[CmdletBinding()]
param(
    [ValidateRange(60, 900)][int]$TimeoutSeconds = 900
)

# Run the owner-asset adapter and Core parity gate in the isolated BuildHost only.
Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

$PluginRoot = [IO.Path]::GetFullPath((Join-Path $PSScriptRoot '..'))
$HostRoot = Join-Path $PluginRoot 'Saved\BuildHost\HostProject'
$HostProject = Join-Path $HostRoot 'HostProject.uproject'
$StagePlugin = Join-Path $HostRoot 'Plugins\VoxelForge'
$OwnerAssetRoot = Join-Path ([IO.Path]::GetFullPath((Join-Path $PluginRoot '..\..'))) 'Content\VoxelForge'
$OutputRoot = Join-Path $StagePlugin 'Saved\CoreAdapterValidation'
$OutputDirectory = Join-Path $OutputRoot 'Output'
$LogDirectory = Join-Path $OutputRoot 'Logs'
$LocalAppData = Join-Path $OutputRoot 'LocalAppData'
$UserDirectory = Join-Path $OutputRoot 'User'
$DerivedDataCache = Join-Path $PluginRoot 'Saved\BuildHost\VFCoreAdapterDDC'
$ZenData = Join-Path $OutputRoot 'ZenData'
$EditorCmd = 'E:\Program Files\Epic Games\UE_5.7\Engine\Binaries\Win64\UnrealEditor-Cmd.exe'
$LogPath = Join-Path $LogDirectory 'CoreAdapterValidation.log'
$StdoutPath = Join-Path $LogDirectory 'CoreAdapterValidation.stdout.log'
$StderrPath = Join-Path $LogDirectory 'CoreAdapterValidation.stderr.log'
$WorldJson = Join-Path $OutputDirectory 'owner_world.json'
$MemoryLimitBytes = 8GB

function Assert-UnderPath([string]$Candidate, [string]$Root) {
    $candidateFull = [IO.Path]::GetFullPath($Candidate).TrimEnd('\', '/')
    $rootFull = [IO.Path]::GetFullPath($Root).TrimEnd('\', '/')
    if (-not ($candidateFull.Equals($rootFull, [StringComparison]::OrdinalIgnoreCase) -or
        $candidateFull.StartsWith($rootFull + '\', [StringComparison]::OrdinalIgnoreCase))) {
        throw "Refusing a commandlet path outside BuildHost: $candidateFull"
    }
}

Assert-UnderPath $HostRoot (Join-Path $PluginRoot 'Saved\BuildHost')
Assert-UnderPath $OutputRoot (Join-Path $PluginRoot 'Saved\BuildHost')
foreach ($required in @($HostProject, $EditorCmd)) {
    if (-not (Test-Path -LiteralPath $required -PathType Leaf)) {
        throw "Required BuildHost commandlet input is missing: $required"
    }
}

$foreignEditors = @(Get-Process -ErrorAction SilentlyContinue |
    Where-Object { $_.ProcessName -like 'UnrealEditor*' })
if ($foreignEditors.Count -gt 0) {
    $ids = ($foreignEditors | ForEach-Object { "$($_.ProcessName):$($_.Id)" }) -join ', '
    throw "An UnrealEditor process is already running; leaving it untouched: $ids"
}

foreach ($assetName in @('DA_Settings', 'DA_Strate1', 'DA_Strate2', 'DA_Strate3', 'DA_Strate4')) {
    $ownerAsset = Join-Path $OwnerAssetRoot "$assetName.uasset"
    $stagedAsset = Join-Path $HostRoot "Content\VoxelForge\$assetName.uasset"
    if (-not (Test-Path -LiteralPath $ownerAsset -PathType Leaf) -or
        -not (Test-Path -LiteralPath $stagedAsset -PathType Leaf)) {
        throw "Owner or BuildHost asset is missing: $assetName"
    }
    if ((Get-FileHash -LiteralPath $ownerAsset -Algorithm SHA256).Hash -ne
        (Get-FileHash -LiteralPath $stagedAsset -Algorithm SHA256).Hash) {
        throw "BuildHost asset copy differs from the owner asset: $assetName"
    }
}

foreach ($directory in @($OutputDirectory, $LogDirectory, $LocalAppData,
    $UserDirectory, $DerivedDataCache, $ZenData)) {
    [IO.Directory]::CreateDirectory($directory) | Out-Null
}

