import os
from gpaw.atom.generator import Generator

"""
SetupGenerators use a name; the generated setup files will be named accordingly
such that several tests can be run simultaneously without overwriting

Each concurrently active generator should, of course, use a different name
"""
class SetupGenerator:

    def __init__(self, name):
        #We don't want anything to mess up with existing files
        #so make sure a proper name is entered with a couple of chars
        #(it should be enough to test for len==0, but what the heck)
        if len(name) < 3:
            raise Exception
        self.name = name


    def new_nitrogen_setup(self, r=1.1, rvbar=None, rcomp=None, 
                           rfilter=None, hfilter=0.4):
        """Generate new nitrogen setup.

        The new setup depends on five parameters (Bohr units):

        * 0.6 < r < 1.9: cutoff radius for projector functions
        * 0.6 < rvbar < 1.9: cutoff radius zero potential (vbar)
        * 0.6 < rcomp < 1.9: cutoff radius for compensation charges
        * 0.6 < rfilter < 1.9: cutoff radius for Fourier-filtered
          projector functions
        * 0.2 < hfilter < 0.6: target grid spacing

        Use the setup like this::

          calc = Calculator(setups={'N': 'opt'}, ...)

        """

        if rvbar is None:
            rvbar = r
        if rcomp is None:
            rcomp = r
        if rfilter is None:
            rfilter = 2 * r

        g = Generator('N', 'PBE', scalarrel=True, nofiles=True)
        g.run(core='[He]',
              rcut=r,
              vbar=('poly', rvbar),
              filter=(hfilter, rfilter / r),
              rcutcomp=rcomp,
              logderiv=False)
        path = os.environ['GPAW_SETUP_PATH'].split(':')[0]
        os.rename('N.PBE', path + '/N.'+self.name+'.PBE')

    def f(self, par):
        self.new_nitrogen_setup(*par)

        #new_nitrogen_setup(1.1, 1.1, 1.1, 1.9, 0.4)
        #f([1.2])
        #f([1.2, 1.0, 1.0])