import sys
import argparse
import json
import random
__author__ = 'm3x1m0m'

class c_num_gen:
    def __init__(self, imax_num, ifname):
        self.max_num = imax_num
        self.fname = ifname
        self.__nums = []
    def __del__(self):
        # Save on object destruction.
        self.__write()
    def __read(self):
        with open(self.fname, "r") as rf:
            self.__nums = json.load(rf)
    def __write(self):
        with open(self.fname, "w") as wf:
            json.dump(self.__nums, wf)
    def __rand_num(self):
        num = random.randint(0, self.max_num)
        return hex(num).upper()
    def create_new_number(self):
        if len(self.__nums) == 0:
            self.__read()
        rand_num = self.__rand_num()
        while rand_num in self.__nums:
            rand_num = self.__rand_num()
        self.__nums.append(rand_num)
        return rand_num

def main():
    parser = argparse.ArgumentParser(description='Random number generator w/ memory.')
    parser.add_argument('-f','--file', help='File name for memory.', required=True)
    parser.add_argument('-c','--create', help='Create a new number.', action='store_true')
    args = parser.parse_args()
    max_num = (1<<16)
    generator = c_num_gen(max_num, args.file)
    if (args.create):
        print("New number: {}".format(generator.create_new_number()))

if __name__ == "__main__":
    main()