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#
#   See COPYING file distributed along with the NiBabel package for the
#   copyright and license terms.
#
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''' Test Analyze headers

See test_wrapstruct.py for tests of the wrapped structarr-ness of the Analyze
header
'''

import os
import re
import logging
import pickle

import numpy as np

from ..externals.six import BytesIO, StringIO
from ..volumeutils import array_to_file
from ..spatialimages import (HeaderDataError, HeaderTypeError)
from ..analyze import AnalyzeHeader, AnalyzeImage
from ..nifti1 import Nifti1Header
from ..loadsave import read_img_data
from .. import imageglobals
from ..casting import as_int

from numpy.testing import (assert_array_equal,
                           assert_array_almost_equal)

from ..testing import (assert_equal, assert_not_equal, assert_true,
                       assert_false, assert_raises, data_path)

from .test_wrapstruct import _TestWrapStructBase
from . import test_spatialimages as tsi

header_file = os.path.join(data_path, 'analyze.hdr')

PIXDIM0_MSG = 'pixdim[1,2,3] should be non-zero; setting 0 dims to 1'

def _write_data(hdr, data, fileobj):
    # auxilary function to write data
    out_dtype = hdr.get_data_dtype()
    offset = hdr.get_data_offset()
    array_to_file(data, fileobj, out_dtype, offset)


class TestAnalyzeHeader(_TestWrapStructBase):
    header_class = AnalyzeHeader
    example_file = header_file

    def test_general_init(self):
        super(TestAnalyzeHeader, self).test_general_init()
        hdr = self.header_class()
        # an empty header has shape (0,) - like an empty array
        # (np.array([]))
        assert_equal(hdr.get_data_shape(), (0,))
        # The affine is always homogenous 3D regardless of shape. The
        # default affine will have -1 as the X zoom iff default_x_flip
        # is True (which it is by default). We have to be careful of the
        # translations though - these arise from SPM's use of the origin
        # field, and the center of the image.
        assert_array_equal(np.diag(hdr.get_base_affine()),
                                 [-1,1,1,1])
        # But zooms only go with number of dimensions
        assert_equal(hdr.get_zooms(), (1.0,))

    def test_header_size(self):
        assert_equal(self.header_class.template_dtype.itemsize, 348)

    def test_empty(self):
        hdr = self.header_class()
        assert_true(len(hdr.binaryblock) == 348)
        assert_true(hdr['sizeof_hdr'] == 348)
        assert_true(np.all(hdr['dim'][1:] == 1))
        assert_true(hdr['dim'][0] == 0        )
        assert_true(np.all(hdr['pixdim'] == 1))
        assert_true(hdr['datatype'] == 16) # float32
        assert_true(hdr['bitpix'] == 32)

    def _set_something_into_hdr(self, hdr):
        # Called from test_bytes test method.  Specific to the header data type
        hdr.set_data_shape((1, 2, 3))

    def test_checks(self):
        # Test header checks
        hdr_t = self.header_class()
        # _dxer just returns the diagnostics as a string
        assert_equal(self._dxer(hdr_t), '')
        hdr = hdr_t.copy()
        hdr['sizeof_hdr'] = 1
        assert_equal(self._dxer(hdr), 'sizeof_hdr should be 348')
        hdr = hdr_t.copy()
        hdr['datatype'] = 0
        assert_equal(self._dxer(hdr), 'data code 0 not supported\n'
                     'bitpix does not match datatype')
        hdr = hdr_t.copy()
        hdr['bitpix'] = 0
        assert_equal(self._dxer(hdr), 'bitpix does not match datatype')
        for i in (1,2,3):
            hdr = hdr_t.copy()
            hdr['pixdim'][i] = -1
            assert_equal(self._dxer(hdr), 'pixdim[1,2,3] should be positive')

