#!/usr/bin/env python

import os
import unittest
import zoneinfo
from datetime import datetime
from timeit import Timer

from croniter import croniter
from croniter.tests import base


class CroniterSpeedTest(base.TestCase):
    def run_long_test(self, iterations=1):
        dt = datetime(2010, 1, 23, 12, 18)
        itr = croniter("*/1 * * * *", dt)
        for i in range(iterations):  # ~ 58
            itr.get_next()

        itr = croniter("*/5 * * * *", dt)
        for i in range(iterations):
            itr.get_next()

        dt = datetime(2010, 1, 24, 12, 2)
        itr = croniter("0 */3 * * *", dt)
        for i in range(iterations):
            itr.get_next()

        dt = datetime(2010, 2, 24, 12, 9)
        itr = croniter("0 0 */3 * *", dt)
        for i in range(iterations):
            itr.get_next(datetime)

        # test leap year
        dt = datetime(1996, 2, 27)
        itr = croniter("0 0 * * *", dt)
        for i in range(iterations):
            itr.get_next(datetime)

        dt2 = datetime(2000, 2, 27)
        itr2 = croniter("0 0 * * *", dt2)
        for i in range(iterations):
            itr2.get_next(datetime)

        dt = datetime(2010, 2, 25)
        itr = croniter("0 0 * * sat", dt)
        for i in range(iterations):
            itr.get_next(datetime)

        dt = datetime(2010, 1, 25)
        itr = croniter("0 0 1 * wed", dt)
        for i in range(iterations):
            itr.get_next(datetime)

        dt = datetime(2010, 1, 25)
        itr = croniter("0 0 1 * *", dt)
        for i in range(iterations):
            itr.get_next()

        dt = datetime(2010, 8, 25, 15, 56)
        itr = croniter("*/1 * * * *", dt)
        for i in range(iterations):
            itr.get_prev(datetime)

        dt = datetime(2010, 8, 25, 15, 0)
        itr = croniter("*/1 * * * *", dt)
        for i in range(iterations):
            itr.get_prev(datetime)

        dt = datetime(2010, 8, 25, 0, 0)
        itr = croniter("*/1 * * * *", dt)
        for i in range(iterations):
            itr.get_prev(datetime)

        dt = datetime(2010, 8, 25, 15, 56)
        itr = croniter("0 0 * * sat,sun", dt)
        for i in range(iterations):
            itr.get_prev(datetime)

        dt = datetime(2010, 2, 25)
        itr = croniter("0 0 * * 7", dt)
        for i in range(iterations):
            itr.get_prev(datetime)

        # dst regression test
        tz = zoneinfo.ZoneInfo("Europe/Bucharest")
        offsets = set()
        dst_cron = "15 0,3 * 3 *"
        dst_iters = int(2 * 31 * (iterations / 40))
        dt = datetime(2010, 1, 25, tzinfo=tz)
        itr = croniter(dst_cron, dt)
        for i in range(dst_iters):
            d = itr.get_next(datetime)
            offsets.add(d.utcoffset())
        itr = croniter(dst_cron, dt)
        for i in range(dst_iters):
            d = itr.get_prev(datetime)
            offsets.add(d.utcoffset())

    def test_large_comma_list_expands_quickly(self):
        # Regression: a long comma list of ranges used to expand in O(n^2)
        # because every expanded value was de-duplicated against the whole
        # pending list. ~20k groups took minutes; it now finishes instantly
        # and yields the same result as a single range.
        expr = ",".join(["0-30"] * 20000) + " * * * *"
        elapsed = Timer(lambda: croniter.expand(expr)).timeit(1)
        self.assertLess(elapsed, 10, f"comma-list expansion too slow ({elapsed}s)")
        self.assertEqual(croniter.expand(expr)[0][0], list(range(31)))

    def test_not_long_time(self):
        iterations = int(os.environ.get("CRONITER_TEST_SPEED_ITERATIONS", "40"))
        globs = globals()
        globs.update(locals())
        t = Timer("self.run_long_test(iterations)", globals=globs)
        limit = 80
        ret = t.timeit(limit)
        self.assertTrue(ret < limit, f"Regression in croniter speed detected ({ret} {limit}).")


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