#!/usr/bin/python
#
# Copyright (C) 2014  Simo Sorce <simo@redhat.com>
#
# see file 'COPYING' for use and warranty information
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

from ipsilon.login.common import LoginMgrsInstall
from ipsilon.info.common import InfoProviderInstall
from ipsilon.providers.common import ProvidersInstall
from ipsilon.helpers.common import EnvHelpersInstall
from ipsilon.util.data import UserStore
from ipsilon.tools import files
import ConfigParser
import argparse
import cherrypy
import logging
import os
import pwd
import shutil
import socket
import subprocess
import sys
import time


TEMPLATES = '/usr/share/ipsilon/templates/install'
CONFDIR = '/etc/ipsilon'
DATADIR = '/var/lib/ipsilon'
HTTPDCONFD = '/etc/httpd/conf.d'
BINDIR = '/usr/sbin'
STATICDIR = '/usr/share/ipsilon'
WSGI_SOCKET_PREFIX = None


class ConfigurationError(Exception):

    def __init__(self, message):
        super(ConfigurationError, self).__init__(message)
        self.message = message

    def __str__(self):
        return repr(self.message)


#Silence cherrypy logging to screen
cherrypy.log.screen = False

# Regular logging
LOGFILE = '/var/log/ipsilon-install.log'
logger = logging.getLogger()


def openlogs():
    global logger  # pylint: disable=W0603
    if os.path.isfile(LOGFILE):
        try:
            created = '%s' % time.ctime(os.path.getctime(LOGFILE))
            shutil.move(LOGFILE, '%s.%s' % (LOGFILE, created))
        except IOError:
            pass
    logger = logging.getLogger()
    try:
        lh = logging.FileHandler(LOGFILE)
    except IOError, e:
        print >> sys.stderr, 'Unable to open %s (%s)' % (LOGFILE, str(e))
        lh = logging.StreamHandler(sys.stderr)
    formatter = logging.Formatter('[%(asctime)s] %(message)s')
    lh.setFormatter(formatter)
    logger.addHandler(lh)


def install(plugins, args):
    logger.info('Installation initiated')
    now = time.strftime("%Y%m%d%H%M%S", time.gmtime())
    instance_conf = os.path.join(CONFDIR, args['instance'])

    logger.info('Installing default config files')
    ipsilon_conf = os.path.join(instance_conf, 'ipsilon.conf')
    idp_conf = os.path.join(instance_conf, 'idp.conf')
    args['httpd_conf'] = os.path.join(HTTPDCONFD,
                                      'ipsilon-%s.conf' % args['instance'])
    args['data_dir'] = os.path.join(DATADIR, args['instance'])
    args['public_data_dir'] = os.path.join(args['data_dir'], 'public')
    args['wellknown_dir'] = os.path.join(args['public_data_dir'],
                                         'well-known')
    if os.path.exists(ipsilon_conf):
        shutil.move(ipsilon_conf, '%s.bakcup.%s' % (ipsilon_conf, now))
    if os.path.exists(idp_conf):
        shutil.move(idp_conf, '%s.backup.%s' % (idp_conf, now))
    if not os.path.exists(instance_conf):
        os.makedirs(instance_conf, 0700)
    confopts = {'instance': args['instance'],
                'datadir': args['data_dir'],
                'publicdatadir': args['public_data_dir'],
                'wellknowndir': args['wellknown_dir'],
                'sysuser': args['system_user'],
                'ipsilondir': BINDIR,
                'staticdir': STATICDIR,
                'admindb': args['database_url'] % {
                    'datadir': args['data_dir'], 'dbname': 'adminconfig'},
                'usersdb': args['database_url'] % {
                    'datadir': args['data_dir'], 'dbname': 'userprefs'},
                'transdb': args['database_url'] % {
                    'datadir': args['data_dir'], 'dbname': 'transactions'},
                'secure': "False" if args['secure'] == "no" else "True",
                'debugging': "True" if args['server_debugging'] else "False"}
    # Testing database sessions
    if 'session_type' in args:
        confopts['sesstype'] = args['session_type']
    else:
        confopts['sesstype'] = 'file'
    if 'session_dburi' in args:
        confopts['sessopt'] = 'dburi'
        confopts['sessval'] = args['session_dburi']
    else:
        confopts['sessopt'] = 'path'
        confopts['sessval'] = os.path.join(args['data_dir'], 'sessions')
    # Whetehr to disable security (for testing)
    if args['secure'] == 'no':
        confopts['secure'] = "False"
        confopts['sslrequiressl'] = ""
    else:
        confopts['secure'] = "True"
        confopts['sslrequiressl'] = "   SSLRequireSSL"
    if WSGI_SOCKET_PREFIX:
        confopts['wsgi_socket'] = 'WSGISocketPrefix %s' % WSGI_SOCKET_PREFIX
    else:
        confopts['wsgi_socket'] = ''
    files.write_from_template(ipsilon_conf,
                              os.path.join(TEMPLATES, 'ipsilon.conf'),
                              confopts)
    files.write_from_template(idp_conf,
                              os.path.join(TEMPLATES, 'idp.conf'),
                              confopts)
    if not os.path.exists(args['httpd_conf']):
        os.symlink(idp_conf, args['httpd_conf'])
    if not os.path.exists(args['public_data_dir']):
        os.makedirs(args['public_data_dir'], 0755)
    if not os.path.exists(args['wellknown_dir']):
        os.makedirs(args['wellknown_dir'], 0755)
    sessdir = os.path.join(args['data_dir'], 'sessions')
    if not os.path.exists(sessdir):
        os.makedirs(sessdir, 0700)
    data_conf = os.path.join(args['data_dir'], 'ipsilon.conf')
    if not os.path.exists(data_conf):
        os.symlink(ipsilon_conf, data_conf)
    # Load the cherrypy config from the newly installed file so
    # that db paths and all is properly set before configuring
    # components
    cherrypy.config.update(ipsilon_conf)

