def __init__(self):
    self.style = color_style()

def create_parser(self, prog_name, subcommand):
    """
    Create and return the ``OptionParser`` which will be used to
    parse the arguments to this command.
    """
    return OptionParser(prog=prog_name,
                        usage=self.usage(subcommand),
                        version=self.get_version(),
                        option_list=self.option_list)

def execute(self, *args, **options):
    """
    Try to execute this command, performing model validation if
    needed (as controlled by the attribute
    ``self.requires_model_validation``, except if force-skipped).
    """
    self.stdout = OutputWrapper(options.get('stdout', sys.stdout))
    self.stderr = OutputWrapper(options.get('stderr', sys.stderr), self.style.ERROR)
    if self.can_import_settings:
        from django.conf import settings
    saved_locale = None
    if not self.leave_locale_alone:
        # Only mess with locales if we can assume we have a working
        # settings file, because django.utils.translation requires settings
        # (The final saying about whether the i18n machinery is active will be
        # found in the value of the USE_I18N setting)
        if not self.can_import_settings:
            raise CommandError("Incompatible values of 'leave_locale_alone' "
                               "(%s) and 'can_import_settings' (%s) command "
                               "options." % (self.leave_locale_alone,
                                             self.can_import_settings))
        # Switch to US English, because django-admin.py creates database
        # content like permissions, and those shouldn't contain any
        # translations.
        from django.utils import translation
        saved_locale = translation.get_language()
        translation.activate('en-us')
    try:
        if self.requires_model_validation and not options.get('skip_validation'):
            self.validate()
        output = self.handle(*args, **options)
        if output:
            if self.output_transaction:
                # This needs to be imported here, because it relies on
                # settings.
                from django.db import connections, DEFAULT_DB_ALIAS
                connection = connections[options.get('database', DEFAULT_DB_ALIAS)]
                if connection.ops.start_transaction_sql():
                    self.stdout.write(self.style.SQL_KEYWORD(connection.ops.start_transaction_sql()))
            self.stdout.write(output)
            if self.output_transaction:
                self.stdout.write('\n' + self.style.SQL_KEYWORD("COMMIT;"))
    finally:
        if saved_locale is not None:
            translation.activate(saved_locale)

def get_version(self):
    """
    Return the Django version, which should be correct for all
    built-in Django commands. User-supplied commands should
    override this method.
    """
    return django.get_version()

def handle(self, *args, **options):
    self.source_dir = os.path.abspath(options.get('source_dir'))
    self.collection_code = options.get('collection_code')
    self.collection_title = options.get('collection_title')
    self.dry_run = options.get('dry-run')
    self.user = None
    self.pattern = options.get('pattern')
    self.force = options.get('force')
    users = User.objects.filter(username=options.get('username'))
    if users:
        self.user = users[0]
    collection, c = MediaCollection.objects.get_or_create(code=self.collection_code, title=self.collection_code)
    if c:
        collection.public_access = 'full'
        collection.save()
        print 'Collection created: ' + self.collection_code
    else:
        print 'Using collection: ' + collection.code
    for root, dirs, files in os.walk(self.source_dir):
        for filename in files:
            path = root + os.sep + filename
            filename_pre, ext = os.path.splitext(filename)
            item_code = collection.code + '_' + filename_pre
            item, c = MediaItem.objects.get_or_create(collection=collection, code=item_code)
            if c:
                item.title = filename_pre
                item.public_access = 'full'
                self.write_file(item, path)
                item.save()
                print 'item created: ' + item.code
            else:
                print 'item already exists: ' + item.code

def print_help(self, prog_name, subcommand):
    """
    Print the help message for this command, derived from
    ``self.usage()``.
    """
    parser = self.create_parser(prog_name, subcommand)
    parser.print_help()

def run_from_argv(self, argv):
    """
    Set up any environment changes requested (e.g., Python path
    and Django settings), then run this command. If the
    command raises a ``CommandError``, intercept it and print it sensibly
    to stderr. If the ``--traceback`` option is present or the raised
    ``Exception`` is not ``CommandError``, raise it.
    """
    parser = self.create_parser(argv[0], argv[1])
    options, args = parser.parse_args(argv[2:])
    handle_default_options(options)
    try:
        self.execute(*args, **options.__dict__)
    except Exception as e:
        if options.traceback or not isinstance(e, CommandError):
            raise
        # self.stderr is not guaranteed to be set here
        stderr = getattr(self, 'stderr', OutputWrapper(sys.stderr, self.style.ERROR))
        stderr.write('%s: %s' % (e.__class__.__name__, e))
        sys.exit(1)

def usage(self, subcommand):
    """
    Return a brief description of how to use this command, by
    default from the attribute ``self.help``.
    """
    usage = '%%prog %s [options] %s' % (subcommand, self.args)
    if self.help:
        return '%s\n\n%s' % (usage, self.help)
    else:
        return usage

def validate(self, app=None, display_num_errors=False):
    """
    Validates the given app, raising CommandError for any errors.
    If app is None, then this will validate all installed apps.
    """
    from django.core.management.validation import get_validation_errors
    s = StringIO()
    num_errors = get_validation_errors(s, app)
    if num_errors:
        s.seek(0)
        error_text = s.read()
        raise CommandError("One or more models did not validate:\n%s" % error_text)
    if display_num_errors:
        self.stdout.write("%s error%s found" % (num_errors, '' if num_errors == 1 else 's'))

def write_file(self, item, media):
    filename = media.split(os.sep)[-1]
    if os.path.exists(media):
        if not item.file or self.force:
            if not self.media_root in self.source_dir:
                print "file not in MEDIA_ROOT, copying..."
                f = open(media, 'r')
                if not self.dry_run:
                    file_content = ContentFile(f.read())
                    item.file.save(filename, file_content)
                    item.save()
                f.close()
            else:
                print "file in MEDIA_ROOT, linking..."
                path = media[len(self.media_root)+1:]
                if not self.dry_run:
                    item.file = path
                    item.save()
            if self.user:
                item.set_revision(self.user)