// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

// <UserAuthConfigSnippet>
import 'isomorphic-fetch';
import { DeviceCodeCredential } from '@azure/identity';
import { Client } from '@microsoft/microsoft-graph-client';
// prettier-ignore
import { TokenCredentialAuthenticationProvider } from
  '@microsoft/microsoft-graph-client/authProviders/azureTokenCredentials/index.js';

let _settings = undefined;
let _deviceCodeCredential = undefined;
let _userClient = undefined;

export function initializeGraphForUserAuth(settings, deviceCodePrompt) {
  // Ensure settings isn't null
  if (!settings) {
    throw new Error('Settings cannot be undefined');
  }

  _settings = settings;

  _deviceCodeCredential = new DeviceCodeCredential({
    clientId: settings.clientId,
    tenantId: settings.tenantId,
    userPromptCallback: deviceCodePrompt,
  });

  const authProvider = new TokenCredentialAuthenticationProvider(
    _deviceCodeCredential,
    {
      scopes: settings.graphUserScopes,
    },
  );

  _userClient = Client.initWithMiddleware({
    authProvider: authProvider,
  });
}
// </UserAuthConfigSnippet>

// <GetUserTokenSnippet>
export async function getUserTokenAsync() {
  // Ensure credential isn't undefined
  if (!_deviceCodeCredential) {
    throw new Error('Graph has not been initialized for user auth');
  }

  // Ensure scopes isn't undefined
  if (!_settings?.graphUserScopes) {
    throw new Error('Setting "scopes" cannot be undefined');
  }

  // Request token with given scopes
  const response = await _deviceCodeCredential.getToken(
    _settings?.graphUserScopes,
  );
  return response.token;
}
// </GetUserTokenSnippet>

// <GetUserSnippet>
export async function getUserAsync() {
  // Ensure client isn't undefined
  if (!_userClient) {
    throw new Error('Graph has not been initialized for user auth');
  }

  // Only request specific properties with .select()
  return _userClient
    .api('/me')
    .select(['displayName', 'mail', 'userPrincipalName'])
    .get();
}
// </GetUserSnippet>

// <GetInboxSnippet>
export async function getInboxAsync() {
  // Ensure client isn't undefined
  if (!_userClient) {
    throw new Error('Graph has not been initialized for user auth');
  }

  return _userClient
    .api('/me/mailFolders/inbox/messages')
    .select(['from', 'isRead', 'receivedDateTime', 'subject'])
    .top(25)
    .orderby('receivedDateTime DESC')
    .get();
}
// </GetInboxSnippet>

// <SendMailSnippet>
export async function sendMailAsync(subject, body, recipient) {
  // Ensure client isn't undefined
  if (!_userClient) {
    throw new Error('Graph has not been initialized for user auth');
  }

  // Create a new message
  const message = {
    subject: subject,
    body: {
      content: body,
      contentType: 'text',
    },
    toRecipients: [
      {
        emailAddress: {
          address: recipient,
        },
      },
    ],
  };

  // Send the message
  return _userClient.api('me/sendMail').post({
    message: message,
  });
}
// </SendMailSnippet>

// <MakeGraphCallSnippet>
// This function serves as a playground for testing Graph snippets
// or other code
export async function makeGraphCallAsync() {
  // INSERT YOUR CODE HERE
}
// </MakeGraphCallSnippet>