"""Tests for SystemHealthMonitor pure methods — no external processes or filesystem."""
import sys
import os

import pytest

sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))

from unittest.mock import patch, MagicMock  # noqa: E402
from hwmonDaemon import SystemHealthMonitor  # noqa: E402


@pytest.fixture(scope='module')
def monitor():
    """Create a minimal monitor instance with all external side-effects patched out."""
    with patch.object(SystemHealthMonitor, 'load_env_config'), \
         patch.object(SystemHealthMonitor, '_check_tool_availability', return_value={}), \
         patch('os.makedirs'):
        return SystemHealthMonitor(dry_run=True)


# ── _format_bytes_human ──────────────────────────────────────────────────────

class TestFormatBytesHuman:
    def test_bytes(self, monitor):
        assert monitor._format_bytes_human(512) == '512.0 B'

    def test_kilobytes(self, monitor):
        assert monitor._format_bytes_human(1024) == '1.0 KB'

    def test_megabytes(self, monitor):
        assert monitor._format_bytes_human(1024 ** 2) == '1.0 MB'

    def test_gigabytes(self, monitor):
        assert monitor._format_bytes_human(1024 ** 3) == '1.0 GB'

    def test_terabytes(self, monitor):
        assert monitor._format_bytes_human(1024 ** 4) == '1.0 TB'

    def test_fractional(self, monitor):
        assert monitor._format_bytes_human(1536) == '1.5 KB'

    def test_zero(self, monitor):
        assert monitor._format_bytes_human(0) == '0.0 B'


# ── _parse_size ───────────────────────────────────────────────────────────────

class TestParseSize:
    def test_gigabytes(self, monitor):
        result = monitor._parse_size('15.7G')
        assert abs(result - 15.7 * 1024**3) < 1

    def test_terabytes(self, monitor):
        result = monitor._parse_size('21.8T')
        assert abs(result - 21.8 * 1024**4) < 1

    def test_megabytes(self, monitor):
        result = monitor._parse_size('512M')
        assert result == 512 * 1024**2

    def test_kilobytes(self, monitor):
        result = monitor._parse_size('100K')
        assert result == 100 * 1024

    def test_bytes(self, monitor):
        result = monitor._parse_size('100B')
        assert result == 100

    def test_invalid_returns_zero(self, monitor):
        assert monitor._parse_size('notasize') == 0.0

    def test_non_string_returns_zero(self, monitor):
        assert monitor._parse_size(None) == 0.0
        assert monitor._parse_size(42) == 0.0


# ── _parse_smart_value ────────────────────────────────────────────────────────

class TestParseSmartValue:
    def test_plain_integer(self, monitor):
        assert monitor._parse_smart_value('42') == 42

    def test_temperature_with_celsius(self, monitor):
        assert monitor._parse_smart_value('38 °C') == 38

    def test_time_format(self, monitor):
        assert monitor._parse_smart_value('15589h+17m+33.939s') == 15589

    def test_hex_value(self, monitor):
        assert monitor._parse_smart_value('0x0a') == 10

    def test_invalid_returns_zero(self, monitor):
        assert monitor._parse_smart_value('not_a_number') == 0


# ── _detect_manufacturer ──────────────────────────────────────────────────────

class TestDetectManufacturer:
    def test_western_digital(self, monitor):
        assert monitor._detect_manufacturer('WDC WD40EFRX') == 'Western Digital'

    def test_hgst(self, monitor):
        assert monitor._detect_manufacturer('HGST HUH728080ALE604') == 'Western Digital'

    def test_seagate(self, monitor):
        assert monitor._detect_manufacturer('ST4000DM004') == 'Seagate'

    def test_samsung(self, monitor):
        assert monitor._detect_manufacturer('Samsung SSD 870 EVO') == 'Samsung'

    def test_intel(self, monitor):
        assert monitor._detect_manufacturer('INTEL SSDSC2KB480G8') == 'Intel'

