import pytest

from pandas.errors import OutOfBoundsDatetime

import pandas as pd
from pandas import Period, offsets
from pandas.util import testing as tm
from pandas._libs.tslibs.frequencies import _period_code_map


class TestFreqConversion(object):
    """Test frequency conversion of date objects"""
    @pytest.mark.parametrize('freq', ['A', 'Q', 'M', 'W', 'B', 'D'])
    def test_asfreq_near_zero(self, freq):
        # GH#19643, GH#19650
        per = Period('0001-01-01', freq=freq)
        tup1 = (per.year, per.hour, per.day)

        prev = per - 1
        assert (per - 1).ordinal == per.ordinal - 1
        tup2 = (prev.year, prev.month, prev.day)
        assert tup2 < tup1

    def test_asfreq_near_zero_weekly(self):
        # GH#19834
        per1 = Period('0001-01-01', 'D') + 6
        per2 = Period('0001-01-01', 'D') - 6
        week1 = per1.asfreq('W')
        week2 = per2.asfreq('W')
        assert week1 != week2
        assert week1.asfreq('D', 'E') >= per1
        assert week2.asfreq('D', 'S') <= per2

    @pytest.mark.xfail(reason='GH#19643 period_helper asfreq functions fail '
                              'to check for overflows')
    def test_to_timestamp_out_of_bounds(self):
        # GH#19643, currently gives Timestamp('1754-08-30 22:43:41.128654848')
        per = Period('0001-01-01', freq='B')
        with pytest.raises(OutOfBoundsDatetime):
            per.to_timestamp()

    def test_asfreq_corner(self):
        val = Period(freq='A', year=2007)
        result1 = val.asfreq('5t')
        result2 = val.asfreq('t')
        expected = Period('2007-12-31 23:59', freq='t')
        assert result1.ordinal == expected.ordinal
        assert result1.freqstr == '5T'
        assert result2.ordinal == expected.ordinal
        assert result2.freqstr == 'T'

    def test_conv_annual(self):
        # frequency conversion tests: from Annual Frequency

        ival_A = Period(freq='A', year=2007)

        ival_AJAN = Period(freq="A-JAN", year=2007)
        ival_AJUN = Period(freq="A-JUN", year=2007)
        ival_ANOV = Period(freq="A-NOV", year=2007)

        ival_A_to_Q_start = Period(freq='Q', year=2007, quarter=1)
        ival_A_to_Q_end = Period(freq='Q', year=2007, quarter=4)
        ival_A_to_M_start = Period(freq='M', year=2007, month=1)
        ival_A_to_M_end = Period(freq='M', year=2007, month=12)
        ival_A_to_W_start = Period(freq='W', year=2007, month=1, day=1)
        ival_A_to_W_end = Period(freq='W', year=2007, month=12, day=31)
        ival_A_to_B_start = Period(freq='B', year=2007, month=1, day=1)
        ival_A_to_B_end = Period(freq='B', year=2007, month=12, day=31)
        ival_A_to_D_start = Period(freq='D', year=2007, month=1, day=1)
        ival_A_to_D_end = Period(freq='D', year=2007, month=12, day=31)
        ival_A_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_A_to_H_end = Period(freq='H', year=2007, month=12, day=31,
                                 hour=23)
        ival_A_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_A_to_T_end = Period(freq='Min', year=2007, month=12, day=31,
                                 hour=23, minute=59)
        ival_A_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_A_to_S_end = Period(freq='S', year=2007, month=12, day=31,
                                 hour=23, minute=59, second=59)

        ival_AJAN_to_D_end = Period(freq='D', year=2007, month=1, day=31)
        ival_AJAN_to_D_start = Period(freq='D', year=2006, month=2, day=1)
        ival_AJUN_to_D_end = Period(freq='D', year=2007, month=6, day=30)
        ival_AJUN_to_D_start = Period(freq='D', year=2006, month=7, day=1)
        ival_ANOV_to_D_end = Period(freq='D', year=2007, month=11, day=30)
        ival_ANOV_to_D_start = Period(freq='D', year=2006, month=12, day=1)

        assert ival_A.asfreq('Q', 'S') == ival_A_to_Q_start
        assert ival_A.asfreq('Q', 'e') == ival_A_to_Q_end
        assert ival_A.asfreq('M', 's') == ival_A_to_M_start
        assert ival_A.asfreq('M', 'E') == ival_A_to_M_end
        assert ival_A.asfreq('W', 'S') == ival_A_to_W_start
        assert ival_A.asfreq('W', 'E') == ival_A_to_W_end
        assert ival_A.asfreq('B', 'S') == ival_A_to_B_start
        assert ival_A.asfreq('B', 'E') == ival_A_to_B_end
        assert ival_A.asfreq('D', 'S') == ival_A_to_D_start
        assert ival_A.asfreq('D', 'E') == ival_A_to_D_end
        assert ival_A.asfreq('H', 'S') == ival_A_to_H_start
        assert ival_A.asfreq('H', 'E') == ival_A_to_H_end
        assert ival_A.asfreq('min', 'S') == ival_A_to_T_start
        assert ival_A.asfreq('min', 'E') == ival_A_to_T_end
        assert ival_A.asfreq('T', 'S') == ival_A_to_T_start
        assert ival_A.asfreq('T', 'E') == ival_A_to_T_end
        assert ival_A.asfreq('S', 'S') == ival_A_to_S_start
        assert ival_A.asfreq('S', 'E') == ival_A_to_S_end

