#!/usr/bin/env python
# FormatTIFFRayonixXPP.py
# Sub class of FormatTIFFRayonix specialized for the XPP Rayonix dectector at LCLS
#
# Images from the XPP Rayonix detector have several unitialized values, such as
# distance, wavelength, etc.  Set these values to zero so the images can be at
# least viewed.
#

from __future__ import division

import struct, re

from dxtbx.format.FormatTIFFRayonix import FormatTIFFRayonix

def check(l):
  """ Sets l or values in l that are less than zero to zero """
  if type(l) != list and type(l) != tuple:
    if l < 0:
      return 0
    else:
      return l
  ret = []
  for val in l:
    if type(val) == list:
      ret.append(check(val))
    else:
      if val < 0:
        val = 0
      ret.append(val)

  if type(l) == tuple:
    return tuple(ret)
  return ret

class FormatTIFFRayonixXPP(FormatTIFFRayonix):
  '''A class for reading TIFF format Rayonix images, and correctly
  constructing a model for the experiment from this.'''

  @staticmethod
  def understand(image_file):
    '''Check to see if this looks like an XPP Rayonix TIFF '''

    def get(ftype,index,typelen,offset=1024):
      f = open(image_file,'rb')
      si_format="<"
      f.seek(offset+index)
      rawdata = f.read(typelen)
      return struct.unpack(si_format+ftype,rawdata)[0]

    data = [get('c',1152+i,1) for i in xrange(128)]
    filepath = "".join([c for c in data if c!=' ' and ord(c)<127 and ord(c)>32])

    pattern = re.compile(".*xpp[a-zA-Z][0-9][0-9][0-9][0-9].*")

    return pattern.match(filepath)

  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))

    from iotbx.detectors.mar import MARImage
    MARImage._read_header_asserts = lambda self: None
    FormatTIFFRayonix.__init__(self, image_file)

    return

  ####################################################################
  #                                                                  #
  # Helper methods to get all of the values out of the TIFF header   #
  # - separated out to assist with code clarity                      #
  #                                                                  #
  ####################################################################

  def _get_rayonix_beam_xy(self):
    '''Get the beam x, y positions which are defined in the standard
    to be in pixels. X and Y are not defined by the documentation, so
    taking as a given that these are horizontal and vertical. N.B.
    the documentation states that the horizontal direction is fast.'''

    beam_x, beam_y = struct.unpack(
        self._ii, self._tiff_header_bytes[1668:1676])[:2]
    pixel_x, pixel_y = struct.unpack(
        self._ii, self._tiff_header_bytes[1796:1804])[:2]

    return beam_x * 1000 / pixel_x, beam_y * 1000 / pixel_y

  def _get_rayonix_detector_rotations(self):
    return check(FormatTIFFRayonix._get_rayonix_detector_rotations(self))

  def _get_rayonix_distance(self):
    return check(FormatTIFFRayonix._get_rayonix_distance(self))

  def _get_rayonix_pixel_size(self):
    return check(FormatTIFFRayonix._get_rayonix_pixel_size(self))

  def _get_rayonix_times(self):
    return check(FormatTIFFRayonix._get_rayonix_times(self))

  def _get_rayonix_timestamp(self):
    return check(FormatTIFFRayonix._get_rayonix_timestamp(self))

  def _get_rayonix_scan_angles(self):
    return check(FormatTIFFRayonix._get_rayonix_scan_angles(self))

  def _get_rayonix_detector_rotations(self):
    return check(FormatTIFFRayonix._get_rayonix_detector_rotations(self))

if __name__ == '__main__':

  import sys

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