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diff --git a/src/leap/soledad/u1db/commandline/command.py b/src/leap/soledad/u1db/commandline/command.py
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+# Copyright 2011 Canonical Ltd.
+#
+# This file is part of u1db.
+#
+# u1db is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation.
+#
+# u1db is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with u1db. If not, see <http://www.gnu.org/licenses/>.
+
+"""Command infrastructure for u1db"""
+
+import argparse
+import inspect
+
+
+class CommandGroup(object):
+ """A collection of commands."""
+
+ def __init__(self, description=None):
+ self.commands = {}
+ self.description = description
+
+ def register(self, cmd):
+ """Register a new command to be incorporated with this group."""
+ self.commands[cmd.name] = cmd
+
+ def make_argparser(self):
+ """Create an argparse.ArgumentParser"""
+ parser = argparse.ArgumentParser(description=self.description)
+ subs = parser.add_subparsers(title='commands')
+ for name, cmd in sorted(self.commands.iteritems()):
+ sub = subs.add_parser(name, help=cmd.__doc__)
+ sub.set_defaults(subcommand=cmd)
+ cmd._populate_subparser(sub)
+ return parser
+
+ def run_argv(self, argv, stdin, stdout, stderr):
+ """Run a command, from a sys.argv[1:] style input."""
+ parser = self.make_argparser()
+ args = parser.parse_args(argv)
+ cmd = args.subcommand(stdin, stdout, stderr)
+ params, _, _, _ = inspect.getargspec(cmd.run)
+ vals = []
+ for param in params[1:]:
+ vals.append(getattr(args, param))
+ return cmd.run(*vals)
+
+
+class Command(object):
+ """Definition of a Command that can be run.
+
+ :cvar name: The name of the command, so that you can run
+ 'u1db-client <name>'.
+ """
+
+ name = None
+
+ def __init__(self, stdin, stdout, stderr):
+ self.stdin = stdin
+ self.stdout = stdout
+ self.stderr = stderr
+
+ @classmethod
+ def _populate_subparser(cls, parser):
+ """Child classes should override this to provide their arguments."""
+ raise NotImplementedError(cls._populate_subparser)
+
+ def run(self, *args):
+ """This is where the magic happens.
+
+ Subclasses should implement this, requesting their specific arguments.
+ """
+ raise NotImplementedError(self.run)