# This file is part of MAUS: http://micewww.pp.rl.ac.uk/projects/maus
#
# MAUS 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.
#
# MAUS 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 MAUS.  If not, see <http://www.gnu.org/licenses/>.
#

"""
Get DAQ cabling from CDB
"""

import cdb
import json
from Configuration import Configuration
from cdb._exceptions import CdbPermanentError
from cdb._exceptions import CdbTemporaryError

class GetCabling:
    """
    Evaluator class to evaluate mathematical expressions 

    Able to see many simple math expressions and some common units; the
    standard geant4 system of units is enabled.
    """

    def __init__(self):
        """
        Initialise the evaluator with math functions and units
        """
        self._current_cabling = {}
        self._run_cabling = {}
        self.reset()
        cfg = Configuration()
        cfgdoc = cfg.getConfigJSON()
        cfgdoc_json = json.loads(cfgdoc)
        cdb_url = cfgdoc_json['cdb_download_url'] + 'cabling?wsdl'
        self.cdb_server = cdb.Cabling()
        try:
            cdb.Cabling().get_status()
        except CdbPermanentError:
            raise CdbPermanentError(\
             "CDB error connecting to Cabling Service") #pylint: disable = E0702
        except CdbTemporaryError:
            raise CdbTemporaryError(\
             "CDB error connecting to Cabling Service") #pylint: disable = E0702
        self.cdb_server.set_url(cdb_url)
        # print '>Server: ', self.cdb_server.get_name(), \
        #                self.cdb_server.get_version()

    def get_cabling_for_date(self, devname, fromdate):
        """
        Evaluate a string expression given by formula
        """
        # print 'Cabling: ', devname, fromdate
        if devname != "": 
            if devname != 'DAQ':
                raise Exception('get_daq_cabling failed. \
                                 Invalid detector.')
            # check whether we are asked for the current cabling 
            # or cabling for an older date
            if fromdate == "" or fromdate == "current":
                # print '>getting current cabling', devname
                try:
                    self._current_cabling = \
                         self.cdb_server.get_current_cabling(devname)
                except CdbPermanentError:
                    self._current_cabling = "cdb_permanent_error"
                except CdbTemporaryError:
                    self._current_cabling = "cdb_temporary_error"
            else:
                # print 'getting cabling for date', fromdate
                try:
                    self._current_cabling = \
                         self.cdb_server.get_cabling_for_date(devname,fromdate)
                except CdbPermanentError:
                    self._current_cabling = "cdb_permanent_error"
                except CdbTemporaryError:
                    self._current_cabling = "cdb_temporary_error"
            # print self._current_cabling
        else:
            raise Exception('get_daq_cabling failed.No device.')
        return self._current_cabling  

    def get_cabling_for_run(self, devname, run_num):
        """
        Evaluate a string expression given by formula
        """
        self.reset()
        # print 'get_cabling_for_run: ', devname, run_num
        if devname != "": 
            if devname != 'DAQ':
                raise Exception('get_daq_cabling failed. \
                                 Invalid detector.')
            if run_num == "" or run_num > 0 and run_num < 1251:
                raise Exception('get_cabling_for_run failed. \
                                 Invalid run number.')
            try:
                # print 'getting cabling for run ',devname,run_num
                self._run_cabling = self.cdb_server.get_cabling_for_run(\
                                                 devname, run_num)
                # print self._run_cabling
                return self._run_cabling
            except CdbPermanentError:
                # print 'failed to get cabling by run. trying by date...'
                fromdate = self.date_from_run(run_num)
                return self.get_cabling_for_date(devname, fromdate)
        else:
            raise Exception('get_daq_cabling failed.No device.')

    def date_from_run(self, run_num):
        """
        This is really hacky because:
         some runs are not registered in the cdb
        So, set the valid date corresponding to this run number
        And do a get_cabling_for_date
        Monte Carlo runs are 0 so just set them to 'current'
        """
        self.reset()
        if run_num >= 1251 and run_num < 6541:
            fromdate = '2015-01-01 00:00:00'
        if run_num >= 6541:
            fromdate = 'current'
        return fromdate
    
    def reset(self):
        """
        Reinitialize cabling 
        """
        self._current_cabling = {}