Android Access Google Photos API via Python REST

import loggingfrom flask import jsonifyfrom googleapiclient.discovery import buildfrom google_auth_oauthlib.flow import Flow# from google.auth.transport.requests import Requestlog = ...def find_google_photos(request):    # userinfo.profile openid required due to    # Warning: Scope has changed from "https://www.googleapis.com/auth/photoslibrary.readonly" to "https://www.googleapis.com/auth/userinfo.profile openid https://www.googleapis.com/auth/photoslibrary.readonly"    # alternative solution: https://stackoverflow.com/a/51643134/561259    scopes = [        'https://www.googleapis.com/auth/userinfo.profile',        'openid',        'https://www.googleapis.com/auth/photoslibrary.readonly'        ]    if not request.is_json:        json_abort(400, message="Invalid request (json)")    data = request.json.get('data')    if not data:        json_abort(400, message="Invalid request (data)")    if 'auth_code' not in data:        json_abort(400, message="Missing auth_code")    # https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html    flow = Flow.from_client_secrets_file(        'keys/oauth2-secret.json',        scopes=scopes)        # if same auth_code is used again        # oauthlib.oauth2.rfc6749.errors.InvalidGrantError: (invalid_grant) Bad Request    flow.fetch_token(code=data['auth_code'])    creds = flow.credentials    # https://github.com/googleapis/google-api-python-client/issues/299    # silence "file_cache is unavailable when using oauth2client >= 4.0.0 or google-auth" with cache_discovery=False    service = build('photoslibrary', 'v1', credentials=creds, cache_discovery=False)    results = service.mediaItems().list(        pageSize=10        ).execute()    items = results.get('mediaItems', [])    if not items:        log.info('No items')    else:        for item in items:            log.info(item['filename'])            # log.info(json.dumps(item, indent=2))    data = {        'media_items': items    }    return jsonify({            'data': data        })

dependencies {
    implementation 'com.google.android.gms:play-services-auth:17.0.0'
    // Optional
    implementation 'com.google.firebase:firebase-functions:19.0.1'
}

class TestFragment : Fragment() {    companion object {        const val REQUEST_GOOGLE_PHOTOS_SIGN_IN = 1    }    fun signIn() {        val serverClientId = ... // from Google Cloud Console -> Credentials -> OAuth Client Id        val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)            .requestScopes(Scope("https://www.googleapis.com/auth/photoslibrary.readonly"))            .requestServerAuthCode(serverClientId)            .build()        val client = GoogleSignIn.getClient(context!!, gso)        startActivityForResult(client.signInIntent, REQUEST_GOOGLE_PHOTOS_SIGN_IN)    }    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {        super.onActivityResult(requestCode, resultCode, data)        if (requestCode == REQUEST_GOOGLE_PHOTOS_SIGN_IN) {            if (resultCode == RESULT_OK) {                GoogleSignIn.getSignedInAccountFromIntent(data)                    .addOnSuccessListener { account ->                        val authCode = account.serverAuthCode                        HttpFunctions.instance.findGooglePhotos(authCode!!)                            .addOnSuccessListener {                                Timber.d(it)                            }                            .addOnFailureListener { e ->                                Timber.e("findGooglePhotos: $e", e)                            }                    }                    .addOnFailureListener { e ->                        Timber.e("REQUEST_GOOGLE_PHOTOS_SIGN_IN fail", e)                    }            }        }    }}

class HttpFunctions {    @Serializable    class FindPlaceResult(val places: List<Place>) {        @Serializable        class Place(@SerialName("place_id") val placeId: String, val name: String, val types: List<String>)    }    companion object {        val instance: HttpFunctions by lazy { HttpFunctions() }    }    private val functions by lazy { FirebaseFunctions.getInstance() }    fun findGooglePhotos(authCode: String): Task<String> {        val data = mapOf(            "auth_code" to authCode        )        return functions.getHttpsCallable("find_google_photos")            .call(data)            .continueWith { task ->                @Suppress("UNCHECKED_CAST")                val result = task.result?.data as Map<String, Any>                // TODO: convert to actual object rather than return json string                JSONObject(result).toString()            }    }}