# emacs: -*- mode: python-mode; py-indent-offset: 4; indent-tabs-mode: nil -*-
# vi: set ft=python sts=4 ts=4 sw=4 et:
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#
#   See COPYING file distributed along with the NiBabel package for the
#   copyright and license terms.
#
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from distutils.version import LooseVersion

import numpy as np
from io import BytesIO

from .cifti2 import (Cifti2MetaData, Cifti2Header, Cifti2Label,
                     Cifti2LabelTable, Cifti2VertexIndices,
                     Cifti2VoxelIndicesIJK, Cifti2BrainModel, Cifti2Matrix,
                     Cifti2MatrixIndicesMap, Cifti2NamedMap, Cifti2Parcel,
                     Cifti2Surface, Cifti2TransformationMatrixVoxelIndicesIJKtoXYZ,
                     Cifti2Vertices, Cifti2Volume, CIFTI_BRAIN_STRUCTURES,
                     CIFTI_MODEL_TYPES, _underscore, Cifti2HeaderError)
from .. import xmlutils as xml
from ..spatialimages import HeaderDataError
from ..batteryrunners import Report
from ..nifti1 import Nifti1Extension, extension_codes, intent_codes
from ..nifti2 import Nifti2Header, Nifti2Image


class Cifti2Extension(Nifti1Extension):
    code = 32

    def __init__(self, code=None, content=None):
        Nifti1Extension.__init__(self, code=code or self.code, content=content)

    def _unmangle(self, value):
        parser = Cifti2Parser()
        parser.parse(string=value)
        self._content = parser.header
        return self._content

    def _mangle(self, value):
        if not isinstance(value, Cifti2Header):
            raise ValueError('Can only mangle a Cifti2Header.')
        return value.to_xml()


extension_codes.add_codes((
    (Cifti2Extension.code, 'cifti', Cifti2Extension),))

intent_codes.add_codes((
    # The codes below appear on the CIFTI-2 standard
    # http://www.nitrc.org/plugins/mwiki/index.php/cifti:ConnectivityMatrixFileFormats
    # https://www.nitrc.org/forum/attachment.php?attachid=341&group_id=454&forum_id=1955
    (3000, 'ConnUnknown', (), 'NIFTI_INTENT_CONNECTIVITY_UNKNOWN'),
    (3001, 'ConnDense', (), 'NIFTI_INTENT_CONNECTIVITY_DENSE'),
    (3002, 'ConnDenseSeries', (),
     'NIFTI_INTENT_CONNECTIVITY_DENSE_SERIES'),
    (3003, 'ConnParcels', (),
     'NIFTI_INTENT_CONNECTIVITY_PARCELLATED'),
    (3004, 'ConnParcelSries', (),
     "NIFTI_INTENT_CONNECTIVITY_PARCELLATED_SERIES"),
    (3006, 'ConnDenseScalar', (),
     'NIFTI_INTENT_CONNECTIVITY_DENSE_SCALARS'),
    (3007, 'ConnDenseLabel', (),
     'NIFTI_INTENT_CONNECTIVITY_DENSE_LABELS'),
    (3008, 'ConnParcelScalr', (),
     'NIFTI_INTENT_CONNECTIVITY_PARCELLATED_SCALAR'),
    (3009, 'ConnParcelDense', (),
     'NIFTI_INTENT_CONNECTIVITY_PARCELLATED_DENSE'),
    (3010, 'ConnDenseParcel', (),
     'NIFTI_INTENT_CONNECTIVITY_DENSE_PARCELLATED'),
    (3011, 'ConnPPSr', (),
     'NIFTI_INTENT_CONNECTIVITY_PARCELLATED_PARCELLATED_SERIES'),
    (3012, 'ConnPPSc', (),
     'NIFTI_INTENT_CONNECTIVITY_PARCELLATED_PARCELLATED_SCALAR')))


class _Cifti2AsNiftiHeader(Nifti2Header):
    """ Class for Cifti2 header extension """

    @classmethod
    def _valid_intent_code(klass, intent_code):
        """ Return True if `intent_code` matches our class `klass`
        """
        return intent_code >= 3000 and intent_code < 3100

