"""Syslog pattern alerts (#6001): a pattern read from its form, the line
test it makes, its metric key, and the per-minute tally its count keeps."""
from datetime import datetime, timedelta, timezone
from types import SimpleNamespace as NS

import pytest
from werkzeug.datastructures import MultiDict

from plugins.syslog.patterns import PRESETS, PatternError, Tally, key_for, matches, parse_form


def test_a_form_reads_into_a_pattern():
    v = parse_form(MultiDict({"name": " NFS ", "phrases": "nfsd:\n\n  lockd: \n", "max_severity": "3",
                              "source_id": "", "window_minutes": "60", "enabled": "on"}))
    assert v == {"name": "NFS", "phrases": ["nfsd:", "lockd:"], "max_severity": 3, "source_id": None,
                 "window_minutes": 60, "enabled": True}
    # A window or severity not offered falls back rather than failing.
    v = parse_form(MultiDict({"name": "x", "phrases": "a", "max_severity": "9", "window_minutes": "7"}))
    assert (v["max_severity"], v["window_minutes"], v["enabled"]) == (None, 15, False)


@pytest.mark.parametrize("form, says", [
    ({"phrases": "a"}, "name"),
    ({"name": "x", "phrases": " \n "}, "at least one phrase"),
    ({"name": "x", "phrases": "\n".join(str(i) for i in range(21))}, "At most 20"),
    ({"name": "x", "phrases": "a" * 201}, "200 characters"),
])
def test_a_form_that_does_not_read_says_what_to_fix(form, says):
    with pytest.raises(PatternError, match=says):
        parse_form(MultiDict(form))


def test_a_line_matches_any_phrase_in_any_case_at_the_severity():
    p = NS(phrases=["I/O error", "medium error"], max_severity=None)
    assert matches(p, 6, "blk_update_request: i/o ERROR, dev sda")
    assert not matches(p, 6, "all well")
    sev = NS(phrases=[], max_severity=3)
    assert matches(sev, 3, "anything") and matches(sev, 0, "") and not matches(sev, 4, "anything")
    both = NS(phrases=["nfsd"], max_severity=3)
    assert matches(both, 2, "nfsd: too many") and not matches(both, 5, "nfsd: too many")


def test_a_key_is_the_name_in_metric_form():
    assert key_for("Disk I/O errors") == "disk_i_o_errors"
    assert key_for("  ---  ") == "pattern" and len(key_for("x" * 90)) == 48
    assert len({p.key for p in PRESETS}) == len(PRESETS)
    assert all(p.phrases or p.max_severity is not None for p in PRESETS)


def test_a_tally_counts_its_window_by_the_minute_and_forgets_older():
    now = datetime(2026, 10, 19, 12, 30, 40, tzinfo=timezone.utc)
    t = Tally(sig=())
    for minutes in (0, 5, 14, 16, 120):
        t.add("s1", now - timedelta(minutes=minutes))
    assert t.count("s1", now - timedelta(minutes=15)) == 3
    assert t.count("s1", now - timedelta(hours=3)) == 3           # what was dropped stays dropped
    assert t.count("s2", now) == 0