<#
Adjust these values only if your vCenter names are different:
$WinTemplateName   Template VM used for all Windows Server VMs.
$LinuxTemplateName Template VM used for DEV-PC (Debian 13 GUI).

This script expects these port groups to already exist:
PG-VLAN10  (CPH-INT)
PG-VLAN11  (CPH-DEV)
PG-VLAN12  (INET)
PG-VLAN20  (AAL-INT)

What the script does:
- Creates the ES2025 Windows topology VMs as linked clones
- Sets each VM to 2 vCPU and 4 GB RAM
- Configures network adapters to match the topology
- Injects cloud-init userdata for DEV-PC only
- Windows VMs are snapshotted without powering on
- DEV-PC boots, runs cloud-init, powers off, then gets snapshotted

Run:
.\Create-VMs.ps1
#>

[CmdletBinding()]
param()

$ErrorActionPreference = 'Stop'

$DatacenterName         = 'Ilica'
$SkillsFolderName       = 'Skills'
$TargetParentFolderName = 'ES2025'
$TargetFolderName       = 'Windows'
$TemplateFolderName     = 'Templates'
$WinTemplateName        = 'ws2022'
$LinuxTemplateName      = 'debian-13-gui-template'
$ReferenceSnapshotName  = 'Start'
$StartSnapshotName      = 'Start'
$CpuCount               = 2
$MemoryGB               = 4
$DefaultUsername        = 'user'
$DefaultPassword        = 'Passw0rd!'
$CloudInitShutdownTimeoutSeconds = 900

function Get-SingleFolder {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Name,

        $Location = $null
    )

    $params = @{ Name = $Name; Type = 'VM'; ErrorAction = 'SilentlyContinue' }
    if ($Location) { $params['Location'] = $Location }
    $folders = @(Get-Folder @params)

    if ($folders.Count -eq 0) { throw "Folder '$Name' was not found." }
    if ($folders.Count -gt 1) { throw "More than one folder named '$Name' was found." }
    return $folders[0]
}

function Get-SingleChildFolder {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Name,

        [Parameter(Mandatory = $true)]
        $ParentFolder
    )

    $folders = @(Get-Folder -Location $ParentFolder -Name $Name -Type VM -ErrorAction SilentlyContinue)

    if ($folders.Count -eq 0) { throw "Folder '$Name' was not found under '$($ParentFolder.Name)'." }
    if ($folders.Count -gt 1) { throw "More than one folder named '$Name' was found under '$($ParentFolder.Name)'." }
    return $folders[0]
}

function Get-SingleVmFromFolder {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Name,

        [Parameter(Mandatory = $true)]
        $Folder
    )

    $vms = @(Get-VM -Location $Folder -Name $Name -ErrorAction SilentlyContinue)

    if ($vms.Count -eq 0) { throw "VM '$Name' was not found in folder '$($Folder.Name)'." }
    if ($vms.Count -gt 1) { throw "More than one VM named '$Name' was found in folder '$($Folder.Name)'." }
    return $vms[0]
}

function Get-OrCreateReferenceSnapshot {
    param(
        [Parameter(Mandatory = $true)]
        $VM,

        [Parameter(Mandatory = $true)]
        [string]$SnapshotName
    )

    $snapshot = Get-Snapshot -VM $VM -Name $SnapshotName -ErrorAction SilentlyContinue
    if (-not $snapshot) {
        Write-Host "Creating snapshot '$SnapshotName' on '$($VM.Name)'"
        $snapshot = New-Snapshot -VM $VM -Name $SnapshotName -Description 'Base snapshot for linked clones' -Memory:$false -Quiesce:$false
    }
    return $snapshot
}

function Set-ExactNetworkAdapters {
    param(
        [Parameter(Mandatory = $true)]
        $VM,

        [Parameter(Mandatory = $true)]
        [string[]]$PortGroupNames
    )

