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

    Fault : FSMO roles are on a domain controller that is gone
    Fix   : Seize the roles and clean up the dead controller
    Source: https://jbtecwiz.com/support/srv-id-fsmo

    Run as     : Elevated PowerShell on the surviving controller
    Expect     : 90 minutes
    Risk       : high
    Reversible : NO -- read the undo note below before running

    WHEN THIS IS THE RIGHT FIX
    The holder is gone for good. Read the warning in the first step before
    proceeding.

    HOW TO UNDO IT
    None. A seizure cannot be undone and the metadata cleanup is permanent.

    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 6"
    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 '  FSMO roles are on a domain controller that is gone' -ForegroundColor White
Write-Host '  Seize the roles and clean up the dead controller' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: high   NOT REVERSIBLE   90 minutes' -ForegroundColor Yellow
Write-Host ''
Show-Prose 'Undo: None. A seizure cannot be undone and the metadata cleanup is permanent.' 'Yellow'
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 'Be certain the old controller will never be powered on again on this network. If it is, the domain will have two controllers claiming the same role, which causes damage that is far harder to unpick than the original fault.' -Why 'This is the one irreversible decision in the whole procedure. Wipe the old machine, or keep it permanently isolated -- do not leave it powered off in a rack where somebody might helpfully start it.' -Manual

Invoke-Step -Number 2 -Do 'Seize the roles.' -Command {
    Move-ADDirectoryServerOperationMasterRole -Identity DC02 -OperationMasterRole PDCEmulator,RIDMaster,InfrastructureMaster,SchemaMaster,DomainNamingMaster -Force
}

Invoke-Step -Number 3 -Do 'Remove the dead controller''s metadata from the directory. Without this it remains as a replication partner that everything keeps trying to reach.' -Command {
    ntdsutil
    metadata cleanup
    connections
    connect to server DC02
    quit
    select operation target
    list domains
}

Invoke-Step -Number 4 -Do 'The modern equivalent is a single cmdlet, which is safer and does the same work.' -Command {
    Get-ADDomainController -Filter { Name -eq 'DC01' } | Remove-ADDomainController -ForceRemovalOfLastDomainControllerInDomain:$false -Confirm:$false
    Remove-ADObject -Identity 'CN=DC01,OU=Domain Controllers,DC=example,DC=local' -Recursive -Confirm:$false
}

Invoke-Step -Number 5 -Do 'Clean up the DNS records the dead controller left behind.' -Command {
    Get-DnsServerResourceRecord -ZoneName example.local -RRType A | Where-Object HostName -eq 'DC01'
    Get-DnsServerZone | Where-Object ZoneName -like '_msdcs*' | Format-Table ZoneName
}

Invoke-Step -Number 6 -Do 'Check the sites and services topology no longer references it.' -Command {
    repadmin /replsummary
    repadmin /showrepl * /csv | ConvertFrom-Csv | Format-Table 'Source DSA','Destination DSA','Number of Failures'
}

Write-Rule "  Confirm it worked"
Show-Prose 'dcdiag passes, replication has no failures, and the dead controller appears nowhere.' 'White'
Write-Host ''
if (-not $DryRun) {
    dcdiag /v | Select-String 'failed'
    repadmin /replsummary
}

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-id-fsmo' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: None. A seizure cannot be undone and the metadata cleanup is permanent.' 'DarkGray'
Write-Rule