    def test_micron(self, monitor):
        assert monitor._detect_manufacturer('Crucial CT500MX500SSD1') == 'Micron'

    def test_toshiba(self, monitor):
        assert monitor._detect_manufacturer('TOSHIBA MG06ACA10TE') == 'Toshiba'

    def test_unknown(self, monitor):
        assert monitor._detect_manufacturer('GENERICDRIVE XYZ') == 'Unknown'

    def test_empty_model(self, monitor):
        assert monitor._detect_manufacturer('') == 'Unknown'

    def test_none_model(self, monitor):
        assert monitor._detect_manufacturer(None) == 'Unknown'


# ── _check_thermal_health ─────────────────────────────────────────────────────

class TestCheckThermalHealth:
    def test_hdd_ok_temperature(self, monitor):
        issues = monitor._check_thermal_health('sda', 45, 'HDD')
        assert issues == []

    def test_hdd_info_temperature(self, monitor):
        issues = monitor._check_thermal_health('sda', 62, 'HDD')
        assert len(issues) == 1
        assert 'INFO' in issues[0]

    def test_hdd_warning_temperature(self, monitor):
        issues = monitor._check_thermal_health('sda', 66, 'HDD')
        assert len(issues) == 1
        assert 'WARNING' in issues[0]

    def test_hdd_critical_temperature(self, monitor):
        issues = monitor._check_thermal_health('sda', 76, 'HDD')
        assert len(issues) == 1
        assert 'CRITICAL' in issues[0]

    def test_ssd_has_higher_warning_threshold(self, monitor):
        # HDD warning=65°C, SSD warning=70°C; at 67°C:
        # HDD → WARNING, SSD → INFO (above optimal_max=65 but below warning=70)
        issues_hdd = monitor._check_thermal_health('sda', 67, 'HDD')
        issues_ssd = monitor._check_thermal_health('sda', 67, 'SSD')
        assert any('WARNING' in i for i in issues_hdd)
        assert not any('WARNING' in i for i in issues_ssd)
        assert any('INFO' in i for i in issues_ssd)

    def test_none_temperature_returns_empty(self, monitor):
        issues = monitor._check_thermal_health('sda', None, 'HDD')
        assert issues == []


# ── _is_excluded_mount ────────────────────────────────────────────────────────

class TestIsExcludedMount:
    def test_exact_excluded_mount(self, monitor):
        assert monitor._is_excluded_mount('/media') is True

    def test_pattern_excluded(self, monitor):
        assert monitor._is_excluded_mount('/media/external') is True

    def test_downloads_excluded(self, monitor):
        assert monitor._is_excluded_mount('/mnt/data/downloads') is True

    def test_normal_mount_not_excluded(self, monitor):
        assert monitor._is_excluded_mount('/') is False
        assert monitor._is_excluded_mount('/var') is False
        assert monitor._is_excluded_mount('/mnt/ceph') is False


# ── _is_new_drive ─────────────────────────────────────────────────────────────

class TestIsNewDrive:
    def test_brand_new_drive(self, monitor):
        assert monitor._is_new_drive(0) is True

    def test_one_hour_drive(self, monitor):
        assert monitor._is_new_drive(1) is True

    def test_under_threshold(self, monitor):
        assert monitor._is_new_drive(719) is True

    def test_at_threshold_is_not_new(self, monitor):
        assert monitor._is_new_drive(720) is False

    def test_old_drive(self, monitor):
        assert monitor._is_new_drive(50000) is False


