<#
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Name:           Get storage used by Office 365 groups
Description:    This script find Office 365 groups' size and exports the report to CSV file
Version:        1.0
Website:        o365reports.com
For detailed script execution: https://o365reports.com/2022/05/18/get-the-storage-used-by-office-365-groups-using-powershell/
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#>
#PARAMETERS
param
( 
   [Parameter(Mandatory = $false)]
   [Switch] $NoMFA,
   [String] $UserName = $null, 
   [String] $Password = $null,
   [String] $TenantName = $null #(Example : If your tenant name is 'contoso.com', then enter 'contoso' as a tenant name )
)

#Check for SharePoint PnPPowerShellOnline module availability
$PnPOnline = (Get-Module PnP.PowerShell -ListAvailable).Name
if($PnPOnline -eq $null)
{ 
  Write-Host "Important: SharePoint PnP PowerShell module is unavailable. It is mandatory to have this module installed in the system to run the script successfully." 
  $Confirm= Read-Host Are you sure you want to install module? [Y] Yes [N] No  
  if($Confirm -match "[yY]")
  { 
    Write-Host "Installing SharePoint PnP PowerShell module..." -ForegroundColor Magenta
    Install-Module PnP.Powershell -Repository PsGallery -Force -AllowClobber 
    Import-Module PnP.Powershell -Force
    #Register a new Azure AD Application and Grant Access to the tenant
    Register-PnPManagementShellAccess
  } 
  else
  { 
    Write-Host "Exiting. `nNote: SharePoint PnP PowerShell module must be available in your system to run the script" 
    Exit 
  }  
}
 

#Check for ExchangeOnline module availability
$Exchange = (Get-Module ExchangeOnlineManagement -ListAvailable).Name
if ($Exchange -eq $null)
{
  Write-Host "Important: Exchange Online PowerShell module is unavailable. It is mandatory to have this module installed in the system to run the script successfully."  
  $Confirm = Read-Host Are you sure you want to install module? [Y] Yes [N] No  
  if ($Confirm -match "[yY]") 
  { 
    Write-Host "Installing ExchangeOnlineManagement module" -ForegroundColor Magenta
    Install-Module ExchangeOnlineManagement -Repository PSGallery -AllowClobber -Force
    Import-Module ExchangeOnlineManagement -Force
  }
  else
  { 
    Write-Host "Exiting. `nNote: ExchangeOnline PowerShell module must be available in your system to run the script." 
    Exit 
  }
}


#Connecting to ExchangeOnline And SharePoint PnPPowerShellOnline module.......
Write-Host "Connecting to ExchangeOnline and SharePoint PnPPowerShellOnline module..." -ForegroundColor Cyan
#Authentication using non-MFA
if($NoMFA.IsPresent)
{
 #Storing credential in script for scheduling purpose/ Passing credential as parameter
 if(($UserName -ne "") -and ($Password -ne ""))
 { 
  $SecuredPassword = ConvertTo-SecureString -AsPlainText $Password -Force
  $Credential  = New-Object System.Management.Automation.PSCredential $UserName,$SecuredPassword
 }
 else
 {
  $Credential= Get-Credential -Credential $null
 }
 if($TenantName -eq "")
 {
  $TenantName = Read-Host "Enter your Tenant Name to complete the proccess (Example : If your tenant name is 'contoso.com', then enter 'contoso' as a tenant name )  "
 }
  
  Connect-PnPOnline -Url https://$TenantName.sharepoint.com/ -Credentials $Credential
  Connect-ExchangeOnline -Credential $Credential
}
#Authentication using MFA
else
{
  $TenantName = Read-Host "Enter your Tenant Name to complete the proccess (Example : If your tenant name is 'contoso.com', then enter 'contoso' as a tenant name )  " 
  Connect-PnPOnline -Url https://$TenantName.sharepoint.com/ -Interactive   
  Connect-ExchangeOnline 
}


#Get storage used by office 365 groups...
Write-Host "Getting office 365 groups storage..."
$OutputCsv=".\Office365GroupsStorageSizeReport_$((Get-Date -format MMM-dd` hh-mm` tt).ToString()).csv"
#Getting all sites which have an underlying Microsoft 365 group
$GroupSites = Get-PnPTenantSite -GroupIdDefined $true | Select-Object StorageUsageCurrent, StorageQuota, Url  
$GroupCount = 0

Get-UnifiedGroup -ResultSize unlimited | ForEach-Object {
 
 $GroupName = $_.DisplayName
 Write-Progress -Activity "Processed Group Count : $GroupCount" "Currently Processing Group : $GroupName"
 $SharePointSiteUrl = $_.SharePointSiteUrl
 if($SharePointSiteUrl -ne $null)
 {   
   $GroupSite = $GroupSites | Where-Object { $_.Url -eq $SharePointSiteUrl } 
   $GroupStorage = @{'Group Name' = $GroupName; 'Group Email' = $_.PrimarySmtpAddress; 'Group Privacy' = $_.AccessType;'Storage Used (GB)' = [math]::round($GroupSite.StorageUsageCurrent/1024,4); 'Storage Limit (GB)' = $GroupSite.StorageQuota/1024;  'Created On' = $_.WhenCreated}  
 }
 else
 {
   $GroupStorage = @{'Group Name' = $GroupName; 'Group Email' = $_.PrimarySmtpAddress; 'Group Privacy' = $_.AccessType;'Storage Used (GB)' = "Group not used yet"; 'Storage Limit (GB)' = "Group not used yet";  'Created On' = $_.WhenCreated} 
 }
 $ExportGroupStorage = New-Object PSObject -Property $GroupStorage
 $ExportGroupStorage | Select-Object 'Group Name','Group Email','Group Privacy','Storage Used (GB)','Storage Limit (GB)','Created On' | Export-Csv -path $OutputCsv -NoType -Append
 $GroupCount++
}

#Groupcount details
if($GroupCount -ne 0)
{
 Write-Host "$GroupCount Office 365 groups found in this organization"
}
else
{
 Write-Host "There is no office 365 group found in your organization"
}


#Open output file after execution 
if((Test-Path -Path $OutputCsv) -eq "True") 
{ 
  Write-Host "The office 365 groups storage report available in : $OutputCsv" -ForegroundColor Green 
  $Prompt = New-Object -ComObject wscript.shell    
  $UserInput = $Prompt.popup("Do you want to open output file?",` 0,"Open Output File",4)    
  If ($UserInput -eq 6)    
  {    
   Invoke-Item "$OutputCsv"    
  }  
} 

#Disconnect the SharePoint PnPPowerShellOnline module
Disconnect-PnPOnline

#Clean up session
Get-PSSession | Remove-PSSession