Synnefo » ./kamaki

# Copyright 2012 GRNET S.A. All rights reserved.

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# without modification, are permitted provided that the following

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#      disclaimer.

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#   2. Redistributions in binary form must reproduce the above

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#      disclaimer in the documentation and/or other materials

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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

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from cmd import Cmd

from os import popen

from sys import stdout

from argparse import ArgumentParser

from kamaki.cli import _exec_cmd, _print_error_message

from kamaki.cli.argument import update_arguments

from kamaki.cli.utils import print_dict, split_input

from kamaki.cli.history import History

from kamaki.cli.errors import CLIError

def _init_shell(exe_string, arguments):

    arguments.pop('version', None)

    arguments.pop('options', None)

    arguments.pop('history', None)

    shell = Shell()

    shell.set_prompt(exe_string)

    from kamaki import __version__ as version

    shell.greet(version)

    shell.do_EOF = shell.do_exit

    from kamaki.cli.command_tree import CommandTree

    shell.cmd_tree = CommandTree(

        'kamaki', 'A command line tool for poking clouds')

    return shell

class Shell(Cmd):

    """Kamaki interactive shell"""

    _prefix = '['

    _suffix = ']:'

    cmd_tree = None

    _history = None

    _arguments = None

    _context_stack = []

    _prompt_stack = []

    undoc_header = 'interactive shell commands:'

    def postcmd(self, post, line):

        if self._context_stack:

            self._roll_command()

            self._restore(self._context_stack.pop())

            self.set_prompt(self._prompt_stack.pop()[1:-2])

        return Cmd.postcmd(self, post, line)

    def precmd(self, line):

        if line.startswith('/'):

            cur_cmd_path = self.prompt.replace(' ', '_')[1:-2]

            if cur_cmd_path != self.cmd_tree.name:

                cur_cmd = self.cmd_tree.get_command(cur_cmd_path)

                self._context_stack.append(self._backup())

                self._prompt_stack.append(self.prompt)

                new_context = self

                self._roll_command(cur_cmd.path)

                new_context.set_prompt(self.cmd_tree.name)

                for grp_cmd in self.cmd_tree.get_subcommands():

                    self._register_command(grp_cmd.path)

            return line[1:]

        return line

    def greet(self, version):

        print('kamaki v%s - Interactive Shell\n\t(exit or ^D to exit)\n'\

            % version)

    def set_prompt(self, new_prompt):

        self.prompt = '[%s]:' % new_prompt

    def do_exit(self, line):

        print('')

        if self.prompt[1:-2] == self.cmd_tree.name:

            exit(0)

        return True

    def do_shell(self, line):

        output = popen(line).read()

        print(output)

    @property

    def path(self):

        if self._cmd:

            return self._cmd.path

        return ''

    @classmethod

    def _register_method(self, method, name):

        self.__dict__[name] = method

    @classmethod

    def _unregister_method(self, name):

        try:

            self.__dict__.pop(name)

        except KeyError:

            pass

    def _roll_command(self, cmd_path=None):

        for subname in self.cmd_tree.get_subnames(cmd_path):

            self._unregister_method('do_%s' % subname)

            self._unregister_method('complete_%s' % subname)

            self._unregister_method('help_%s' % subname)

    @classmethod

    def _backup(self):

        return dict(self.__dict__)

    @classmethod

    def _restore(self, oldcontext):

        self.__dict__ = oldcontext

    def _register_command(self, cmd_path):

        cmd = self.cmd_tree.get_command(cmd_path)

        arguments = self._arguments

        def do_method(new_context, line):

            """ Template for all cmd.Cmd methods of the form do_<cmd name>

                Parse cmd + args and decide to execute or change context

                <cmd> <term> <term> <args> is always parsed to most specific

                even if cmd_term_term is not a terminal path

            """

            subcmd, cmd_args = cmd.parse_out(split_input(line))

            if self._history:

                self._history.add(' '.join([cmd.path.replace('_', ' '), line]))

            cmd_parser = ArgumentParser(cmd.name, add_help=False)

            cmd_parser.description = subcmd.help

            # exec command or change context

            if subcmd.is_command:  # exec command

                cls = subcmd.get_class()

                instance = cls(dict(arguments))

                cmd_parser.prog = '%s %s' % (cmd_parser.prog.replace('_', ' '),

                    cls.syntax)

                update_arguments(cmd_parser, instance.arguments)

                if '-h' in cmd_args or '--help' in cmd_args:

                    cmd_parser.print_help()

                    return

                parsed, unparsed = cmd_parser.parse_known_args(cmd_args)

                for name, arg in instance.arguments.items():

                    arg.value = getattr(parsed, name, arg.default)

                try:

                    _exec_cmd(instance, unparsed, cmd_parser.print_help)

                except CLIError as err:

                    _print_error_message(err)

            elif ('-h' in cmd_args or '--help' in cmd_args) \

            or len(cmd_args):  # print options

                print('%s: %s' % (cmd.name, subcmd.help))

                options = {}

                for sub in subcmd.get_subcommands():

                    options[sub.name] = sub.help

                print_dict(options)

            else:  # change context

                #new_context = this

                backup_context = self._backup()

                old_prompt = self.prompt

                new_context._roll_command(cmd.parent_path)

                new_context.set_prompt(subcmd.path.replace('_', ' '))

                newcmds = [subcmd for subcmd in subcmd.get_subcommands()]

                for subcmd in newcmds:

                    new_context._register_command(subcmd.path)

                new_context.cmdloop()

                self.prompt = old_prompt

                #when new context is over, roll back to the old one

                self._restore(backup_context)

        self._register_method(do_method, 'do_%s' % cmd.name)

        def help_method(self):

            print('%s (%s -h for more options)' % (cmd.help, cmd.name))

        self._register_method(help_method, 'help_%s' % cmd.name)

        def complete_method(self, text, line, begidx, endidx):

            subcmd, cmd_args = cmd.parse_out(split_input(line)[1:])

            if subcmd.is_command:

                cls = subcmd.get_class()

                instance = cls(dict(arguments))

                empty, sep, subname = subcmd.path.partition(cmd.path)

                cmd_name = '%s %s' % (cmd.name, subname.replace('_', ' '))

                print('\n%s\nSyntax:\t%s %s'\

                    % (cls.description, cmd_name, cls.syntax))

                cmd_args = {}

                for arg in instance.arguments.values():

                    cmd_args[','.join(arg.parsed_name)] = arg.help

                print_dict(cmd_args, ident=2)

                stdout.write('%s %s' % (self.prompt, line))

            return subcmd.get_subnames()

        self._register_method(complete_method, 'complete_%s' % cmd.name)

    @property

    def doc_header(self):

        tmp_partition = self.prompt.partition(self._prefix)

        tmp_partition = tmp_partition[2].partition(self._suffix)

        hdr = tmp_partition[0].strip()

        return '%s commands:' % hdr

    def run(self, arguments, path=''):

        self._history = History(arguments['config'].get('history', 'file'))

        self._arguments = arguments

        if path:

            cmd = self.cmd_tree.get_command(path)

            intro = cmd.path.replace('_', ' ')

        else:

            intro = self.cmd_tree.name

        for subcmd in self.cmd_tree.get_subcommands(path):

            self._register_command(subcmd.path)

        self.set_prompt(intro)

        self.cmdloop()