from __future__ import annotations

import json
import shutil
import subprocess
from copy import deepcopy
from pathlib import Path
from typing import Any

import pytest


ROOT = Path(__file__).resolve().parents[3]
PREFLIGHT = ROOT / "scripts/reboot-recovery/agent99-live-preflight.ps1"


def _function_source() -> str:
    source = PREFLIGHT.read_text(encoding="utf-8")
    start = source.index("function Get-AgentLivePreflightDecision")
    end = source.index("function Get-TaskReadback", start)
    return source[start:end]


def _base_case() -> dict[str, Any]:
    return {
        "agentRootPresent": True,
        "manifest": {
            "exists": True,
            "sourceRevision": "a" * 40,
            "runtimeMatched": True,
            "fileCount": 14,
            "mismatchCount": 0,
            "parseError": "",
        },
        "taskFailureCount": 0,
        "relayListenerCount": 1,
        "requiredEvidenceStaleCount": 0,
        "requiredEvidenceParseFailureCount": 0,
        "requiredEvidenceContentFailureCount": 0,
        "selfHealthSeverity": "ok",
        "selfHealthPerformanceIssueCount": 0,
        "staleAlertExecutionCount": 0,
        "alertIncomingCount": 0,
        "staleAlertIncomingCount": 0,
        "pendingCommandCount": 0,
    }


def _with_overrides(**overrides: Any) -> dict[str, Any]:
    case = deepcopy(_base_case())
    manifest_overrides = overrides.pop("manifest", None)
    case.update(overrides)
    if manifest_overrides:
        case["manifest"].update(manifest_overrides)
    return case


def _as_list(value: Any) -> list[str]:
    if value is None:
        return []
    if isinstance(value, list):
        return [str(item) for item in value]
    return [str(value)]


def _run_decision(powershell: str, case: dict[str, Any]) -> dict[str, Any]:
    fixture = json.dumps(case, separators=(",", ":"))
    command = f"""
{_function_source()}
$case = @'
{fixture}
'@ | ConvertFrom-Json
$parameters = @{{
  AgentRootPresent = [bool]$case.agentRootPresent
  Manifest = $case.manifest
  ExpectedRuntimeFileCount = 14
  TaskFailureCount = [int]$case.taskFailureCount
  RelayListenerCount = [int]$case.relayListenerCount
  RequiredEvidenceStaleCount = [int]$case.requiredEvidenceStaleCount
  RequiredEvidenceParseFailureCount = [int]$case.requiredEvidenceParseFailureCount
  RequiredEvidenceContentFailureCount = [int]$case.requiredEvidenceContentFailureCount
  SelfHealthSeverity = [string]$case.selfHealthSeverity
  SelfHealthPerformanceIssueCount = [int]$case.selfHealthPerformanceIssueCount
  StaleAlertExecutionCount = [int]$case.staleAlertExecutionCount
  AlertIncomingCount = [int]$case.alertIncomingCount
  StaleAlertIncomingCount = [int]$case.staleAlertIncomingCount
  PendingCommandCount = [int]$case.pendingCommandCount
}}
Get-AgentLivePreflightDecision @parameters |
  ConvertTo-Json -Depth 6 -Compress
"""
    result = subprocess.run(
        [powershell, "-NoProfile", "-NonInteractive", "-Command", command],
        check=False,
        capture_output=True,
        text=True,
    )
    assert result.returncode == 0, result.stdout + result.stderr
    payload = next(
        line for line in reversed(result.stdout.splitlines()) if line.startswith("{")
    )
    return json.loads(payload)


def test_warning_receipt_is_visible_without_weakening_integrity_blockers() -> None:
    source = PREFLIGHT.read_text(encoding="utf-8")
    decision = _function_source()

