MsTeamsChannelProvider Readme

Update from 05th Feb. 2019

MsTeamsManager.Console project was added to solution which demonstrates MSTeamsManager class functionality in native applications. Before start using it you need to grant permissions for MsManager.Console application on your Azure AD apps page.

Note that on the first run application requires your MS login/password to obtain token. Next times it will read it from cache file. There is also ability to login and obtain token through web-browser (see MSTeamsManager.UserLogin()).

Also I've added alias methods to IExternalChannelProvider interace to manage teams. Such as GetTeamUsers, AddUserToTeam, RemoveUserFromTeam which is equal to GetChannelUsers, AddUserToChannel and RemoveUserFromChannel. See Program.cs for example of usage MSTeamsManager synchronous methods.

General notes:

The main class that implements IExternalChannelProvider is MsTeamsChannelProvider. It is in _Siemplify folder inside GraphApi.Web project.
MsTeamsChannelProvider also implements IExternalChannelProviderAsync interface that duplicates methods from IExternalChannelProvider with Async postfix. You could remove synchronous methods from class if not needed.
Base project for MsTeamsChannelProvider implementation is GraphApi.Web sample from here https://github.com/microsoftgraph/csharp-teams-sample-graph.
To test project properly you have to create application in Azure Active Directory. You may use that guide as a starting point (if not yet). You also need to give application Read/Write access for Users and Groups in Graph API category (add it to app in Azure AD).
Then you need to obtain AppId and obtain encrypted password from Azure AD App registration. And then create Web.config.secrets file and paste AppId and AppSecret (encrypted) there.
The test page is http://localhost:55069/ allows you to test/trace all features of MsTeamsChannelProvider class. On first run and further it will redirect you to Microsoft Login Page. You have to login with account that could manage O365 accounts and which has access to Azure Active Directory App.

Notes regarding MsTeamsChannelProvider class:

MsTeamsChannelProvider.CurrentTeamId - this property have to be set before any call. By default it sets to first team on Connect() call. There is also SelectFirstTeam() method that assigns CurrentTeamId to first team.
Actually, MS Teams architecture implies to manipulate teams and users, instead of channels (like in Slack).
GetChannelUsers=GetAllUsers: because all users in team has access to any channel
AddUserToChannel(teamName, displayUserName) - will add user to team and she will have access to all channels at once. If user already in team then exception occurred.
RemoveUserFromChannel(teamName, displayUserName) - removes user from team. If user not in team then exception occurred.
CreateChannel(name, userList): will not process user list. As users that already in team will have access to channel. Use AddUserToChannel call which adds existing Office 365 users to the team.
I left 'Channel' postfix for compatibility with IExternalChannelProvider interface. Actually, XyzChannel calls will manipulate teams, not channels: AddUserToChannel, RemoveUserFromChannel, GetChannelUsers. Exceptions are CloseChannel and CreateChannel which does what it means.

Recommendations:

Use async methods of IExternalChannelProviderAsync to avoid additional calls for synchronous methods. I.e., for instance, use 'await GetAllUsersAsync()' instead of GetAllUsers.
If you don't need synchronous methods then it may be removed from code at all. The reason of using async methods is that most of internal calls of library classes are async as well (e.g to access token and Graph API).
In addition, synchonous methods are just a wrappers arround async methods.
Rename XyzChannel(channelName, userName) to XyzTeam(teamName, userName). E.g., AddUserToChannel -> AddUserToTeam
This is specific for MS Teams, but such naming is not confusing.
Pass teamName or even better teamId to methods instead of using implicit property CurrentTeamId

Future improvements:

As I used already existed project to save time, then the main class MsTeamsExternalProvider may be refactored and trimmed from unnecessary dependencies of that project, like FormOutput class, which is uses to show test application results. Some of the Models classes are not need in MsTeamsExternalProvider class now.
In general, MsTeamsExternalProvider class is a wrapper of existed GraphService class. This may be refactored too.
ChannelUser.Picture isn't filled for now. We may use this API call https://docs.microsoft.com/en-us/graph/api/profilephoto-get?view=graph-rest-1.0 . It returns the binary data of the requested photo, not string or url.
Namespaces needs refactoring
Login to Microsoft account probably may be moved to Connect() method. For now its in Startup.Auth.cs.