param(
    [Parameter(Mandatory=$true)][string]$Executable,
    [Parameter(Mandatory=$true)][string]$OutputPath
)
$ErrorActionPreference = 'Stop'
if (Test-Path $OutputPath) { throw 'Do not overwrite earlier gate evidence.' }
$exe = (Resolve-Path $Executable).Path
$session = [Diagnostics.Process]::GetCurrentProcess().SessionId
if ($session -eq 0) { throw 'Run in the interactive WeChat session, not Session 0.' }
$lockPath = Join-Path ([Environment]::GetFolderPath('LocalApplicationData')) "WxAgent\ui-session-$session.lock"
$before = & $exe recover-ui --timeout 30
$beforeCode = $LASTEXITCODE
if ($beforeCode -ne 0) { throw 'Baseline recovery failed; a contention test would not be meaningful.' }
$lease = [IO.File]::Open($lockPath, [IO.FileMode]::OpenOrCreate, [IO.FileAccess]::ReadWrite, [IO.FileShare]::None)
try {
    $blocked = & $exe recover-ui --timeout 3
    $blockedCode = $LASTEXITCODE
    $errorCode = (($blocked -join [Environment]::NewLine) | ConvertFrom-Json).error
    # The legacy listener must honor its own duration while another process holds the gate.
    $listenOutput = @(& $exe chat listen --seconds 1 --timeout 10)
    $listenCode = $LASTEXITCODE
    $listenResult = ($listenOutput -join [Environment]::NewLine) | ConvertFrom-Json
    $messageCount = @($listenResult.messages).Count
} finally { $lease.Dispose() }
$after = & $exe recover-ui --timeout 30
$afterCode = $LASTEXITCODE
$result = @{
    SessionId=$session
    BaselineExit=$beforeCode
    ContendedExit=$blockedCode
    ContendedError=$errorCode
    ListenerExit=$listenCode
    UnexpectedListenerMessageCount=$messageCount
    RecoveryAfterReleaseExit=$afterCode
    Passed=($beforeCode -eq 0 -and $blockedCode -eq 124 -and $errorCode -eq 'Timeout' -and
        $listenCode -eq 0 -and $messageCount -eq 0 -and $afterCode -eq 0)
}
[IO.File]::WriteAllText([IO.Path]::GetFullPath($OutputPath), ($result | ConvertTo-Json), (New-Object Text.UTF8Encoding($false)))
if (!$result.Passed) { exit 2 }
exit 0