#!/usr/bin/python
"""
Shish's AV simulator. Designed primarily for readability, it misses out
the corner case of tied votes.


Example run:

{'Mint': 22, 'Strawberry': 7, 'Fudge': 9, 'Vanilla': 15, 'Chocolate': 13}
Strawberry is the least popular, removing it and re-counting

{'Mint': 23, 'Vanilla': 18, 'Fudge': 10, 'Chocolate': 15}
Fudge is the least popular, removing it and re-counting

{'Vanilla': 22, 'Mint': 26, 'Chocolate': 18}
Chocolate is the least popular, removing it and re-counting

{'Vanilla': 33, 'Mint': 32}
Vanilla has over 50%, it wins!


Feel free to modify and redistribute under the terms of CC-BY-SA:
  http://creativecommons.org/licenses/by-sa/3.0/
"""

def main():
    all_voter_preferences = read_vote_file("votes.txt")

    while True:
        active_votes = get_highest_preferences(all_voter_preferences)

        votes_for_each_candidate = count_votes(active_votes)
        print votes_for_each_candidate

        # if somebody has more than 50% of the votes, they win
        most_popular = get_most_popular_candidate(votes_for_each_candidate)
        if votes_for_each_candidate[most_popular] > len(active_votes)/2:
            print most_popular, "has over 50%, it wins!"
            break

        # nobody has over 50%, knock out the least popular candidate
        least_popular = get_least_popular_candidate(votes_for_each_candidate)
        print least_popular, "is the least popular, removing it and re-counting\n"
        for voter_preferences in all_voter_preferences:
            remove_candidate(voter_preferences, least_popular)


#
# utility functions, to separate the code grind from the actual logic above
#

def read_vote_file(f):
    return [line.strip().split(",") for line in file(f).readlines()]

def get_highest_preferences(voter_preferences):
    return [prefs[0] for prefs in voter_preferences if len(prefs) > 0]

def get_most_popular_candidate(votes):
    return max(votes, key=votes.get)

def get_least_popular_candidate(votes):
    return min(votes, key=votes.get)

def remove_candidate(voter, lpc):
    while lpc in voter:
        voter.remove(lpc)

def count_votes(raw_votes):
    votes = {}
    for vote in raw_votes:
        votes[vote] = votes.get(vote, 0) + 1
    return votes

if __name__ == "__main__":
    main()