# ── _is_physical_disk ────────────────────────────────────────────────────────

class TestIsPhysicalDisk:
    def test_real_sata_disk(self, monitor):
        # /dev/sda should pass (no exclusion pattern matches)
        # Note: _is_physical_disk also checks os.path.exists and reads sysfs,
        # but the exclusion logic runs first and can return False early.
        # We test the exclusion cases which are pure.
        assert monitor._is_physical_disk('/dev/mapper/data') is False

    def test_device_mapper_excluded(self, monitor):
        assert monitor._is_physical_disk('/dev/dm-0') is False

    def test_loop_device_excluded(self, monitor):
        assert monitor._is_physical_disk('/dev/loop0') is False

    def test_partition_excluded(self, monitor):
        assert monitor._is_physical_disk('/dev/sda1') is False

    def test_rbd_excluded(self, monitor):
        assert monitor._is_physical_disk('/dev/rbd0') is False


# ── _get_manufacturer_profile ────────────────────────────────────────────────

class TestGetManufacturerProfile:
    def test_seagate_model_matched(self, monitor):
        profile = monitor._get_manufacturer_profile('ST4000DM004')
        assert 'High_Fly_Writes' in profile['attributes']

    def test_seagate_command_timeout_disabled(self, monitor):
        profile = monitor._get_manufacturer_profile('ST4000DM004')
        assert profile['attributes']['Command_Timeout']['monitor'] is False

    def test_wd_model_matched(self, monitor):
        profile = monitor._get_manufacturer_profile('WDC WD40EFRX')
        assert profile['attributes']['Command_Timeout']['monitor'] is False

    def test_samsung_model_matched(self, monitor):
        profile = monitor._get_manufacturer_profile('Samsung SSD 870 EVO')
        assert 'Program_Fail_Cnt_Total' in profile['attributes']
        assert profile['attributes']['Program_Fail_Cnt_Total']['monitor'] is False

    def test_samsung_erase_fail_chip_disabled(self, monitor):
        profile = monitor._get_manufacturer_profile('Samsung SSD 870 EVO')
        assert profile['attributes']['Erase_Fail_Count_Chip']['monitor'] is False

    def test_toshiba_mg08_model_matched_by_prefix(self, monitor):
        # MG08 prefix — model string without "TOSHIBA" word
        profile = monitor._get_manufacturer_profile('MG08ACP16TE')
        assert profile['attributes']['Command_Timeout']['monitor'] is True
        assert profile['attributes']['Command_Timeout']['warning_threshold'] == 1000

    def test_toshiba_command_timeout_raised_threshold(self, monitor):
        profile = monitor._get_manufacturer_profile('TOSHIBA MG06ACA10TE')
        assert profile['attributes']['Command_Timeout']['critical_threshold'] == 5000

    def test_oos_model_matched(self, monitor):
        profile = monitor._get_manufacturer_profile('OOS14000G')
        assert profile['attributes']['Command_Timeout']['monitor'] is False
        assert profile['attributes']['Seek_Error_Rate']['monitor'] is False

    def test_ridata_firmware_match(self, monitor):
        profile = monitor._get_manufacturer_profile('SSD 512GB', firmware='HT3618B7')
        assert profile['attributes']['Erase_Fail_Count_Chip']['monitor'] is False

    def test_unknown_model_returns_generic(self, monitor):
        profile = monitor._get_manufacturer_profile('GENERICDRIVE XYZ')
        assert profile is monitor.MANUFACTURER_SMART_PROFILES['Generic']


# ── _should_monitor_attribute ────────────────────────────────────────────────

class TestShouldMonitorAttribute:
    def test_disabled_attribute_returns_false(self, monitor):
        seagate = monitor._get_manufacturer_profile('ST4000DM004')
        assert monitor._should_monitor_attribute('Command_Timeout', seagate) is False

    def test_enabled_attribute_returns_true(self, monitor):
        seagate = monitor._get_manufacturer_profile('ST4000DM004')
        assert monitor._should_monitor_attribute('High_Fly_Writes', seagate) is True

    def test_unknown_attribute_defaults_to_true(self, monitor):
        seagate = monitor._get_manufacturer_profile('ST4000DM004')
        assert monitor._should_monitor_attribute('Some_Unknown_Attr', seagate) is True

    def test_none_profile_defaults_to_true(self, monitor):
        assert monitor._should_monitor_attribute('Anything', None) is True

    def test_samsung_program_fail_total_disabled(self, monitor):
        samsung = monitor._get_manufacturer_profile('Samsung SSD 870 EVO')
        assert monitor._should_monitor_attribute('Program_Fail_Cnt_Total', samsung) is False