        assert ival_AJAN.asfreq('D', 'S') == ival_AJAN_to_D_start
        assert ival_AJAN.asfreq('D', 'E') == ival_AJAN_to_D_end

        assert ival_AJUN.asfreq('D', 'S') == ival_AJUN_to_D_start
        assert ival_AJUN.asfreq('D', 'E') == ival_AJUN_to_D_end

        assert ival_ANOV.asfreq('D', 'S') == ival_ANOV_to_D_start
        assert ival_ANOV.asfreq('D', 'E') == ival_ANOV_to_D_end

        assert ival_A.asfreq('A') == ival_A

    def test_conv_quarterly(self):
        # frequency conversion tests: from Quarterly Frequency

        ival_Q = Period(freq='Q', year=2007, quarter=1)
        ival_Q_end_of_year = Period(freq='Q', year=2007, quarter=4)

        ival_QEJAN = Period(freq="Q-JAN", year=2007, quarter=1)
        ival_QEJUN = Period(freq="Q-JUN", year=2007, quarter=1)

        ival_Q_to_A = Period(freq='A', year=2007)
        ival_Q_to_M_start = Period(freq='M', year=2007, month=1)
        ival_Q_to_M_end = Period(freq='M', year=2007, month=3)
        ival_Q_to_W_start = Period(freq='W', year=2007, month=1, day=1)
        ival_Q_to_W_end = Period(freq='W', year=2007, month=3, day=31)
        ival_Q_to_B_start = Period(freq='B', year=2007, month=1, day=1)
        ival_Q_to_B_end = Period(freq='B', year=2007, month=3, day=30)
        ival_Q_to_D_start = Period(freq='D', year=2007, month=1, day=1)
        ival_Q_to_D_end = Period(freq='D', year=2007, month=3, day=31)
        ival_Q_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_Q_to_H_end = Period(freq='H', year=2007, month=3, day=31, hour=23)
        ival_Q_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_Q_to_T_end = Period(freq='Min', year=2007, month=3, day=31,
                                 hour=23, minute=59)
        ival_Q_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_Q_to_S_end = Period(freq='S', year=2007, month=3, day=31, hour=23,
                                 minute=59, second=59)

        ival_QEJAN_to_D_start = Period(freq='D', year=2006, month=2, day=1)
        ival_QEJAN_to_D_end = Period(freq='D', year=2006, month=4, day=30)

        ival_QEJUN_to_D_start = Period(freq='D', year=2006, month=7, day=1)
        ival_QEJUN_to_D_end = Period(freq='D', year=2006, month=9, day=30)

        assert ival_Q.asfreq('A') == ival_Q_to_A
        assert ival_Q_end_of_year.asfreq('A') == ival_Q_to_A

        assert ival_Q.asfreq('M', 'S') == ival_Q_to_M_start
        assert ival_Q.asfreq('M', 'E') == ival_Q_to_M_end
        assert ival_Q.asfreq('W', 'S') == ival_Q_to_W_start
        assert ival_Q.asfreq('W', 'E') == ival_Q_to_W_end
        assert ival_Q.asfreq('B', 'S') == ival_Q_to_B_start
        assert ival_Q.asfreq('B', 'E') == ival_Q_to_B_end
        assert ival_Q.asfreq('D', 'S') == ival_Q_to_D_start
        assert ival_Q.asfreq('D', 'E') == ival_Q_to_D_end
        assert ival_Q.asfreq('H', 'S') == ival_Q_to_H_start
        assert ival_Q.asfreq('H', 'E') == ival_Q_to_H_end
        assert ival_Q.asfreq('Min', 'S') == ival_Q_to_T_start
        assert ival_Q.asfreq('Min', 'E') == ival_Q_to_T_end
        assert ival_Q.asfreq('S', 'S') == ival_Q_to_S_start
        assert ival_Q.asfreq('S', 'E') == ival_Q_to_S_end

        assert ival_QEJAN.asfreq('D', 'S') == ival_QEJAN_to_D_start
        assert ival_QEJAN.asfreq('D', 'E') == ival_QEJAN_to_D_end
        assert ival_QEJUN.asfreq('D', 'S') == ival_QEJUN_to_D_start
        assert ival_QEJUN.asfreq('D', 'E') == ival_QEJUN_to_D_end

