.NET C# web site SSO login using Azure AD Premium

We have a multi-client .net web application written in c# running on Windows Server 2012. We have implemented a number of SSO mechanisms in the past. Now a new client has asked us to replace our current authentication by integrating with their corporate AD system running on Azure AD Premium. In particular the service must use SAML2 for the Single Sign On. We need a simple standalone .NET C# demonstrator that can be installed on our web servers that will talk securely to their Azure AD Premium directory and conduct a login, handle incorrect passwords, indicate a successful login to the application and then pass on any role data attributes that may be returned from AD on successful login. The aim is : 1. to demonstrate it working to the client to prove concept and understand the configuration issues 2. to train our developers 3. to form the basis of the code we bolt on to our current software poduct to minimise the development time needed and project risk. We cannot help with a connection to Azure AD Premium during the development so the developer will need access to this to test the software before handover. We would like to see it demonstrated online before the code is handed over. The code would need enough documentation for us to understand how it works and we would like support to configure it to connect to the client system if we have trouble. Additionally we would appreciate any guidance on setting up and running secure exports from AD of the essential user identification data needed to keep our system users records synchronised.