import re, random, sys
from pathlib import Path
import pickle

def format_line(strin):
    out = re.sub('[^a-zA-Z?!àùòèé\'\., ]+', ' ', strin)
    out = re.sub('[ ]+', ' ', out)
    if( out != "" and out != " " ):
        return out
    return None

def buildchain(messages, dim):
    out = dict()
    for message in messages:
        x = message.split(' ')[:-1]
        for i in range(0, len(x) - dim):
            if tuple(x[i:i+dim]) in out:
                out[tuple(x[i:i+dim])].append(x[i+dim])
            else:
                out[tuple(x[i:i+dim])] = [x[i+dim]]

    return out

def findnext(chains, text):
    out = ''
    words = text.split(' ')
    if(text == ''):
        out = random.choice(chains[0])
    else:
        for i in range(len(chains)-1, 0, -1):
            if i <= len(words):
                #print(words[-i:])
                if tuple(words[-i:]) in chains[i]:
                    out = random.choice(chains[i][tuple(words[-i:])])
                    break;

    if out == '':
        out = random.choice(chains[0])
        #print("fallback")

    return out



def main():
    myDb = Path("markov.db")

    if(myDb.is_file()):
        with open('markov.db', 'rb') as i_f:
            chains = pickle.load(i_f)
    else:
        print("regenerating database...")
        chains = [[]]
        with open('intext') as f:
            content = f.readlines()

        for a in range(0,len(content)):
            content[a] = format_line(content[a])
            if(content[a]):
                for i in content[a].split(' '):
                    if(i != ''):
                        chains[0].append(i)

        content = [x.lower() for x in content if x] #remove empty lines

        chains.append(buildchain(content, 1))
        chains.append(buildchain(content, 2))
        chains.append(buildchain(content, 3))
        chains.append(buildchain(content, 4))
        chains.append(buildchain(content, 5))

        with open('markov.db', 'wb') as o_f:
            pickle.dump(chains, o_f, pickle.HIGHEST_PROTOCOL)
        print("done")

    if(len(sys.argv) > 1):
        try:
            dim = int(sys.argv[1])
        except:
            dim = 20
        if( dim > 100 or dim < 1 ):
            dim = 20
    else:
        dim = 20

    if(len(sys.argv) > 2):
        text = ' '.join(sys.argv[2:])
    else:
        text = ''

    for i in range(0,dim):
        text += ' ' + findnext(chains,text)

    print(text)

main()