[CmdletBinding()]
param(
    [Parameter(Mandatory = $true)][string]$ArchivePath,
    [Parameter(Mandatory = $true)][string]$ProjectPath,
    [Parameter(Mandatory = $true)][string]$InvocationId,
    [Parameter(Mandatory = $true)]
    [ValidatePattern('^[0-9A-Fa-f]{64}$')]
    [string]$ExpectedArchiveSha256,
    [Parameter(Mandatory = $true)][string]$ProductionSiteName,
    [Parameter(Mandatory = $true)][string]$ProductionPoolName,
    [Parameter(Mandatory = $true)][int]$ProductionPort,
    [Parameter(Mandatory = $true)][string]$ProductionBaseUrl,
    [Parameter(Mandatory = $true)][string]$TestSiteName,
    [Parameter(Mandatory = $true)][string]$TestPoolName,
    [Parameter(Mandatory = $true)][int]$TestPort,
    [Parameter(Mandatory = $true)][string]$TestBaseUrl,
    [switch]$RunTests
)

$ErrorActionPreference = 'Stop'
Set-StrictMode -Version 2.0

function Quote-PowerShellLiteral {
    param([Parameter(Mandatory = $true)][string]$Value)
    return "'" + $Value.Replace("'", "''") + "'"
}

function Invoke-WindowsPowerShell {
    param([Parameter(Mandatory = $true)][string]$Command)
    $encoded = [Convert]::ToBase64String([Text.Encoding]::Unicode.GetBytes($Command))
    $process = Start-Process -FilePath 'powershell.exe' -ArgumentList @(
        '-NoProfile', '-NonInteractive', '-ExecutionPolicy', 'Bypass', '-EncodedCommand', $encoded
    ) -Wait -PassThru -NoNewWindow
    return $process.ExitCode
}

function Assert-Administrator {
    $identity = [Security.Principal.WindowsIdentity]::GetCurrent()
    $principal = New-Object Security.Principal.WindowsPrincipal($identity)
    if (-not $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
        throw 'Remote installation requires an elevated Windows account.'
    }
}

function Get-SiteSnapshot {
    param([string]$Name)
    if (-not (Test-Path "IIS:\Sites\$Name")) { return $null }
    $site = Get-Website -Name $Name
    $parentPaths = (Get-WebConfigurationProperty -PSPath 'MACHINE/WEBROOT/APPHOST' -Location $Name -Filter 'system.webServer/asp' -Name 'enableParentPaths').Value
    return [PSCustomObject]@{
        Name = $Name
        State = [string]$site.State
        PhysicalPath = [string]$site.PhysicalPath
        ApplicationPool = [string]$site.ApplicationPool
        EnableParentPaths = [bool]$parentPaths
    }
}

function Assert-SiteTarget {
    param(
        [string]$Name,
        [string]$PoolName,
        [string]$PhysicalPath,
        [int]$Port
    )

    $snapshot = Get-SiteSnapshot -Name $Name
    if ($snapshot) {
        if ([IO.Path]::GetFullPath($snapshot.PhysicalPath).TrimEnd('\') -ne [IO.Path]::GetFullPath($PhysicalPath).TrimEnd('\')) {
            throw "Existing site '$Name' has physical path '$($snapshot.PhysicalPath)', expected '$PhysicalPath'. Refusing to adopt or rewrite it."
        }
        if ($snapshot.ApplicationPool -ne $PoolName) {
            throw "Existing site '$Name' uses app pool '$($snapshot.ApplicationPool)', expected '$PoolName'. Refusing to adopt it."
        }
        $httpBinding = @(Get-WebBinding -Name $Name -Protocol http | Where-Object { $_.bindingInformation -match ":$Port`:" })
        if ($httpBinding.Count -ne 1) {
            throw "Existing site '$Name' must have exactly one HTTP binding on port $Port."
        }
    }