    # Move pre-existing admin db away
    admin_db = cherrypy.config['admin.config.db']
    if os.path.exists(admin_db):
        shutil.move(admin_db, '%s.backup.%s' % (admin_db, now))

    # Rebuild user db
    users_db = cherrypy.config['user.prefs.db']
    if os.path.exists(users_db):
        shutil.move(users_db, '%s.backup.%s' % (users_db, now))
    db = UserStore()
    db.save_user_preferences(args['admin_user'], {'is_admin': 1})

    logger.info('Configuring environment helpers')
    for plugin_name in plugins['Environment Helpers']:
        plugin = plugins['Environment Helpers'][plugin_name]
        if plugin.configure_server(args) == False:
            print 'Configuration of environment helper %s failed' % plugin_name

    logger.info('Configuring login managers')
    for plugin_name in args['lm_order']:
        plugin = plugins['Login Managers'][plugin_name]
        if plugin.configure(args) == False:
            print 'Configuration of login manager %s failed' % plugin_name

    logger.info('Configuring Info provider')
    for plugin_name in plugins['Info Provider']:
        plugin = plugins['Info Provider'][plugin_name]
        if plugin.configure(args) == False:
            print 'Configuration of info provider %s failed' % plugin_name

    logger.info('Configuring Authentication Providers')
    for plugin_name in plugins['Auth Providers']:
        plugin = plugins['Auth Providers'][plugin_name]
        if plugin.configure(args) == False:
            print 'Configuration of auth provider %s failed' % plugin_name

    # Fixup permissions so only the ipsilon user can read these files
    files.fix_user_dirs(instance_conf, opts['system_user'])
    files.fix_user_dirs(args['data_dir'], opts['system_user'])
    try:
        subprocess.call(['/usr/sbin/restorecon', '-R', args['data_dir']])
    except Exception:  # pylint: disable=broad-except
        pass


def uninstall(plugins, args):
    logger.info('Uninstallation initiated')
    instance_conf = os.path.join(CONFDIR, args['instance'])

    httpd_conf = os.path.join(HTTPDCONFD,
                              'ipsilon-%s.conf' % args['instance'])
    data_dir = os.path.join(DATADIR, args['instance'])

    if not os.path.exists(instance_conf):
        raise Exception('Could not find instance %s configuration'
                        % args['instance'])
    if not os.path.exists(httpd_conf):
        raise Exception('Could not find instance %s httpd configuration'
                        % args['instance'])
    if not args['yes']:
        sure = raw_input(('Are you certain you want to erase instance %s ' +
                          '[yes/NO]: ')
                         % args['instance'])
        if sure != 'yes':
            raise Exception('Aborting')

    logger.info('Removing environment helpers')
    for plugin_name in plugins['Environment Helpers']:
        plugin = plugins['Environment Helpers'][plugin_name]
        if plugin.unconfigure(args) == False:
            print 'Removal of environment helper %s failed' % plugin_name

    logger.info('Removing login managers')
    for plugin_name in args['lm_order']:
        plugin = plugins['Login Managers'][plugin_name]
        if plugin.unconfigure(args) == False:
            print 'Removal of login manager %s failed' % plugin_name

    logger.info('Removing Info providers')
    for plugin_name in plugins['Info Provider']:
        plugin = plugins['Info Provider'][plugin_name]
        if plugin.unconfigure(args) == False:
            print 'Removal of info provider %s failed' % plugin_name

    logger.info('Removing Authentication Providers')
    for plugin_name in plugins['Auth Providers']:
        plugin = plugins['Auth Providers'][plugin_name]
        if plugin.unconfigure(args) == False:
            print 'Removal of auth provider %s failed' % plugin_name

