"""The rule form's target pickers (#5475): for a host source, the hosts in
one picker and the chosen host's parts in another, grouped by kind, each
offering only the metrics it reports that a rule can watch; a part that
reports nothing a rule can watch (an interface's traffic) is left out."""
from types import SimpleNamespace

import pytest

from steward.alerts import service as alert_svc

CATALOG = {"host_agent": ["cpu_pct", "disk_used_pct", "uptime_secs", "seconds_since_seen"]}
REPORTED = [("h1", "cpu_pct"), ("h1", "uptime_secs"), ("h1", "seconds_since_seen"),
            ("h1:/", "disk_used_pct"), ("h1:/var", "disk_used_pct"),
            ("h1:core10", "cpu_pct"), ("h1:core2", "cpu_pct"),
            ("h1:net:eth0", "net_rx_bps"), ("h1:temp:Core 0", "temp_c"),
            ("h2", "cpu_pct")]


@pytest.fixture(autouse=True)
def _catalog(monkeypatch):
    monkeypatch.setattr(alert_svc, "metric_catalog", lambda: CATALOG)


def _db(rows=REPORTED):
    async def execute(stmt):
        return SimpleNamespace(all=lambda: list(rows))
    return SimpleNamespace(execute=execute)


@pytest.mark.parametrize("part, kind, label", [
    ("/", "mount", "/"), ("/nfs/media", "mount", "/nfs/media"), ("core7", "core", "core 7"),
    ("diskio:sda", "disk", "sda"), ("net:bond0", "net", "bond0"),
    ("temp:Package id 0", "temp", "Package id 0"), ("corex", "other", "corex")])
def test_a_part_is_known_by_its_name(part, kind, label):
    assert alert_svc.part_kind(part) == (kind, label)


async def test_hosts_and_their_parts_are_picked_apart():
    got = await alert_svc.rule_target(_db(), "host_agent")
    assert got["hosts"] == ["h1", "h2"] and (got["host"], got["resource"]) == ("h1", "h1")
    assert got["parts"] == [
        ("", [("h1", "The whole host")]),
        ("Mounts", [("h1:/", "/"), ("h1:/var", "/var")]),
        ("CPU cores", [("h1:core2", "core 2"), ("h1:core10", "core 10")])]
    assert got["metrics"] == ["cpu_pct", "uptime_secs", "seconds_since_seen"]   # catalog order


async def test_a_part_offers_only_what_it_reports():
    got = await alert_svc.rule_target(_db(), "host_agent", resource="h1:/var", metric="cpu_pct")
    assert (got["host"], got["resource"]) == ("h1", "h1:/var")
    assert got["metrics"] == ["disk_used_pct"] and got["metric"] == ""   # cpu_pct isn't a mount's


async def test_picking_another_host_starts_at_the_whole_host():
    got = await alert_svc.rule_target(_db(), "host_agent", host="h2", resource="h1:/var")
    assert (got["host"], got["resource"]) == ("h2", "h2")
    assert got["parts"] == [("", [("h2", "The whole host")])]


async def test_a_rule_s_own_resource_stays_on_offer_after_it_goes_quiet():
    got = await alert_svc.rule_target(_db(), "host_agent", resource="h3:/data",
                                      metric="disk_used_pct", keep=True)
    assert "h3" in got["hosts"] and got["host"] == "h3"
    assert got["parts"] == [("Mounts", [("h3:/data", "/data")])]
    assert got["metric"] == "disk_used_pct"
    # A reporting part whose metric went quiet keeps it on the rule's own page.
    got = await alert_svc.rule_target(_db(), "host_agent", resource="h1:/var", metric="disk_free_pct",
                                      keep=True)
    assert got["metric"] == ""                                     # not in the catalog: not offered
    got = await alert_svc.rule_target(_db(), "host_agent", resource="h1:/var", metric="uptime_secs",
                                      keep=True)
    assert got["metrics"] == ["disk_used_pct", "uptime_secs"] and got["metric"] == "uptime_secs"