# ── _get_attribute_thresholds ────────────────────────────────────────────────

class TestGetAttributeThresholds:
    def test_seagate_high_fly_writes_thresholds(self, monitor):
        seagate = monitor._get_manufacturer_profile('ST4000DM004')
        t = monitor._get_attribute_thresholds('High_Fly_Writes', seagate)
        assert t['warning'] == 100
        assert t['critical'] == 500

    def test_toshiba_command_timeout_thresholds(self, monitor):
        toshiba = monitor._get_manufacturer_profile('MG08ACP16TE')
        t = monitor._get_attribute_thresholds('Command_Timeout', toshiba)
        assert t['warning'] == 1000
        assert t['critical'] == 5000

    def test_base_threshold_reallocated_sector(self, monitor):
        generic = monitor.MANUFACTURER_SMART_PROFILES['Generic']
        t = monitor._get_attribute_thresholds('Reallocated_Sector_Ct', generic)
        assert t['warning'] == 5
        assert t['critical'] == 10

    def test_base_threshold_high_fly_writes_raised(self, monitor):
        # Default (non-Seagate) High_Fly_Writes threshold is now 100/500
        generic = monitor.MANUFACTURER_SMART_PROFILES['Generic']
        t = monitor._get_attribute_thresholds('High_Fly_Writes', generic)
        assert t['warning'] == 100
        assert t['critical'] == 500

    def test_unknown_attribute_returns_none(self, monitor):
        generic = monitor.MANUFACTURER_SMART_PROFILES['Generic']
        assert monitor._get_attribute_thresholds('Made_Up_Attribute', generic) is None

    def test_behavior_defaults_to_countup(self, monitor):
        generic = monitor.MANUFACTURER_SMART_PROFILES['Generic']
        t = monitor._get_attribute_thresholds('Reallocated_Sector_Ct', generic)
        assert t['behavior'] == 'countup'


# ── _get_issue_type ───────────────────────────────────────────────────────────

class TestGetIssueType:
    def test_smart_issue(self, monitor):
        assert monitor._get_issue_type('SMART attribute warning on /dev/sda') == 'SMART Health Issue'

    def test_drive_issue(self, monitor):
        assert monitor._get_issue_type('Drive /dev/sdb has reallocated sectors') == 'Storage Issue'

    def test_ceph_issue(self, monitor):
        assert monitor._get_issue_type('Ceph cluster is HEALTH_WARN') == 'Ceph Cluster Issue'

    def test_ecc_issue(self, monitor):
        assert monitor._get_issue_type('ECC memory errors detected') == 'Memory Issue'

    def test_cpu_issue(self, monitor):
        assert monitor._get_issue_type('CPU usage at 95%') == 'Performance Issue'

    def test_network_issue(self, monitor):
        assert monitor._get_issue_type('Network interface eth0 down') == 'Network Issue'

    def test_lxc_issue(self, monitor):
        assert monitor._get_issue_type('LXC container storage usage at 90%') == 'Container Storage Issue'

    def test_unknown_defaults_to_hardware(self, monitor):
        assert monitor._get_issue_type('Something completely unknown') == 'Hardware Issue'