    def test_log_checks(self):
        # Test logging, fixing, errors for header checking
        HC = self.header_class
        # magic
        hdr = HC()
        hdr['sizeof_hdr'] = 350 # severity 30
        fhdr, message, raiser = self.log_chk(hdr, 30)
        assert_equal(fhdr['sizeof_hdr'], 348)
        assert_equal(message, 'sizeof_hdr should be 348; '
                           'set sizeof_hdr to 348')
        assert_raises(*raiser)
        # RGB datatype does not raise error
        hdr = HC()
        hdr.set_data_dtype('RGB')
        fhdr, message, raiser = self.log_chk(hdr, 0)
        # datatype not recognized
        hdr = HC()
        hdr['datatype'] = -1 # severity 40
        fhdr, message, raiser = self.log_chk(hdr, 40)
        assert_equal(message, 'data code -1 not recognized; '
                           'not attempting fix')
        assert_raises(*raiser)
        # datatype not supported
        hdr['datatype'] = 255 # severity 40
        fhdr, message, raiser = self.log_chk(hdr, 40)
        assert_equal(message, 'data code 255 not supported; '
                           'not attempting fix')
        assert_raises(*raiser)
        # bitpix
        hdr = HC()
        hdr['datatype'] = 16 # float32
        hdr['bitpix'] = 16 # severity 10
        fhdr, message, raiser = self.log_chk(hdr, 10)
        assert_equal(fhdr['bitpix'], 32)
        assert_equal(message, 'bitpix does not match datatype; '
                           'setting bitpix to match datatype')
        assert_raises(*raiser)
        # pixdim positive
        hdr = HC()
        hdr['pixdim'][1] = -2 # severity 35
        fhdr, message, raiser = self.log_chk(hdr, 35)
        assert_equal(fhdr['pixdim'][1], 2)
        assert_equal(message, 'pixdim[1,2,3] should be positive; '
                           'setting to abs of pixdim values')
        assert_raises(*raiser)
        hdr = HC()
        hdr['pixdim'][1] = 0 # severity 30
        fhdr, message, raiser = self.log_chk(hdr, 30)
        assert_equal(fhdr['pixdim'][1], 1)
        assert_equal(message, PIXDIM0_MSG)
        assert_raises(*raiser)
        # both
        hdr = HC()
        hdr['pixdim'][1] = 0 # severity 30
        hdr['pixdim'][2] = -2 # severity 35
        fhdr, message, raiser = self.log_chk(hdr, 35)
        assert_equal(fhdr['pixdim'][1], 1)
        assert_equal(fhdr['pixdim'][2], 2)
        assert_equal(message, 'pixdim[1,2,3] should be '
                           'non-zero and pixdim[1,2,3] should '
                           'be positive; setting 0 dims to 1 '
                           'and setting to abs of pixdim values')
        assert_raises(*raiser)

    def test_logger_error(self):
        # Check that we can reset the logger and error level
        HC = self.header_class
        hdr = HC()
        # Make a new logger
        str_io = StringIO()
        logger = logging.getLogger('test.logger')
        logger.setLevel(30) # defaultish level
        logger.addHandler(logging.StreamHandler(str_io))
        # Prepare an error
        hdr['pixdim'][1] = 0 # severity 30
        log_cache = imageglobals.logger, imageglobals.error_level
        try:
            # Check log message appears in new logger
            imageglobals.logger = logger
            hdr.copy().check_fix()
            assert_equal(str_io.getvalue(), PIXDIM0_MSG + '\n')
            # Check that error_level in fact causes error to be raised
            imageglobals.error_level = 30
            assert_raises(HeaderDataError, hdr.copy().check_fix)
        finally:
            imageglobals.logger, imageglobals.error_level = log_cache

    def test_data_dtype(self):
        # check getting and setting of data type
        # codes / types supported by all binary headers
        supported_types = ((2, np.uint8),
                           (4, np.int16),
                           (8, np.int32),
                           (16, np.float32),
                           (32, np.complex64),
                           (64, np.float64),
                           (128, np.dtype([('R','u1'),
                                           ('G', 'u1'),
                                           ('B', 'u1')])))
        # and unsupported - here using some labels instead
        unsupported_types = (np.void, 'none', 'all', 0)
        hdr = self.header_class()
        for code, npt in supported_types:
            # Can set with code value, or numpy dtype, both return the
            # dtype as output on get
            hdr.set_data_dtype(code)
            assert_equal(hdr.get_data_dtype(), npt)
            hdr.set_data_dtype(npt)
            assert_equal(hdr.get_data_dtype(), npt)
        for inp in unsupported_types:
            assert_raises(HeaderDataError,
                                hdr.set_data_dtype,
                                inp)

