import pytest

import pandas as pd


class TestFlags:
    def test_equality(self):
        a = pd.DataFrame().set_flags(allows_duplicate_labels=True).flags
        b = pd.DataFrame().set_flags(allows_duplicate_labels=False).flags

        assert a == a
        assert b == b
        assert a != b
        assert a != 2

    def test_set(self):
        df = pd.DataFrame().set_flags(allows_duplicate_labels=True)
        a = df.flags
        a.allows_duplicate_labels = False
        assert a.allows_duplicate_labels is False
        a["allows_duplicate_labels"] = True
        assert a.allows_duplicate_labels is True

    def test_repr(self):
        a = repr(pd.DataFrame({"A"}).set_flags(allows_duplicate_labels=True).flags)
        assert a == "<Flags(allows_duplicate_labels=True)>"
        a = repr(pd.DataFrame({"A"}).set_flags(allows_duplicate_labels=False).flags)
        assert a == "<Flags(allows_duplicate_labels=False)>"

    def test_obj_ref(self):
        df = pd.DataFrame()
        flags = df.flags
        del df
        with pytest.raises(ValueError, match="object has been deleted"):
            flags.allows_duplicate_labels = True

    def test_getitem(self):
        df = pd.DataFrame()
        flags = df.flags
        assert flags["allows_duplicate_labels"] is True
        flags["allows_duplicate_labels"] = False
        assert flags["allows_duplicate_labels"] is False

        with pytest.raises(KeyError):
            flags["a"]

        with pytest.raises(ValueError):
            flags["a"] = 10
