#!/usr/bin/env python
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import mkl_fft.interfaces as mfi
import pytest
import numpy as np


def test_interfaces_has_numpy():
    assert hasattr(mfi, 'numpy_fft')


def test_interfaces_has_scipy():
    assert hasattr(mfi, 'scipy_fft')


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64, np.complex64, np.complex128])
def test_scipy_fft(norm, dtype):
    x = np.ones(511, dtype=dtype)
    w = mfi.scipy_fft.fft(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.ifft(w, norm=norm, workers=None, plan=None)
    tol = 128 * np.finfo(np.dtype(dtype)).eps
    np.testing.assert_allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64, np.complex64, np.complex128])
def test_numpy_fft(norm, dtype):
    x = np.ones(511, dtype=dtype)
    w = mfi.numpy_fft.fft(x, norm=norm)
    xx = mfi.numpy_fft.ifft(w, norm=norm)
    tol = 128 * np.finfo(np.dtype(dtype)).eps
    np.testing.assert_allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64])
def test_scipy_rfft(norm, dtype):
    x = np.ones(511, dtype=dtype)
    w = mfi.scipy_fft.rfft(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.irfft(w, n=x.shape[0], norm=norm, workers=None, plan=None)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)
    
    x = np.ones(510, dtype=dtype)
    w = mfi.scipy_fft.rfft(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.irfft(w, norm=norm, workers=None, plan=None)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64])
def test_numpy_rfft(norm, dtype):
    x = np.ones(511, dtype=dtype)
    w = mfi.numpy_fft.rfft(x, norm=norm)
    xx = mfi.numpy_fft.irfft(w, n=x.shape[0], norm=norm)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64, np.complex64, np.complex128])
def test_scipy_fftn(norm, dtype):
    x = np.ones((37, 83), dtype=dtype)
    w = mfi.scipy_fft.fftn(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.ifftn(w, norm=norm, workers=None, plan=None)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64, np.complex64, np.complex128])
def test_numpy_fftn(norm, dtype):
    x = np.ones((37, 83), dtype=dtype)
    w = mfi.numpy_fft.fftn(x, norm=norm)
    xx = mfi.numpy_fft.ifftn(w, norm=norm)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64])
def test_scipy_rfftn(norm, dtype):
    x = np.ones((37, 83), dtype=dtype)
    w = mfi.scipy_fft.rfftn(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.irfftn(w, s=x.shape, norm=norm, workers=None, plan=None)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)

    x = np.ones((36, 82), dtype=dtype)
    w = mfi.scipy_fft.rfftn(x, norm=norm, workers=None, plan=None)
    xx = mfi.scipy_fft.irfftn(w, norm=norm, workers=None, plan=None)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


@pytest.mark.parametrize('norm', [None, "forward", "backward", "ortho"])
@pytest.mark.parametrize('dtype', [np.float32, np.float64])
def test_numpy_rfftn(norm, dtype):
    x = np.ones((37, 83), dtype=dtype)
    w = mfi.numpy_fft.rfftn(x, norm=norm)
    xx = mfi.numpy_fft.irfftn(w, s=x.shape, norm=norm)
    tol = 64 * np.finfo(np.dtype(dtype)).eps
    assert np.allclose(x, xx, atol=tol, rtol=tol)


def _get_blacklisted_dtypes():
    bl_list = []
    for dt in ['float16', 'float128', 'complex256']:
        if hasattr(np, dt):
            bl_list.append(getattr(np, dt))
    return bl_list

    
@pytest.mark.parametrize('dtype', _get_blacklisted_dtypes())
def test_scipy_no_support_for(dtype):
    x = np.ones(16, dtype=dtype)
    w = mfi.scipy_fft.fft(x)
    assert w is NotImplemented


def test_scipy_fft_arg_validate():
    with pytest.raises(ValueError):
        mfi.scipy_fft.fft([1,2,3,4], norm=b"invalid")

    with pytest.raises(NotImplementedError):
        mfi.scipy_fft.fft([1,2,3,4], plan="magic")