1414 */
1515package com.amazonaws.amplify.amplify_api.auth
1616
17+ import android.os.Looper
1718import com.amplifyframework.api.ApiException
1819import com.amplifyframework.api.aws.ApiAuthProviders
1920import com.amplifyframework.api.aws.AuthorizationType
2021import com.amplifyframework.api.aws.sigv4.FunctionAuthProvider
2122import com.amplifyframework.api.aws.sigv4.OidcAuthProvider
23+ import io.flutter.Log
24+ import io.flutter.plugin.common.MethodChannel
25+ import kotlinx.coroutines.*
2226
2327/* *
2428 * Manages the shared state of all [FlutterAuthProvider] instances.
2529 */
26- object FlutterAuthProviders {
30+ class FlutterAuthProviders (private val methodChannel : MethodChannel ) {
31+
32+ private companion object {
33+ /* *
34+ * Timeout on a single [getToken] call.
35+ */
36+ const val getTokenTimeoutMillis = 2000L
37+
38+ /* *
39+ * Logger tag.
40+ */
41+ const val tag = " FlutterAuthProviders"
42+
43+ /* *
44+ * Name for suspending block in [getToken]. Used for debugging
45+ */
46+ val coroutineName = CoroutineName (tag)
47+ }
48+
2749 /* *
2850 * A factory of [FlutterAuthProvider] instances.
2951 */
3052 val factory: ApiAuthProviders by lazy {
3153 ApiAuthProviders
3254 .Builder ()
33- .functionAuthProvider(FlutterAuthProvider (AuthorizationType .AWS_LAMBDA ))
34- .oidcAuthProvider(FlutterAuthProvider (AuthorizationType .OPENID_CONNECT ))
55+ .functionAuthProvider(FlutterAuthProvider (this , AuthorizationType .AWS_LAMBDA ))
56+ .oidcAuthProvider(FlutterAuthProvider (this , AuthorizationType .OPENID_CONNECT ))
3557 .build()
3658 }
3759
38- /* *
39- * Token cache for all [FlutterAuthProvider] instances.
40- */
41- private var tokens: MutableMap <AuthorizationType , String ?> = mutableMapOf ()
42-
4360 /* *
4461 * Retrieves the token for [authType] or `null`, if unavailable.
62+ *
63+ * This function is typically called from within the Amplify library and from a thread besides
64+ * the main one, where it is safe to block. In API REST, the calling thread is main and we must
65+ * return `null`.
66+ *
67+ * Not blocking the main thread is required for making platform channel calls without deadlock.
4568 */
46- fun getToken (authType : AuthorizationType ): String? = tokens[authType]
69+ fun getToken (authType : AuthorizationType ): String? {
70+ if (Thread .currentThread() == Looper .getMainLooper().thread) {
71+ // API REST will call this function from the main thread on configuration. This is bad.
72+ // Since we have to block the calling thread to retrieve the token, just return null.
73+ Log .e(tag, " REST OIDC/Lambda is not supported yet."
74+ return null
75+ }
76+ try {
77+ return runBlocking(coroutineName) {
78+ val completer = Job ()
4779
48- /* *
49- * Sets the token for [authType] to [value].
50- */
51- fun setToken (authType : AuthorizationType , value : String? ) {
52- tokens[authType] = value
80+ val result = object : MethodChannel .Result {
81+ var token: String? = null
82+
83+ override fun success (result : Any? ) {
84+ token = result as ? String
85+ launch(Dispatchers .Main ) {
86+ completer.complete()
87+ }
88+ }
89+
90+ override fun error (
91+ errorCode : String? ,
92+ errorMessage : String? ,
93+ errorDetails : Any?
94+ ) {
95+ launch(Dispatchers .Main ) {
96+ completer.complete()
97+ }
98+ }
99+
100+ override fun notImplemented () {
101+ launch(Dispatchers .Main ) {
102+ completer.complete()
103+ }
104+ }
105+ }
106+ launch(Dispatchers .Main ) {
107+ methodChannel.invokeMethod(
108+ " getLatestAuthToken"
109+ authType.name,
110+ result
111+ )
112+ }
113+
114+ withTimeout(getTokenTimeoutMillis) {
115+ completer.join()
116+ }
117+
118+ return @runBlocking result.token
119+ }
120+ } catch (e: Exception ) {
121+ Log .e(tag, " Exception in getToken"
122+ return null
123+ }
53124 }
54125}
55126
56127/* *
57128 * A provider which manages token retrieval for its [AuthorizationType].
58129 */
59- class FlutterAuthProvider (private val type : AuthorizationType ) : FunctionAuthProvider,
130+ class FlutterAuthProvider (
131+ private val provider : FlutterAuthProviders ,
132+ private val type : AuthorizationType
133+ ) : FunctionAuthProvider,
60134 OidcAuthProvider {
61135 private companion object {
62136 /* *
63137 * Thrown when there is no token available for [type].
64138 */
65139 fun noTokenAvailable (type : AuthorizationType ) = ApiException .ApiAuthException (
66- " No $type token available"
67- " Ensure that `getLatestAuthToken` returns a value"
140+ " Unable to retrieve token for $type "
141+ """
142+ Make sure you register your auth providers in the addPlugin call and
143+ that getLatestAuthToken returns a value.
144+ """ .trimIndent()
68145 )
69146 }
70147
71148 override fun getLatestAuthToken (): String =
72- FlutterAuthProviders .getToken(type) ? : throw noTokenAvailable(type)
149+ provider .getToken(type) ? : throw noTokenAvailable(type)
73150}
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