    def test_shapes(self):
        # Test that shape checks work
        hdr = self.header_class()
        for shape in ((2, 3, 4), (2, 3, 4, 5), (2, 3), (2,)):
            hdr.set_data_shape(shape)
            assert_equal(hdr.get_data_shape(), shape)
        # Check max works, but max+1 raises error
        dim_dtype = hdr.structarr['dim'].dtype
        # as_int for safety to deal with numpy 1.4.1 int conversion errors
        mx = as_int(np.iinfo(dim_dtype).max)
        shape = (mx,)
        hdr.set_data_shape(shape)
        assert_equal(hdr.get_data_shape(), shape)
        shape = (mx+1,)
        assert_raises(HeaderDataError, hdr.set_data_shape, shape)
        # Lists or tuples or arrays will work for setting shape
        shape = (2, 3, 4)
        for constructor in (list, tuple, np.array):
            hdr.set_data_shape(constructor(shape))
            assert_equal(hdr.get_data_shape(), shape)

    def test_read_write_data(self):
        # Check reading and writing of data
        hdr = self.header_class()
        # Trying to read data from an empty header gives no data
        bytes = hdr.data_from_fileobj(BytesIO())
        assert_equal(len(bytes), 0)
        # Setting no data into an empty header results in - no data
        str_io = BytesIO()
        hdr.data_to_fileobj([], str_io)
        assert_equal(str_io.getvalue(), b'')
        # Setting more data then there should be gives an error
        assert_raises(HeaderDataError,
                      hdr.data_to_fileobj,
                      np.zeros(3),
                      str_io)
        # Test valid write
        hdr.set_data_shape((1,2,3))
        hdr.set_data_dtype(np.float32)
        S = BytesIO()
        data = np.arange(6, dtype=np.float64)
        # data have to be the right shape
        assert_raises(HeaderDataError, hdr.data_to_fileobj, data, S)
        data = data.reshape((1,2,3))
        # and size
        assert_raises(HeaderDataError, hdr.data_to_fileobj, data[:,:,:-1], S)
        assert_raises(HeaderDataError, hdr.data_to_fileobj, data[:,:-1,:], S)
        # OK if so
        hdr.data_to_fileobj(data, S)
        # Read it back
        data_back = hdr.data_from_fileobj(S)
        # Should be about the same
        assert_array_almost_equal(data, data_back)
        # but with the header dtype, not the data dtype
        assert_equal(hdr.get_data_dtype(), data_back.dtype)
        # this is with native endian, not so for swapped
        S2 = BytesIO()
        hdr2 = hdr.as_byteswapped()
        hdr2.set_data_dtype(np.float32)
        hdr2.set_data_shape((1,2,3))
        hdr2.data_to_fileobj(data, S2)
        data_back2 = hdr2.data_from_fileobj(S2)
        # Compares the same
        assert_array_almost_equal(data_back, data_back2)
        # Same dtype names
        assert_equal(data_back.dtype.name, data_back2.dtype.name)
        # But not the same endianness
        assert_not_equal(data.dtype.byteorder, data_back2.dtype.byteorder)
        # Try scaling down to integer
        hdr.set_data_dtype(np.uint8)
        S3 = BytesIO()
        # Analyze header cannot do scaling, but, if not scaling, AnalyzeHeader
        # is OK
        _write_data(hdr, data, S3)
        data_back = hdr.data_from_fileobj(S3)
        assert_array_almost_equal(data, data_back)
        # But, the data won't always be same as input if not scaling
        data = np.arange(6, dtype=np.float64).reshape((1,2,3)) + 0.5
        _write_data(hdr, data, S3)
        data_back = hdr.data_from_fileobj(S3)
        assert_false(np.allclose(data, data_back))
        # Test RGB image
        dtype = np.dtype([('R', 'uint8'), ('G', 'uint8'), ('B', 'uint8')])
        data = np.ones((1, 2, 3), dtype)
        hdr.set_data_dtype(dtype)
        S4 = BytesIO()
        hdr.data_to_fileobj(data, S4)
        data_back = hdr.data_from_fileobj(S4)
        assert_array_equal(data, data_back)