    @classmethod
    def may_contain_header(klass, binaryblock):
        if not super(_Cifti2AsNiftiHeader, klass).may_contain_header(binaryblock):
            return False
        hdr = klass(binaryblock=binaryblock[:klass.sizeof_hdr])
        return klass._valid_intent_code(hdr.get_intent('code')[0])

    @staticmethod
    def _chk_qfac(hdr, fix=False):
        # Allow qfac of 0 without complaint for CIFTI-2
        rep = Report(HeaderDataError)
        if hdr['pixdim'][0] in (-1, 0, 1):
            return hdr, rep
        rep.problem_level = 20
        rep.problem_msg = 'pixdim[0] (qfac) should be 1 (default) or 0 or -1'
        if fix:
            hdr['pixdim'][0] = 1
            rep.fix_msg = 'setting qfac to 1'
        return hdr, rep

    @staticmethod
    def _chk_pixdims(hdr, fix=False):
        rep = Report(HeaderDataError)
        pixdims = hdr['pixdim']
        spat_dims = pixdims[1:4]
        if not np.any(spat_dims < 0):
            return hdr, rep
        rep.problem_level = 35
        rep.problem_msg = 'pixdim[1,2,3] should be zero or positive'
        if fix:
            hdr['pixdim'][1:4] = np.abs(spat_dims)
            rep.fix_msg = 'setting to abs of pixdim values'
        return hdr, rep


class _Cifti2AsNiftiImage(Nifti2Image):
    """ Load a NIfTI2 image with a Cifti2 header """
    header_class = _Cifti2AsNiftiHeader
    makeable = False


class Cifti2Parser(xml.XmlParser):
    """Class to parse an XML string into a CIFTI-2 header object"""
    def __init__(self, encoding=None, buffer_size=3500000, verbose=0):
        super(Cifti2Parser, self).__init__(encoding=encoding,
                                           buffer_size=buffer_size,
                                           verbose=verbose)
        self.fsm_state = []
        self.struct_state = []

        # where to write CDATA:
        self.write_to = None
        self.header = None

        # Collecting char buffer fragments
        self._char_blocks = None

    __init__.__doc__ = xml.XmlParser.__init__.__doc__

    def StartElementHandler(self, name, attrs):
        self.flush_chardata()
        if self.verbose > 0:
            print('Start element:\n\t', repr(name), attrs)

        if name == 'CIFTI':
            # create cifti2 image
            self.header = Cifti2Header()
            self.header.version = attrs['Version']
            if LooseVersion(self.header.version) < LooseVersion('2'):
                raise ValueError('Only CIFTI-2 files are supported')
            self.fsm_state.append('CIFTI')
            self.struct_state.append(self.header)

        elif name == 'Matrix':
            self.fsm_state.append('Matrix')
            matrix = Cifti2Matrix()
            parent = self.struct_state[-1]
            if not isinstance(parent, Cifti2Header):
                raise Cifti2HeaderError(
                    'Matrix element can only be a child of the CIFTI-2 Header element'
                )
            parent.matrix = matrix
            self.struct_state.append(matrix)

        elif name == 'MetaData':
            self.fsm_state.append('MetaData')
            meta = Cifti2MetaData()
            parent = self.struct_state[-1]
            if not isinstance(parent, (Cifti2Matrix, Cifti2NamedMap)):
                raise Cifti2HeaderError(
                    'MetaData element can only be a child of the CIFTI-2 Matrix '
                    'or NamedMap elements'
                )

            self.struct_state.append(meta)

        elif name == 'MD':
            pair = ['', '']
            self.fsm_state.append('MD')
            self.struct_state.append(pair)

        elif name == 'Name':
            self.write_to = 'Name'

        elif name == 'Value':
            self.write_to = 'Value'

