[CmdletBinding()]
param (
    [Parameter(Mandatory)]
    [string]$vmname,

    [Parameter(Mandatory)]
    [string]$metric
)
$metric = $metric -Replace " ", "%20"

$clientid = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
$clientsecret = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
$subscriptionid = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
$tenantid = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"

$resource = "https://management.azure.com/"
$tokenendpoint = "https://login.microsoftonline.com/$tenantid/oauth2/token"
$body = @{
    grant_type    = "client_credentials"
    resource      = $resource
    client_id     = $clientid
    client_secret = $clientsecret
}
$tokenresponse = Invoke-RestMethod -Method Post -Uri $tokenendpoint -Body $body -ContentType "application/x-www-form-urlencoded"
$accesstoken = $tokenresponse.access_token

$headers = @{
    'Authorization' = "Bearer $accesstoken"
    'Content-Type'  = 'application/json'
}

$requesturi  = "https://management.azure.com/subscriptions/$subscriptionid/providers/Microsoft.Compute/virtualMachines?api-version=2024-07-01"
$ret = (Invoke-RestMethod -Uri $requesturi -Headers $headers -Method Get)
$vms = $ret.value | ForEach-Object {
    [pscustomobject]@{
        Name     = $_.name
        id = $_.id
    }
}
$resourceId = ""
foreach ($vm in $vms) {
  if($vm.Name -eq $vmname){
     $resourceId = $vm.id 
  }
}

if ($resourceId -ne "") {
  $end   = (Get-Date).ToUniversalTime()
  $start = $end.AddMinutes(-5)
  $timespan = "{0}/{1}" -f `
    $start.ToString("yyyy-MM-ddTHH:mm:00Z"), `
    $end.ToString("yyyy-MM-ddTHH:mm:00Z")
    $requesturi = "https://management.azure.com$resourceId/providers/microsoft.insights/metrics" +
       "?api-version=2023-10-01" +
       "&metricnames=$metric" +
       "&timespan=$timespan"
    $ret = Invoke-RestMethod -Uri $requesturi -Headers $headers -Method Get
  if ($ret.value.errorCode -eq "Success") {
    $normalized = $ret.Value.TimeSeries.data |
    Select-Object timeStamp,
    @{
        Name = "Value"
        Expression = {
            foreach ($p in 'average','total','maximum','minimum') {
                if ($_.PSObject.Properties.Name -contains $p) {
                    return $_.$p
                }
            }
            $null
        }
    }
    $normalized = $normalized | Where-Object { $_.Value -ne $null }
    if ($normalized.Count -eq 0) {
      $avg = 0
    } else {
      $avg = ($normalized |Measure-Object -Property Value -Average).Average
    }
    return [Math]::Round($avg)
  } else {
    throw $ret.value.errorCode
  }
} else {
  throw "$($vmname) does not exist. "
}