    def test_datatype(self):
        ehdr = self.header_class()
        codes = self.header_class._data_type_codes
        for code in codes.value_set():
            npt = codes.type[code]
            if npt is np.void:
                assert_raises(
                       HeaderDataError,
                       ehdr.set_data_dtype,
                       code)
                continue
            dt = codes.dtype[code]
            ehdr.set_data_dtype(npt)
            assert_true(ehdr['datatype'] == code)
            assert_true(ehdr['bitpix'] == dt.itemsize*8)
            ehdr.set_data_dtype(code)
            assert_true(ehdr['datatype'] == code)
            ehdr.set_data_dtype(dt)
            assert_true(ehdr['datatype'] == code)

    def test_data_shape_zooms_affine(self):
        hdr = self.header_class()
        for shape in ((1,2,3),(0,),(1,),(1,2),(1,2,3,4)):
            L = len(shape)
            hdr.set_data_shape(shape)
            if L:
                assert_equal(hdr.get_data_shape(), shape)
            else:
                assert_equal(hdr.get_data_shape(), (0,))
            # Default zoom - for 3D - is 1(())
            assert_equal(hdr.get_zooms(), (1,) * L)
            # errors if zooms do not match shape
            if len(shape):
                assert_raises(HeaderDataError, 
                                    hdr.set_zooms,
                                    (1,) * (L-1))
                # Errors for negative zooms
                assert_raises(HeaderDataError,
                                    hdr.set_zooms,
                                    (-1,) + (1,)*(L-1))
            assert_raises(HeaderDataError,
                                hdr.set_zooms,
                                (1,) * (L+1))
            # Errors for negative zooms
            assert_raises(HeaderDataError,
                                hdr.set_zooms,
                                (-1,) * L)
        # reducing the dimensionality of the array and then increasing
        # it again reverts the previously set zoom values to 1.0
        hdr = self.header_class()
        hdr.set_data_shape((1,2,3))
        hdr.set_zooms((4,5,6))
        assert_array_equal(hdr.get_zooms(), (4,5,6))
        hdr.set_data_shape((1,2))
        assert_array_equal(hdr.get_zooms(), (4,5))
        hdr.set_data_shape((1,2,3))
        assert_array_equal(hdr.get_zooms(), (4,5,1))
        # Setting zooms changes affine
        assert_array_equal(np.diag(hdr.get_base_affine()),
                           [-4,5,1,1])
        hdr.set_zooms((1,1,1))
        assert_array_equal(np.diag(hdr.get_base_affine()),
                           [-1,1,1,1])

    def test_default_x_flip(self):
        hdr = self.header_class()
        hdr.default_x_flip = True
        hdr.set_data_shape((1,2,3))
        hdr.set_zooms((1,1,1))
        assert_array_equal(np.diag(hdr.get_base_affine()),
                           [-1,1,1,1])
        hdr.default_x_flip = False
        # Check avoids translations
        assert_array_equal(np.diag(hdr.get_base_affine()),
                           [1,1,1,1])

    def test_from_eg_file(self):
        fileobj = open(self.example_file, 'rb')
        hdr = self.header_class.from_fileobj(fileobj, check=False)
        assert_equal(hdr.endianness, '>')
        assert_equal(hdr['sizeof_hdr'], 348)

    def test_orientation(self):
        # Test flips
        hdr = self.header_class()
        assert_true(hdr.default_x_flip)
        hdr.set_data_shape((3,5,7))
        hdr.set_zooms((4,5,6))
        aff = np.diag((-4,5,6,1))
        aff[:3,3] = np.array([1,2,3]) * np.array([-4,5,6]) * -1
        assert_array_equal(hdr.get_base_affine(), aff)
        hdr.default_x_flip = False
        assert_false(hdr.default_x_flip)
        aff[0]*=-1
        assert_array_equal(hdr.get_base_affine(), aff)

    def test_str(self):
        super(TestAnalyzeHeader, self).test_str()
        hdr = self.header_class()
        s1 = str(hdr)
        # check the datacode recoding
        rexp = re.compile('^datatype +: float32', re.MULTILINE)
        assert_true(rexp.search(s1) is not None)

