#!/usr/bin/env python

import sys, operator, string, os
from util import getch, cls
from time import sleep

def refresh_screen(data):
    # clear screen
    cls()
    print data
    sys.stdout.flush()

def update_display(tuples):
    data_str = ""
    for tf in tuples:
        data_str += str(tf[0]) + ' - ' + str(tf[1]) + '\n'
    refresh_screen(data_str)

automatic = False
def get_input():
    global automatic
    if automatic:
        return True

    while True: 
        key = ord(getch())
        if key == 32: # space bar
            return True
        elif key == 27: # ESC
            automatic = True
            return True
        else: pass

f = open(sys.argv[1])

def characters(filename):
    c = f.read(1)
    if c != "":
        yield c
    else:
        raise StopIteration()

def all_words(filename):
    found_word = False
    start_char = True
    while not found_word:
        try:
            c = characters(filename).next()
        except StopIteration:
            raise StopIteration()

        if start_char == True:
            word = ""
            if c.isalnum():
                # We found the start of a word
                word = c.lower()
                start_char = False
        else:
            if c.isalnum():
                word += c.lower()
            else:
                # We found the end of a word, emit it
                start_char = True
                found_word = True
                yield word

def non_stop_words(filename):
    stopwords = set(open('../stop_words.txt').read().split(',')  + list(string.ascii_lowercase))
    while True:
        w = all_words(filename).next()
        if not w in stopwords:
            yield w

def count_and_sort(filename):
    freqs_0 = ()
    freqs_1 = ()
    freqs = {}
    while get_input():
        try:
            w = non_stop_words(filename).next()
            freqs[w] = 1 if w not in freqs else freqs[w]+1
            freqs_0 = freqs_1
            freqs_1 = sorted(freqs.iteritems(), key=operator.itemgetter(1), reverse=True)
            if (freqs_1[0:25] != freqs_0[0:25]):
                update_display(freqs_1[0:25])
        except StopIteration:
            break
    return freqs_1

#
# The main function
#

print "Press space bar to fetch words from the file one by one"
print "Press ESC to switch to automatic mode"
count_and_sort(sys.argv[1])