from diff import parse_ics_events, compute_diff, parse_ics_events_with_data

class TestParseIcsEvents:
    def test_parse_basic(self, ics_sample):
        result = parse_ics_events(ics_sample)
        assert "evt-001@test.com" in result
        assert "evt-002@test.com" in result
        assert len(result) == 2

    def test_parse_no_uid(self):
        ics = """BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
DTSTAMP:20240101T000000Z
DTSTART:20240101T100000Z
SUMMARY:No UID
END:VEVENT
END:VCALENDAR"""
        result = parse_ics_events(ics)
        assert len(result) == 0

    def test_hashes_are_sha256(self, ics_sample):
        result = parse_ics_events(ics_sample)
        for uid, h in result.items():
            assert len(h) == 64
            int(h, 16)

    def test_same_event_same_hash(self, ics_sample):
        r1 = parse_ics_events(ics_sample)
        r2 = parse_ics_events(ics_sample)
        for uid in r1:
            assert r1[uid] == r2[uid]

    def test_modified_event_different_hash(self, ics_sample, ics_sample_modified):
        r1 = parse_ics_events(ics_sample)
        r2 = parse_ics_events(ics_sample_modified)
        assert r1["evt-001@test.com"] != r2["evt-001@test.com"]

class TestComputeDiff:
    def test_no_changes(self, ics_sample):
        ics_uids = parse_ics_events(ics_sample)
        deltas = compute_diff(ics_uids, ics_uids)
        assert len(deltas["to_add"]) == 0
        assert len(deltas["to_update"]) == 0
        assert len(deltas["to_delete"]) == 0

    def test_add_events(self, ics_sample, ics_sample_modified):
        original = parse_ics_events(ics_sample)
        modified = parse_ics_events(ics_sample_modified)
        deltas = compute_diff(modified, original)
        assert ("evt-003@test.com", modified["evt-003@test.com"]) in deltas["to_add"]

    def test_delete_events(self, ics_sample, ics_sample_modified):
        original = parse_ics_events(ics_sample)
        modified = parse_ics_events(ics_sample_modified)
        deltas = compute_diff(modified, original)
        assert "evt-002@test.com" in deltas["to_delete"]

    def test_update_events(self, ics_sample, ics_sample_modified):
        original = parse_ics_events(ics_sample)
        modified = parse_ics_events(ics_sample_modified)
        deltas = compute_diff(modified, original)
        uid, new_hash = deltas["to_update"][0]
        assert uid == "evt-001@test.com"
        assert new_hash == modified["evt-001@test.com"]

class TestParseIcsEventsWithData:
    def test_returns_bytes(self, ics_sample):
        result = parse_ics_events_with_data(ics_sample)
        assert len(result) == 2
        for uid, data in result.items():
            assert isinstance(data, bytes)
            assert b"VEVENT" in data