    def test_from_header(self):
        # check from header class method.
        klass = self.header_class
        empty = klass.from_header()
        assert_equal(klass(), empty)
        empty = klass.from_header(None)
        assert_equal(klass(), empty)
        hdr = klass()
        hdr.set_data_dtype(np.float64)
        hdr.set_data_shape((1,2,3))
        hdr.set_zooms((3.0, 2.0, 1.0))
        copy = klass.from_header(hdr)
        assert_equal(hdr, copy)
        assert_false(hdr is copy)
        class C(object):
            def get_data_dtype(self): return np.dtype('i2')
            def get_data_shape(self): return (5,4,3)
            def get_zooms(self): return (10.0, 9.0, 8.0)
        converted = klass.from_header(C())
        assert_true(isinstance(converted, klass))
        assert_equal(converted.get_data_dtype(), np.dtype('i2'))
        assert_equal(converted.get_data_shape(), (5,4,3))
        assert_equal(converted.get_zooms(), (10.0,9.0,8.0))

    def test_base_affine(self):
        klass = self.header_class
        hdr = klass()
        hdr.set_data_shape((3, 5, 7))
        hdr.set_zooms((3, 2, 1))
        assert_true(hdr.default_x_flip)
        assert_array_almost_equal(
            hdr.get_base_affine(),
            [[-3.,  0.,  0.,  3.],
             [ 0.,  2.,  0., -4.],
             [ 0.,  0.,  1., -3.],
             [ 0.,  0.,  0.,  1.]])
        hdr.set_data_shape((3, 5))
        assert_array_almost_equal(
            hdr.get_base_affine(),
            [[-3.,  0.,  0.,  3.],
             [ 0.,  2.,  0., -4.],
             [ 0.,  0.,  1., -0.],
             [ 0.,  0.,  0.,  1.]])
        hdr.set_data_shape((3, 5, 7))
        assert_array_almost_equal(
            hdr.get_base_affine(),
            [[-3.,  0.,  0.,  3.],
             [ 0.,  2.,  0., -4.],
             [ 0.,  0.,  1., -3.],
             [ 0.,  0.,  0.,  1.]])


def test_best_affine():
    hdr = AnalyzeHeader()
    hdr.set_data_shape((3,5,7))
    hdr.set_zooms((4,5,6))
    assert_array_equal(hdr.get_base_affine(), hdr.get_best_affine())


def test_scaling():
    # Test integer scaling from float
    # Analyze headers cannot do float-integer scaling '''
    hdr = AnalyzeHeader()
    assert_true(hdr.default_x_flip)
    shape = (1,2,3)
    hdr.set_data_shape(shape)
    hdr.set_data_dtype(np.float32)
    data = np.ones(shape, dtype=np.float64)
    S = BytesIO()
    # Writing to float datatype doesn't need scaling
    hdr.data_to_fileobj(data, S)
    rdata = hdr.data_from_fileobj(S)
    assert_array_almost_equal(data, rdata)
    # Writing to integer datatype does, and raises an error
    hdr.set_data_dtype(np.int32)
    assert_raises(HeaderTypeError, hdr.data_to_fileobj, data, BytesIO())
    # unless we aren't scaling, in which case we convert the floats to
    # integers and write
    _write_data(hdr, data, S)
    rdata = hdr.data_from_fileobj(S)
    assert_true(np.allclose(data, rdata))
    # This won't work for floats that aren't close to integers
    data_p5 = data + 0.5
    _write_data(hdr, data_p5, S)
    rdata = hdr.data_from_fileobj(S)
    assert_false(np.allclose(data_p5, rdata))


def test_slope_inter():
    hdr = AnalyzeHeader()
    assert_equal(hdr.get_slope_inter(), (None, None))
    for slinter in ((None,),
                    (None, None),
                    (1.0,),
                    (1.0, None),
                    (None, 0),
                    (1.0, 0)):
        hdr.set_slope_inter(*slinter)
        assert_equal(hdr.get_slope_inter(), (None, None))
    assert_raises(HeaderTypeError, hdr.set_slope_inter, 1.1)
    assert_raises(HeaderTypeError, hdr.set_slope_inter, 1.0, 0.1)


def test_data_code_error():
    # test analyze raising error for unsupported codes
    hdr = Nifti1Header()
    hdr['datatype'] = 256
    assert_raises(HeaderDataError, AnalyzeHeader.from_header, hdr)


