#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : DFSR event 4012 -- replication stopped after exceeding MaxOfflineTimeInDays
    Fix   : Resume replication on a data folder
    Source: https://jbtecwiz.com/support/srv-dfsr-4012

    Run as     : Elevated PowerShell on the affected member
    Expect     : 30 minutes plus sync time
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    A normal replicated folder. Be aware that resuming will re-replicate
    deletions that happened while this member was offline.

    HOW TO UNDO IT
    Restore from the backup taken in step 2 if convergence removed something
    needed.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 4"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  DFSR event 4012 -- replication stopped after exceeding MaxOfflineTimeInDays' -ForegroundColor White
Write-Host '  Resume replication on a data folder' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   30 minutes plus sync time'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Confirm the state and read which folder is stopped.' -Command {
    Get-WinEvent -LogName 'DFS Replication' -MaxEvents 30 | Where-Object Id -in 4012,2213,5002 | Format-List TimeCreated, Id, Message
}

Invoke-Step -Number 2 -Do 'Understand what resuming means: any file deleted on the other members while this one was offline will be deleted here too. If this server has the only copy of something, take a backup of the folder first.' -Why 'DFSR does not merge -- it converges. That is the whole reason it stopped rather than resuming automatically.' -Manual

Invoke-Step -Number 3 -Do 'Resume the replicated folder using the volume GUID from the event.' -Command {
    $d = Get-WmiObject -Namespace root\microsoftdfs -Class DfsrVolumeConfig -Filter "VolumePath='\\\\.\\C:'"
    $d.ResumeReplication()
}

Invoke-Step -Number 4 -Do 'Watch the backlog drain.' -Command {
    dfsrdiag backlog /rgname:"Group" /rfname:"Folder" /smem:SRV01 /rmem:SRV02
}

Write-Rule "  Confirm it worked"
Show-Prose 'The backlog reaches zero and event 4012 stops recurring.' 'White'
Write-Host ''
if (-not $DryRun) {
    dfsrdiag replicationstate /all
}

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/srv-dfsr-4012' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Restore from the backup taken in step 2 if convergence removed something needed.' 'DarkGray'
Write-Rule