fix SSO login flow: use two-phase login then authorize to bypass d1kt redirect bug

android/sample-app/src/main/java/cn/learningpad/oraltrainer/sample/MainActivity.kt

@@ -130,6 +130,7 @@ class MainActivity : Activity() {
     private var showingPhoneBinding = false
     private var ssoPendingToken: String? = null
     private var ssoWebView: WebView? = null
+    private var ssoPhase = 0 // 0=login page, 1=authorize, 2=done
     private var myContentList: LinearLayout? = null
     private var sentenceBoundaryRequestGeneration = 0
     private var catalogVideos: List<TrainingVideoSummary> = emptyList()
@@ -565,6 +566,8 @@ class MainActivity : Activity() {
 
     @Suppress("SetJavaScriptEnabled")
     private fun createSsoWebView(): View {
+        ssoPhase = 0
+
         val authorizeUrl = Uri.parse(SSO_AUTHORIZE_URL).buildUpon()
             .appendQueryParameter("client_id", SSO_CLIENT_ID)
             .appendQueryParameter("redirect_uri", SSO_REDIRECT_URI)
@@ -593,9 +596,18 @@ class MainActivity : Activity() {
             settings.javaScriptEnabled = true
             settings.domStorageEnabled = true
             webViewClient = object : WebViewClient() {
+                override fun onPageFinished(view: WebView?, url: String?) {
+                    super.onPageFinished(view, url)
+                    if (ssoPhase == 0 && url != null && !url.contains("/login")) {
+                        // 用户已登录（离开了登录页），现在加载授权页
+                        ssoPhase = 1
+                        view?.post { view.loadUrl(authorizeUrl) }
+                    }
+                }
+
                 override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
                     val url = request?.url ?: return false
-                    if (url.toString().startsWith(SSO_REDIRECT_URI)) {
+                    if (ssoPhase >= 1 && url.toString().startsWith(SSO_REDIRECT_URI)) {
                         val code = url.getQueryParameter("code")
                         handleSsoCallback(code)
                         return true
@@ -603,7 +615,8 @@ class MainActivity : Activity() {
                     return false
                 }
             }
-            loadUrl(authorizeUrl)
+            // 阶段 1：直接打开第一课堂登录页（绕过授权接口的错误重定向）
+            loadUrl(SSO_LOGIN_URL)
         }
         container.addView(ssoWebView, LinearLayout.LayoutParams(
             ViewGroup.LayoutParams.MATCH_PARENT, 0, 1f
@@ -2447,6 +2460,7 @@ class MainActivity : Activity() {
         const val ASSESSMENT_API_KEY = "fcf60fa10bc1c49e5ddb93d570bc54df5648e187b64096962498d57661c14220"
 
         // 第一课堂 OAuth2 SSO 配置
+        const val SSO_LOGIN_URL = "https://d1kt.cn/login"
         const val SSO_AUTHORIZE_URL = "https://d1kt.cn/api/oauth2/authorize"
         const val SSO_TOKEN_URL = "https://d1kt.cn/api/oauth2/token"
         const val SSO_CLIENT_ID = "oral-trainer-app"