    $adapters = @(Get-NetworkAdapter -VM $VM | Sort-Object Name)

    while ($adapters.Count -gt $PortGroupNames.Count) {
        Remove-NetworkAdapter -NetworkAdapter $adapters[-1] -Confirm:$false | Out-Null
        $adapters = @(Get-NetworkAdapter -VM $VM | Sort-Object Name)
    }

    for ($i = 0; $i -lt $PortGroupNames.Count; $i++) {
        if ($i -ge $adapters.Count) {
            New-NetworkAdapter -VM $VM -Type Vmxnet3 -NetworkName $PortGroupNames[$i] -StartConnected:$true -Confirm:$false | Out-Null
            $adapters = @(Get-NetworkAdapter -VM $VM | Sort-Object Name)
        }
        Set-NetworkAdapter -NetworkAdapter $adapters[$i] -NetworkName $PortGroupNames[$i] -StartConnected:$true -Confirm:$false | Out-Null
    }
}

function Set-AdvancedSettingValue {
    param(
        [Parameter(Mandatory = $true)]
        $Entity,

        [Parameter(Mandatory = $true)]
        [string]$Name,

        [Parameter(Mandatory = $true)]
        [string]$Value
    )

    $setting = Get-AdvancedSetting -Entity $Entity -Name $Name -ErrorAction SilentlyContinue
    if ($setting) {
        Set-AdvancedSetting -AdvancedSetting $setting -Value $Value -Confirm:$false | Out-Null
        return
    }
    New-AdvancedSetting -Entity $Entity -Name $Name -Value $Value -Confirm:$false | Out-Null
}

function Set-CloudInitUserData {
    param(
        [Parameter(Mandatory = $true)]
        $VM,

        [Parameter(Mandatory = $true)]
        [string]$Username,

        [Parameter(Mandatory = $true)]
        [string]$Password
    )

    $userData = @"
#cloud-config
hostname: $($VM.Name)
users:
  - default
  - name: $Username
    lock_passwd: false
    plain_text_passwd: '$Password'
    shell: /bin/bash
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: sudo
ssh_pwauth: true
disable_root: false
chpasswd:
  expire: false
  list: |
    root:$Password
    ${Username}:$Password
power_state:
  mode: poweroff
  timeout: 30
  condition: true
"@

    $encoded = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($userData))
    Set-AdvancedSettingValue -Entity $VM -Name 'guestinfo.userdata' -Value $encoded
    Set-AdvancedSettingValue -Entity $VM -Name 'guestinfo.userdata.encoding' -Value 'base64'
}

function Wait-ForVmToPowerOff {
    param(
        [Parameter(Mandatory = $true)]
        $VM,

        [Parameter(Mandatory = $true)]
        [int]$TimeoutSeconds
    )

    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    do {
        if ((Get-VM -Id $VM.Id).PowerState -eq 'PoweredOff') { return }
        Start-Sleep -Seconds 5
    } while ((Get-Date) -lt $deadline)

    throw "VM '$($VM.Name)' did not power off within $TimeoutSeconds seconds."
}

# ── Folder and template lookup ────────────────────────────────────────────────
$datacenter         = Get-Datacenter        -Name $DatacenterName -ErrorAction Stop
$skillsFolder       = Get-SingleFolder      -Name $SkillsFolderName       -Location $datacenter
$templateFolder     = Get-SingleChildFolder -Name $TemplateFolderName     -ParentFolder $skillsFolder
$targetParentFolder = Get-SingleChildFolder -Name $TargetParentFolderName -ParentFolder $skillsFolder
$targetFolder       = Get-SingleChildFolder -Name $TargetFolderName       -ParentFolder $targetParentFolder

$winTemplate   = Get-SingleVmFromFolder -Name $WinTemplateName   -Folder $templateFolder
$linuxTemplate = Get-SingleVmFromFolder -Name $LinuxTemplateName -Folder $templateFolder

