#!/usr/bin/python
# -*- coding: utf-8 -*-
# \file markov.py
# \brief TODO
# \author Florent Guiotte <florent.guiotte@gmail.com>
# \version 0.2
# \date 04 sept. 2017
#
# TODO details

import sys
import random
import pickle
import getopt

def main():
    # parse command line options
    opts, args = getopt.getopt(sys.argv[1:], "hf:n:o:l:", ["help","create-dic"])
    create = False
    loadpk = "out.pickle"
    output = "out.pickle"
    infile = "markov.log"
    nb = 1
    for o, a in opts:
        if '--create-dic' == o:
            create = True
        elif o in ('--help', '-h'):
            print(__doc__)
            sys.exit(0)
        elif o == "-o":
            output = a
        elif o == "-f":
            infile = a
        elif o == "-n":
            nb = int(a)
        elif o == "-l":
            loadpk = a

    if create:
        megadic = {}
        buildDic(megadic, infile)
        #cslist = computeProbCSList(dic)
        #print(randomPick(cslist))
        megacslist = megaComputeProbCSList(megadic)
        #print(megacslist)
        pickle.dump(megacslist, open(output, 'wb'))
    else:
        try:
            megacslist = pickle.load(open(loadpk, 'rb'))
        except:
            print("No pickle file provided")
            sys.exit(2)

        #print(megacslist)
        for i in range(nb):
            print(megaRandomPic(megacslist))

def buildDic(dic, logfile):
    log = open(logfile, "r")
    for line in log:
        #print("L: " + line)
        pre = ("__firstword__", "__firstword__")
        for word in line.split():
            #print("W: " + word)
            addInDic(dic, word, pre)
            pre = (pre[1], word)
        addInDic(dic, "__eol__", pre)

def addInDic(dic, w, pre):
    if not pre in dic:
        dic[pre] = {}
    if not w in dic[pre]:
        dic[pre][w] = 1
    else:
        dic[pre][w] = dic[pre][w] + 1

def megaComputeProbCSList(megadic):
    megacsdic = {}
    for dic in megadic.items():
        cslist = computeProbCSList(dic[1])
        megacsdic[dic[0]] = cslist
    return megacsdic

def computeProbCSList(dic):
    tsum = sum(dic.values())
    sortedDic = sorted(dic.items(), key=lambda x:x[1])
    sortedDicProb = []
    dsum = 0
    for t in sortedDic:
        dsum = t[1]/tsum + dsum
        sortedDicProb.append((t[0], dsum))
    return sortedDicProb

def megaRandomPic(megacsdic):
    index = ("__firstword__", "__firstword__")
    currentw = randomPick(megacsdic[index])
    string = ""
    while currentw != "__eol__":
        string = string + currentw + " "
        index = (index[1], currentw)
        currentw = randomPick(megacsdic[index])
    return string

def randomPick(CSlist):
    r = random.random()
    for t in CSlist:
        if r < t[1]:
            return t[0]
    return None

if __name__ == "__main__":
    main()