#!/usr/bin/python
#
#
 
import tarfile
import tempfile
import json
import os
import sys
import base64
import shutil
import subprocess
 
class Bundle():
    """This class represent a bundle of an application
    that can be easily moved around."""
 
    def __init__(self, appname = None):
        """
        :param appname The name of the application
        whose this bundle refers to
        """
        self._appname = appname
        self._bundle = None
        self._appcmd = None
 
 
    def bundle_app (self, appdir, appcmd):
        """Bundle an application and prepare it for
        distribution."""
        if self._bundle is not None:
            raise RuntimeError ("Only a single application can be bundled")
        self._appcmd = appcmd
        self._appdir = appdir
        if (self._appdir.endswith ("/")):
            self._appdir = appdir[:-1]
 
        # Create the tar archive to be packed
        tmp_f = tempfile.NamedTemporaryFile (delete = False)
        tar = tarfile.TarFile (fileobj = tmp_f, mode = 'w')
 
        # Create packing information
        package_info = {
            'name': self._appname,
            'appcmd': self._appcmd,
            'appdir': os.path.basename (self._appdir),
            }
 
        # Add the directory that needs to be packed together
        # with the info on how to run the package. We need to
        # chdir to the right place to have directory structure
        # packed right
        old_dir = os.getcwd ()
        os.chdir (os.path.dirname (self._appdir))
        tar.add  (os.path.basename (self._appdir))
 
        # Create the info file
        with open ("info.bundle", "w") as handle:
            handle.write (json.dumps (package_info))
        tar.add ("info.bundle")
 
        # Close the tar file and copy the tar in my home
        tar.close ()
        tmp_f.close ()
 
        # Read the file
        with open (tmp_f.name, "rb") as handle:
            self._bundle = handle.read ()
 
        # Remove the file since we don't need it anymore
        os.remove (tmp_f.name)
 
        # Pack the application with this python code to make
        # it unbundlable.
        os.chdir (old_dir)
        with open(__file__, "rb") as handle:
            file_content = handle.read ()
 
        file_content += b"\n\n\n" + 15 * b"#" + base64.b64encode (self._bundle)
 
        # Dump file_content
        with open(self._appname + ".bundle", "w") as handle:
            handle.write (file_content.decode ("utf-8"))
 
 
    def unbundle_app (self):
        """Unbundle app assuming that it is contained in this file"""
        with open(__file__, "rb") as handle:
            self._bundle = handle.read ()
 
        # Decode the content of the file
        start = self._bundle.index(15 * "#")
        self._bundle = base64.b64decode (self._bundle[start + 14:])
 
        tmp_d = tempfile.mkdtemp ()
        os.chdir (tmp_d)
 
        with open (os.path.join (tmp_d, "bundle.tar"), "wb") as handle:
            handle.write (self._bundle)
        tar = tarfile.open (os.path.join (tmp_d, "bundle.tar"))
        tar.extractall ()
        tar.close ()
 
        package_info = json.load (open ("info.bundle", "r"))
        os.chdir (package_info["appdir"])
        p = subprocess.Popen (package_info["appcmd"], shell = True)
        p.wait ()
        shutil.rmtree (tmp_d)
 
 
 
if __name__ == "__main__":
 
    print ("Starting bundle framework")
 
    if len (sys.argv) <= 1:
        print ("Entering unbundle mode")
        bundle = Bundle ()
        bundle.unbundle_app ()
    else:
        if sys.argv[1] == "bundle":
            bundle = Bundle (sys.argv[2])
            bundle.bundle_app (sys.argv[3], sys.argv[4])