        assert ival_Q.asfreq('Q') == ival_Q

    def test_conv_monthly(self):
        # frequency conversion tests: from Monthly Frequency

        ival_M = Period(freq='M', year=2007, month=1)
        ival_M_end_of_year = Period(freq='M', year=2007, month=12)
        ival_M_end_of_quarter = Period(freq='M', year=2007, month=3)
        ival_M_to_A = Period(freq='A', year=2007)
        ival_M_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_M_to_W_start = Period(freq='W', year=2007, month=1, day=1)
        ival_M_to_W_end = Period(freq='W', year=2007, month=1, day=31)
        ival_M_to_B_start = Period(freq='B', year=2007, month=1, day=1)
        ival_M_to_B_end = Period(freq='B', year=2007, month=1, day=31)
        ival_M_to_D_start = Period(freq='D', year=2007, month=1, day=1)
        ival_M_to_D_end = Period(freq='D', year=2007, month=1, day=31)
        ival_M_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_M_to_H_end = Period(freq='H', year=2007, month=1, day=31, hour=23)
        ival_M_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_M_to_T_end = Period(freq='Min', year=2007, month=1, day=31,
                                 hour=23, minute=59)
        ival_M_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_M_to_S_end = Period(freq='S', year=2007, month=1, day=31, hour=23,
                                 minute=59, second=59)

        assert ival_M.asfreq('A') == ival_M_to_A
        assert ival_M_end_of_year.asfreq('A') == ival_M_to_A
        assert ival_M.asfreq('Q') == ival_M_to_Q
        assert ival_M_end_of_quarter.asfreq('Q') == ival_M_to_Q

        assert ival_M.asfreq('W', 'S') == ival_M_to_W_start
        assert ival_M.asfreq('W', 'E') == ival_M_to_W_end
        assert ival_M.asfreq('B', 'S') == ival_M_to_B_start
        assert ival_M.asfreq('B', 'E') == ival_M_to_B_end
        assert ival_M.asfreq('D', 'S') == ival_M_to_D_start
        assert ival_M.asfreq('D', 'E') == ival_M_to_D_end
        assert ival_M.asfreq('H', 'S') == ival_M_to_H_start
        assert ival_M.asfreq('H', 'E') == ival_M_to_H_end
        assert ival_M.asfreq('Min', 'S') == ival_M_to_T_start
        assert ival_M.asfreq('Min', 'E') == ival_M_to_T_end
        assert ival_M.asfreq('S', 'S') == ival_M_to_S_start
        assert ival_M.asfreq('S', 'E') == ival_M_to_S_end

        assert ival_M.asfreq('M') == ival_M

    def test_conv_weekly(self):
        # frequency conversion tests: from Weekly Frequency
        ival_W = Period(freq='W', year=2007, month=1, day=1)

        ival_WSUN = Period(freq='W', year=2007, month=1, day=7)
        ival_WSAT = Period(freq='W-SAT', year=2007, month=1, day=6)
        ival_WFRI = Period(freq='W-FRI', year=2007, month=1, day=5)
        ival_WTHU = Period(freq='W-THU', year=2007, month=1, day=4)
        ival_WWED = Period(freq='W-WED', year=2007, month=1, day=3)
        ival_WTUE = Period(freq='W-TUE', year=2007, month=1, day=2)
        ival_WMON = Period(freq='W-MON', year=2007, month=1, day=1)

        ival_WSUN_to_D_start = Period(freq='D', year=2007, month=1, day=1)
        ival_WSUN_to_D_end = Period(freq='D', year=2007, month=1, day=7)
        ival_WSAT_to_D_start = Period(freq='D', year=2006, month=12, day=31)
        ival_WSAT_to_D_end = Period(freq='D', year=2007, month=1, day=6)
        ival_WFRI_to_D_start = Period(freq='D', year=2006, month=12, day=30)
        ival_WFRI_to_D_end = Period(freq='D', year=2007, month=1, day=5)
        ival_WTHU_to_D_start = Period(freq='D', year=2006, month=12, day=29)
        ival_WTHU_to_D_end = Period(freq='D', year=2007, month=1, day=4)
        ival_WWED_to_D_start = Period(freq='D', year=2006, month=12, day=28)
        ival_WWED_to_D_end = Period(freq='D', year=2007, month=1, day=3)
        ival_WTUE_to_D_start = Period(freq='D', year=2006, month=12, day=27)
        ival_WTUE_to_D_end = Period(freq='D', year=2007, month=1, day=2)
        ival_WMON_to_D_start = Period(freq='D', year=2006, month=12, day=26)
        ival_WMON_to_D_end = Period(freq='D', year=2007, month=1, day=1)