    assert '$warningReasons += "self_health_warning"' in decision
    assert '$warningReasons += "performance_warning"' in decision
    assert '$warningReasons += "fresh_alert_pending_next_inbox_tick"' in decision
    assert '"critical" { $blockingReasons += "self_health_not_ok" }' in decision
    assert 'default { $blockingReasons += "self_health_unclassified" }' in decision
    assert '$blockingReasons += "runtime_manifest_identity_invalid"' in decision
    assert '$blockingReasons += "runtime_manifest_mismatch"' in decision
    assert '$blockingReasons += "scheduled_task_unhealthy"' in decision
    assert '$blockingReasons += "sre_alert_relay_not_listening"' in decision
    assert "deploymentEligible = [bool]($blockingReasons.Count -eq 0)" in decision
    assert "preflightGreen = [bool]$decision.deploymentEligible" in source
    assert "warningReasons = $warningReasons" in source
    assert "selfHealthPerformanceIssues = @(" in source
    assert 'if ($safeHost -notmatch "^[A-Za-z0-9.:-]{1,128}$")' in source
    assert 'if ($reason -match "^[a-z0-9_]{1,80}$")' in source
    assert (
        "[int]$selfCheckEvidence.safeSummary.selfHealthPerformanceIssueCount"
        in source
    )
    assert 'if ($result.summary.deploymentEligible)' in source
    assert 'if ($selfHealthSeverity -ne "ok")' not in source


def test_decision_behavior_when_powershell_is_available() -> None:
    powershell = shutil.which("pwsh") or shutil.which("powershell")
    if powershell is None:
        pytest.skip("PowerShell runtime is not installed on this macOS verifier")

    cases = (
        (_base_case(), True, (), ()),
        (
            _with_overrides(
                selfHealthSeverity="warning",
                selfHealthPerformanceIssueCount=1,
            ),
            True,
            (),
            ("self_health_warning", "performance_warning"),
        ),
        (
            _with_overrides(selfHealthSeverity="critical"),
            False,
            ("self_health_not_ok",),
            (),
        ),
        (
            _with_overrides(taskFailureCount=1),
            False,
            ("scheduled_task_unhealthy",),
            (),
        ),
        (
            _with_overrides(manifest={"runtimeMatched": False, "mismatchCount": 1}),
            False,
            ("runtime_manifest_mismatch",),
            (),
        ),
        (
            _with_overrides(manifest={"sourceRevision": "not-a-full-sha"}),
            False,
            ("runtime_manifest_identity_invalid",),
            (),
        ),
        (
            _with_overrides(relayListenerCount=0),
            False,
            ("sre_alert_relay_not_listening",),
            (),
        ),
        (
            _with_overrides(alertIncomingCount=1),
            True,
            (),
            ("fresh_alert_pending_next_inbox_tick",),
        ),
        (
            _with_overrides(
                alertIncomingCount=1,
                staleAlertIncomingCount=1,
            ),
            False,
            ("pending_work_before_reboot",),
            (),
        ),
        (
            _with_overrides(pendingCommandCount=1),
            False,
            ("pending_work_before_reboot",),
            (),
        ),
    )

    for case, expected_eligible, expected_blockers, expected_warnings in cases:
        result = _run_decision(powershell, case)
        assert result["deploymentEligible"] is expected_eligible
        assert set(_as_list(result.get("blockingReasons"))) == set(expected_blockers)
        assert set(_as_list(result.get("warningReasons"))) == set(expected_warnings)

    preflight_path = str(PREFLIGHT).replace("'", "''")
    parser_command = (
        "$tokens=$null; $errors=$null; "
        "[System.Management.Automation.Language.Parser]::ParseFile("
        f"'{preflight_path}', [ref]$tokens, [ref]$errors) | Out-Null; "
        "if ($errors.Count -gt 0) { "
        "$errors | ForEach-Object { $_.Message }; exit 1 }"
    )
    parsed = subprocess.run(
        [
            powershell,
            "-NoProfile",
            "-NonInteractive",
            "-Command",
            parser_command,
        ],
        check=False,
        capture_output=True,
        text=True,
    )
    assert parsed.returncode == 0, parsed.stdout + parsed.stderr