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# Source code for fabio.dm3image

    """
    Authors: Henning O. Sorensen & Erik Knudsen
             Center for Fundamental Research: Metal Structures in Four Dimensions
             Risoe National Laboratory
             Frederiksborgvej 399
             DK-4000 Roskilde
             email:erik.knudsen@risoe.dk

            + Jon Wright, ESRF
    """
    import logging
    import numpy
    from fabioimage import fabioimage
    logger = logging.getLogger("dm3image")

    DATA_TYPES = {  2     :  numpy.int16,
                    4     :  numpy.uint16,
                    3     :  numpy.int32,
                    5     :  numpy.uint32,
                    6     :  numpy.float32,
                    7     :  numpy.float,
                    8     :  numpy.int8,
                    9     :  None,
                    10    :  None,
                    15    :  'Struct',
                    18    :  None,
                    20    :  None
                    }

    DATA_BYTES = {  2     :  2,
                    4     :  2,
                    3     :  4,
                    5     :  4,
                    6     :  4,
                    7     :  8,
                    8     :  1,
                    9     :  None,
                    10    :  None,
                    15    :  'Struct',
                    18    :  None,
                    20    :  None
                    }

    class dm3image(fabioimage):
        """ Read and try to write the dm3 data format """
        def __init__(self, *args, **kwargs):
            fabioimage.__init__(self, *args, **kwargs)
            self.encoded_datatype = None
            self.no_data_elements = None
            self.grouptag_is_sorted = None
            self.grouptag_is_open = None
            self.tag_encoded_type = None
            self.tag_data_type = None
            self.tag_is_data = None
            self.grouptag_no_tags = None
            self.bytes_in_file = None
            self.tag_label_length = None
            self.go_on = None

        def _readheader(self):
            self.infile.seek(0)
            file_format = self.readbytes(4, numpy.uint32)[0] # should be 3
            assert file_format == 3, 'Wrong file type '
            self.bytes_in_file = self.readbytes(4, numpy.uint32)[0]
            self.byte_order = self.readbytes(4, numpy.uint32)[0] # 0 = big, 1= little
            print 'read dm3 file - file format ', file_format
            print 'Bytes in file : ' , self.bytes_in_file
            print 'Byte order :', self.byte_order, '  - 0 = bigEndian , 1 = littleEndian'

            if self.byte_order == 0:
                self.swap = True
            elif self.byte_order == 1:
                self.swap = False
            else:
                raise ValueError

        def read(self, fname, frame=None):
            self.header = {}
            self.resetvals()
            self.infile = self._open(fname, "rb")
            self._readheader()
            self.go_on = True
            print self.go_on
            while self.go_on:
                self.read_tag_group()
                self.read_tag_entry()
                if self.infile.tell() > self.bytes_in_file: break

                while self.tag_is_data == 21:
                    self.read_tag_entry()
                    if self.infile.tell() > self.bytes_in_file:
                        self.go_on = False

            (dim1_raw, dim2_raw) = self.header['Active Size (pixels)'].split()
            (dim1_raw, dim2_raw) = (eval(dim1_raw), eval(dim2_raw))
            (dim1_binning, dim2_binning) = self.header['Binning'].split()
            (dim1_binning, dim2_binning) = (eval(dim1_binning), eval(dim2_binning))
            self.dim1 = dim1_raw / dim1_binning
            self.dim2 = dim2_raw / dim2_binning
            #print dim1,dim2
            if self.header.has_key('Data'):
                self.data = self.header['Data'].reshape(self.dim1, self.dim2)

        def readbytes(self, bytes_to_read, format, swap=True):
            raw = self.infile.read(bytes_to_read)
            if format != None:
                data = numpy.fromstring(raw, format)
            else:
                data = raw
            if swap:
                data = data.byteswap()
            return data

        def read_tag_group(self):

            self.grouptag_is_sorted = self.readbytes(1, numpy.uint8)[0]
            self.grouptag_is_open = self.readbytes(1, numpy.uint8)[0]
            self.grouptag_no_tags = self.readbytes(4, numpy.uint32)[0]
            logger.debug('TagGroup is sorted? %s', self.grouptag_is_sorted)
            logger.debug('TagGroup is open? %s', self.grouptag_is_open)
            logger.debug('no of tags in TagGroup %s', self.grouptag_no_tags)

        def read_tag_entry(self):

