# -*- coding: utf-8 -*-

from .context import encdec8b10b
from encdec8b10b import EncDec8B10B
import random

import unittest

import sys
if sys.version_info.major != 3:
	raise RuntimeError('invalid major version of python')

class TestClass(unittest.TestCase):
	def test_to10b(self):
		to10b = EncDec8B10B._to10b

		self.assertEqual(to10b(0), '0' * 10)
		self.assertEqual(to10b(2**10-1), '1' * 10)
		self.assertEqual(to10b(0x20f), '1' * 4 + '000001')
		self.assertEqual(to10b(0x0ff), '1' * 8 + '00')

	dispminmax = [ 2, 3, 2, 3, 2, 1, 2, 1, 2, 1 ]

	def test_disparity(self):
		failures = []
		for i in range(512):
			disp = i >> 8
			din = i & 0xff
			ndisp, out = EncDec8B10B.enc_8b10b(din, disp)
			cnt = +1 if disp else -1

			for j in range(10):
				out, bit = divmod(out, 2)
				cnt += +1 if bit else -1
				minmax = self.dispminmax[j]
				if cnt < -minmax or cnt > minmax:
					failures.append((disp, din))

			if cnt != 1 if ndisp else cnt != -1:
				failures.append((disp, din))

		if failures:
			raise RuntimeError('failures(%d): %s' % (len(failures), repr(failures)))

	def test_bitdecoding(self):
		coder = EncDec8B10B()

		with self.assertRaises(ValueError):
		    coder.decode('asioj')

		self.assertIsNone(coder.decode(''))

		self.assertFalse(coder.issyncd())
		self.assertIsNone(coder.decode('101011011010101101'))

		self.assertFalse(coder.issyncd())

		self.assertEqual(coder.decode(coder.encode(EncDec8B10B.COMMA)), EncDec8B10B.COMMA)
		self.assertTrue(coder.issyncd())

		astr = coder.encode(b'a')

		self.assertIsNone(coder.decode(astr[:5]))

		self.assertEqual(coder.decode(astr[5:]), b'a')

		self.assertEqual(coder.decode(coder.encode(b'abc123')), b'abc123')

		chrctrlstr = coder.encode(b'xx') + coder.encode(EncDec8B10B.K_28_0)

		self.assertIsNone(coder.decode(chrctrlstr[:5]))

		self.assertEqual(coder.decode(chrctrlstr[5:]), b'xx')
		self.assertEqual(coder.decode(''), EncDec8B10B.K_28_0)
		self.assertEqual(coder.decode(coder.encode(EncDec8B10B.K_28_2)), EncDec8B10B.K_28_2)

		# that when junk is delivered, it is ignored
		self.assertIsNone(coder.decode('111111111000011111'))

		# and is no longer synced
		self.assertFalse(coder.issyncd())

		commaastr = coder.encode(EncDec8B10B.COMMA) + \
		    coder.encode(b'a')

		# But it will sync back up
		self.assertEqual(coder.decode(commaastr), EncDec8B10B.COMMA)
		self.assertEqual(coder.decode(''), b'a')

		self.assertIsNone(coder.decode(''))

		self.assertEqual(coder.decode(coder.encode(EncDec8B10B.COMMA)), EncDec8B10B.COMMA)

	def test_bitencoding(self):
		coder = EncDec8B10B()

		self.assertEqual(coder.encode(b'a'), '0111010011')
		# +
		s = ''.join((
		    '1000101100', # a -
		    '1011010011', # b +
		    '1100010011', # c +
		    '1000111001', # 1 +
		    '0100111001', # 2 +
		    '1100101001', # 3 +
		))

		self.assertEqual(coder.encode(b'abc123'), s)
		self.assertEqual(coder.encode(EncDec8B10B.COMMA), '1100000101')
		self.assertEqual(coder.encode(EncDec8B10B.COMMA), '0011111010')