#!/usr/bin/env python
# encoding: utf-8
#
# Copyright (c) 2008 Doug Hellmann All rights reserved.
#
"""
"""

__version__ = "$Id$"
#end_pymotw_header

import readline
import logging

LOG_FILENAME = '/tmp/completer.log'
logging.basicConfig(filename=LOG_FILENAME,
                    level=logging.DEBUG,
                    )

class BufferAwareCompleter(object):

    def __init__(self, options):
        self.options = options
        self.current_candidates = []
        return

    def complete(self, text, state):
        response = None
        if state == 0:
            # This is the first time for this text,
            # so build a match list.

            origline = readline.get_line_buffer()
            begin = readline.get_begidx()
            end = readline.get_endidx()
            being_completed = origline[begin:end]
            words = origline.split()

            logging.debug('origline=%s', repr(origline))
            logging.debug('begin=%s', begin)
            logging.debug('end=%s', end)
            logging.debug('being_completed=%s', being_completed)
            logging.debug('words=%s', words)

            if not words:
                self.current_candidates = sorted(self.options.keys())
            else:
                try:
                    if begin == 0:
                        # first word
                        candidates = self.options.keys()
                    else:
                        # later word
                        first = words[0]
                        candidates = self.options[first]

                    if being_completed:
                        # match options with portion of input
                        # being completed
                        self.current_candidates = [
                            w for w in candidates
                            if w.startswith(being_completed)
                            ]
                    else:
                        # matching empty string so use all candidates
                        self.current_candidates = candidates

                    logging.debug('candidates=%s',
                                  self.current_candidates)

                except (KeyError, IndexError), err:
                    logging.error('completion error: %s', err)
                    self.current_candidates = []

        try:
            response = self.current_candidates[state]
        except IndexError:
            response = None
        logging.debug('complete(%s, %s) => %s',
                      repr(text), state, response)
        return response


def input_loop():
    line = ''
    while line != 'stop':
        line = raw_input('Prompt ("stop" to quit): ')
        print 'Dispatch %s' % line

# Register our completer function
readline.set_completer(BufferAwareCompleter(
    {'list':['files', 'directories'],
     'print':['byname', 'bysize'],
     'stop':[],
    }).complete)

# Use the tab key for completion
readline.parse_and_bind('tab: complete')

# Prompt the user for text
input_loop()