# NIFTy
# Copyright (C) 2017  Theo Steininger
#
# Author: Theo Steininger
#
# This program 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.
#
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

import unittest

import numpy as np
from numpy.testing import assert_,\
                          assert_equal, \
                          assert_allclose
from nifty.config import dependency_injector as di

from nifty import Field,\
                  RGSpace,\
                  LMSpace,\
                  GLSpace,\
                  FieldArray, \
                  RGRGTransformation, \
                  LMGLTransformation, \
                  LMHPTransformation, \
                  FFTOperator

from itertools import product
from test.common import expand

from nose.plugins.skip import SkipTest

def _harmonic_type(itp):
    otp=itp
    if otp==np.float64:
        otp=np.complex128
    elif otp==np.float32:
        otp=np.complex64
    return otp

def _get_rtol(tp):
    if (tp==np.float64) or (tp==np.complex128):
        return 1e-10
    else:
        return 1e-5

class Misc_Tests(unittest.TestCase):
    @expand(product([10,11],[False,True],[0.1,1,3.7]))
    def test_RG_distance_1D(self,dim1,zc1,d):
        foo = RGSpace([dim1],zerocenter=zc1,distances=d)
        res = foo.get_distance_array('not')
        assert_equal(res[zc1*(dim1//2)],0.)

    @expand(product([10,11],[9,28],[False,True],[False,True],[0.1,1,3.7]))
    def test_RG_distance_2D(self, dim1, dim2, zc1, zc2, d):
        foo = RGSpace([dim1,dim2],zerocenter=[zc1,zc2],distances=d)
        res = foo.get_distance_array('not')
        assert_equal(res[zc1*(dim1//2),zc2*(dim2//2)],0.)

    @expand(product(["numpy","fftw"],[10,11],[False,True],[False,True],[0.1,1,3.7],
                    [np.float64,np.complex128,np.float32,np.complex64]))
    def test_fft1D(self,module,dim1,zc1,zc2,d,itp):
        if module=="fftw" and "pyfftw" not in di:
            raise SkipTest
        tol=_get_rtol(itp)
        a = RGSpace(dim1, zerocenter=zc1, distances=d)
        b = RGRGTransformation.get_codomain(a, zerocenter=zc2)
        fft = FFTOperator(domain=a, target=b, domain_dtype=itp,
                          target_dtype=_harmonic_type(itp),module=module)
        inp = Field.from_random(domain=a,random_type='normal',std=7,mean=3,
                                dtype=itp)
        out = fft.inverse_times(fft.times(inp))
        assert_allclose(inp.val, out.val,rtol=tol,atol=tol)

    @expand(product(["numpy","fftw"],[10,11],[9,12],[False,True],[False,True],
                    [False,True], [False,True],[0.1,1,3.7],
                    [np.float64,np.complex128,np.float32,np.complex64]))
    def test_fft2D(self,module,dim1,dim2,zc1,zc2,zc3,zc4,d,itp):
        if module=="fftw" and "pyfftw" not in di:
            raise SkipTest
        tol=_get_rtol(itp)
        a = RGSpace([dim1,dim2], zerocenter=[zc1,zc2], distances=d)
        b = RGRGTransformation.get_codomain(a, zerocenter=[zc3,zc4])
        fft = FFTOperator(domain=a, target=b, domain_dtype=itp,
                          target_dtype=_harmonic_type(itp),module=module)
        inp = Field.from_random(domain=a,random_type='normal',std=7,mean=3,
                                dtype=itp)
        out = fft.inverse_times(fft.times(inp))
        assert_allclose(inp.val, out.val,rtol=tol,atol=tol)

    @expand(product([0,3,6,11,30],
                    [np.float64,np.complex128,np.float32,np.complex64]))
    def test_sht(self,lm,tp):
        if 'pyHealpix' not in di:
            raise SkipTest
        tol=_get_rtol(tp)
        a = LMSpace(lmax=lm)
        b = LMGLTransformation.get_codomain(a)
        fft = FFTOperator(domain=a, target=b, domain_dtype=tp, target_dtype=tp)
        inp = Field.from_random(domain=a,random_type='normal',std=7,mean=3,
                                dtype=tp)
        out = fft.inverse_times(fft.times(inp))
        assert_allclose(inp.val, out.val,rtol=tol,atol=tol)

    @expand(product([128,256],
                    [np.float64,np.complex128,np.float32,np.complex64]))
    def test_sht2(self,lm,tp):
        if 'pyHealpix' not in di:
            raise SkipTest
        a = LMSpace(lmax=lm)
        b = LMHPTransformation.get_codomain(a)
        fft = FFTOperator(domain=a, target=b, domain_dtype=tp, target_dtype=tp)
        inp = Field.from_random(domain=a,random_type='normal',std=1,mean=0,
                                dtype=tp)
        out = fft.inverse_times(fft.times(inp))
        assert_allclose(inp.val, out.val,rtol=1e-3,atol=1e-3)