$CrashRoots = @((Join-Path $HostRoot 'Saved\Crashes'), (Join-Path $StagePlugin 'Saved\Crashes'))
$CrashBefore = @{}
foreach ($CrashRoot in $CrashRoots) {
    if (Test-Path -LiteralPath $CrashRoot -PathType Container) {
        foreach ($Crash in @(Get-ChildItem -LiteralPath $CrashRoot -Directory -Filter 'UECC-*' -Recurse -Force)) {
            $CrashBefore[$Crash.FullName.ToLowerInvariant()] = $Crash.LastWriteTimeUtc.Ticks
        }
    }
}

function Get-NewCrashFolders {
    $Found = [Collections.Generic.List[string]]::new()
    foreach ($CrashRoot in $CrashRoots) {
        if (Test-Path -LiteralPath $CrashRoot -PathType Container) {
            foreach ($Crash in @(Get-ChildItem -LiteralPath $CrashRoot -Directory -Filter 'UECC-*' -Recurse -Force)) {
                if (-not $CrashBefore.ContainsKey($Crash.FullName.ToLowerInvariant())) {
                    [void]$Found.Add($Crash.FullName)
                }
            }
        }
    }
    return @($Found.ToArray())
}

$Arguments = @(
    ('-project="{0}"' -f $HostProject),
    '-nullrhi', '-unattended', '-nop4', '-nosplash', '-NoSound',
    '-stdout', '-FullStdOutLogOutput', '-forcelogflush', '-NoZenAutoLaunch',
    '-notraceserver', '-nocrashreports', '-ddc=NoZenLocalFallback',
    ('-userdir="{0}"' -f $UserDirectory),
    ('-ZenDataPath="{0}"' -f $ZenData),
    ('-LocalDataCachePath="{0}"' -f $DerivedDataCache),
    '-run=VoxelForgeExplore', '-seed=0', '-archetype=TunnelNetwork', '-slot=0',
    '-modes=export', '-blockearlyout=0', '-gameconfig=1', '-standaloneworldexport=1',
    '-settingsref=/Game/VoxelForge/DA_Settings.DA_Settings',
    ('-out="{0}"' -f $OutputDirectory)
)

