import random, re, sys

GREETING = "hello! how are you?"
RBTMSG   = "  Robot: "
USRMSG   = "   User: "
CSLMSG   = "Console: "

brain = {}
words = lambda x: tuple(map(str.lower, re.findall(r"\b(\w+?)\b", x)))
def addDict(original, other):
    for i in other:
        if i not in original: original[i] = 0
        original[i] += 1
    return original

print(f"{RBTMSG}{GREETING}")
botwords = words(GREETING)
while True:
    human = input(USRMSG).lower()
    if human.startswith("/"):
        if human == "/exit":
            sys.exit()
        elif human == "/brain":
            print(f"{CSLMSG}{brain}")
        else:
            print(f"{CSLMSG}command not found")
    else:
        humanwords = words(human)
        if human not in brain.keys(): brain[human] = {}
        brain[human] = addDict(brain[human], botwords)
        matches = []
        for i in brain:
            matchid = 0
            for j in humanwords:
                if j.lower() in brain[i]:
                    matchid += brain[i][j]
            matches.append([i, matchid])
        best = [[None, 0]]
        for k in matches:
            if best[0][1] < k[1]:
                best = [k]
            elif best[0][1] == k[1]:
                best.append(k)
        if best[0][0] == None: best = best[1:]
        response = random.choice(best)[0]
        print(f"{RBTMSG}{response}")
        botwords = words(response)