#!/usr/bin/env python
# FormatSMVADSCSN926.py
#   Copyright (C) 2013 Diamond Light Source, Graeme Winter
#
#   This code is distributed under the BSD license, a copy of which is
#   included in the root directory of this package.
#
# An implementation of the SMV image reader for ADSC images. Inherits from
# FormatSMVADSC, customised for beamline 8.3.1 at the ALS where J. Holton uses
# two-theta offsets in the vertical direction, as well as idiosyncratic ways
# of recording the beam centre... which work fine for ADXV...

from __future__ import division

from dxtbx.format.FormatSMVADSCSN import FormatSMVADSCSN

class FormatSMVADSCSN926(FormatSMVADSCSN):
  '''A class for reading SMV format ADSC images, and correctly constructing
  a model for the experiment from this, for instrument number 926.'''

  @staticmethod
  def understand(image_file):
    '''Check to see if this is ADSC SN 926.'''

    # check this is detector serial number 926

    size, header = FormatSMVADSCSN.get_smv_header(image_file)

    if int(header['DETECTOR_SN']) != 926:
      return False

    return True

  def __init__(self, image_file):
    '''Initialise the image structure from the given file, including a
    proper model of the experiment.'''

    assert(self.understand(image_file))

    FormatSMVADSCSN.__init__(self, image_file)

    return

  def _detector(self):
    '''Return a model for a simple detector, allowing for the installation
    on on a two-theta stage. Assert that the beam centre is provided in
    the Mosflm coordinate frame.'''

    import math

    distance = float(self._header_dictionary['DISTANCE'])
    beam_x = float(self._header_dictionary['BEAM_CENTER_X'])
    beam_y = float(self._header_dictionary['BEAM_CENTER_Y'])
    pixel_size = float(self._header_dictionary['PIXEL_SIZE'])
    image_size = (float(self._header_dictionary['SIZE1']),
                  float(self._header_dictionary['SIZE2']))
    two_theta = float(self._header_dictionary['TWOTHETA'])
    overload = 65535
    underload = 0

    # now correct for some idiosyncracies...

    # two-theta included in beam centre - so remove this
    beam_y += distance * math.tan(two_theta * math.pi / 180.0)

    return self._detector_factory.two_theta(
        'CCD', distance, (beam_y, beam_x), '+x', '-y',
        '+x', two_theta, (pixel_size, pixel_size), image_size,
        (underload, overload), [])

if __name__ == '__main__':

  import sys

  for arg in sys.argv[1:]:
    print FormatSMVADSC.understand(arg)