from secrets import SystemRandom

random = SystemRandom()

'''
def find_big_odd(k):
	
	num = random.getrandbits(k)
	while num % 2 == 0:
		num = 
'''


def enc(m, pk):
	S = 1000
	c = m + sum(random.sample(pk, S))
	return c


class Alice:
	def __init__(self, ya, yb, yr):
		self.ya = ya
		self.yb = yb
		self.yr = yr
		# p is the secret key
		self.p = random.getrandbits(2000)*2 + 1 # odd integer
		n = 2000
		bigInts = [random.getrandbits(10**7) for _ in range(n)]
		smallInts = [random.getrandbits(60) for _ in range(n)]

		self.pk = [self.p*bigInts[i] + 2*smallInts[i] for i in range(n)]
		self.cya = enc(ya, self.pk)
		self.cyb = enc(yb, self.pk)
		self.cyr = enc(yr, self.pk)

	def send(self):
		return self.cya, self.cyb, self.cyr, self.pk

	def dec(self, c):
		m = (c % self.p) % 2
		return m


class Bob:
	def __init__(self, xa, xb, xr):
		self.xa = xa
		self.xb = xb
		self.xr = xr

	def receive(self, cya, cyb, cyr, pk):
		self.pk = pk

		# these are ciphered values from alice
		self.cya = cya
		self.cyb = cyb
		self.cyr = cyr

		# these are ciphered values from bob
		self.cxa = enc(self.xa, pk)
		self.cxb = enc(self.xb, pk)
		self.cxr = enc(self.xr, pk)

	def compute_bloodcompatiblity(self):


		#f = (1 ^ (self.xa & (1 ^ self.cya))) & (1 ^ (self.xb & (1 ^ self.cyb))) & (1 ^ (self.xr & (1 ^ self.cyr)))
		#z = enc(f, self.pk)
		#return z
		pass

def protocol(donor, recipient):
	# Alice is recipient
	alice = Alice(0,1,1)
	bob = Bob(1,0,0)
	pass