        ival_W_end_of_year = Period(freq='W', year=2007, month=12, day=31)
        ival_W_end_of_quarter = Period(freq='W', year=2007, month=3, day=31)
        ival_W_end_of_month = Period(freq='W', year=2007, month=1, day=31)
        ival_W_to_A = Period(freq='A', year=2007)
        ival_W_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_W_to_M = Period(freq='M', year=2007, month=1)

        if Period(freq='D', year=2007, month=12, day=31).weekday == 6:
            ival_W_to_A_end_of_year = Period(freq='A', year=2007)
        else:
            ival_W_to_A_end_of_year = Period(freq='A', year=2008)

        if Period(freq='D', year=2007, month=3, day=31).weekday == 6:
            ival_W_to_Q_end_of_quarter = Period(freq='Q', year=2007, quarter=1)
        else:
            ival_W_to_Q_end_of_quarter = Period(freq='Q', year=2007, quarter=2)

        if Period(freq='D', year=2007, month=1, day=31).weekday == 6:
            ival_W_to_M_end_of_month = Period(freq='M', year=2007, month=1)
        else:
            ival_W_to_M_end_of_month = Period(freq='M', year=2007, month=2)

        ival_W_to_B_start = Period(freq='B', year=2007, month=1, day=1)
        ival_W_to_B_end = Period(freq='B', year=2007, month=1, day=5)
        ival_W_to_D_start = Period(freq='D', year=2007, month=1, day=1)
        ival_W_to_D_end = Period(freq='D', year=2007, month=1, day=7)
        ival_W_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_W_to_H_end = Period(freq='H', year=2007, month=1, day=7, hour=23)
        ival_W_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_W_to_T_end = Period(freq='Min', year=2007, month=1, day=7,
                                 hour=23, minute=59)
        ival_W_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_W_to_S_end = Period(freq='S', year=2007, month=1, day=7, hour=23,
                                 minute=59, second=59)

        assert ival_W.asfreq('A') == ival_W_to_A
        assert ival_W_end_of_year.asfreq('A') == ival_W_to_A_end_of_year

        assert ival_W.asfreq('Q') == ival_W_to_Q
        assert ival_W_end_of_quarter.asfreq('Q') == ival_W_to_Q_end_of_quarter

        assert ival_W.asfreq('M') == ival_W_to_M
        assert ival_W_end_of_month.asfreq('M') == ival_W_to_M_end_of_month

        assert ival_W.asfreq('B', 'S') == ival_W_to_B_start
        assert ival_W.asfreq('B', 'E') == ival_W_to_B_end

        assert ival_W.asfreq('D', 'S') == ival_W_to_D_start
        assert ival_W.asfreq('D', 'E') == ival_W_to_D_end

        assert ival_WSUN.asfreq('D', 'S') == ival_WSUN_to_D_start
        assert ival_WSUN.asfreq('D', 'E') == ival_WSUN_to_D_end
        assert ival_WSAT.asfreq('D', 'S') == ival_WSAT_to_D_start
        assert ival_WSAT.asfreq('D', 'E') == ival_WSAT_to_D_end
        assert ival_WFRI.asfreq('D', 'S') == ival_WFRI_to_D_start
        assert ival_WFRI.asfreq('D', 'E') == ival_WFRI_to_D_end
        assert ival_WTHU.asfreq('D', 'S') == ival_WTHU_to_D_start
        assert ival_WTHU.asfreq('D', 'E') == ival_WTHU_to_D_end
        assert ival_WWED.asfreq('D', 'S') == ival_WWED_to_D_start
        assert ival_WWED.asfreq('D', 'E') == ival_WWED_to_D_end
        assert ival_WTUE.asfreq('D', 'S') == ival_WTUE_to_D_start
        assert ival_WTUE.asfreq('D', 'E') == ival_WTUE_to_D_end
        assert ival_WMON.asfreq('D', 'S') == ival_WMON_to_D_start
        assert ival_WMON.asfreq('D', 'E') == ival_WMON_to_D_end

        assert ival_W.asfreq('H', 'S') == ival_W_to_H_start
        assert ival_W.asfreq('H', 'E') == ival_W_to_H_end
        assert ival_W.asfreq('Min', 'S') == ival_W_to_T_start
        assert ival_W.asfreq('Min', 'E') == ival_W_to_T_end
        assert ival_W.asfreq('S', 'S') == ival_W_to_S_start
        assert ival_W.asfreq('S', 'E') == ival_W_to_S_end

        assert ival_W.asfreq('W') == ival_W

        msg = pd._libs.tslibs.frequencies._INVALID_FREQ_ERROR
        with tm.assert_raises_regex(ValueError, msg):
            ival_W.asfreq('WK')

    def test_conv_weekly_legacy(self):
        # frequency conversion tests: from Weekly Frequency
        msg = pd._libs.tslibs.frequencies._INVALID_FREQ_ERROR
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK', year=2007, month=1, day=1)

