#!/net/python/bin/python
from Header import *
from Function1D import *
from Spectrum import *
from extinction import CardelliExtinction

class Filter(Function1D):
    def __init__(self,filterset='',filtername=''):
        self.name = filtername
        self.getfromfile(FilterFile(filterset,filtername))
        self.mean_l = None
              #will hold mean wavelength when calculated
              # to save computation time
        self.vegaflux = None

    def copy(self):
        selfcopy = self.__class__()
        selfcopy.x = self.x.copy()
        selfcopy.y = self.y.copy()

        selfcopy.mean_l = self.mean_l
        selfcopy.vegaflux = self.vegaflux

        return selfcopy

    def CCDflux(self,spectrum,ZP):
        sourceSignal = self.PhotonFlux( spectrum )
        if self.vegaflux is None:
            self.vegaflux = self.PhotonFlux( GetRefSpectrum() )
        return sourceSignal/self.vegaflux * 10**(0.4*ZP)
    
    def Mag(self,spectrum):
        sourceSignal = self.PhotonFlux( spectrum )
        if self.vegaflux is None:
            self.vegaflux = self.PhotonFlux( GetRefSpectrum() )
        return -2.5*num.log10(sourceSignal/self.vegaflux)

    def mean(self):
        if self.mean_l == None:
            self.mean_l = self.xmean()
        return self.mean_l

    def PhotonFlux(self,spectrum):
        #  number of photons = energy/(h*nu) = energy * lam/(2*pi*hbar*c)
        #   2*pi* hbar*c
        #    = 2* pi * 197 eV nm
        #    = 6.28*197 * 1.60e-12 * 10 ergs angst
        #    = 1.97946e-08
        #    = 1/5.006909561e07
        return 5.006909561E07 * (self * spectrum * (lambda x:x)).integrate()

    def ErgFlux(self,spectrum):
        return (self*spectrum).integrate()

    #--Redshifting functions-------------
    def redshift(self,z):
        selfcopy = self.xshift( 1.+z )
        if self.mean_l is not None:
            selfcopy.mean_l = self.mean_l*(1.+z)
        else:
            selfcopy.mean_l = None
        selfcopy.vegaflux = None
        return selfcopy

    def blueshift(self,z):
        selfcopy = self.xshift( 1./(1.+z) )
        if self.mean_l is not None:
            selfcopy.mean_l = self.mean_l/(1.+z)
        else:
            selfcopy.mean_l = None
        selfcopy.vegaflux = None
        return selfcopy

    def unredshift(self,z):
        return self.blueshift(z)

    def unblueshift(self,z):
        return self.redshift(z)
    #-------------------------------------

    def extincted(self,EBV,Rv=3.1):
        """
        returns a copy of self adjusted according to Cardelli
        extinction law
        """
        #CardelliExtinction function comes from extinction.py
        selfcopy = self.copy()
        selfcopy.vegaflux = None
        selfcopy.mean_l = None
        
        for i in range(len(selfcopy)):
            lam = selfcopy.x[i]
            selfcopy.y[i] *= CardelliExtinction(lam,EBV,Rv)
        
        return selfcopy

    def z_where_tossed(self,BlueCutoff=3460.0,RedCutoff=6600.0):
        mean_l = self.mean()
        Rcut = mean_l/RedCutoff - 1
        Bcut = mean_l/BlueCutoff -1

        if Rcut > 0:
            return '%.3f < z < %.3f' % (Rcut,Bcut)
        else:
            return 'z < %.3f' % Bcut

if __name__ == '__main__':
    for f in 'ugriz':
        F = Filter('SDSS',f)
        F.graph()
        print "%s: %.3f" % ( f,F.mean() )
    p.show()