# ── _get_impact_level ─────────────────────────────────────────────────────────

class TestGetImpactLevel:
    def test_critical_issue(self, monitor):
        level = monitor._get_impact_level('CRITICAL: drive failure imminent')
        assert '[CRIT]' in level

    def test_unhealthy_is_critical(self, monitor):
        level = monitor._get_impact_level('Ceph is UNHEALTHY')
        assert '[CRIT]' in level

    def test_warning_issue(self, monitor):
        level = monitor._get_impact_level('WARNING: temperature elevated')
        assert '[WARN]' in level

    def test_storage_usage_is_warn_not_crit(self, monitor):
        # "STORAGE USAGE" keyword takes priority over "CRITICAL" substring check
        level = monitor._get_impact_level('CRITICAL storage usage at 95%')
        assert '[WARN]' in level

    def test_cpu_usage_is_warn(self, monitor):
        level = monitor._get_impact_level('CPU usage at 80% threshold exceeded')
        assert '[WARN]' in level

    def test_low_priority(self, monitor):
        level = monitor._get_impact_level('Informational: drive age notification')
        assert '[LOW]' in level

    def test_health_err_is_critical(self, monitor):
        level = monitor._get_impact_level('Ceph status: HEALTH_ERR')
        assert '[CRIT]' in level

    def test_down_is_warning(self, monitor):
        level = monitor._get_impact_level('OSD.3 is DOWN')
        assert '[WARN]' in level


# ── _categorize_issue ─────────────────────────────────────────────────────────

class TestCategorizeIssue:
    def test_smart_critical_is_hardware_issue(self, monitor):
        cat, ttype, _, _ = monitor._categorize_issue('SMART critical error on /dev/sda')
        assert cat == monitor.TICKET_CATEGORIES['HARDWARE']
        assert ttype == monitor.TICKET_TYPES['ISSUE']

    def test_smart_warning_is_hardware_problem(self, monitor):
        cat, ttype, _, _ = monitor._categorize_issue('SMART warning: High_Fly_Writes elevated')
        assert cat == monitor.TICKET_CATEGORIES['HARDWARE']
        assert ttype == monitor.TICKET_TYPES['PROBLEM']

    def test_lxc_critical_is_software_issue(self, monitor):
        cat, ttype, _, _ = monitor._categorize_issue('LXC container storage critical')
        assert cat == monitor.TICKET_CATEGORIES['SOFTWARE']
        assert ttype == monitor.TICKET_TYPES['ISSUE']

    def test_temperature_is_hardware(self, monitor):
        cat, _, _, _ = monitor._categorize_issue('temperature warning on /dev/sdb')
        assert cat == monitor.TICKET_CATEGORIES['HARDWARE']

    def test_nvme_is_hardware(self, monitor):
        cat, _, _, _ = monitor._categorize_issue('NVMe drive warning on /dev/nvme0')
        assert cat == monitor.TICKET_CATEGORIES['HARDWARE']


# ── _check_system_drive_indicators (dmesg scan) ───────────────────────────────

def _dmesg(monitor, lines):
    """Run _check_system_drive_indicators with a faked `dmesg` output."""
    fake = MagicMock(returncode=0, stdout='\n'.join(lines), stderr='')
    with patch('subprocess.run', return_value=fake):
        return monitor._check_system_drive_indicators()


class TestSystemDriveIndicators:
    def test_rbd_buffer_io_errors_are_ignored(self, monitor):
        """Ceph RBD Buffer I/O errors are storage-connectivity, not local hardware —
        they must not raise a CRITICAL drive alert (regression for the false
        '[hardware] CRITICAL: Buffer I/O errors' ticket)."""
        lines = [
            f'[Wed Jul 15 03:2{i}:51 2026] Buffer I/O error on dev rbd2, '
            'logical block 8999, lost sync page write'
            for i in range(75)
        ]
        res = _dmesg(monitor, lines)
        assert res['status'] == 'OK'
        assert res['issues'] == []

    def test_local_disk_buffer_io_errors_still_counted(self, monitor):
        """Genuine local-disk Buffer I/O errors must still be reported."""
        lines = [
            f'[Wed Jul 15 03:30:0{i} 2026] Buffer I/O error on dev sda1, '
            'logical block 42, lost async page write'
            for i in range(5)
        ]
        res = _dmesg(monitor, lines)
        assert res['status'] == 'CRITICAL'
        assert any('Buffer I/O errors' in i and '5 occurrences' in i for i in res['issues'])