        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-SAT', year=2007, month=1, day=6)
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-FRI', year=2007, month=1, day=5)
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-THU', year=2007, month=1, day=4)
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-WED', year=2007, month=1, day=3)
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-TUE', year=2007, month=1, day=2)
        with tm.assert_raises_regex(ValueError, msg):
            Period(freq='WK-MON', year=2007, month=1, day=1)

    def test_conv_business(self):
        # frequency conversion tests: from Business Frequency"

        ival_B = Period(freq='B', year=2007, month=1, day=1)
        ival_B_end_of_year = Period(freq='B', year=2007, month=12, day=31)
        ival_B_end_of_quarter = Period(freq='B', year=2007, month=3, day=30)
        ival_B_end_of_month = Period(freq='B', year=2007, month=1, day=31)
        ival_B_end_of_week = Period(freq='B', year=2007, month=1, day=5)

        ival_B_to_A = Period(freq='A', year=2007)
        ival_B_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_B_to_M = Period(freq='M', year=2007, month=1)
        ival_B_to_W = Period(freq='W', year=2007, month=1, day=7)
        ival_B_to_D = Period(freq='D', year=2007, month=1, day=1)
        ival_B_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_B_to_H_end = Period(freq='H', year=2007, month=1, day=1, hour=23)
        ival_B_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_B_to_T_end = Period(freq='Min', year=2007, month=1, day=1,
                                 hour=23, minute=59)
        ival_B_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_B_to_S_end = Period(freq='S', year=2007, month=1, day=1, hour=23,
                                 minute=59, second=59)

        assert ival_B.asfreq('A') == ival_B_to_A
        assert ival_B_end_of_year.asfreq('A') == ival_B_to_A
        assert ival_B.asfreq('Q') == ival_B_to_Q
        assert ival_B_end_of_quarter.asfreq('Q') == ival_B_to_Q
        assert ival_B.asfreq('M') == ival_B_to_M
        assert ival_B_end_of_month.asfreq('M') == ival_B_to_M
        assert ival_B.asfreq('W') == ival_B_to_W
        assert ival_B_end_of_week.asfreq('W') == ival_B_to_W

        assert ival_B.asfreq('D') == ival_B_to_D

        assert ival_B.asfreq('H', 'S') == ival_B_to_H_start
        assert ival_B.asfreq('H', 'E') == ival_B_to_H_end
        assert ival_B.asfreq('Min', 'S') == ival_B_to_T_start
        assert ival_B.asfreq('Min', 'E') == ival_B_to_T_end
        assert ival_B.asfreq('S', 'S') == ival_B_to_S_start
        assert ival_B.asfreq('S', 'E') == ival_B_to_S_end

        assert ival_B.asfreq('B') == ival_B

    def test_conv_daily(self):
        # frequency conversion tests: from Business Frequency"

        ival_D = Period(freq='D', year=2007, month=1, day=1)
        ival_D_end_of_year = Period(freq='D', year=2007, month=12, day=31)
        ival_D_end_of_quarter = Period(freq='D', year=2007, month=3, day=31)
        ival_D_end_of_month = Period(freq='D', year=2007, month=1, day=31)
        ival_D_end_of_week = Period(freq='D', year=2007, month=1, day=7)

        ival_D_friday = Period(freq='D', year=2007, month=1, day=5)
        ival_D_saturday = Period(freq='D', year=2007, month=1, day=6)
        ival_D_sunday = Period(freq='D', year=2007, month=1, day=7)

        # TODO: unused?
        # ival_D_monday = Period(freq='D', year=2007, month=1, day=8)

        ival_B_friday = Period(freq='B', year=2007, month=1, day=5)
        ival_B_monday = Period(freq='B', year=2007, month=1, day=8)

        ival_D_to_A = Period(freq='A', year=2007)

        ival_Deoq_to_AJAN = Period(freq='A-JAN', year=2008)
        ival_Deoq_to_AJUN = Period(freq='A-JUN', year=2007)
        ival_Deoq_to_ADEC = Period(freq='A-DEC', year=2007)

        ival_D_to_QEJAN = Period(freq="Q-JAN", year=2007, quarter=4)
        ival_D_to_QEJUN = Period(freq="Q-JUN", year=2007, quarter=3)
        ival_D_to_QEDEC = Period(freq="Q-DEC", year=2007, quarter=1)

        ival_D_to_M = Period(freq='M', year=2007, month=1)
        ival_D_to_W = Period(freq='W', year=2007, month=1, day=7)

