#!/usr/bin/python2
#
# Solver for the GCHQ Director's 2015 Christmas puzzle (part 2C)
# --------------------------------------------------------------
# Copyright Brian Starkey 2015 <stark3y@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

code = {
    'a': '.-',
    'b': '-...',
    'c': '-.-.',
    'd': '-..',
    'e': '.',
    'f': '..-.',
    'g': '--.',
    'h': '....',
    'i': '..',
    'j': '.---',
    'k': '-.-',
    'l': '.-..',
    'm': '--',
    'n': '-.',
    'o': '---',
    'p': '.--.',
    'q': '--.-',
    'r': '.-.',
    's': '...',
    't': '-',
    'u': '..-',
    'v': '...-',
    'w': '.--',
    'x': '-..-',
    'y': '-.--',
    'z': '--..',
};

def encode(s):
    enc = [code[l] for l in s]
    return ''.join(enc)

def opposite(c):
    return c.replace('.','*').replace('-', '.').replace('*', '-')

# Morse decoding is apparently very ambiguous
# So we have to filter with a dictionary
def filter(l):
    f = open('words.list', 'r')
    d = []
    out = []
    for line in f:
        d.append(line.rstrip(' \n\r').lower())
    f.close()
    for cdd in l:
        for word in d:
            if (word == cdd):
                out.append(word)
    return out

def decode(c, s = '', depth = 0, r = None):
    # Took me a long time to figure out why I couldn't do
    # r = [] as a default argument...
    # http://stackoverflow.com/questions/3887079/why-does-initializing-a-variable-via-a-python-default-variable-keep-state-across
    # Python is weird.
    if (r == None):
        r = []
    if (len(c) == 0):
        r.append(s)
        return
    for (letter, symbol) in code.iteritems():
        if (c.find(symbol) == 0):
            decode(c[len(symbol):], s + letter, depth + 1, r)
    if (s == ''):
        return filter(r)

clues = ['agony', 'denial', 'witty', 'tepid', 'smart']

print "Clues: %s" % clues
print "Working..."
for c in clues:
    print "%s: %s" % (c, encode(c))
    print "%s%s = %s" % (' ' * (len(c) + 2), opposite(encode(c)), decode(opposite(encode(c))))