param(
    [Parameter(Mandatory=$true)]
    [string]$url,
    [Parameter(Mandatory=$true)]
    [string]$oldPmcRelativeUrl,
    [Parameter(Mandatory=$true)]
    [string]$newPmcRelativeUrl
)

function Write-File($msg)
{
    ($msg) | Out-File "log-page-layouts.txt" -Append
}

function Write-Info($msg)
{
    Write-Host $msg -foregroundcolor green
    Write-File $msg
}

function Write-Warn($msg)
{
    Write-Host $msg -foregroundcolor yellow
    Write-File $msg
}

function Update-Page-Layout-Page($publishingPage, $oldPmcRelativeUrl, $newPmcRelativeUrl)
{
    $file = $publishingPage.ListItem.File
    Write-Info ("Check page: " + $file.Url)
    Write-Info ("Current page layout: " + $file.Properties["PublishingPageLayout"].ToString())
    
    if ((-not [System.String]::IsNullOrEmpty($file.Properties["PublishingPageLayout"])) -and $file.Properties["PublishingPageLayout"].ToString().Contains("/" + $oldPmcRelativeUrl + "/"))
    {
        if ($file.CheckOutStatus -eq [Microsoft.SharePoint.SPFile+SPCheckOutStatus]::None)
        {
            $file.CheckOut()
        }
        else
        {
            $file.UndoCheckOut()
            $file.CheckOut()
        }

        $file.Properties["PublishingPageLayout"] = $file.Properties["PublishingPageLayout"].ToString().Replace("/" + $oldPmcRelativeUrl + "/", "/" + $newPmcRelativeUrl + "/")
        $file.Update()
        $file.CheckIn("Update page layout via PowerShell", [Microsoft.SharePoint.SPCheckinType]::MajorCheckIn)
        if ($publishingPage.ListItem.ParentList.EnableModeration)
        {
            $file.Approve("Update page layout via PowerShell");
        }
        Write-Warn "Page layout was successfully updated"
    }
}

function Update-Page-Layout-Web($web, $oldPmcRelativeUrl, $newPmcRelativeUrl)
{
    Write-Info ("Update page layouts for web: " + $web.Url)
    $pubWeb = [Microsoft.SharePoint.Publishing.PublishingWeb]::GetPublishingWeb($web);
    $pages = $pubWeb.GetPublishingPages()
    foreach ($page in $pages)
    {
        Update-Page-Layout-Page $page $oldPmcRelativeUrl $newPmcRelativeUrl
    }

    foreach ($subWeb in $web.Webs)
    {
        Update-Page-Layout-Web $subWeb $oldPmcRelativeUrl $newPmcRelativeUrl
    }
}

function Update-Page-Layout-Site($site, $oldPmcRelativeUrl, $newPmcRelativeUrl)
{
    foreach ($web in $site.RootWeb.Webs)
    {
        Update-Page-Layout-Web $web $oldPmcRelativeUrl $newPmcRelativeUrl
    }
}

$site = Get-SPSite $url
Update-Page-Layout-Site $site $oldPmcRelativeUrl $newPmcRelativeUrl
#$web = Get-SPWeb $url
#Update-Page-Layout-Web $web $oldPmcRelativeUrl $newPmcRelativeUrl