import os
from ...Utilities import f90nml
from datetime import datetime as dt
from string import lower
import string


class LUCYParams:
    def __init__(self, file):
        '''
        Read LUCY parameters file and return object or exception
        :param file: Location of LUCY config file
        '''
        if not os.path.exists(file):
            raise IOError('Parameters file ' + str(file) + ' not found')
        self.inputFile = file
        self.TResponse = None # Optional temperature response model
        self.landCoverWeights =  {} # Holder for land cover weights

        nml = f90nml.read(file)

        try:
            # Maths params
            self.avg_speed =         float(nml['params']['avgspeed'])
            if self.avg_speed > 64000:
                raise ValueError('Average vehicle speed must not exceed 64 kph')
            self.emission_factors = map(float, nml['params']['emissionfactors'])
            self.BP_temp =          float(nml['params']['balance_point_temperature'])
            self.QV_multfactor =    float(nml['params']['QV_multfactor'])
            self.sleep_metab =      float(nml['params']['sleep_metab'])
            self.work_metab =       float(nml['params']['work_metab'])

        except ValueError, e:
            raise ValueError('Invalid parameter provided: ' + str(e))
        except KeyError,e:
            raise KeyError('Entry missing from parameters file: ' + str(e))

        # Model date options
        try:
            self.timezone = nml['params']['timezone']
        except KeyError:
            raise KeyError('Entry "timezone" not found in parameters file')
        except Exception:
            raise ValueError('Invalid "timezone" entry. Must be a recognised time zone string in the format Continent/City (e.g. "Europe/London")')

        try:
            self.use_uk_hols = True if nml['params']['use_uk_holidays'] == 1 else False
            self.use_custom_hols = True if nml['params']['use_custom_holidays'] == 1 else False
            self.custom_holidays = []
        except KeyError, e:
            raise KeyError('Entry %s not found in parameters file'%(str(e),))

        if self.use_custom_hols: # Only try and deal with custom holidays entry if it's set to 1
            def toDate(x): return dt.strptime(x, '%Y-%m-%d').date()
            try:
                self.custom_holidays = map(toDate, nml['params']['custom_holidays'])
            except Exception:
                raise ValueError('Custom holidays in parameters file must be in formatted YYYY-mm-dd')

        try:
            a=nml['landCoverWeights']
        except Exception:
            raise ValueError('Section \'landCoverWeights\' not in configuration file ' + file)

        self.lcw(nml, file) # Dict of land cover weightings for extra disaggregation {class: {building: float, transport: float, metabolism: float}}
        self.tresp(nml, file) # Optional: User-defined temperature response


    def lcw(self, PARAMS, paramsFile):
        # Validate land cover weightings (used for additional disaggregation)
        expectedClasses = ["paved", "buildings", "evergreentrees", "decidioustrees", "grass", "baresoil", "water"]
        types = ['building', 'transport', 'metabolism']
        missing = set(map(lower,expectedClasses)).difference(map(lower, PARAMS['landCoverWeights'].keys()))
        if len(missing) > 0:
            raise ValueError(paramsFile + ' is missing the following entries under "landCoverWeights": ' + string.join(list(missing), ","))

        for cl in expectedClasses:
            if len(PARAMS['landCoverWeights'][cl]) != 3:
                raise ValueError('Land cover weights in parameters file should each have 3 entries, but ' + str(cl) + ' does not')

            self.landCoverWeights[cl] = {}
            for ty in range(0,len(types)):
                try:
                    self.landCoverWeights[cl][types[ty]] = float(PARAMS['landCoverWeights'][cl][ty])
                except Exception:
                    raise ValueError('Land cover weights in parameters file had invalid number in entry: ' + str(cl))

    def tresp(self, PARAMS, paramsFile):
        ''' Check for optional CustomTemperatureResponse entries
        :param PARAMS:
        :param paramsFile:
        :return:
        '''
        try:
            a = PARAMS['CustomTemperatureResponse']
        except KeyError:
            self.TemperatureResponse = None
            return

        expectedEntries = ['Th', 'Tc', 'Ah', 'Ac', 'c', 'Tmax', 'Tmin']

        missing = set(map(lower, expectedEntries)).difference(map(lower, PARAMS['CustomTemperatureResponse'].keys()))
        if len(missing) > 0:
            raise ValueError(paramsFile + ' is missing the following entries under "CustomTemperatureResponse": ' + string.join(list(missing), ","))
        self.TResponse = {}
        for cl in expectedEntries:
            try:
                self.TResponse[cl] = float(PARAMS['CustomTemperatureResponse'][cl.lower()])
            except ValueError:
                raise ValueError('Custom temperature response parameters had invalid number in entry: ' + str(cl))
            except Exception, e:
                raise Exception(str(e))

