<#
    .SYNOPSIS
        Check the status of VM Replications.

    .DESCRIPTION 
        This script will check the replication status on VM's primairy and secondairy replication on the host the script is running on,
        This script should be deployed as a Check Script. 

    .OUTPUTS
        Errorcodes: 
        0 - All OK
        1 - There is an error in one of the replications

    .EXAMPLE
        Check_scripts/Win - Hyper-V replication health.ps1

    .NOTES
        Author: D.de Kooker <info@dcomputers.nl>
        Source: n/a

    .CHANGELOG
        17-09-2023 - Initial script. 
#>

# Import the Hyper-V module if not already loaded
if (-not (Get-Module -Name Hyper-V -ListAvailable)) {
    Import-Module Hyper-V
}

# Specify the Hyper-V server you want to check
$HyperVServer = "localhost" # Use "localhost" to check the local Hyper-V server

# Get a list of all replicated virtual machines on the specified Hyper-V server
$ReplicatedVMs = Get-VMReplication -ComputerName $HyperVServer

$ErrorFound = $false # Initialize an error flag

# Loop through each replicated VM and check its replication state
foreach ($VM in $ReplicatedVMs) {
    $ReplicationStatus = Get-VMReplication -VMName $VM.Name -ComputerName $HyperVServer
    $ExtendedReplicationStatus = Get-VMReplication -VMName $VM.Name -ComputerName $HyperVServer -ExtendedReplication

    Write-Host "VM Name: $($VM.Name)"
    Write-Host "Primary Replication State: $($ReplicationStatus.ReplicationState)"
    Write-Host "Primary Last Successful Replication Time: $($ReplicationStatus.LastReplicationTime)"

    Write-Host "Extended Replication State: $($ExtendedReplicationStatus.ReplicationState)"
    Write-Host "Extended Last Successful Replication Time: $($ExtendedReplicationStatus.LastReplicationTime)"
    
    # Check for errors in primary replication state
    if ($ReplicationStatus.ReplicationState -ne "Normal") {
        $ErrorFound = $true
        $LastError = $ReplicationStatus.LastErrorDescription
        Write-Host "Last Primary Error: $LastError"
    }
    
    # Check for errors in extended replication state
    if ($ExtendedReplicationStatus.ReplicationState -ne "Normal") {
        $ErrorFound = $true
        $LastExtendedError = $ExtendedReplicationStatus.LastErrorDescription
        Write-Host "Last Extended Error: $LastExtendedError"
    }

    Write-Host "------------------------"
}

# Output the error code based on whether errors were found or not
if ($ErrorFound) {
    Write-Host "Errors were found in VM replication."
    exit 1 # Use exit code 1 to indicate errors found
} else {
    Write-Host "No errors found in VM replication."
    exit 0 # Use exit code 0 to indicate no errors found
}