    $conflictingSiteNames = @()
    foreach ($otherSite in @(Get-Website | Where-Object { $_.Name -ne $Name })) {
        $matchingBindings = @(Get-WebBinding -Name $otherSite.Name -Protocol http | Where-Object { $_.bindingInformation -match ":$Port`:" })
        if ($matchingBindings.Count -gt 0) { $conflictingSiteNames += $otherSite.Name }
    }
    if ($conflictingSiteNames.Count -gt 0) {
        throw "HTTP port $Port is already used by unrelated site(s): $($conflictingSiteNames -join ', ')."
    }
}

function Assert-PoolTarget {
    param([string]$PoolName, [string]$AllowedSiteName)
    if (-not (Test-Path "IIS:\AppPools\$PoolName")) { return }
    $otherUsers = @(Get-Website | Where-Object { $_.ApplicationPool -eq $PoolName -and $_.Name -ne $AllowedSiteName })
    if ($otherUsers.Count -gt 0) {
        throw "App pool '$PoolName' is used by unrelated site(s): $($otherUsers.Name -join ', ')."
    }
}

function Get-ComponentRegistrationMode {
    param(
        [Parameter(Mandatory = $true)][string]$ExistingProjectPath,
        [Parameter(Mandatory = $true)][object[]]$Components
    )

    $absentCount = 0
    $ownedCount = 0
    foreach ($component in $Components) {
        $progIdKey = "HKLM:\SOFTWARE\Classes\$($component.ProgId)"
        $clsidKey = "HKLM:\SOFTWARE\Classes\CLSID\$($component.ClassId)"
        $progIdExists = Test-Path -LiteralPath $progIdKey
        $clsidExists = Test-Path -LiteralPath $clsidKey

        if (-not $progIdExists -and -not $clsidExists) {
            $absentCount++
            continue
        }
        if (-not $progIdExists -or -not $clsidExists) {
            throw "Component registration is partial for '$($component.ProgId)'. Refusing to overwrite or repair registry state that this invocation does not own."
        }

        $registeredClassId = (Get-ItemProperty -LiteralPath (Join-Path $progIdKey 'CLSID')).'(default)'
        if ($registeredClassId -ne $component.ClassId) {
            throw "ProgID '$($component.ProgId)' maps to '$registeredClassId', not this project's CLSID '$($component.ClassId)'."
        }

        $scriptletKey = Join-Path $clsidKey 'ScriptletURL'
        if (-not (Test-Path -LiteralPath $scriptletKey)) {
            throw "CLSID '$($component.ClassId)' has no ScriptletURL. Refusing to overwrite it."
        }
        $registeredPath = [string](Get-ItemProperty -LiteralPath $scriptletKey).'(default)'
        $expectedPath = [IO.Path]::GetFullPath((Join-Path $ExistingProjectPath $component.RelativePath))
        $registeredFilePath = $null
        if (-not [string]::IsNullOrWhiteSpace($registeredPath)) {
            $registeredUri = $null
            if ([Uri]::TryCreate($registeredPath, [UriKind]::Absolute, [ref]$registeredUri) -and $registeredUri.IsFile) {
                $registeredFilePath = [IO.Path]::GetFullPath($registeredUri.LocalPath)
            } elseif ([IO.Path]::IsPathRooted($registeredPath)) {
                $registeredFilePath = [IO.Path]::GetFullPath($registeredPath)
            }
        }
        if (-not $registeredFilePath -or $registeredFilePath.TrimEnd('\') -ne $expectedPath.TrimEnd('\')) {
            throw "CLSID '$($component.ClassId)' is registered from '$registeredPath', not the existing deployment path '$expectedPath'."
        }
        $ownedCount++
    }

    if ($absentCount -eq $Components.Count) { return 'Absent' }
    if ($ownedCount -eq $Components.Count) { return 'Owned' }
    throw 'Component registrations are a mixture of absent and existing entries. Refusing a deployment that could overwrite or delete unrelated registry state.'
}

function Restore-SiteState {
    param($Snapshot)
    if (-not $Snapshot -or -not (Test-Path "IIS:\Sites\$($Snapshot.Name)")) { return }
    $parentPathsValue = if ($Snapshot.EnableParentPaths) { 'True' } else { 'False' }
    $appcmd = "$env:windir\system32\inetsrv\appcmd.exe"
    & $appcmd set config $Snapshot.Name -section:system.webServer/asp "/enableParentPaths:$parentPathsValue" /commit:apphost | Out-Null
    if ($LASTEXITCODE -ne 0) { throw "Unable to restore enableParentPaths for site '$($Snapshot.Name)'." }
    if ($Snapshot.State -eq 'Started') {
        Start-Website -Name $Snapshot.Name -ErrorAction SilentlyContinue
    } else {
        Stop-Website -Name $Snapshot.Name -ErrorAction SilentlyContinue
    }
}

