#!/usr/bin/env python
import urllib2
import os
import tarfile

import shutil

name = 'asap_data.tar.bz2'
dataurl  = "http://www.atnf.csiro.au/pub/software/asap/data/"
tmpdata = '/tmp/asap_data.tar.bz2'
tmpmd5 = tmpdata+'.md5sum'

print "Checking if an update is required."
md5req = urllib2.Request(dataurl+name+'.md5sum')
response = urllib2.urlopen(md5req)
md5file = file(tmpmd5,'w')
md5file.write(response.read())
md5file.close()
md5file = file(tmpmd5)
md5new = md5file.readlines()[0].split()[0]

# use ASAPDATA if set - allows non-root update
if os.environ.has_key("ASAPDATA"):
    asapbase = os.environ["ASAPDATA"]
else:
    import asap
    # get asap module path
    asapbase = asap.__path__[0]
try:
    fl = os.path.join(asapbase, name+".md5sum")
    data_md5 = file(fl)
    ls = data_md5.readlines()[0]
    data_md5.close()
    md5old = ls.split()[0]
except IOError:
    md5old =''

if md5new != md5old:
    dreq = urllib2.Request(dataurl+name)
    src = urllib2.urlopen(dreq)
    print "Update required. Downloading asap data archive...."
    dst = open(tmpdata, 'w')
    dst.write(src.read())
    dst.close()
    os.chdir(asapbase)
    tf = tarfile.TarFile.bz2open(tmpdata)
    print "Extracting data archive in %s.." % asapbase
    for member in tf.getmembers():
        tf.extract(member)
    shutil.copy(tmpmd5, asapbase)
else:
    print """Data already at latest available version.
If you still get errors running asap, please report this."""