        ival_D_to_H_start = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_D_to_H_end = Period(freq='H', year=2007, month=1, day=1, hour=23)
        ival_D_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_D_to_T_end = Period(freq='Min', year=2007, month=1, day=1,
                                 hour=23, minute=59)
        ival_D_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_D_to_S_end = Period(freq='S', year=2007, month=1, day=1, hour=23,
                                 minute=59, second=59)

        assert ival_D.asfreq('A') == ival_D_to_A

        assert ival_D_end_of_quarter.asfreq('A-JAN') == ival_Deoq_to_AJAN
        assert ival_D_end_of_quarter.asfreq('A-JUN') == ival_Deoq_to_AJUN
        assert ival_D_end_of_quarter.asfreq('A-DEC') == ival_Deoq_to_ADEC

        assert ival_D_end_of_year.asfreq('A') == ival_D_to_A
        assert ival_D_end_of_quarter.asfreq('Q') == ival_D_to_QEDEC
        assert ival_D.asfreq("Q-JAN") == ival_D_to_QEJAN
        assert ival_D.asfreq("Q-JUN") == ival_D_to_QEJUN
        assert ival_D.asfreq("Q-DEC") == ival_D_to_QEDEC
        assert ival_D.asfreq('M') == ival_D_to_M
        assert ival_D_end_of_month.asfreq('M') == ival_D_to_M
        assert ival_D.asfreq('W') == ival_D_to_W
        assert ival_D_end_of_week.asfreq('W') == ival_D_to_W

        assert ival_D_friday.asfreq('B') == ival_B_friday
        assert ival_D_saturday.asfreq('B', 'S') == ival_B_friday
        assert ival_D_saturday.asfreq('B', 'E') == ival_B_monday
        assert ival_D_sunday.asfreq('B', 'S') == ival_B_friday
        assert ival_D_sunday.asfreq('B', 'E') == ival_B_monday

        assert ival_D.asfreq('H', 'S') == ival_D_to_H_start
        assert ival_D.asfreq('H', 'E') == ival_D_to_H_end
        assert ival_D.asfreq('Min', 'S') == ival_D_to_T_start
        assert ival_D.asfreq('Min', 'E') == ival_D_to_T_end
        assert ival_D.asfreq('S', 'S') == ival_D_to_S_start
        assert ival_D.asfreq('S', 'E') == ival_D_to_S_end

        assert ival_D.asfreq('D') == ival_D

    def test_conv_hourly(self):
        # frequency conversion tests: from Hourly Frequency"

        ival_H = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_H_end_of_year = Period(freq='H', year=2007, month=12, day=31,
                                    hour=23)
        ival_H_end_of_quarter = Period(freq='H', year=2007, month=3, day=31,
                                       hour=23)
        ival_H_end_of_month = Period(freq='H', year=2007, month=1, day=31,
                                     hour=23)
        ival_H_end_of_week = Period(freq='H', year=2007, month=1, day=7,
                                    hour=23)
        ival_H_end_of_day = Period(freq='H', year=2007, month=1, day=1,
                                   hour=23)
        ival_H_end_of_bus = Period(freq='H', year=2007, month=1, day=1,
                                   hour=23)

        ival_H_to_A = Period(freq='A', year=2007)
        ival_H_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_H_to_M = Period(freq='M', year=2007, month=1)
        ival_H_to_W = Period(freq='W', year=2007, month=1, day=7)
        ival_H_to_D = Period(freq='D', year=2007, month=1, day=1)
        ival_H_to_B = Period(freq='B', year=2007, month=1, day=1)

        ival_H_to_T_start = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=0, minute=0)
        ival_H_to_T_end = Period(freq='Min', year=2007, month=1, day=1, hour=0,
                                 minute=59)
        ival_H_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_H_to_S_end = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                 minute=59, second=59)

        assert ival_H.asfreq('A') == ival_H_to_A
        assert ival_H_end_of_year.asfreq('A') == ival_H_to_A
        assert ival_H.asfreq('Q') == ival_H_to_Q
        assert ival_H_end_of_quarter.asfreq('Q') == ival_H_to_Q
        assert ival_H.asfreq('M') == ival_H_to_M
        assert ival_H_end_of_month.asfreq('M') == ival_H_to_M
        assert ival_H.asfreq('W') == ival_H_to_W
        assert ival_H_end_of_week.asfreq('W') == ival_H_to_W
        assert ival_H.asfreq('D') == ival_H_to_D
        assert ival_H_end_of_day.asfreq('D') == ival_H_to_D
        assert ival_H.asfreq('B') == ival_H_to_B
        assert ival_H_end_of_bus.asfreq('B') == ival_H_to_B

        assert ival_H.asfreq('Min', 'S') == ival_H_to_T_start
        assert ival_H.asfreq('Min', 'E') == ival_H_to_T_end
        assert ival_H.asfreq('S', 'S') == ival_H_to_S_start
        assert ival_H.asfreq('S', 'E') == ival_H_to_S_end