function Wait-WebAppPoolState {
    param(
        [Parameter(Mandatory = $true)][string]$Name,
        [Parameter(Mandatory = $true)][string]$DesiredState,
        [int]$TimeoutSeconds = 30
    )
    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        $current = [string](Get-WebAppPoolState -Name $Name).Value
        if ($current -eq $DesiredState) { return }
        Start-Sleep -Milliseconds 250
    } while ((Get-Date) -lt $deadline)
    throw "App pool '$Name' did not reach state '$DesiredState' within $TimeoutSeconds seconds (current: $current)."
}

function Sync-DirectoryTree {
    param(
        [Parameter(Mandatory = $true)][string]$Source,
        [Parameter(Mandatory = $true)][string]$Destination
    )

    if (-not (Test-Path -LiteralPath $Source -PathType Container)) {
        throw "Directory sync source does not exist: $Source"
    }

    & robocopy.exe $Source $Destination /MIR /COPY:DAT /DCOPY:DAT /R:2 /W:1 /NFL /NDL /NJH /NJS /NP
    $exitCode = $LASTEXITCODE
    if ($exitCode -ge 8) {
        throw "robocopy failed while mirroring '$Source' to '$Destination' (exit code $exitCode)."
    }
}

function Restore-PoolState {
    param([string]$Name, [string]$State)
    if (-not $State -or -not (Test-Path "IIS:\AppPools\$Name")) { return }
    $current = [string](Get-WebAppPoolState -Name $Name).Value
    if ($State -eq 'Started') {
        if ($current -eq 'Stopping') {
            Wait-WebAppPoolState -Name $Name -DesiredState 'Stopped'
            $current = 'Stopped'
        }
        if ($current -ne 'Started') { Start-WebAppPool -Name $Name }
        Wait-WebAppPoolState -Name $Name -DesiredState 'Started'
    } else {
        if ($current -eq 'Starting') {
            Wait-WebAppPoolState -Name $Name -DesiredState 'Started'
            $current = 'Started'
        }
        if ($current -ne 'Stopped') { Stop-WebAppPool -Name $Name }
        Wait-WebAppPoolState -Name $Name -DesiredState 'Stopped'
    }
}

Assert-Administrator
Import-Module WebAdministration

if (-not (Test-Path -LiteralPath $ArchivePath -PathType Leaf)) { throw "Deployment archive not found: $ArchivePath" }
$actualArchiveSha256 = (Get-FileHash -LiteralPath $ArchivePath -Algorithm SHA256).Hash
if ($actualArchiveSha256 -ne $ExpectedArchiveSha256) {
    throw "Deployment archive SHA-256 mismatch (expected $ExpectedArchiveSha256, got $actualArchiveSha256)."
}
Write-Output "Verified package SHA-256: $($actualArchiveSha256.ToLowerInvariant())"
if (-not [IO.Path]::IsPathRooted($ProjectPath)) { throw 'ProjectPath must be an absolute Windows path.' }
if ($ProductionSiteName -eq $TestSiteName -or $ProductionPoolName -eq $TestPoolName) { throw 'Production and test IIS names must differ.' }
if ($ProductionPort -eq $TestPort) { throw 'Production and test ports must differ.' }

$projectFullPath = [IO.Path]::GetFullPath($ProjectPath).TrimEnd('\')
$projectParent = Split-Path -Parent $projectFullPath
if (-not $projectParent -or $projectFullPath -eq [IO.Path]::GetPathRoot($projectFullPath).TrimEnd('\')) {
    throw "Unsafe ProjectPath: $ProjectPath"
}
$projectParentExisted = Test-Path -LiteralPath $projectParent -PathType Container
$targetExisted = Test-Path -LiteralPath $projectFullPath
if ($targetExisted) {
    $targetItem = Get-Item -LiteralPath $projectFullPath -Force
    if (-not $targetItem.PSIsContainer) { throw "ProjectPath exists but is not a directory: $projectFullPath" }
    if (($targetItem.Attributes -band [IO.FileAttributes]::ReparsePoint) -ne 0) { throw "ProjectPath may not be a reparse point: $projectFullPath" }
    if (-not (Test-Path -LiteralPath (Join-Path $projectFullPath 'tools\Register-Components.ps1'))) {
        throw 'Existing ProjectPath is not a rollback-capable WSC-MVC deployment.'
    }
}

$stagingPath = "$projectFullPath.staging.$InvocationId"
$backupPath = "$projectFullPath.rollback.$InvocationId"
$failedPath = "$projectFullPath.failed.$InvocationId"
foreach ($ownedPath in @($stagingPath, $backupPath, $failedPath)) {
    if (Test-Path -LiteralPath $ownedPath) { throw "Invocation-owned path already exists: $ownedPath" }
}