        elif name == 'MatrixIndicesMap':
            self.fsm_state.append('MatrixIndicesMap')
            dimensions = [int(value) for value in attrs["AppliesToMatrixDimension"].split(',')]
            mim = Cifti2MatrixIndicesMap(
                applies_to_matrix_dimension=dimensions,
                indices_map_to_data_type=attrs["IndicesMapToDataType"])
            for key, dtype in [("NumberOfSeriesPoints", int),
                               ("SeriesExponent", int),
                               ("SeriesStart", float),
                               ("SeriesStep", float),
                               ("SeriesUnit", str)]:
                if key in attrs:
                    setattr(mim, _underscore(key), dtype(attrs[key]))
            matrix = self.struct_state[-1]
            if not isinstance(matrix, Cifti2Matrix):
                raise Cifti2HeaderError(
                    'MatrixIndicesMap element can only be a child of the CIFTI-2 Matrix element'
                )
            matrix.append(mim)
            self.struct_state.append(mim)

        elif name == 'NamedMap':
            self.fsm_state.append('NamedMap')
            named_map = Cifti2NamedMap()
            mim = self.struct_state[-1]
            if not isinstance(mim, Cifti2MatrixIndicesMap):
                raise Cifti2HeaderError(
                    'NamedMap element can only be a child of the CIFTI-2 MatrixIndicesMap element'
                )
            self.struct_state.append(named_map)
            mim.append(named_map)

        elif name == 'LabelTable':
            named_map = self.struct_state[-1]
            mim = self.struct_state[-2]
            if mim.indices_map_to_data_type != "CIFTI_INDEX_TYPE_LABELS":
                raise Cifti2HeaderError(
                    'LabelTable element can only be a child of a MatrixIndicesMap '
                    'with CIFTI_INDEX_TYPE_LABELS type'
                )
            lata = Cifti2LabelTable()
            if not isinstance(named_map, Cifti2NamedMap):
                raise Cifti2HeaderError(
                    'LabelTable element can only be a child of the CIFTI-2 NamedMap element'
                )
            self.fsm_state.append('LabelTable')
            self.struct_state.append(lata)
            named_map.label_table = lata

        elif name == 'Label':
            lata = self.struct_state[-1]
            if not isinstance(lata, Cifti2LabelTable):
                raise Cifti2HeaderError(
                    'Label element can only be a child of the CIFTI-2 LabelTable element'
                )
            label = Cifti2Label()
            label.key = int(attrs["Key"])
            label.red = float(attrs["Red"])
            label.green = float(attrs["Green"])
            label.blue = float(attrs["Blue"])
            label.alpha = float(attrs["Alpha"])
            self.write_to = 'Label'
            self.fsm_state.append('Label')
            self.struct_state.append(label)

        elif name == "MapName":
            named_map = self.struct_state[-1]
            if not isinstance(named_map, Cifti2NamedMap):
                raise Cifti2HeaderError(
                    'MapName element can only be a child of the CIFTI-2 NamedMap element'
                )

            self.fsm_state.append('MapName')
            self.write_to = 'MapName'

        elif name == "Surface":
            surface = Cifti2Surface()
            mim = self.struct_state[-1]
            if not isinstance(mim, Cifti2MatrixIndicesMap):
                raise Cifti2HeaderError(
                    'Surface element can only be a child of the CIFTI-2 MatrixIndicesMap element'
                )
            if mim.indices_map_to_data_type != "CIFTI_INDEX_TYPE_PARCELS":
                raise Cifti2HeaderError(
                    'Surface element can only be a child of a MatrixIndicesMap '
                    'with CIFTI_INDEX_TYPE_PARCELS type'
                )
            surface.brain_structure = attrs["BrainStructure"]
            surface.surface_number_of_vertices = int(attrs["SurfaceNumberOfVertices"])
            mim.append(surface)

        elif name == "Parcel":
            parcel = Cifti2Parcel()
            mim = self.struct_state[-1]
            if not isinstance(mim, Cifti2MatrixIndicesMap):
                raise Cifti2HeaderError(
                    'Parcel element can only be a child of the CIFTI-2 MatrixIndicesMap element'
                )
            parcel.name = attrs["Name"]
            mim.append(parcel)
            self.fsm_state.append('Parcel')
            self.struct_state.append(parcel)

        elif name == "Vertices":
            vertices = Cifti2Vertices()
            parcel = self.struct_state[-1]
            if not isinstance(parcel, Cifti2Parcel):
                raise Cifti2HeaderError(
                    'Vertices element can only be a child of the CIFTI-2 Parcel element'
                )
            vertices.brain_structure = attrs["BrainStructure"]
            if vertices.brain_structure not in CIFTI_BRAIN_STRUCTURES:
                raise Cifti2HeaderError(
                    'BrainStructure for this Vertices element is not valid'
                )
            parcel.append_cifti_vertices(vertices)
            self.fsm_state.append('Vertices')
            self.struct_state.append(vertices)
            self.write_to = 'Vertices'

