import os
import sys
import unittest

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import bl_decimate as bd


class TestDecimateRatio(unittest.TestCase):
    def test_normal_reduction(self):
        self.assertAlmostEqual(bd.decimate_ratio(5000, 1500000), 5000 / 1500000.0)

    def test_current_below_target_returns_one(self):
        self.assertEqual(bd.decimate_ratio(5000, 3000), 1.0)

    def test_current_equal_target_returns_one(self):
        self.assertEqual(bd.decimate_ratio(5000, 5000), 1.0)

    def test_zero_current_returns_one(self):
        self.assertEqual(bd.decimate_ratio(5000, 0), 1.0)


class TestWithinTolerance(unittest.TestCase):
    def test_exact_hit(self):
        self.assertTrue(bd.within_tolerance(5000, 5000))

    def test_within_3_percent(self):
        self.assertTrue(bd.within_tolerance(5000, 5150))   # +3%
        self.assertTrue(bd.within_tolerance(5000, 4850))   # -3%

    def test_outside_3_percent(self):
        self.assertFalse(bd.within_tolerance(5000, 5200))
        self.assertFalse(bd.within_tolerance(5000, 4700))

    def test_zero_target_is_false(self):
        self.assertFalse(bd.within_tolerance(0, 0))


if __name__ == "__main__":
    unittest.main()