import os, sys

### Setup the path to the dictionaries. WARNING: this needs to be done
#   BEFORE importation of the shadow classse generated by swig as found
#   in gdcm, since the dynamic library loads the standard dictionary
#   when dynamically loaded.
#   We consider we succefully found the dictionaries path when we encounter
#   the standard dictionary i.e. the file dicomV3.dic.

try:
	### First consider the environnement variable.
	os.environ["GDCM_DICT_PATH"]
	if not os.path.isfile(os.path.join(os.environ["GDCM_DICT_PATH"],
	                                   "dicomV3.dic")):
		raise KeyError
except KeyError:
	# When environnement variable is unavailable assume the package was
	# properly installed i.e. the layout is such that the directory containing
	# the dictionaries is BELOW (the root is at the top) the current file.
	# Note: when importing this __init__ file the pathes are relative to the
	#       invocation directory. In order to get them relative to the package
	#       (or more simply to this file) we rely on the __path__ variable.
	InstallModePath = os.path.join(__path__[0], "Dicts/")
	if os.path.isfile(os.path.join(InstallModePath, "dicomV3.dic")):
		os.environ["GDCM_DICT_PATH"] = InstallModePath
		PreInstallModePath = None
	else:
		# When both environnement variable and proper package installation 
		# strategy fail we eventually consider the pre-installation mode
		# i.e. when developpers are toying in a CVS tree. In this case
		# the layout is such that the directory containing the dictionaries is
		# ABOVE (the root is at the top) the current directory.
		PreInstallModePath = os.path.join(__path__[0], "..", "Dicts/")
		if os.path.isfile(os.path.join(PreInstallModePath, "dicomV3.dic")):
			os.environ["GDCM_DICT_PATH"] = PreInstallModePath
			InstallModePath = None
		else:
			print "Unfound gdcm dictionaries path"
			sys.exit(1)

### Set up the path to the data images (for the test suite and the demo
#   examples). As for GDCM_DICT_PATH we offer both proper python package
#   installation scheme and the pre-install mode (see above).
if InstallModePath:
	GDCM_DATA_PATH = os.path.join(__path__[0], "Data")
else:
	if PreInstallModePath:
		GDCM_DATA_PATH = os.path.join(__path__[0], "..","Data")
	else:
		print "Unfound data path"
		sys.exit(1)

### Import the swig generated shadow classes.
try:
	import gdcm
except ImportError,e:
	print e
	raise ImportError, "gdcm extension not imported."

### Expose only the necessary stuff
gdcmHeader = gdcm.gdcmHeader
gdcmDictSet = gdcm.gdcmDictSet
gdcmFile = gdcm.gdcmFile