$OldLocalAppData = $env:LOCALAPPDATA
$env:LOCALAPPDATA = $LocalAppData
try {
    $PeakPrivateBytes = [int64]0
    $Succeeded = $false
    for ($Attempt = 1; $Attempt -le 2 -and -not $Succeeded; ++$Attempt) {
        $AttemptLogPath = if ($Attempt -eq 1) { $LogPath } else {
            Join-Path $LogDirectory 'CoreAdapterValidation.retry.log'
        }
        $AttemptStdoutPath = if ($Attempt -eq 1) { $StdoutPath } else {
            Join-Path $LogDirectory 'CoreAdapterValidation.retry.stdout.log'
        }
        $AttemptStderrPath = if ($Attempt -eq 1) { $StderrPath } else {
            Join-Path $LogDirectory 'CoreAdapterValidation.retry.stderr.log'
        }
        $AttemptArguments = @($Arguments) + ('-abslog="{0}"' -f $AttemptLogPath)
        Write-Host "BuildHost adapter commandlet attempt $Attempt of 2; normal priority."
        $Process = Start-Process -FilePath $EditorCmd -ArgumentList $AttemptArguments -WorkingDirectory $HostRoot `
            -RedirectStandardOutput $AttemptStdoutPath -RedirectStandardError $AttemptStderrPath `
            -WindowStyle Hidden -PassThru
        $Process.PriorityClass = [Diagnostics.ProcessPriorityClass]::Normal
        $StartedUtc = [datetime]::UtcNow
        while (-not $Process.HasExited) {
            Start-Sleep -Seconds 2
            $Process.Refresh()
            if (-not $Process.HasExited) {
                $PeakPrivateBytes = [Math]::Max($PeakPrivateBytes, [int64]$Process.PrivateMemorySize64)
            }
            if (([datetime]::UtcNow - $StartedUtc).TotalSeconds -gt $TimeoutSeconds) {
                Stop-Process -Id $Process.Id -Force -ErrorAction SilentlyContinue
                throw "BuildHost adapter commandlet exceeded the $TimeoutSeconds-second time box."
            }
            if (-not $Process.HasExited -and $Process.PrivateMemorySize64 -gt $MemoryLimitBytes) {
                Stop-Process -Id $Process.Id -Force -ErrorAction SilentlyContinue
                throw 'BuildHost adapter commandlet exceeded the 8 GiB private-memory limit.'
            }
        }
        $Process.WaitForExit()
        $Process.Refresh()
        $ProcessExitCode = $Process.ExitCode
        if ([string]::IsNullOrEmpty([string]$ProcessExitCode) -and (Test-Path -LiteralPath $AttemptLogPath -PathType Leaf)) {
            $CompletedLog = Get-Content -LiteralPath $AttemptLogPath -Raw
            if ((($CompletedLog -match 'Commandlet->Main return this error code: 0') -or
                ($CompletedLog -match 'Commandlet VoxelForgeExploreCommandlet_\d+ finished execution \(result 0\)')) -and
                ($CompletedLog -match '\[VoxelForgeCoreAdapter\] pass schema=1')) {
                # Unreal returned its commandlet result through the log, but Start-Process did not
                # retain an ExitCode value for this editor process handle.
                $ProcessExitCode = 0
            }
        }
        if ($ProcessExitCode -eq -1073741502 -and $Attempt -eq 1) {
            Write-Warning 'BuildHost adapter commandlet exited with 0xC0000142; retrying once.'
            continue
        }
        if ($ProcessExitCode -ne 0) {
            $FailedRunCrashes = @(Get-NewCrashFolders)
            $CrashDetail = if ($FailedRunCrashes.Count -gt 0) {
                " New UECC folders: $($FailedRunCrashes -join '; ')."
            } else { '' }
            throw "BuildHost adapter commandlet attempt $Attempt failed with exit code '$ProcessExitCode'.$CrashDetail See $AttemptLogPath."
        }
        $LogPath = $AttemptLogPath
        $Succeeded = $true
    }
    if (-not $Succeeded) {
        throw 'BuildHost adapter commandlet did not complete successfully.'
    }
} finally {
    if ($null -eq $OldLocalAppData) {
        Remove-Item Env:LOCALAPPDATA -ErrorAction SilentlyContinue
    } else {
        $env:LOCALAPPDATA = $OldLocalAppData
    }
}

if (-not (Test-Path -LiteralPath $WorldJson -PathType Leaf)) {
    throw "The adapter commandlet did not write $WorldJson."
}
$BuildLogText = Get-Content -LiteralPath $LogPath -Raw
foreach ($WorkerCount in @(1, 8, 16)) {
    $ExpectedAdapterPass = "\[VoxelForgeCoreAdapter\] pass schema=1 workers=$WorkerCount asset_clip_radius=\d+ asset_max_level=\d+ reference_clip_radius=3 reference_max_level=8 tiles=2226 density=0xdb2991c73215af4c mesh=0x8236c5edd7fc8e4f payload=0x4c48fa75a543d58e topology=0xbea22e76b34a4dfc walk=5642/5642"
    if ($BuildLogText -notmatch $ExpectedAdapterPass) {
        throw "The BuildHost log is missing the exact Core adapter parity result for workers=$WorkerCount. See $LogPath."
    }
}

$NewCrashes = @(Get-NewCrashFolders)
if ($NewCrashes.Count -gt 0) {
    throw "New UECC crash folders appeared during adapter validation: $($NewCrashes -join '; ')"
}

Write-Host 'VOXELFORGE_CORE_ADAPTER_PASS tiles=2226 walkability=5642/5642'
Write-Host "Core adapter log: $LogPath"
Write-Host "Schema-v1 JSON: $WorldJson"
Write-Host "Peak commandlet private bytes sampled: $PeakPrivateBytes"