            self.tag_is_data = self.readbytes(1, numpy.uint8)[0]
            self.tag_label_length = self.readbytes(2, numpy.uint16)[0]
            logger.debug('does Tag have data ? %s  -  20 = Tag group , 21 = data ', self.tag_is_data)
            logger.debug('length of tag_label ', self.tag_label_length)
            if self.tag_label_length != 0:
                tag_label = self.infile.read(self.tag_label_length)
            else:
                tag_label = None

            if self.tag_is_data == 21:
                # This is data
                self.header[tag_label] = self.read_tag_type()
                logger.debug("%s: %s", tag_label, self.header[tag_label])

        def read_tag_type(self):
            if self.infile.read(4) != '%%%%':
                raise IOError
            self.tag_data_type = self.readbytes(4, numpy.uint32)[0]
            logger.debug('data is of type : %s  - 1 = simple, 2= string, 3 = array, >3 structs', self.tag_data_type)
            self.tag_encoded_type = self.readbytes(4, numpy.uint32)[0]
            logger.debug('encode type: %s %s', self.tag_encoded_type, DATA_TYPES[ self.tag_encoded_type])
            if self.tag_data_type == 1:
                # simple type
                return self.readbytes(DATA_BYTES[ self.tag_encoded_type],
                                      DATA_TYPES[ self.tag_encoded_type],
                                      swap=self.swap)[0]
            # are the data stored in a simple array?
            if self.tag_encoded_type == 20 and self.tag_data_type == 3 :
                self.data_type = self.readbytes(4, numpy.uint32)[0]
                self.no_data_elements = self.readbytes(4, numpy.uint32)[0]
                if self.data_type == 10:
                    logger.debug('skip bytes %s', self.no_data_elements)
                    dump = self.infile.read(self.no_data_elements)
                    return None

                logger.debug('Data are stored as a simple a array -')
                logger.debug('%s data elemets stored as %s', self.no_data_elements, self.data_type)
                read_no_bytes = DATA_BYTES[self.data_type] * self.no_data_elements
                format = DATA_TYPES[self.data_type]
                return self.readbytes(read_no_bytes, format, swap=self.swap)

            # are the data stored in a complex array ?
            # print 'tag_type + data_type', self.tag_encoded_type,self.tag_data_type

            #print self.tag_encoded_type , self.tag_data_type
            if self.tag_encoded_type == 20 and self.tag_data_type > 3 :
                self.tag_encoded_type = self.readbytes(4, numpy.uint32)[0]
                logger.debug('found array - new tag_encoded_type %s', self.tag_encoded_type)
                if self.tag_encoded_type == 15:            # struct type
                     ###type = self.readbytes(4,numpy.int32)
                    struct_name_length = self.readbytes(4, numpy.int32)[0]
                    struct_number_fields = self.readbytes(4, numpy.int32)[0]
                    #print 'struct - name_length, number_field',  struct_name_length,struct_number_fields
                    #print self.infile.read(struct_name_length)
                    field_info = []
                    for i in range(struct_number_fields):
                        field_info.append([self.readbytes(4, numpy.int32)[0], self.readbytes(4, numpy.int32)[0]])
                    #print field_info
                    self.no_data_elements = self.readbytes(4, numpy.int32)[0]
                    #print '%i data elemets stored as ' %self.no_data_elements
                    bytes_in_struct = 0
                    for i in range(struct_number_fields):
                        bytes_in_struct += DATA_BYTES[field_info[i][1]]
                    logger.debug('skip bytes %s', self.no_data_elements * bytes_in_struct)
                    dump = self.infile.read(self.no_data_elements * bytes_in_struct)
                    return None

            if self.tag_encoded_type == 15:            # struct type
                ###type = self.readbytes(4,numpy.int32)
                struct_name_length = self.readbytes(4, numpy.int32)[0]
                struct_number_fields = self.readbytes(4, numpy.int32)[0]
                #print 'struct - name_length, number_field',  struct_name_length,struct_number_fields
                #print self.infile.read(struct_name_length)
                field_info = []
                for i in range(struct_number_fields):
                    field_info.append([self.readbytes(4, numpy.int32)[0], self.readbytes(4, numpy.int32)[0]])
                #print field_info
                field_data = ''
                for i in range(struct_number_fields):
                    #print type(i)
                    field_data = field_data + self.readbytes(field_info[i][0], None, swap=False) + ' '
                    field_data = field_data + '%i  ' % self.readbytes(DATA_BYTES[field_info[i][1]],
                                                                     DATA_TYPES[field_info[i][1]],
                                                                     swap=self.swap)[0]
                return field_data

        def read_data(self):
            self.encoded_datatype = numpy.fromstring(self.infile.read(4), numpy.uint32).byteswap()

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