param(
    [Parameter(Mandatory = $true)][string]$ArchivePath,
    [string]$TargetCodexHome = (Join-Path $env:USERPROFILE ".codex"),
    [switch]$NoBackup
)

$ErrorActionPreference = "Stop"

function New-CleanDirectory {
    param([Parameter(Mandatory = $true)][string]$Path)

    if (Test-Path -LiteralPath $Path) {
        Remove-Item -LiteralPath $Path -Recurse -Force
    }

    New-Item -ItemType Directory -Path $Path -Force | Out-Null
}

if (-not (Test-Path -LiteralPath $ArchivePath)) {
    throw "Archive not found: $ArchivePath"
}

$extractRoot = Join-Path $env:TEMP ("codex-restore-" + (Get-Date -Format "yyyyMMdd-HHmmss"))
New-CleanDirectory -Path $extractRoot

try {
    Expand-Archive -LiteralPath $ArchivePath -DestinationPath $extractRoot -Force

    $manifestPath = Join-Path $extractRoot "manifest.json"
    $payloadCodexHome = Join-Path $extractRoot "payload\.codex"

    if (-not (Test-Path -LiteralPath $manifestPath)) {
        throw "Invalid archive: manifest.json missing"
    }

    if (-not (Test-Path -LiteralPath $payloadCodexHome)) {
        throw "Invalid archive: payload/.codex missing"
    }

    if ((Test-Path -LiteralPath $TargetCodexHome) -and -not $NoBackup) {
        $backupPath = "$TargetCodexHome.before-import-$(Get-Date -Format 'yyyyMMdd-HHmmss')"
        Move-Item -LiteralPath $TargetCodexHome -Destination $backupPath
        Write-Output "Existing Codex config moved to: $backupPath"
    } elseif (Test-Path -LiteralPath $TargetCodexHome) {
        Remove-Item -LiteralPath $TargetCodexHome -Recurse -Force
    }

    Copy-Item -LiteralPath $payloadCodexHome -Destination $TargetCodexHome -Recurse -Force

    $payloadRoot = Join-Path $extractRoot "payload"
    Get-ChildItem -LiteralPath $payloadRoot -Force -File -ErrorAction SilentlyContinue |
        Where-Object { $_.Name -like ".codex*" } |
        ForEach-Object {
            Copy-Item -LiteralPath $_.FullName -Destination (Join-Path $env:USERPROFILE $_.Name) -Force
        }

    Write-Output "Codex config restored to: $TargetCodexHome"
} finally {
    if (Test-Path -LiteralPath $extractRoot) {
        Remove-Item -LiteralPath $extractRoot -Recurse -Force
    }
}