdir(domdir)

                if os.path.isdir(userdir):

                    mdstat = os.stat(userdir)

                    if (mdstat.st_uid, mdstat.st_gid) != (uid, gid):

                        raise VMMError(_(

                          u'Detected owner/group mismatch in home directory.'),

                          ERR.MAILDIR_PERM_MISMATCH)

                    rmtree(userdir, ignore_errors=True)

                else:

                    raise VMMError(_(u"No such directory: %s") %

                        os.path.join(domdir, userdir), ERR.NO_SUCH_DIRECTORY)

    def __domDirDelete(self, domdir, gid):

        if gid > 0:

            if not self.__isdir(domdir):

                return

            basedir = self._Cfg.dget('misc.base_directory')

            domdirdirs = domdir.replace(basedir + '/', '').split('/')

            domdirparent = os.path.join(basedir, domdirdirs[0])

            if basedir.count('..') or domdir.count('..'):

                raise VMMError(_(u'Found ".." in domain directory path.'),

                        ERR.FOUND_DOTS_IN_PATH)

            if os.path.isdir(domdirparent):

                os.chdir(domdirparent)

                if os.lstat(domdirdirs[1]).st_gid != gid:

                    raise VMMError(_(

                        u'Detected group mismatch in domain directory.'),

                        ERR.DOMAINDIR_GROUP_MISMATCH)

                rmtree(domdirdirs[1], ignore_errors=True)

    def __getSalt(self):

        from random import choice

        salt = None

        if self._scheme == 'CRYPT':

            salt = '%s%s' % (choice(SALTCHARS), choice(SALTCHARS))

        elif self._scheme in ['MD5', 'MD5-CRYPT']:

            salt = '$1$%s$' % ''.join([choice(SALTCHARS) for x in xrange(8)])

        return salt

    def __pwCrypt(self, password):

        # for: CRYPT, MD5 and MD5-CRYPT

        from crypt import crypt

        return crypt(password, self.__getSalt())

    def __pwSHA1(self, password):

        # for: SHA/SHA1

        import sha

        from base64 import standard_b64encode

        sha1 = sha.new(password)

        return standard_b64encode(sha1.digest())

    def __pwMD5(self, password, emailaddress=None):

        import md5

        _md5 = md5.new(password)

        if self._scheme == 'LDAP-MD5':

            from base64 import standard_b64encode

            return standard_b64encode(_md5.digest())

        elif self._scheme == 'PLAIN-MD5':

            return _md5.hexdigest()

        elif self._scheme == 'DIGEST-MD5' and emailaddress is not None:

            # use an empty realm - works better with usenames like user@dom

            _md5 = md5.new('%s::%s' % (emailaddress, password))