$productionPublicPath = Join-Path $projectFullPath 'public'
$testPublicPath = Join-Path $projectFullPath 'test-app\public'
$components = @(
    [PSCustomObject]@{ RelativePath = 'Framework\RequestContext.wsc'; ProgId = 'WscMvc.RequestContext'; ClassId = '{1C36FA55-34DF-4974-94B9-D657389362B2}' },
    [PSCustomObject]@{ RelativePath = 'Framework\Router.wsc'; ProgId = 'WscMvc.Router'; ClassId = '{C92F9338-B478-4EAD-B865-892FFB1E1C51}' },
    [PSCustomObject]@{ RelativePath = 'Framework\ViewRenderer.wsc'; ProgId = 'WscMvc.ViewRenderer'; ClassId = '{4948DF84-5DC6-448A-9F1B-EB596C28842B}' },
    [PSCustomObject]@{ RelativePath = 'Framework\Application.wsc'; ProgId = 'WscMvc.Application'; ClassId = '{851C7763-1638-42FE-A166-BF3DD3A96A88}' },
    [PSCustomObject]@{ RelativePath = 'Controllers\HomeController.wsc'; ProgId = 'WscMvc.HomeController'; ClassId = '{87488446-60BE-4068-8368-0B709BB68F3F}' },
    [PSCustomObject]@{ RelativePath = 'test-app\Controllers\SelfTestController.wsc'; ProgId = 'WscMvc.SelfTestController'; ClassId = '{D2634944-4646-4C55-956E-4C05E7E10904}' }
)

# Validate every archive entry before Expand-Archive can write anything.
Add-Type -AssemblyName System.IO.Compression.FileSystem
$zip = [IO.Compression.ZipFile]::OpenRead($ArchivePath)
try {
    foreach ($entry in $zip.Entries) {
        $entryName = $entry.FullName.Replace('/', '\')
        if ([IO.Path]::IsPathRooted($entryName) -or $entryName -match '(^|\\)\.\.(\\|$)') {
            throw "Unsafe archive entry: $($entry.FullName)"
        }
        $entryDestination = [IO.Path]::GetFullPath((Join-Path $stagingPath $entryName))
        if (-not $entryDestination.StartsWith($stagingPath + '\', [StringComparison]::OrdinalIgnoreCase)) {
            throw "Archive entry escapes staging directory: $($entry.FullName)"
        }
    }
} finally {
    $zip.Dispose()
}

# Read-only filesystem and IIS inspection completes before any target, registration, site, or pool mutation.
$productionSnapshot = Get-SiteSnapshot -Name $ProductionSiteName
$testSnapshot = Get-SiteSnapshot -Name $TestSiteName
$productionPoolExisted = Test-Path "IIS:\AppPools\$ProductionPoolName"
$testPoolExisted = Test-Path "IIS:\AppPools\$TestPoolName"
$productionPoolState = if ($productionPoolExisted) { [string](Get-WebAppPoolState -Name $ProductionPoolName).Value } else { $null }
$testPoolState = if ($testPoolExisted) { [string](Get-WebAppPoolState -Name $TestPoolName).Value } else { $null }
Assert-SiteTarget -Name $ProductionSiteName -PoolName $ProductionPoolName -PhysicalPath $productionPublicPath -Port $ProductionPort
Assert-SiteTarget -Name $TestSiteName -PoolName $TestPoolName -PhysicalPath $testPublicPath -Port $TestPort
Assert-PoolTarget -PoolName $ProductionPoolName -AllowedSiteName $ProductionSiteName
Assert-PoolTarget -PoolName $TestPoolName -AllowedSiteName $TestSiteName
$componentRegistrationMode = Get-ComponentRegistrationMode -ExistingProjectPath $projectFullPath -Components $components

$createdProductionSite = -not [bool]$productionSnapshot
$createdTestSite = -not [bool]$testSnapshot
$createdProductionPool = -not $productionPoolExisted
$createdTestPool = -not $testPoolExisted
$targetUpdated = $false
$backupCreated = $false
$installSucceeded = $false

try {
    if (-not $projectParentExisted) {
        New-Item -ItemType Directory -Path $projectParent | Out-Null
    }
    Expand-Archive -LiteralPath $ArchivePath -DestinationPath $stagingPath

