# Ensure TLS 1.2 for secure connections
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

# Check PowerShell version
$psVersion = $PSVersionTable.PSVersion.Major
if ($psVersion -ge 7) {
    Write-Warning "PowerShell $psVersion may have compatibility issues with ExchangeOnlineManagement. Windows PowerShell 5.1 is recommended."
} else {
    Write-Host "PowerShell $psVersion detected. Proceeding." -ForegroundColor Green
}

# Check and install ExchangeOnlineManagement module
$module = Get-Module -ListAvailable -Name ExchangeOnlineManagement
if (-not $module) {
    Write-Host "Installing ExchangeOnlineManagement module..." -ForegroundColor Yellow
    try {
        Install-Module -Name ExchangeOnlineManagement -Force -Scope CurrentUser -ErrorAction Stop
        Write-Host "Module installed successfully." -ForegroundColor Green
    } catch {
        Write-Host "Failed to install module. Error: $_" -ForegroundColor Red
        exit
    }
} else {
    Write-Host "ExchangeOnlineManagement module already installed." -ForegroundColor Green
}

# Import module
Import-Module ExchangeOnlineManagement

# Connect to Exchange Online
try {
    Connect-ExchangeOnline -ShowProgress $true -ErrorAction Stop
} catch {
    Write-Host "Failed to connect to Exchange Online. Error: $_" -ForegroundColor Red
    exit
}

# Get shared mailboxes with licenses
$results = Get-Mailbox -RecipientTypeDetails SharedMailbox -ResultSize Unlimited |
    ForEach-Object {
        $user = Get-User -Identity $_.UserPrincipalName -ErrorAction SilentlyContinue
        if ($user -and $user.IsLicensed) {
            [PSCustomObject]@{
                DisplayName        = $_.DisplayName
                UserPrincipalName  = $_.UserPrincipalName
                PrimarySmtpAddress = $_.PrimarySmtpAddress
                LicenseStatus      = "Licensed"
            }
        }
    }

# Disconnect from Exchange Online
Disconnect-ExchangeOnline -Confirm:$false

# Export results to CSV
$csvPath = "C:\Temp\LicensedSharedMailboxes.csv"
if ($results) {
    $results | Export-Csv -Path $csvPath -NoTypeInformation -Encoding UTF8
    Write-Host "Licensed shared mailboxes exported to $csvPath" -ForegroundColor Green
} else {
    Write-Host "No licensed shared mailboxes found." -ForegroundColor Yellow
}

# Display results
$results | Format-Table -AutoSize