import subprocess

from migen.fhdl.std import *

from lib.sata.std import *
from lib.sata.link.crc import *
from lib.sata.link.test.common import *

class TB(Module):
	def __init__(self, length, random):
		self.submodules.crc = SATACRC()
		self.length = length
		self.random = random

	def get_c_crc(self, datas):
		stdin = ""
		for data in datas:
			stdin += "0x%08x " %data
		stdin += "exit"
		with subprocess.Popen("./crc", stdin=subprocess.PIPE, stdout=subprocess.PIPE) as process:
			process.stdin.write(stdin.encode("UTF-8"))
			out, err = process.communicate()
		return int(out.decode("UTF-8"), 16)

	def gen_simulation(self, selfp):
		# init CRC
		selfp.crc.d = 0
		selfp.crc.ce = 1
		selfp.crc.reset = 1
		yield
		selfp.crc.reset = 0

		# feed CRC with datas
		datas = []
		for i in range(self.length):
			data = seed_to_data(i, self.random)
			datas.append(data)
			selfp.crc.d = data
			yield

		# log results
		yield
		sim_crc = selfp.crc.value

		# stop
		selfp.crc.ce = 0
		for i in range(32):
			yield

		# get C core reference
		c_crc = self.get_c_crc(datas)

		# check results
		s, l, e = check(c_crc, sim_crc)
		print("shift "+ str(s) + " / length " + str(l) + " / errors " + str(e))

if __name__ == "__main__":
	from migen.sim.generic import run_simulation
	length = 8192
	run_simulation(TB(length, True), ncycles=length+100, vcd_name="my.vcd")