#Get-O365usagedata
#
# Connect to graph to query office 365 reports
#
# 20190207  initial Version

param (
    [string]$LoginUrl = "https://login.microsoft.com",  # Graph API URLs.
    [string]$ResourceUrl = "https://graph.microsoft.com",  # Ressource API URLs.
    [string]$AppID = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", # App ID aus dem Azure Portal .
    [string]$AppKey = "xxxxxxxxxxxx", # App Key from Portal
    [string]$TenantName = "xxxxxxx.onmicrosoft.com", #  tenant name.
    #[string]$GraphUrl = "https://graph.microsoft.com/v1.0/reports/getOffice365ActivationCounts", # The Graph URL to retrieve data.  
    #[string]$GraphUrl = "https://graph.microsoft.com/v1.0/reports/getOffice365ActivationsUserCounts", # The Graph URL to retrieve data.  
    [string]$GraphUrl = "https://graph.microsoft.com/v1.0/reports/getOffice365ActivationsUserDetail", # The Graph URL to retrieve data.  
    #[string]$GraphUrl = "https://graph.microsoft.com/v1.0/me", 
    #[string]$GraphUrl = "https://graph.microsoft.com/v1.0/reports/getSharePointActivityUserDetail(period='D7')", 
    [string]$csvfilename = ".\report.csv"
)

write-host "Get-O365UsageData: Start"
# Get OAUTH Token

write-host "Get-O365UsageData: Create OAUTh Request"
$Body = @{ grant_type = "client_credentials"; 
            resource = $ResourceUrl;
            client_id = $AppID; 
            client_secret = $AppKey
        }
write-host "Get-O365UsageData: Send OAuth Request"
[object]$OAuth = Invoke-RestMethod -Method Post -Uri "$($LoginUrl)/$($TenantName)/oauth2/token?api-version=1.0" -Body $Body

# Check if authentication is successfull.
if ($null -eq $OAuth.access_token) {
    write-host "Get-O365UsageData: No Token received" -ForegroundColor red
}
else  {  # Perform REST call.
    write-host "Get-O365UsageData: prepare Authorization Header with TokenType $($OAuth.token_type)"
    $HeaderParams = @{ 'Authorization' = "$($OAuth.token_type) $($OAuth.access_token)" }
    try {
        write-host "Get-O365UsageData: Send WebRequest"
        Invoke-WebRequest -UseBasicParsing -Headers $HeaderParams -Uri $GraphUrl -OutFile $csvfilename
        write-host "Get-O365UsageData: Webrequest done: File $($csvfilename) for details"
    }
    catch {
        write-host "Get-O365UsageData: WebRequest failed" -ForegroundColor red
        $_.Exception
        $resultstream = $_.Exception.Response.GetResponseStream()
        $reader = New-Object System.IO.StreamReader($resultstream)
        $ErrorBody = $reader.ReadToEnd();
        write-host "  ResultError:"
        $ErrorBody 
    }
}

write-host "Get-O365UsageData: End"