    def test_rbd_noise_does_not_inflate_real_errors(self, monitor):
        """RBD errors mixed with real disk errors: only the real ones count."""
        lines = [f'Buffer I/O error on dev rbd4, logical block {i}, lost sync page write'
                 for i in range(75)]
        lines += [
            'Buffer I/O error on dev sda1, logical block 1, lost async page write',
            'Buffer I/O error on dev sda1, logical block 2, lost async page write',
        ]
        res = _dmesg(monitor, lines)
        # 2 real occurrences → WARNING (>=2), not CRITICAL (>=5)
        assert res['status'] == 'WARNING'
        assert any('Buffer I/O errors' in i and '2 occurrences' in i for i in res['issues'])

    def test_device_mapper_and_loop_ignored(self, monitor):
        """Device-mapper and loop devices are also non-physical and ignored."""
        lines = [
            'Buffer I/O error on dev dm-3, logical block 5, lost sync page write',
            'Buffer I/O error on dev loop0, logical block 6, lost sync page write',
        ]
        res = _dmesg(monitor, lines)
        assert res['status'] == 'OK'
        assert res['issues'] == []


# ── _get_attribute_thresholds (drive age is not ticketed) ─────────────────────

class TestAttributeThresholds:
    def test_power_on_hours_has_no_threshold(self, monitor):
        """Drive age must not raise a ticket: we run to hard-failure (Ceph redundancy +
        PBS backups), so Power_On_Hours has no warning/critical threshold. Regression for
        the '[hardware] Drive ... has SMART issues: Warning Power_On_Hours' age tickets."""
        assert monitor._get_attribute_thresholds('Power_On_Hours', {}) is None

    def test_real_failure_predictors_still_alert(self, monitor):
        """Genuine failure-predictor attributes must keep their thresholds."""
        for attr in ('Reallocated_Sector_Ct', 'Current_Pending_Sector',
                     'Offline_Uncorrectable', 'Reported_Uncorrect'):
            th = monitor._get_attribute_thresholds(attr, {})
            assert th is not None and 'warning' in th and 'critical' in th

    def test_power_on_hours_still_recorded_for_new_drive_logic(self, monitor):
        """Age is still *tracked* (just not ticketed) — new-drive detection must work."""
        assert monitor._is_new_drive(100) is True      # ~4 days
        assert monitor._is_new_drive(64860) is False   # ~7.4 years


# ── _format_lxc_dry_run (LXC storage shown in --dry-run summary; issue #23) ────

class TestLxcDryRunSummary:
    def test_includes_container_usage_and_flags_over_threshold(self, monitor):
        """Regression for issue #23: dry-run summary must surface LXC storage."""
        lxc = {
            'status': 'WARNING',
            'issues': ['LXC 105 high storage usage: 84.0% on /'],
            'containers': [
                {'vmid': '105', 'filesystems': [{'mountpoint': '/', 'usage_percent': 84.0}]},
            ],
        }
        text = '\n'.join(monitor._format_lxc_dry_run(lxc))
        assert 'LXC Storage:' in text
        assert 'CT105 /' in text and '84.0% used' in text
        assert '⚠️' in text               # flagged: over the 80% warning threshold
        assert 'Issues: 1 found' in text

    def test_healthy_container_not_flagged(self, monitor):
        lxc = {'status': 'OK', 'issues': [],
               'containers': [{'vmid': '119', 'filesystems': [{'mountpoint': '/', 'usage_percent': 26.0}]}]}
        text = '\n'.join(monitor._format_lxc_dry_run(lxc))
        assert 'CT119 /' in text and '26.0% used' in text
        assert '⚠️' not in text

    def test_empty_when_no_containers(self, monitor):
        assert monitor._format_lxc_dry_run({'status': 'OK', 'containers': [], 'issues': []}) == []

    def test_error_status_is_reported(self, monitor):
        lines = monitor._format_lxc_dry_run({'status': 'ERROR', 'containers': [], 'issues': ['boom']})
        assert any('check error' in ln for ln in lines)