        assert ival_H.asfreq('H') == ival_H

    def test_conv_minutely(self):
        # frequency conversion tests: from Minutely Frequency"

        ival_T = Period(freq='Min', year=2007, month=1, day=1, hour=0,
                        minute=0)
        ival_T_end_of_year = Period(freq='Min', year=2007, month=12, day=31,
                                    hour=23, minute=59)
        ival_T_end_of_quarter = Period(freq='Min', year=2007, month=3, day=31,
                                       hour=23, minute=59)
        ival_T_end_of_month = Period(freq='Min', year=2007, month=1, day=31,
                                     hour=23, minute=59)
        ival_T_end_of_week = Period(freq='Min', year=2007, month=1, day=7,
                                    hour=23, minute=59)
        ival_T_end_of_day = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=23, minute=59)
        ival_T_end_of_bus = Period(freq='Min', year=2007, month=1, day=1,
                                   hour=23, minute=59)
        ival_T_end_of_hour = Period(freq='Min', year=2007, month=1, day=1,
                                    hour=0, minute=59)

        ival_T_to_A = Period(freq='A', year=2007)
        ival_T_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_T_to_M = Period(freq='M', year=2007, month=1)
        ival_T_to_W = Period(freq='W', year=2007, month=1, day=7)
        ival_T_to_D = Period(freq='D', year=2007, month=1, day=1)
        ival_T_to_B = Period(freq='B', year=2007, month=1, day=1)
        ival_T_to_H = Period(freq='H', year=2007, month=1, day=1, hour=0)

        ival_T_to_S_start = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                   minute=0, second=0)
        ival_T_to_S_end = Period(freq='S', year=2007, month=1, day=1, hour=0,
                                 minute=0, second=59)

        assert ival_T.asfreq('A') == ival_T_to_A
        assert ival_T_end_of_year.asfreq('A') == ival_T_to_A
        assert ival_T.asfreq('Q') == ival_T_to_Q
        assert ival_T_end_of_quarter.asfreq('Q') == ival_T_to_Q
        assert ival_T.asfreq('M') == ival_T_to_M
        assert ival_T_end_of_month.asfreq('M') == ival_T_to_M
        assert ival_T.asfreq('W') == ival_T_to_W
        assert ival_T_end_of_week.asfreq('W') == ival_T_to_W
        assert ival_T.asfreq('D') == ival_T_to_D
        assert ival_T_end_of_day.asfreq('D') == ival_T_to_D
        assert ival_T.asfreq('B') == ival_T_to_B
        assert ival_T_end_of_bus.asfreq('B') == ival_T_to_B
        assert ival_T.asfreq('H') == ival_T_to_H
        assert ival_T_end_of_hour.asfreq('H') == ival_T_to_H

        assert ival_T.asfreq('S', 'S') == ival_T_to_S_start
        assert ival_T.asfreq('S', 'E') == ival_T_to_S_end

        assert ival_T.asfreq('Min') == ival_T

    def test_conv_secondly(self):
        # frequency conversion tests: from Secondly Frequency"

        ival_S = Period(freq='S', year=2007, month=1, day=1, hour=0, minute=0,
                        second=0)
        ival_S_end_of_year = Period(freq='S', year=2007, month=12, day=31,
                                    hour=23, minute=59, second=59)
        ival_S_end_of_quarter = Period(freq='S', year=2007, month=3, day=31,
                                       hour=23, minute=59, second=59)
        ival_S_end_of_month = Period(freq='S', year=2007, month=1, day=31,
                                     hour=23, minute=59, second=59)
        ival_S_end_of_week = Period(freq='S', year=2007, month=1, day=7,
                                    hour=23, minute=59, second=59)
        ival_S_end_of_day = Period(freq='S', year=2007, month=1, day=1,
                                   hour=23, minute=59, second=59)
        ival_S_end_of_bus = Period(freq='S', year=2007, month=1, day=1,
                                   hour=23, minute=59, second=59)
        ival_S_end_of_hour = Period(freq='S', year=2007, month=1, day=1,
                                    hour=0, minute=59, second=59)
        ival_S_end_of_minute = Period(freq='S', year=2007, month=1, day=1,
                                      hour=0, minute=0, second=59)

        ival_S_to_A = Period(freq='A', year=2007)
        ival_S_to_Q = Period(freq='Q', year=2007, quarter=1)
        ival_S_to_M = Period(freq='M', year=2007, month=1)
        ival_S_to_W = Period(freq='W', year=2007, month=1, day=7)
        ival_S_to_D = Period(freq='D', year=2007, month=1, day=1)
        ival_S_to_B = Period(freq='B', year=2007, month=1, day=1)
        ival_S_to_H = Period(freq='H', year=2007, month=1, day=1, hour=0)
        ival_S_to_T = Period(freq='Min', year=2007, month=1, day=1, hour=0,
                             minute=0)