    $requiredRelativePaths = @(
        'public\Default.asp',
        'test-app\public\Default.asp',
        'Framework\ViewRenderer.wsc',
        'tools\Register-Components.ps1',
        'tools\Setup-Site.ps1',
        'tests\Invoke-SelfTest.ps1',
        'tests\Test-Http.ps1'
    )
    foreach ($relativePath in $requiredRelativePaths) {
        if (-not (Test-Path -LiteralPath (Join-Path $stagingPath $relativePath))) {
            throw "Package is missing required path: $relativePath"
        }
    }

    Get-ChildItem -LiteralPath $stagingPath -Recurse -Force | ForEach-Object {
        $resolved = [IO.Path]::GetFullPath($_.FullName)
        if (-not $resolved.StartsWith($stagingPath + '\', [StringComparison]::OrdinalIgnoreCase)) {
            throw "Archive entry escaped staging directory: $resolved"
        }
        if (($_.Attributes -band [IO.FileAttributes]::ReparsePoint) -ne 0) {
            throw "Archive contains a reparse point: $resolved"
        }
    }

    # Stop only this deployment's two sites and dedicated pools before copying
    # the release. The live root itself can remain open on IIS hosts even after
    # its dedicated pools stop, so keep the path stable and mirror a verified
    # backup/release tree instead of relying on a root-directory rename.
    foreach ($siteSnapshot in @($productionSnapshot, $testSnapshot)) {
        if ($siteSnapshot -and $siteSnapshot.State -eq 'Started') {
            Stop-Website -Name $siteSnapshot.Name
        }
    }
    foreach ($poolName in @($ProductionPoolName, $TestPoolName)) {
        if (Test-Path "IIS:\AppPools\$poolName") {
            $poolStateNow = [string](Get-WebAppPoolState -Name $poolName).Value
            if ($poolStateNow -eq 'Started') { Stop-WebAppPool -Name $poolName }
            Wait-WebAppPoolState -Name $poolName -DesiredState 'Stopped'
        }
    }

    if ($targetExisted) {
        Sync-DirectoryTree -Source $projectFullPath -Destination $backupPath
        $backupCreated = $true
    }
    Sync-DirectoryTree -Source $stagingPath -Destination $projectFullPath
    $targetUpdated = $true
    Remove-Item -LiteralPath $stagingPath -Recurse -Force

    & (Join-Path $projectFullPath 'tools\Register-Components.ps1') -ProjectRoot $projectFullPath
    & (Join-Path $projectFullPath 'tools\Setup-Site.ps1') -SiteName $ProductionSiteName -PoolName $ProductionPoolName -PhysicalPath $productionPublicPath -Port $ProductionPort
    & (Join-Path $projectFullPath 'tools\Setup-Site.ps1') -SiteName $TestSiteName -PoolName $TestPoolName -PhysicalPath $testPublicPath -Port $TestPort

    if ($RunTests) {
        & cscript.exe //nologo (Join-Path $projectFullPath 'tests\Test-Components.vbs')
        if ($LASTEXITCODE -ne 0) { throw "Test-Components.vbs failed with exit code $LASTEXITCODE" }

        $httpTestCommand = "& $(Quote-PowerShellLiteral (Join-Path $projectFullPath 'tests\Test-Http.ps1')) -BaseUrl $(Quote-PowerShellLiteral $ProductionBaseUrl) -TestBaseUrl $(Quote-PowerShellLiteral $TestBaseUrl)"
        $httpTestExitCode = Invoke-WindowsPowerShell -Command $httpTestCommand
        if ($httpTestExitCode -ne 0) { throw "Test-Http.ps1 failed with exit code $httpTestExitCode" }

        $apiTestCommand = "& $(Quote-PowerShellLiteral (Join-Path $projectFullPath 'tests\Invoke-SelfTest.ps1')) -BaseUrl $(Quote-PowerShellLiteral $TestBaseUrl)"
        $apiTestExitCode = Invoke-WindowsPowerShell -Command $apiTestCommand
        if ($apiTestExitCode -ne 0) { throw "Invoke-SelfTest.ps1 failed with exit code $apiTestExitCode" }
    }

    $installSucceeded = $true
    Write-Output "Deployment succeeded: $projectFullPath"
    if ($backupCreated) {
        Write-Output "Timestamped rollback retained at: $backupPath"
    } else {
        Write-Output 'No previous project tree existed; no rollback directory was created.'
    }
} catch {
    $failure = $_
    $rollbackErrors = New-Object System.Collections.Generic.List[string]
    Write-Warning "Deployment failed; rolling back only changes owned by invocation $InvocationId."

