param(
    [string]$ZipPath,
    [string]$DestinationHome = ([Environment]::GetFolderPath('UserProfile')),
    [string]$BackupRoot = 'D:\notatnik-ai\codex',
    [switch]$NoBackup
)

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

if (-not (Test-Path -LiteralPath $BackupRoot)) {
    New-Item -ItemType Directory -Path $BackupRoot -Force | Out-Null
}

if (-not $ZipPath) {
    $latest = Get-ChildItem -LiteralPath $BackupRoot -Filter 'codex-backup-*.zip' -File |
        Sort-Object LastWriteTime -Descending |
        Select-Object -First 1

    if (-not $latest) {
        throw 'Brak pliku backup ZIP. Podaj -ZipPath.'
    }

    $ZipPath = $latest.FullName
}

$resolvedZip = (Resolve-Path -LiteralPath $ZipPath).Path
$extractRoot = Join-Path ([System.IO.Path]::GetTempPath()) ('codex-import-' + [guid]::NewGuid().ToString('N'))
New-Item -ItemType Directory -Path $extractRoot -Force | Out-Null

Expand-Archive -LiteralPath $resolvedZip -DestinationPath $extractRoot -Force

$manifestPath = Join-Path $extractRoot 'manifest.json'
if (-not (Test-Path -LiteralPath $manifestPath)) {
    throw 'W archiwum brakuje manifest.json.'
}

$manifest = Get-Content -LiteralPath $manifestPath -Raw | ConvertFrom-Json
$payloadRoot = Join-Path $extractRoot 'payload'
if (-not (Test-Path -LiteralPath $payloadRoot)) {
    throw 'W archiwum brakuje katalogu payload.'
}

$preBackupDir = $null
if (-not $NoBackup) {
    $preBackupDir = Join-Path $BackupRoot ('pre-import-backup-' + (Get-Date -Format 'yyyyMMdd-HHmmss'))
    New-Item -ItemType Directory -Path $preBackupDir -Force | Out-Null
}

foreach ($item in $manifest.items) {
    $payloadItem = Join-Path $payloadRoot $item.payload_name
    if (-not (Test-Path -LiteralPath $payloadItem)) {
        Write-Warning ('Pomijam brakujacy element payload: {0}' -f $item.payload_name)
        continue
    }

    $targetPath = $null
    if ($item.destination_type -eq 'user_profile_relative') {
        $targetPath = Join-Path $DestinationHome $item.profile_relative_path
    } elseif ($item.destination_type -eq 'absolute') {
        $targetPath = $item.absolute_path
    }

    if (-not $targetPath) {
        Write-Warning ('Pomijam element z nieznanym celem: {0}' -f $item.payload_name)
        continue
    }

    $targetParent = Split-Path -Parent $targetPath
    if ($targetParent -and -not (Test-Path -LiteralPath $targetParent)) {
        New-Item -ItemType Directory -Path $targetParent -Force | Out-Null
    }

    if (Test-Path -LiteralPath $targetPath) {
        if (-not $NoBackup -and $preBackupDir) {
            $backupTarget = Join-Path $preBackupDir ($item.payload_name + '-before-import')
            Copy-Item -LiteralPath $targetPath -Destination $backupTarget -Recurse -Force
        }

        Remove-Item -LiteralPath $targetPath -Recurse -Force
    }

    Copy-Item -LiteralPath $payloadItem -Destination $targetPath -Recurse -Force
}

Remove-Item -LiteralPath $extractRoot -Recurse -Force
Write-Output ('Codex import completed from: {0}' -f $resolvedZip)
if ($preBackupDir) {
    Write-Output ('Pre-import backup: {0}' -f $preBackupDir)
}