# ── _check_cpu_usage (ticket on sustained load, not transient spikes) ──────────

def _cpu(monitor, instantaneous, load15, cpu_count=4):
    """Run _check_cpu_usage with mocked psutil + load average."""
    with patch('psutil.cpu_percent', return_value=instantaneous), \
         patch('psutil.cpu_count', return_value=cpu_count), \
         patch('os.getloadavg', return_value=(load15, load15, load15)):
        return monitor._check_cpu_usage()


def _report_with_cpu(cpu_health):
    """Minimal health_report skeleton (all sections empty) with cpu_health overridden,
    sufficient for _detect_issues which direct-indexes several sections for logging."""
    return {
        'drives_health': {'drives': [], 'overall_status': 'HEALTHY'},
        'memory_health': {'status': 'OK'},
        'cpu_health': cpu_health,
        'network_health': {'management_network': {}, 'ceph_network': {}},
        'ceph_health': {},
        'lxc_health': {'status': 'OK', 'issues': []},
        'system_health': {'status': 'OK', 'issues': []},
        'pbs_health': {},
    }


class TestCpuSustainedGating:
    def test_transient_spike_does_not_warn(self, monitor):
        """Instantaneous 100% but low 15-min load (e.g. 0.4/core = 10%) -> OK, no ticket."""
        h = _cpu(monitor, instantaneous=100.0, load15=1.6, cpu_count=4)   # 1.6/4 = 40%/core
        assert h['status'] == 'OK'
        assert h['sustained_high'] is False
        assert h['cpu_usage_percent'] == 100.0          # still reported for context
        assert h['load15_per_core_percent'] == 40.0

    def test_sustained_high_load_warns(self, monitor):
        """15-min load 3.9/4 cores = 97.5%/core >= 95% threshold -> WARNING."""
        h = _cpu(monitor, instantaneous=20.0, load15=3.9, cpu_count=4)
        assert h['status'] == 'WARNING'
        assert h['sustained_high'] is True
        assert h['load15_per_core_percent'] == 97.5

    def test_detect_issues_ignores_transient_spike(self, monitor):
        """A high instantaneous sample with sustained_high False must not create a CPU issue."""
        report = _report_with_cpu({'cpu_usage_percent': 99.0, 'sustained_high': False,
                                   'load15_per_core_percent': 30.0, 'status': 'OK'})
        issues = monitor._detect_issues(report)
        assert not any('CPU' in i for i in issues)

    def test_detect_issues_flags_sustained(self, monitor):
        """sustained_high True must create exactly one stable, value-free CPU issue."""
        report = _report_with_cpu({'cpu_usage_percent': 96.0, 'sustained_high': True,
                                   'load15_per_core_percent': 98.0, 'status': 'WARNING'})
        issues = monitor._detect_issues(report)
        cpu_issues = [i for i in issues if 'CPU' in i]
        assert len(cpu_issues) == 1
        # Title-stable: no measured value baked into the message (only the threshold constant)
        assert '98' not in cpu_issues[0]
        assert 'sustained' in cpu_issues[0].lower()

    def test_falls_back_to_instantaneous_without_loadavg(self, monitor):
        """If os.getloadavg is unavailable, don't go silent — use the instantaneous sample."""
        with patch('psutil.cpu_percent', return_value=97.0), \
             patch('psutil.cpu_count', return_value=4), \
             patch('os.getloadavg', side_effect=OSError):
            h = monitor._check_cpu_usage()
        assert h['status'] == 'WARNING'
        assert h['load15_per_core_percent'] is None