        assert ival_S.asfreq('A') == ival_S_to_A
        assert ival_S_end_of_year.asfreq('A') == ival_S_to_A
        assert ival_S.asfreq('Q') == ival_S_to_Q
        assert ival_S_end_of_quarter.asfreq('Q') == ival_S_to_Q
        assert ival_S.asfreq('M') == ival_S_to_M
        assert ival_S_end_of_month.asfreq('M') == ival_S_to_M
        assert ival_S.asfreq('W') == ival_S_to_W
        assert ival_S_end_of_week.asfreq('W') == ival_S_to_W
        assert ival_S.asfreq('D') == ival_S_to_D
        assert ival_S_end_of_day.asfreq('D') == ival_S_to_D
        assert ival_S.asfreq('B') == ival_S_to_B
        assert ival_S_end_of_bus.asfreq('B') == ival_S_to_B
        assert ival_S.asfreq('H') == ival_S_to_H
        assert ival_S_end_of_hour.asfreq('H') == ival_S_to_H
        assert ival_S.asfreq('Min') == ival_S_to_T
        assert ival_S_end_of_minute.asfreq('Min') == ival_S_to_T

        assert ival_S.asfreq('S') == ival_S

    def test_asfreq_mult(self):
        # normal freq to mult freq
        p = Period(freq='A', year=2007)
        # ordinal will not change
        for freq in ['3A', offsets.YearEnd(3)]:
            result = p.asfreq(freq)
            expected = Period('2007', freq='3A')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq
        # ordinal will not change
        for freq in ['3A', offsets.YearEnd(3)]:
            result = p.asfreq(freq, how='S')
            expected = Period('2007', freq='3A')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq

        # mult freq to normal freq
        p = Period(freq='3A', year=2007)
        # ordinal will change because how=E is the default
        for freq in ['A', offsets.YearEnd()]:
            result = p.asfreq(freq)
            expected = Period('2009', freq='A')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq
        # ordinal will not change
        for freq in ['A', offsets.YearEnd()]:
            result = p.asfreq(freq, how='S')
            expected = Period('2007', freq='A')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq

        p = Period(freq='A', year=2007)
        for freq in ['2M', offsets.MonthEnd(2)]:
            result = p.asfreq(freq)
            expected = Period('2007-12', freq='2M')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq
        for freq in ['2M', offsets.MonthEnd(2)]:
            result = p.asfreq(freq, how='S')
            expected = Period('2007-01', freq='2M')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq

        p = Period(freq='3A', year=2007)
        for freq in ['2M', offsets.MonthEnd(2)]:
            result = p.asfreq(freq)
            expected = Period('2009-12', freq='2M')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq
        for freq in ['2M', offsets.MonthEnd(2)]:
            result = p.asfreq(freq, how='S')
            expected = Period('2007-01', freq='2M')

            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq

    def test_asfreq_combined(self):
        # normal freq to combined freq
        p = Period('2007', freq='H')

        # ordinal will not change
        expected = Period('2007', freq='25H')
        for freq, how in zip(['1D1H', '1H1D'], ['E', 'S']):
            result = p.asfreq(freq, how=how)
            assert result == expected
            assert result.ordinal == expected.ordinal
            assert result.freq == expected.freq

        # combined freq to normal freq
        p1 = Period(freq='1D1H', year=2007)
        p2 = Period(freq='1H1D', year=2007)

        # ordinal will change because how=E is the default
        result1 = p1.asfreq('H')
        result2 = p2.asfreq('H')
        expected = Period('2007-01-02', freq='H')
        assert result1 == expected
        assert result1.ordinal == expected.ordinal
        assert result1.freq == expected.freq
        assert result2 == expected
        assert result2.ordinal == expected.ordinal
        assert result2.freq == expected.freq

        # ordinal will not change
        result1 = p1.asfreq('H', how='S')
        result2 = p2.asfreq('H', how='S')
        expected = Period('2007-01-01', freq='H')
        assert result1 == expected
        assert result1.ordinal == expected.ordinal
        assert result1.freq == expected.freq
        assert result2 == expected
        assert result2.ordinal == expected.ordinal
        assert result2.freq == expected.freq

    def test_asfreq_MS(self):
        initial = Period("2013")

        assert initial.asfreq(freq="M", how="S") == Period('2013-01', 'M')

        msg = pd._libs.tslibs.frequencies._INVALID_FREQ_ERROR
        with tm.assert_raises_regex(ValueError, msg):
            initial.asfreq(freq="MS", how="S")

        with tm.assert_raises_regex(ValueError, msg):
            pd.Period('2013-01', 'MS')

        assert _period_code_map.get("MS") is None
