# Function to acquire an access token and return the token and its expiration time
function Get-GraphAccessToken {
    $tokenUrl = "https://login.microsoftonline.com/$tenantId/oauth2/v2.0/token"
    $body = @{
        client_id     = $clientId
        scope         = "https://graph.microsoft.com/.default"
        client_secret = $clientSecret
        grant_type    = "client_credentials"
    }

    $tokenResponse = Invoke-RestMethod -Uri $tokenUrl -Method Post -Body $body -ContentType "application/x-www-form-urlencoded"
    $accessToken = $tokenResponse.access_token
    $expiresIn = $tokenResponse.expires_in
    $tokenExpiration = (Get-Date).AddSeconds($expiresIn - 300) # Refresh 5 minutes before expiration

    return $accessToken, $tokenExpiration
}

# Acquire the token
$accessToken, $tokenExpiration = Get-GraphAccessToken
$headers = @{
    Authorization  = "Bearer $accessToken"
    "Content-Type" = "application/json"
}

# Target SharePoint site
$siteUrl = "https://taco.sharepoint.com/sites/test-site" 

# Extract the hostname and site path
$uri = [System.Uri]::new($siteUrl)
$hostname = $uri.Host
$sitePath = $uri.AbsolutePath.TrimStart('/')

# Define the endpoint URL to get the SharePoint site ID
$graphSiteUrl = "https://graph.microsoft.com/v1.0/sites/${hostname}:/${sitePath}"

# Make the request to get the site ID
$siteResponse = Invoke-RestMethod -Uri $graphSiteUrl -Headers $headers -Method Get

# Extract the relevant part of the site ID
$siteIdParts = $siteResponse.id.Split(',')
$siteId = "$($siteIdParts[1]),$($siteIdParts[2])"

# Output the site ID
Write-Output "Site Collection ID: $($siteResponse.siteCollection.hostname)"
Write-Output "Site ID--------> $siteId"
Write-Output "Site Display Name: $($siteResponse.displayName)"
Write-Output "Site Web URL: $($siteResponse.webUrl)"