$winSnapshot   = Get-OrCreateReferenceSnapshot -VM $winTemplate   -SnapshotName $ReferenceSnapshotName
$linuxSnapshot = Get-OrCreateReferenceSnapshot -VM $linuxTemplate -SnapshotName $ReferenceSnapshotName

# ── VM definitions ────────────────────────────────────────────────────────────
$vmDefinitions = @(
    @{ Name = 'INET';    Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN12');                          IsLinux = $false },
    @{ Name = 'RTR-CPH'; Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN12', 'PG-VLAN10', 'PG-VLAN11'); IsLinux = $false },
    @{ Name = 'RTR-AAL'; Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN12', 'PG-VLAN20');             IsLinux = $false },
    @{ Name = 'DC';      Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN10');                          IsLinux = $false },
    @{ Name = 'SRV1';    Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN10');                          IsLinux = $false },
    @{ Name = 'SRV2';    Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN10');                          IsLinux = $false },
    @{ Name = 'RODC';    Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN20');                          IsLinux = $false },
    @{ Name = 'DEV-SRV'; Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN11');                          IsLinux = $false },
    @{ Name = 'DEV-PC';  Template = $linuxTemplate; Snapshot = $linuxSnapshot; Networks = @('PG-VLAN11');                          IsLinux = $true  },
    @{ Name = 'CLIENT';  Template = $winTemplate;   Snapshot = $winSnapshot;   Networks = @('PG-VLAN20');                          IsLinux = $false }
)

foreach ($definition in $vmDefinitions) {
    $vm = Get-VM -Name $definition.Name -ErrorAction SilentlyContinue

    if (-not $vm) {
        Write-Host "Creating $($definition.Name)"

        $resourcePool = Get-ResourcePool -Id $definition.Template.ExtensionData.ResourcePool
        $vmHost = Get-VMHost -Id $definition.Template.ExtensionData.Runtime.Host

        $vm = New-VM `
            -Name $definition.Name `
            -VM $definition.Template `
            -ReferenceSnapshot $definition.Snapshot `
            -LinkedClone `
            -Location $targetFolder `
            -ResourcePool $resourcePool `
            -VMHost $vmHost
    } else {
        Write-Host "$($definition.Name) already exists, updating configuration"
    }

    Set-VM -VM $vm -NumCpu $CpuCount -MemoryGB $MemoryGB -Confirm:$false | Out-Null
    Set-ExactNetworkAdapters -VM $vm -PortGroupNames $definition.Networks

    $templateCdroms = @(Get-CDDrive -VM $definition.Template | Sort-Object Name)
    $vmCdroms       = @(Get-CDDrive -VM $vm               | Sort-Object Name)
    for ($i = 0; $i -lt $templateCdroms.Count; $i++) {
        $vmCdroms[$i] | Set-CDDrive -IsoPath $templateCdroms[$i].IsoPath -StartConnected $true -Confirm:$false | Out-Null
    }

    if ($definition.IsLinux) {
        Set-CloudInitUserData -VM $vm -Username $DefaultUsername -Password $DefaultPassword
    }

    $startSnapshot = Get-Snapshot -VM $vm -Name $StartSnapshotName -ErrorAction SilentlyContinue

    if (-not $startSnapshot) {
        if ($definition.IsLinux) {
            if ((Get-VM -Id $vm.Id).PowerState -eq 'PoweredOn') {
                Stop-VMGuest -VM $vm -Confirm:$false -ErrorAction SilentlyContinue | Out-Null
                Wait-ForVmToPowerOff -VM $vm -TimeoutSeconds $CloudInitShutdownTimeoutSeconds
            }
            Start-VM -VM $vm | Out-Null
            Wait-ForVmToPowerOff -VM $vm -TimeoutSeconds $CloudInitShutdownTimeoutSeconds
        }

        New-Snapshot -VM $vm -Name $StartSnapshotName -Description 'Initial state' -Memory:$false -Quiesce:$false | Out-Null
    }

    Write-Host "$($definition.Name) ready"
}