#!/usr/bin/env python3

# SY 301 Fall 2016
# Project 3: Zemor hashing
# YOUR NAME HERE
# This is the beginning of a program that you must complete to
# compute the Zemor hash of a given bit sequence, string, or file.

import sys
from cayley import Cayley
from graph import Graph

# (your code here, or feel free to put classes in other Python files.)

def usage():
    # Help message for command-line usage. Shouldn't need to change this.
    print("Usage: {} OPTIONS".format(sys.argv[0]))
    print("You have one option to specify the source of the graph, either:")
    print("  -g graphfile  Read the graph from the given file, or")
    print("  -p prime      Use the Zemor graph with the given prime number")
    print("Then you have to specify what you're hashing, with one of:")
    print("  -b bits    Hash the given bitstring like 010010")
    print("  -s string  Hash the regular string given like hello")
    print("  -f file    Hash the contents of the given file")

if __name__ == '__main__':
    # This is the code that gets run when this program is executed on the
    # command-line. You shouldn't need to change it too much, but feel free
    # to modify to suit your code as long as you don't change the way the
    # command-line works.
    graph = None
    sourceType = None
    source = None

    # process command line arguments
    i = 1
    while i < len(sys.argv):
        if sys.argv[i] == '-h' or i+1 >= len(sys.argv):
            usage()
            exit(0)
        opt = sys.argv[i]
        arg = sys.argv[i+1]
        if opt == '-g' and graph is None:
            # You'll need a Graph class that takes a filename as argument to init
            graph = Graph(arg)
        elif opt == '-p' and graph is None:
            # The Zemor class is given to you.
            graph = Zemor(int(arg))
        elif opt == '-b' and source is None:
            sourceType = "bits"
            source = arg
        elif opt == '-s' and source is None:
            sourceType = "string"
            source = arg
        elif opt == '-f' and source is None:
            sourceType = "file"
            source = arg
        else:
            usage()
            exit(1)
        i += 2
    if graph is None or source is None: 
        usage()
        exit(1)

    # I made a class called ExpanderHash that gets __init__'d from
    # a given graph object, and has three methods to hash the three
    # different kinds of inputs.
    h = ExpanderHash(graph) 
    if sourceType == 'bits':
        print(h.hashBits(source))
    elif sourceType == 'string':
        print(h.hashString(source))
    elif sourceType == 'file':
        print(h.hashFile(source))