        elif name == "VoxelIndicesIJK":
            parent = self.struct_state[-1]
            if not isinstance(parent, (Cifti2Parcel, Cifti2BrainModel)):
                raise Cifti2HeaderError(
                    'VoxelIndicesIJK element can only be a child of the CIFTI-2 '
                    'Parcel or BrainModel elements'
                )
            parent.voxel_indices_ijk = Cifti2VoxelIndicesIJK()
            self.write_to = 'VoxelIndices'

        elif name == "Volume":
            mim = self.struct_state[-1]
            if not isinstance(mim, Cifti2MatrixIndicesMap):
                raise Cifti2HeaderError(
                    'Volume element can only be a child of the CIFTI-2 MatrixIndicesMap element'
                )
            dimensions = tuple([int(val) for val in
                                attrs["VolumeDimensions"].split(',')])
            volume = Cifti2Volume(volume_dimensions=dimensions)
            mim.append(volume)
            self.fsm_state.append('Volume')
            self.struct_state.append(volume)

        elif name == "TransformationMatrixVoxelIndicesIJKtoXYZ":
            volume = self.struct_state[-1]
            if not isinstance(volume, Cifti2Volume):
                raise Cifti2HeaderError(
                    'TransformationMatrixVoxelIndicesIJKtoXYZ element can only be a child '
                    'of the CIFTI-2 Volume element'
                )
            transform = Cifti2TransformationMatrixVoxelIndicesIJKtoXYZ()
            transform.meter_exponent = int(attrs["MeterExponent"])
            volume.transformation_matrix_voxel_indices_ijk_to_xyz = transform
            self.fsm_state.append('TransformMatrix')
            self.struct_state.append(transform)
            self.write_to = 'TransformMatrix'

        elif name == "BrainModel":
            model = Cifti2BrainModel()
            mim = self.struct_state[-1]
            if not isinstance(mim, Cifti2MatrixIndicesMap):
                raise Cifti2HeaderError(
                    'BrainModel element can only be a child '
                    'of the CIFTI-2 MatrixIndicesMap element'
                )
            if mim.indices_map_to_data_type != "CIFTI_INDEX_TYPE_BRAIN_MODELS":
                raise Cifti2HeaderError(
                    'BrainModel element can only be a child of a MatrixIndicesMap '
                    'with CIFTI_INDEX_TYPE_BRAIN_MODELS type'
                )
            for key, dtype in [("IndexOffset", int),
                               ("IndexCount", int),
                               ("ModelType", str),
                               ("BrainStructure", str),
                               ("SurfaceNumberOfVertices", int)]:
                if key in attrs:
                    setattr(model, _underscore(key), dtype(attrs[key]))
            if model.brain_structure not in CIFTI_BRAIN_STRUCTURES:
                raise Cifti2HeaderError(
                    'BrainStructure for this BrainModel element is not valid'
                )
            if model.model_type not in CIFTI_MODEL_TYPES:
                raise Cifti2HeaderError(
                    'ModelType for this BrainModel element is not valid'
                )
            mim.append(model)
            self.fsm_state.append('BrainModel')
            self.struct_state.append(model)

        elif name == "VertexIndices":
            index = Cifti2VertexIndices()
            model = self.struct_state[-1]
            if not isinstance(model, Cifti2BrainModel):
                raise Cifti2HeaderError(
                    'VertexIndices element can only be a child '
                    'of the CIFTI-2 BrainModel element'
                )
            self.fsm_state.append('VertexIndices')
            model.vertex_indices = index
            self.struct_state.append(index)
            self.write_to = "VertexIndices"

    def EndElementHandler(self, name):
        self.flush_chardata()
        if self.verbose > 0:
            print('End element:\n\t', repr(name))

        if name == 'CIFTI':
            # remove last element of the list
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == 'Matrix':
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == 'MetaData':
            self.fsm_state.pop()
            meta = self.struct_state.pop()
            parent = self.struct_state[-1]
            parent.metadata = meta

