#!/usr/bin/env python3

def dec2banana(num, alphastart = None, shiftend = None, minlength = None, alphabet = None):
    #defaults
    if alphastart is None: alphastart = 0
    if shiftend is None: shiftend = 0
    if minlength is None: minlength = 1
    if alphabet is None: alphabet = [list("bcdfglmnprstvz"), list("aeiou")]
    
    numdict = len(alphabet)
    v = num
    st = ""
    l = 0

    i = (numdict - 1 + alphastart + shiftend) % numdict
    while not (v == 0 and i == (numdict - 1 + alphastart) % numdict and l >= minlength):
        r = v % len(alphabet[i])
        v = int(v / len(alphabet[i]))
        st = alphabet[i][r] + st
        i = (i - 1) % numdict
        l += 1
   
    return(st)

    
def banana2dec(banana, alphastart = None, shiftend = None, alphabet = None):
    #defaults
    if alphastart is None: alphastart = 0
    if shiftend is None: shiftend = 0
    if alphabet is None: alphabet = [list("bcdfglmnprstvz"), list("aeiou")] #, list("123456")

    numdict = len(alphabet)
    if (len(banana) - shiftend) % numdict != 0:
        return("Banana non valida")
    v = 0
    for i in range(len(banana)):
        r = (numdict + i + alphastart) % numdict
        try:
            v = v * len(alphabet[r]) + alphabet[r].index(banana[i])
        except:
            return("Carattere non valido in posizione", i+1)
    
    return(v)

def bananarandom(alphastart = None, shiftend = None, minlength = None, alphabet = None):
    import random

    #defaults
    if alphastart is None: alphastart = 0
    if shiftend is None: shiftend = 0
    if minlength is None: minlength = 6
    if alphabet is None: alphabet = [list("bcdfglmnprstvz"), list("aeiou")]
    
    numdict = len(alphabet)
    st = ""
    l = 0

    i = (numdict - 1 + alphastart + shiftend) % numdict
    while not (i == (numdict - 1 + alphastart) % numdict and l >= minlength):
        r = random.randint(0, len(alphabet[i]) - 1)
        st = alphabet[i][r] + st
        i = (i - 1) % numdict
        l += 1
   
    return(st)

def isbanana(banana, alphastart = None, shiftend = None, alphabet = None):
    #defaults
    if alphastart is None: alphastart = 0
    if shiftend is None: shiftend = 0
    if alphabet is None: alphabet = [list("bcdfglmnprstvz"), list("aeiou")] #, list("123456")

    numdict = len(alphabet)
    if (len(banana) - shiftend) % numdict != 0:
        return(False)
    for i in range(len(banana)):
        r = (numdict + i + alphastart) % numdict
        if banana[i] not in alphabet[r]:
            return(False)

    return(True)





if __name__ == "__main__":
    print("Ciao sono la libreria banana")