import unittest
import logging
import random

from datetime import datetime, timedelta
from util.migrate.allocator import CompletedKeys, NoAvailableKeysError, yield_random_entries


class CompletedTestCase(unittest.TestCase):
  def test_merge_blocks_operations(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)
    candidates.mark_completed(1, 5)

    self.assertTrue(candidates.is_available(5))
    self.assertTrue(candidates.is_available(0))
    self.assertFalse(candidates.is_available(1))
    self.assertFalse(candidates.is_available(4))
    self.assertFalse(candidates.is_available(11))
    self.assertFalse(candidates.is_available(10))
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(6, candidates.num_remaining)

    candidates.mark_completed(5, 6)
    self.assertFalse(candidates.is_available(5))
    self.assertTrue(candidates.is_available(6))
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(5, candidates.num_remaining)

    candidates.mark_completed(3, 8)
    self.assertTrue(candidates.is_available(9))
    self.assertTrue(candidates.is_available(8))
    self.assertFalse(candidates.is_available(7))
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(3, candidates.num_remaining)

  def test_adjust_max(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)
    self.assertEqual(0, len(candidates._slabs))

    self.assertTrue(candidates.is_available(9))
    candidates.mark_completed(5, 12)
    self.assertEqual(0, len(candidates._slabs))
    self.assertEqual(5, candidates.num_remaining)

    self.assertFalse(candidates.is_available(9))
    self.assertTrue(candidates.is_available(4))

  def test_adjust_min(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)
    self.assertEqual(0, len(candidates._slabs))

    self.assertTrue(candidates.is_available(2))
    candidates.mark_completed(0, 3)
    self.assertEqual(0, len(candidates._slabs))
    self.assertEqual(7, candidates.num_remaining)

    self.assertFalse(candidates.is_available(2))
    self.assertTrue(candidates.is_available(4))

  def test_inside_block(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)
    candidates.mark_completed(1, 8)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(3, candidates.num_remaining)

    candidates.mark_completed(2, 5)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(3, candidates.num_remaining)
    self.assertFalse(candidates.is_available(1))
    self.assertFalse(candidates.is_available(5))

  def test_wrap_block(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)
    candidates.mark_completed(2, 5)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(7, candidates.num_remaining)

    candidates.mark_completed(1, 8)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(3, candidates.num_remaining)
    self.assertFalse(candidates.is_available(1))
    self.assertFalse(candidates.is_available(5))

  def test_non_contiguous(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)

    candidates.mark_completed(1, 5)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(6, candidates.num_remaining)
    self.assertTrue(candidates.is_available(5))
    self.assertTrue(candidates.is_available(6))

    candidates.mark_completed(6, 8)
    self.assertEqual(2, len(candidates._slabs))
    self.assertEqual(4, candidates.num_remaining)
    self.assertTrue(candidates.is_available(5))
    self.assertFalse(candidates.is_available(6))

  def test_big_merge(self):
    candidates = CompletedKeys(10)
    self.assertEqual(10, candidates.num_remaining)

    candidates.mark_completed(1, 5)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(6, candidates.num_remaining)

    candidates.mark_completed(6, 8)
    self.assertEqual(2, len(candidates._slabs))
    self.assertEqual(4, candidates.num_remaining)

    candidates.mark_completed(5, 6)
    self.assertEqual(1, len(candidates._slabs))
    self.assertEqual(3, candidates.num_remaining)

  def test_range_limits(self):
    candidates = CompletedKeys(10)
    self.assertFalse(candidates.is_available(-1))
    self.assertFalse(candidates.is_available(10))

    self.assertTrue(candidates.is_available(9))
    self.assertTrue(candidates.is_available(0))

  def test_random_saturation(self):
    candidates = CompletedKeys(100)
    with self.assertRaises(NoAvailableKeysError):
      for _ in range(101):
        start = candidates.get_block_start_index(10)
        self.assertTrue(candidates.is_available(start))
        candidates.mark_completed(start, start + 10)

    self.assertEqual(0, candidates.num_remaining)

  def test_huge_dataset(self):
    candidates = CompletedKeys(1024 * 1024)
    start_time = datetime.now()
    iterations = 0
    with self.assertRaises(NoAvailableKeysError):
      while (datetime.now() - start_time) < timedelta(seconds=10):
        start = candidates.get_block_start_index(1024)
        self.assertTrue(candidates.is_available(start))
        candidates.mark_completed(start, start + random.randint(512, 1024))
        iterations += 1

    self.assertGreater(iterations, 1024)
    self.assertEqual(0, candidates.num_remaining)


class FakeQuery(object):
  def __init__(self, result_list):
    self._result_list = result_list

  def limit(self, *args, **kwargs):
    return self

  def where(self, *args, **kwargs):
    return self

  def order_by(self, *args, **kwargs):
    return self

  def __iter__(self):
    return self._result_list.__iter__()


class QueryAllocatorTest(unittest.TestCase):
  FAKE_PK_FIELD = 10  # Must be able to compare to integers

  def test_no_work(self):
    def create_empty_query():
      return FakeQuery([])

    for _ in yield_random_entries(create_empty_query, self.FAKE_PK_FIELD, 1, 10):
      self.fail('There should never be any actual work!')


if __name__ == '__main__':
  logging.basicConfig(level=logging.DEBUG)
  unittest.main()