        elif name == 'MD':
            self.fsm_state.pop()
            pair = self.struct_state.pop()
            meta = self.struct_state[-1]
            meta[pair[0]] = pair[1]

        elif name == 'Name':
            self.write_to = None

        elif name == 'Value':
            self.write_to = None

        elif name == 'MatrixIndicesMap':
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == 'NamedMap':
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == 'LabelTable':
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == 'Label':
            self.fsm_state.pop()
            label = self.struct_state.pop()
            lata = self.struct_state[-1]
            lata.append(label)
            self.write_to = None

        elif name == "MapName":
            self.fsm_state.pop()
            self.write_to = None

        elif name == "Parcel":
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == "Vertices":
            self.fsm_state.pop()
            self.struct_state.pop()
            self.write_to = None

        elif name == "VoxelIndicesIJK":
            self.write_to = None

        elif name == "Volume":
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == "TransformationMatrixVoxelIndicesIJKtoXYZ":
            self.fsm_state.pop()
            self.struct_state.pop()
            self.write_to = None

        elif name == "BrainModel":
            self.fsm_state.pop()
            self.struct_state.pop()

        elif name == "VertexIndices":
            self.fsm_state.pop()
            self.struct_state.pop()
            self.write_to = None

    def CharacterDataHandler(self, data):
        """ Collect character data chunks pending collation

        The parser breaks the data up into chunks of size depending on the
        buffer_size of the parser.  A large bit of character data, with standard
        parser buffer_size (such as 8K) can easily span many calls to this
        function.  We thus collect the chunks and process them when we hit start
        or end tags.
        """
        if self._char_blocks is None:
            self._char_blocks = []
        self._char_blocks.append(data)

    def flush_chardata(self):
        """ Collate and process collected character data
        """
        if self._char_blocks is None:
            return
        # Just join the strings to get the data.  Maybe there are some memory
        # optimizations we could do by passing the list of strings to the
        # read_data_block function.
        data = ''.join(self._char_blocks)
        # Reset the char collector
        self._char_blocks = None
        # Process data
        if self.write_to == 'Name':
            data = data.strip()  # .decode('utf-8')
            pair = self.struct_state[-1]
            pair[0] = data

        elif self.write_to == 'Value':
            data = data.strip()  # .decode('utf-8')
            pair = self.struct_state[-1]
            pair[1] = data

        elif self.write_to == 'Vertices':
            # conversion to numpy array
            c = BytesIO(data.strip().encode('utf-8'))
            vertices = self.struct_state[-1]
            vertices.extend(np.loadtxt(c, dtype=int, ndmin=1))
            c.close()

        elif self.write_to == 'VoxelIndices':
            # conversion to numpy array
            c = BytesIO(data.strip().encode('utf-8'))
            parent = self.struct_state[-1]
            parent.voxel_indices_ijk.extend(np.loadtxt(c, dtype=int).reshape(-1, 3))
            c.close()

        elif self.write_to == 'VertexIndices':
            # conversion to numpy array
            c = BytesIO(data.strip().encode('utf-8'))
            index = self.struct_state[-1]
            index.extend(np.loadtxt(c, dtype=int, ndmin=1))
            c.close()

        elif self.write_to == 'TransformMatrix':
            # conversion to numpy array
            c = BytesIO(data.strip().encode('utf-8'))
            transform = self.struct_state[-1]
            transform.matrix = np.loadtxt(c, dtype=np.float64)
            c.close()

        elif self.write_to == 'Label':
            label = self.struct_state[-1]
            label.label = data.strip()

        elif self.write_to == 'MapName':
            named_map = self.struct_state[-1]
            named_map.map_name = data.strip()  # .decode('utf-8')

    @property
    def pending_data(self):
        " True if there is character data pending for processing "
        return self._char_blocks is not None


# class _Cifti2DenseDataSeriesNiftiHeader(_Cifti2AsNiftiHeader):
#
#    @classmethod
#    def _valid_intent_code(klass, intent_code):
#        """ Return True if `intent_code` matches our class `klass`
#        """
#        return intent_code == 3002
