#!/usr/bin/env python

'''The XML-RPC Bcfg2 Server'''
__revision__ = '$Revision$'

import Bcfg2.Server.Plugins.Metadata 

from Bcfg2.Settings import settings
from Bcfg2.Server.Core import Core, CoreInitError
from xmlrpclib import Fault
from lxml.etree import XML, Element, tostring

import logging, select, signal, socket, sys
import Bcfg2.Logging, Bcfg2.Options, Bcfg2.Component, Bcfg2.Daemon

logger = logging.getLogger('bcfg2-server')

def critical_error(operation):
    '''Log and err, traceback and return an xmlrpc fault to client'''
    logger.error(operation, exc_info=1)
    raise Fault, (7, "Critical unexpected failure: %s" % (operation))

class SetupError(Exception):
    '''Used when the server cant be setup'''
    pass

class Bcfg2Serv(Bcfg2.Component.Component):
    """The Bcfg2 Server component providing XML-RPC access to Bcfg methods"""
    __name__ = 'bcfg2'
    __implementation__ = 'bcfg2'
    fork_funcs = ['GetConfig', 'GetProbes']

    request_queue_size = 15

    def __init__(self, setup):
        try:
            Bcfg2.Component.Component.__init__(self, setup)
            self.shut = False
        except Bcfg2.Component.ComponentInitError:
            raise SetupError

        try:
            self.Core = Core()
        except CoreInitError, msg:
            logger.critical("Fatal error: %s" % (msg))
            raise SystemExit, 1

        self.funcs.update({
            "AssertProfile": self.Bcfg2AssertProfile, 
            "GetConfig": self.Bcfg2GetConfig,
            "GetProbes": self.Bcfg2GetProbes,
            "RecvProbeData": self.Bcfg2RecvProbeData,
            "RecvStats": self.Bcfg2RecvStats
            })
        for plugin in self.Core.plugins.values():
            for method in plugin.__rmi__:
                self.register_function(getattr(self.Core.plugins[plugin.__name__], method),
                                       "%s.%s" % (plugin.__name__, method))
        famfd = self.Core.fam.fileno()
        events = False
        while True:
            try:
                rsockinfo = select.select([famfd], [], [], 15)[0]
                if not rsockinfo:
                    if events:
                        break
                    else:
                        logger.error("Hit event timeout without getting any events; GAMIN/FAM problem?")
                        continue
                events = True
                self.Core.Service()
            except socket.error:
                continue

    def get_request(self):
        '''We need to do work between requests, so select with timeout instead of blocking in accept'''
        rsockinfo = []
        famfd = self.Core.fam.fileno()
        while self.socket not in rsockinfo:
            if self.shut:
                raise socket.error
            try:
                rsockinfo = select.select([self.socket, famfd], [], [], 15)[0]
            except select.error:
                continue
            
            if famfd in rsockinfo:
                self.Core.Service()
            if self.socket in rsockinfo:
                return self.socket.accept()

    def Bcfg2GetProbes(self, address):
        '''Fetch probes for a particular client'''
        resp = Element('probes')
        try:
            name = self.Core.metadata.resolve_client(address)
            meta = self.Core.metadata.get_metadata(name)
            
            for plugin in self.Core.plugins.values():
                for probe in plugin.GetProbes(meta):
                    resp.append(probe)
            return tostring(resp)
        except Bcfg2.Server.Plugins.Metadata.MetadataConsistencyError:
            warning = 'Client metadata resolution error for %s' % address[0]
            self.logger.warning(warning)
            raise Fault, (6, warning)
        except:
            critical_error("error determining client probes")

    def Bcfg2RecvProbeData(self, address, probedata):
        '''Receive probe data from clients'''
        try:
            name = self.Core.metadata.resolve_client(address)
            meta = self.Core.metadata.get_metadata(name)
        except Bcfg2.Server.Plugins.Metadata.MetadataConsistencyError:
            warning = 'metadata consistency error'
            self.logger.warning(warning)
            raise Fault, (6, warning)
        # clear dynamic groups
        self.Core.metadata.cgroups[meta.hostname] = []
        try:
            xpdata = XML(probedata)
        except:
            self.logger.error("Failed to parse probe data from client %s" % (address[0]))
            return False

        for data in xpdata:
            if self.Core.plugins.has_key(data.get('source')):
                try:
                    self.Core.plugins[data.get('source')].ReceiveData(meta, data)
                except:
                    self.logger.error("Failed to process probe data from client %s" % (address[0]), exc_info=1)
            else:
                self.logger.warning("Failed to locate plugin %s" % (data.get('source')))
        return True

    def Bcfg2AssertProfile(self, address, profile):
        '''Set profile for a client'''
        try:
            client = self.Core.metadata.resolve_client(address)
            self.Core.metadata.set_profile(client, profile, address)
        except (Bcfg2.Server.Plugins.Metadata.MetadataConsistencyError, Bcfg2.Server.Plugins.Metadata.MetadataRuntimeError):
            warning = 'metadata consistency error'
            self.logger.warning(warning)
            raise Fault, (6, warning)
        return True

    def Bcfg2GetConfig(self, address, _=False, profile=False):
        '''Build config for a client'''
        try:
            client = self.Core.metadata.resolve_client(address)
            return tostring(self.Core.BuildConfiguration(client))
        except Bcfg2.Server.Plugins.Metadata.MetadataConsistencyError:
            self.logger.warning("Metadata consistency failure for %s" % (address))
            raise Fault, (6, "Metadata consistency failure")

    def Bcfg2RecvStats(self, address, stats):
        '''Act on statistics upload'''
        sdata = XML(stats)
        state = sdata.find(".//Statistics")
        # Versioned stats to prevent tied client/server upgrade
        if state.get('version') >= '2.0':
            client = self.Core.metadata.resolve_client(address)
            meta = self.Core.metadata.get_metadata(client)
            
            # Update statistics
            self.Core.stats.updateStats(sdata, meta.hostname)

        self.logger.info("Client %s reported state %s" % 
                         (client, state.attrib['state']))
        return "<ok/>"

    def _authenticate_connection(self, _, user, password, address):
        return self.Core.metadata.AuthenticateConnection(user, password, address)

if __name__ == '__main__':

    OPTINFO = {
        'verbose': (('-v', False, 'enable verbose output'),
                    False, False, False, True),
        'debug': (('-d', False, 'enable debugging output'),
                  False, False, False, True),
        'help': (('-h', False, 'display this usage information'),
                 False, False, False, True),
        'daemon': (('-D', '<pidfile>', 'daemonize the server, storing PID'),
                   False, False, False, False),
        'configfile': (('-C', '<conffile>', 'use this config file'),
                       False, False, False, False),
        }
    
    SSETUP = Bcfg2.Options.OptionParser('bcfg2', OPTINFO).parse()
    level = 0
    if '-D' in sys.argv:
        Bcfg2.Logging.setup_logging('bcfg2-server', to_console=False, level=level)
    else:
        Bcfg2.Logging.setup_logging('bcfg2-server', level=level)
    if SSETUP['daemon']:
        Bcfg2.Daemon.daemonize(SSETUP['daemon'])

    # override default settings
    settings.read_config_file(SSETUP['configfile'])

    try:
        BSERV = Bcfg2Serv(SSETUP)
    except SetupError:
        raise SystemExit, 1
    while not BSERV.shut:
        try:
            BSERV.serve_forever()
        except:
            critical_error('error in service loop')
    logger.info("Shutting down")