import unittest

from reactivex import operators as ops
from reactivex.testing import ReactiveTest, TestScheduler

on_next = ReactiveTest.on_next
on_completed = ReactiveTest.on_completed
on_error = ReactiveTest.on_error
subscribe = ReactiveTest.subscribe
subscribed = ReactiveTest.subscribed
disposed = ReactiveTest.disposed
created = ReactiveTest.created


class TestPairwise(unittest.TestCase):
    def test_pairwise_empty(self):
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(on_next(180, 5), on_completed(210))

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create)

        assert results.messages == [on_completed(210)]

        assert xs.subscriptions == [subscribe(200, 210)]

    def test_pairwise_single(self):
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(
            on_next(180, 5), on_next(210, 4), on_completed(220)
        )

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create)

        assert results.messages == [on_completed(220)]
        assert xs.subscriptions == [subscribe(200, 220)]

    def test_pairwise_completed(self):
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(
            on_next(180, 5),
            on_next(210, 4),
            on_next(240, 3),
            on_next(290, 2),
            on_next(350, 1),
            on_completed(360),
        )

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create)

        assert results.messages == [
            on_next(240, (4, 3)),
            on_next(290, (3, 2)),
            on_next(350, (2, 1)),
            on_completed(360),
        ]

        assert xs.subscriptions == [subscribe(200, 360)]

    def test_pairwise_not_completed(self):
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(
            on_next(180, 5),
            on_next(210, 4),
            on_next(240, 3),
            on_next(290, 2),
            on_next(350, 1),
        )

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create)

        assert results.messages == [
            on_next(240, (4, 3)),
            on_next(290, (3, 2)),
            on_next(350, (2, 1)),
        ]

        assert xs.subscriptions == [subscribe(200, 1000)]

    def test_pairwise_error(self):
        error = Exception()
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(
            on_next(180, 5),
            on_next(210, 4),
            on_next(240, 3),
            on_error(290, error),
            on_next(350, 1),
            on_completed(360),
        )

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create)

        assert results.messages == [on_next(240, (4, 3)), on_error(290, error)]

        assert xs.subscriptions == [subscribe(200, 290)]

    def test_pairwise_disposed(self):
        scheduler = TestScheduler()

        xs = scheduler.create_hot_observable(
            on_next(180, 5),
            on_next(210, 4),
            on_next(240, 3),
            on_next(290, 2),
            on_next(350, 1),
            on_completed(360),
        )

        def create():
            return xs.pipe(ops.pairwise())

        results = scheduler.start(create, disposed=280)

        assert results.messages == [on_next(240, (4, 3))]

        assert xs.subscriptions == [subscribe(200, 280)]