    try {
        if ($targetUpdated -and (Test-Path -LiteralPath (Join-Path $projectFullPath 'tools\Unregister-Components.ps1'))) {
            & (Join-Path $projectFullPath 'tools\Unregister-Components.ps1') -ProjectRoot $projectFullPath
        }
    } catch { $rollbackErrors.Add("Unregister new components: $($_.Exception.Message)") }

    try {
        if ($createdProductionSite -and (Test-Path "IIS:\Sites\$ProductionSiteName")) { Remove-Website -Name $ProductionSiteName }
    } catch { $rollbackErrors.Add("Remove production site: $($_.Exception.Message)") }
    try {
        if ($createdTestSite -and (Test-Path "IIS:\Sites\$TestSiteName")) { Remove-Website -Name $TestSiteName }
    } catch { $rollbackErrors.Add("Remove test site: $($_.Exception.Message)") }
    try {
        if ($createdProductionPool -and (Test-Path "IIS:\AppPools\$ProductionPoolName")) { Remove-WebAppPool -Name $ProductionPoolName }
    } catch { $rollbackErrors.Add("Remove production pool: $($_.Exception.Message)") }
    try {
        if ($createdTestPool -and (Test-Path "IIS:\AppPools\$TestPoolName")) { Remove-WebAppPool -Name $TestPoolName }
    } catch { $rollbackErrors.Add("Remove test pool: $($_.Exception.Message)") }

    try {
        if ($targetUpdated -and (Test-Path -LiteralPath $projectFullPath)) {
            Sync-DirectoryTree -Source $projectFullPath -Destination $failedPath
        }
    } catch { $rollbackErrors.Add("Retain failed release: $($_.Exception.Message)") }
    try {
        if ($backupCreated -and (Test-Path -LiteralPath $backupPath)) {
            Sync-DirectoryTree -Source $backupPath -Destination $projectFullPath
        } elseif ($targetUpdated -and -not $targetExisted -and (Test-Path -LiteralPath $projectFullPath)) {
            Remove-Item -LiteralPath $projectFullPath -Recurse -Force
        }
    } catch { $rollbackErrors.Add("Restore previous project tree: $($_.Exception.Message)") }
    try {
        if ($backupCreated -and $componentRegistrationMode -eq 'Owned' -and
            (Test-Path -LiteralPath (Join-Path $projectFullPath 'tools\Register-Components.ps1'))) {
            & (Join-Path $projectFullPath 'tools\Register-Components.ps1') -ProjectRoot $projectFullPath
        }
    } catch { $rollbackErrors.Add("Restore previous component registrations: $($_.Exception.Message)") }

    try { Restore-PoolState -Name $ProductionPoolName -State $productionPoolState } catch { $rollbackErrors.Add("Restore production pool state: $($_.Exception.Message)") }
    try { Restore-PoolState -Name $TestPoolName -State $testPoolState } catch { $rollbackErrors.Add("Restore test pool state: $($_.Exception.Message)") }
    try { Restore-SiteState -Snapshot $productionSnapshot } catch { $rollbackErrors.Add("Restore production site state: $($_.Exception.Message)") }
    try { Restore-SiteState -Snapshot $testSnapshot } catch { $rollbackErrors.Add("Restore test site state: $($_.Exception.Message)") }

    if ($rollbackErrors.Count -gt 0) {
        throw "Deployment failed: $($failure.Exception.Message) Rollback also reported: $($rollbackErrors -join ' | ')"
    }
    throw $failure
} finally {
    if (-not $installSucceeded -and (Test-Path -LiteralPath $stagingPath)) {
        # Staging was created by this invocation and never became the live target.
        Remove-Item -LiteralPath $stagingPath -Recurse -Force
    }
    if (-not $installSucceeded -and -not $projectParentExisted -and (Test-Path -LiteralPath $projectParent)) {
        $remaining = @(Get-ChildItem -LiteralPath $projectParent -Force)
        if ($remaining.Count -eq 0) { Remove-Item -LiteralPath $projectParent -Force }
    }
    if (Test-Path -LiteralPath $ArchivePath) {
        Remove-Item -LiteralPath $ArchivePath -Force
    }
    $selfPath = $MyInvocation.MyCommand.Path
    if ($selfPath -and $selfPath -like "$env:windir\Temp\*") {
        Remove-Item -LiteralPath $selfPath -Force -ErrorAction SilentlyContinue
    }
}