"""Author: Sandeep Belgavi. Routing, admission and accounting tests."""
import unittest
from pattern_13 import Router


class RouterTests(unittest.TestCase):
    def test_capability_floor(self):
        r = Router(budget=2)
        self.assertEqual(r.admit('1', 2, 100), 'budget_denied')
        self.assertEqual(r.remaining, 2)

    def test_cheapest_eligible_route(self):
        r = Router()
        self.assertEqual(r.admit('1', 1, 100), 'fast')
        self.assertEqual(r.remaining, 5)

    def test_overload_no_charge(self):
        r = Router()
        r.admit('1', 1, 100)
        self.assertEqual(r.admit('2', 1, 100), 'overloaded')
        self.assertEqual(r.remaining, 5)

    def test_expired_no_reservation(self):
        r = Router()
        self.assertEqual(r.admit('1', 1, 0), 'expired')
        self.assertEqual(r.remaining, 7)

    def test_settlement_refunds_unused_units(self):
        r = Router()
        r.admit('1', 2, 100)
        r.settle('1', 3)
        self.assertEqual(r.remaining, 4)
        self.assertEqual(r.active, {})

    def test_duplicate_cannot_double_charge(self):
        r = Router()
        r.admit('1', 1, 100)
        with self.assertRaises(ValueError): r.admit('1', 1, 100)
        self.assertEqual(r.remaining, 5)

    def test_bad_charge_retains_reservation(self):
        r = Router()
        r.admit('1', 1, 100)
        with self.assertRaises(ValueError): r.settle('1', 3)
        self.assertIn('1', r.active)
        self.assertEqual(r.remaining, 5)

    def test_double_settlement_rejected(self):
        r = Router()
        r.admit('1', 1, 100)
        r.settle('1', 1)
        with self.assertRaises(KeyError): r.settle('1', 1)
        self.assertEqual(r.remaining, 6)


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