    logger.info('Removing httpd configuration')
    os.remove(httpd_conf)
    logger.info('Erasing instance configuration')
    shutil.rmtree(instance_conf)
    logger.info('Erasing instance data')
    shutil.rmtree(data_dir)
    logger.info('Uninstalled instance %s' % args['instance'])


def find_plugins():
    plugins = {
        'Environment Helpers': EnvHelpersInstall().plugins,
        'Login Managers': LoginMgrsInstall().plugins,
        'Info Provider': InfoProviderInstall().plugins,
        'Auth Providers': ProvidersInstall().plugins
    }
    return plugins


def parse_config_profile(args):
    config = ConfigParser.RawConfigParser()
    files = config.read(args['config_profile'])
    if len(files) == 0:
        raise ConfigurationError('Config Profile file %s not found!' %
                                 args['config_profile'])

    if 'globals' in config.sections():
        G = config.options('globals')
        for g in G:
            val = config.get('globals', g)
            if g in globals():
                globals()[g] = val
            else:
                for k in globals().keys():
                    if k.lower() == g.lower():
                        globals()[k] = val
                        break

    if 'arguments' in config.sections():
        A = config.options('arguments')
        for a in A:
            args[a] = config.get('arguments', a)

    return args


def parse_args(plugins):
    parser = argparse.ArgumentParser(description='Ipsilon Install Options')
    parser.add_argument('--version',
                        action='version', version='%(prog)s 0.1')
    parser.add_argument('-o', '--login-managers-order', dest='lm_order',
                        help='Comma separated list of login managers')
    parser.add_argument('--hostname',
                        help="Machine's fully qualified host name")
    parser.add_argument('--instance', default='idp',
                        help="IdP instance name, each is a separate idp")
    parser.add_argument('--system-user', default='ipsilon',
                        help="User account used to run the server")
    parser.add_argument('--admin-user', default='admin',
                        help="User account that is assigned admin privileges")
    parser.add_argument('--database-url',
                        default='sqlite:///%(datadir)s/%(dbname)s.sqlite',
                        help="The (templatized) database URL to use")
    parser.add_argument('--secure', choices=['yes', 'no'], default='yes',
                        help="Turn on all security checks")
    parser.add_argument('--config-profile', default=None,
                        help="File containing install options")
    parser.add_argument('--server-debugging', action='store_true',
                        help="Enable debugging")
    parser.add_argument('--uninstall', action='store_true',
                        help="Uninstall the server and all data")
    parser.add_argument('--yes', action='store_true',
                        help="Always answer yes")

    lms = []

    for plugin_group in plugins:
        group = parser.add_argument_group(plugin_group)
        for plugin_name in plugins[plugin_group]:
            plugin = plugins[plugin_group][plugin_name]
            if plugin.ptype == 'login':
                lms.append(plugin.name)
            plugin.install_args(group)

    args = vars(parser.parse_args())

    if args['config_profile']:
        args = parse_config_profile(args)

    if not args['hostname']:
        args['hostname'] = socket.getfqdn()

    if len(args['hostname'].split('.')) < 2:
        raise ConfigurationError('Hostname: %s is not a FQDN')

    try:
        pwd.getpwnam(args['system_user'])
    except KeyError:
        raise ConfigurationError('User: %s not found on the system')

    if args['lm_order'] is None:
        args['lm_order'] = []
        for name in lms:
            if args[name] == 'yes':
                args['lm_order'].append(name)
    else:
        args['lm_order'] = args['lm_order'].split(',')

    if len(args['lm_order']) == 0:
        #force the basic pam provider if nothing else is selected
        if 'pam' not in args:
            parser.print_help()
            sys.exit(-1)
        args['lm_order'] = ['pam']
        args['pam'] = 'yes'

    #FIXME: check instance is only alphanums

    return args

if __name__ == '__main__':
    opts = []
    out = 0
    openlogs()
    try:
        fplugins = find_plugins()
        opts = parse_args(fplugins)

        logger.setLevel(logging.DEBUG)

        logger.info('Intallation arguments:')
        for k in sorted(opts.iterkeys()):
            logger.info('%s: %s', k, opts[k])

        if 'uninstall' in opts and opts['uninstall'] is True:
            if not os.path.exists(os.path.join(CONFDIR, opts['instance'])):
                print 'Instance %s could not be found' % opts['instance']
                sys.exit(0)
            uninstall(fplugins, opts)
        else:
            install(fplugins, opts)
    except Exception, e:  # pylint: disable=broad-except
        logger.exception(e)
        if 'uninstall' in opts and opts['uninstall'] is True:
            print 'Uninstallation aborted.'
        else:
            print 'Installation aborted.'
        print 'See log file %s for details' % LOGFILE
        out = 1
    finally:
        if out == 0:
            if 'uninstall' in opts and opts['uninstall'] is True:
                print 'Uninstallation complete.'
            else:
                print 'Installation complete.'
                print 'Please restart HTTPD to enable the IdP instance.'
    sys.exit(out)