class TestAnalyzeImage(tsi.TestSpatialImage):
    image_class = AnalyzeImage

    def test_data_hdr_cache(self):
        # test the API for loaded images, such that the data returned
        # from img.get_data() is not affected by subsequent changes to
        # the header.
        IC = self.image_class
        # save an image to a file map
        fm = IC.make_file_map()
        for key, value in fm.items():
            fm[key].fileobj = BytesIO()
        shape = (2,3,4)
        data = np.arange(24, dtype=np.int8).reshape(shape)
        affine = np.eye(4)
        hdr = IC.header_class()
        hdr.set_data_dtype(np.int16)
        img = IC(data, affine, hdr)
        img.to_file_map(fm)
        img2 = IC.from_file_map(fm)
        assert_equal(img2.shape, shape)
        assert_equal(img2.get_data_dtype().type, np.int16)
        hdr = img2.get_header()
        hdr.set_data_shape((3,2,2))
        assert_equal(hdr.get_data_shape(), (3,2,2))
        hdr.set_data_dtype(np.uint8)
        assert_equal(hdr.get_data_dtype(), np.dtype(np.uint8))
        assert_array_equal(img2.get_data(), data)
        # now check read_img_data function - here we do see the changed
        # header
        sc_data = read_img_data(img2)
        assert_equal(sc_data.shape, (3,2,2))
        us_data = read_img_data(img2, prefer='unscaled')
        assert_equal(us_data.shape, (3,2,2))

    def test_affine_44(self):
        IC = self.image_class
        shape = (2,3,4)
        data = np.arange(24, dtype=np.int16).reshape(shape)
        affine = np.diag([2, 3, 4, 1])
        # OK - affine correct shape
        img = IC(data, affine)
        assert_array_equal(affine, img.get_affine())
        # OK - affine can be array-like
        img = IC(data, affine.tolist())
        assert_array_equal(affine, img.get_affine())
        # Not OK - affine wrong shape
        assert_raises(ValueError, IC, data, np.diag([2, 3, 4]))

    def test_header_updating(self):
        # Only update on changes
        img_klass = self.image_class
        # With a None affine - don't overwrite zooms
        img = img_klass(np.zeros((2,3,4)), None)
        hdr = img.get_header()
        hdr.set_zooms((4,5,6))
        # Save / reload using bytes IO objects
        for key, value in img.file_map.items():
            value.fileobj = BytesIO()
        img.to_file_map()
        hdr_back = img.from_file_map(img.file_map).get_header()
        assert_array_equal(hdr_back.get_zooms(), (4,5,6))
        # With a real affine, update zooms
        img = img_klass(np.zeros((2,3,4)), np.diag([2,3,4,1]), hdr)
        hdr = img.get_header()
        assert_array_equal(hdr.get_zooms(), (2, 3, 4))
        # Modify affine in-place? Update on save.
        img.get_affine()[0,0] = 9
        for key, value in img.file_map.items():
            value.fileobj = BytesIO()
        img.to_file_map()
        hdr_back = img.from_file_map(img.file_map).get_header()
        assert_array_equal(hdr.get_zooms(), (9, 3, 4))
        # Modify data in-place?  Update on save
        data = img.get_data()
        data.shape = (3, 2, 4)
        img.to_file_map()
        img_back = img.from_file_map(img.file_map)
        assert_array_equal(img_back.shape, (3, 2, 4))

    def test_pickle(self):
        # Test that images pickle
        # Image that is not proxied can pickle
        img_klass = self.image_class
        img = img_klass(np.zeros((2,3,4)), None)
        img_str = pickle.dumps(img)
        img2 = pickle.loads(img_str)
        assert_array_equal(img.get_data(), img2.get_data())
        assert_equal(img.get_header(), img2.get_header())
        # Save / reload using bytes IO objects
        for key, value in img.file_map.items():
            value.fileobj = BytesIO()
        img.to_file_map()
        img_prox = img.from_file_map(img.file_map)
        img_str = pickle.dumps(img_prox)
        img2_prox = pickle.loads(img_str)
        assert_array_equal(img.get_data(), img2_prox.get_data())


def test_unsupported():
    # analyze does not support uint32
    data = np.arange(24, dtype=np.int32).reshape((2,3,4))
    affine = np.eye(4)
    data = np.arange(24, dtype=np.uint32).reshape((2,3,4))
    assert_raises(HeaderDataError, AnalyzeImage, data, affine)
