"""What an SNMP device is asked for and how each answer reads (milestone 491)."""
import pytest

from plugins.snmp.readings import (device_readings, format_value, interface_readings, parse_custom,
                                   parse_interfaces, stored_unit)


def test_interface_numbers_read_as_a_list():
    assert parse_interfaces("1, 2 5-7,2") == [1, 2, 5, 6, 7]
    assert parse_interfaces("") == []
    for bad in ("eth0", "7-3", "1-100"):
        with pytest.raises(ValueError):
            parse_interfaces(bad)


def test_interfaces_read_64_bit_counters_except_on_v1():
    v2 = {r.key: r for r in interface_readings([3], "2c")}
    v1 = {r.key: r for r in interface_readings([3], "1")}
    assert set(v2) == {"if3_status", "if3_in", "if3_out"}
    assert v2["if3_in"].oid == "1.3.6.1.2.1.31.1.1.1.6.3" and v2["if3_in"].counter
    assert v1["if3_in"].oid == "1.3.6.1.2.1.2.2.1.10.3"
    assert stored_unit(v2["if3_out"]) == "bits_per_second" and not v2["if3_status"].counter


def test_a_custom_line_is_an_oid_a_name_and_a_unit():
    got = parse_custom("# a comment\n.1.3.6.1.4.1.9.1.0 fan_speed\n1.3.6.1.4.1.9.2.0 inlet_temp celsius\n")
    assert [(r.oid, r.key, r.name, r.unit) for r in got] == [
        ("1.3.6.1.4.1.9.1.0", "fan_speed", "Fan speed", "number"),
        ("1.3.6.1.4.1.9.2.0", "inlet_temp", "Inlet temp", "celsius")]


@pytest.mark.parametrize("line, says", [
    ("1.3.6.1", "OID name"),
    ("sysUpTime uptime", "is not an OID"),
    ("1.3.6.1.2 Bad-Name", "must start with a letter"),
    ("1.3.6.1.2 temp furlongs", "is not a unit"),
])
def test_a_custom_line_that_does_not_read_says_which_and_why(line, says):
    with pytest.raises(ValueError, match="Line 1") as exc:
        parse_custom(line)
    assert says in str(exc.value)


def test_presets_come_in_order_and_names_may_not_repeat():
    keys = [r.key for r in device_readings(["ups", "system", "interfaces"], [1], "", "2c")]
    assert keys[:4] == ["uptime", "if1_status", "if1_in", "if1_out"] and "battery_charge" in keys
    with pytest.raises(ValueError, match="uptime"):
        device_readings(["system"], [], "1.3.6.1.2.1.1.3.0 uptime", "2c")


@pytest.mark.parametrize("unit, value, text", [
    ("centiseconds", 105_120_000, "12d 4h"),
    ("percent", 99.6, "100%"),
    ("volts", 121.0, "121 V"),
    ("decivolts", 1203, "120.3 V"),
    ("minutes", 45, "45m"),
    ("kilobytes", 2048, "2.0 MiB"),
    ("bits_per_second", 12_345_678, "12.3 Mbit/s"),
    ("bits_per_second", 950, "950 bit/s"),
    ("if_status", 2, "down"),
    ("ups_battery", 3, "low"),
    ("if_status", 99, "code 99"),
    ("number", 41.25, "41.25"),
    ("number", None, "—"),
])
def test_a_value_reads_in_its_unit(unit, value, text):
    assert format_value(unit, value) == text