Migrating Android Google Drive authorization from Deprecated GoogleSignin API to authorization

drive.kt

import android.app.Activity
import android.content.Context
import android.content.Intent
import android.content.IntentSender.SendIntentException
import androidx.core.app.ActivityCompat.startIntentSenderForResult
import com.google.android.gms.auth.api.identity.AuthorizationRequest
import com.google.android.gms.auth.api.identity.AuthorizationResult
import com.google.android.gms.auth.api.identity.Identity
import com.google.android.gms.common.api.Scope
import com.google.android.gms.tasks.Tasks
import com.google.api.client.http.javanet.NetHttpTransport
import com.google.api.client.json.gson.GsonFactory
import com.google.api.services.drive.Drive
import com.google.api.services.drive.DriveScopes
import com.google.auth.http.HttpCredentialsAdapter
import com.google.auth.oauth2.AccessToken
import com.google.auth.oauth2.IdTokenCredentials

/**
 * GoogleSignIn (com.google.android.gms.auth.api.signin.GoogleSignIn) is now deprecated. We are advised to use Authorization for Android ( https://developers.google.com/identity/authorization/android )
 * Sample provided there is quite minimal and does not go in to detail on how to proceed after getting the "AuthorizationResult"
 * This sample shows how to create "Drive" object after getting the "AuthorizationResult"
 * 
 * Dependencies needed are:
 * com.google.auth:google-auth-library-oauth2-http
 * com.google.android.gms:play-services-auth
 * com.google.http-client:google-http-client-gson
 * com.google.api-client:google-api-client-android
 * com.google.apis:google-api-services-drive
 */
class GoogleSigningHelper {

    companion object {
        private const val tag = "GoogleSigningHelper"
        const val REQUEST_GOOGLE_SIGN_IN_CODE = 0
        private fun getAuthorizationRequest() = AuthorizationRequest
            .builder()
            .setRequestedScopes(listOf(Scope(DriveScopes.DRIVE_FILE)))
            .build()

        private fun getAccessToken(context: Context): String? {
            val accessToken = try {
                val authorizationRequest = getAuthorizationRequest()
                val task = Identity.getAuthorizationClient(context)
                    .authorize(authorizationRequest)
                Tasks.await(task).accessToken

            } catch (e: Exception) {
                CLog.logPrintStackTrace(e)
                null
            }
            return accessToken
        }

        fun getDriveService(context: Context): GoogleDriveAuthResult {
            val accessTokenString = getAccessToken(context)
            return if (accessTokenString != null) {
                val accessToken = AccessToken.newBuilder().setTokenValue(accessTokenString).build()
                val idTokenCredentials = IdTokenCredentials.create(accessToken)
                val httpCredentialsAdapter = HttpCredentialsAdapter(idTokenCredentials)

                GoogleDriveAuthResult.Success(
                    Drive.Builder(NetHttpTransport(), GsonFactory(), httpCredentialsAdapter)
                        .setApplicationName("NLL Drive Client")
                        .build()
                )

            } else {
                GoogleDriveAuthResult.RequireLogin
            }
        }


        fun signOut(context: Context) {
            //Sign out out is not supported by Identity.getAuthorizationClient
        }
    }


    fun requestSignIn(activity: Activity, onAlreadyConnected: (AuthorizationResult?) -> Unit) {
        val authorizationRequest = getAuthorizationRequest()
        Identity.getAuthorizationClient(activity)
            .authorize(authorizationRequest)
            .addOnSuccessListener { authorizationResult ->
                if (authorizationResult.hasResolution()) {
                    // Access needs to be granted by the user
                    try {
                        authorizationResult.pendingIntent?.let { pendingIntent ->
                            startIntentSenderForResult(activity, pendingIntent.intentSender, REQUEST_GOOGLE_SIGN_IN_CODE, null, 0, 0, 0, null)
                        }

                    } catch (e: SendIntentException) {
                        CLog.logPrintStackTrace(e)
                    }
                } else {
                    onAlreadyConnected(authorizationResult)
                }
            }
            .addOnFailureListener { e ->
                CLog.logPrintStackTrace(e)
            }
    }


    fun handleSignInResult(activity: Activity, requestCode: Int, resultData: Intent?): AuthorizationResult? {
        if (requestCode == REQUEST_GOOGLE_SIGN_IN_CODE) {

            if (resultData != null) {
                val authorizationResultFromIntent = Identity
                    .getAuthorizationClient(activity)
                    .getAuthorizationResultFromIntent(resultData)

                return authorizationResultFromIntent
            }
        }

        return null
    }