android app

saars/android-app/app/src/main/AndroidManifest.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <application
+        android:name=".ChatPlatformApp"
+        android:allowBackup="true"
+        android:icon="@android:drawable/ic_menu_send"
+        android:roundIcon="@android:drawable/ic_menu_send"
+        android:label="@string/app_name"
+        android:theme="@style/Theme.ChatPlatform">
+        <activity android:name=".presentation.login.LoginActivity" android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+        <activity android:name=".presentation.MainActivity" android:exported="false" />
+        <activity android:name=".presentation.chat.ChatActivity" android:exported="false" />
+        <activity android:name=".presentation.agent.AgentChatActivity" android:exported="false" />
+        <service android:name=".fcm.ChatFirebaseMessagingService" android:exported="false">
+            <intent-filter>
+                <action android:name="com.google.firebase.MESSAGING_EVENT" />
+            </intent-filter>
+        </service>
+    </application>
+</manifest>

saars/android-app/app/src/main/java/com/saars/chatplatform/ChatPlatformApp.java

@@ -0,0 +1,17 @@
+package com.saars.chatplatform;
+
+import android.app.Application;
+
+import com.saars.chatplatform.data.local.SyncHelper;
+import com.saars.chatplatform.data.remote.RetrofitClient;
+import com.saars.chatplatform.data.remote.SocketManager;
+
+public class ChatPlatformApp extends Application {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        RetrofitClient.init(this);
+        SyncHelper syncHelper = new SyncHelper(this);
+        SocketManager.init(syncHelper);
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/AppDatabase.java

@@ -0,0 +1,35 @@
+package com.saars.chatplatform.data.local;
+
+import android.content.Context;
+
+import androidx.room.Database;
+import androidx.room.Room;
+import androidx.room.RoomDatabase;
+
+import com.saars.chatplatform.data.local.dao.ConversationDao;
+import com.saars.chatplatform.data.local.dao.MessageDao;
+import com.saars.chatplatform.data.local.entity.ConversationEntity;
+import com.saars.chatplatform.data.local.entity.MessageEntity;
+
+@Database(entities = {ConversationEntity.class, MessageEntity.class}, version = 1, exportSchema = false)
+public abstract class AppDatabase extends RoomDatabase {
+    private static volatile AppDatabase instance;
+
+    public abstract ConversationDao conversationDao();
+    public abstract MessageDao messageDao();
+
+    public static AppDatabase getInstance(Context context) {
+        if (instance == null) {
+            synchronized (AppDatabase.class) {
+                if (instance == null) {
+                    instance = Room.databaseBuilder(
+                            context.getApplicationContext(),
+                            AppDatabase.class,
+                            "chat_platform_db"
+                    ).fallbackToDestructiveMigration().build();
+                }
+            }
+        }
+        return instance;
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/SyncHelper.java

@@ -0,0 +1,95 @@
+package com.saars.chatplatform.data.local;
+
+import android.content.Context;
+
+import com.saars.chatplatform.data.local.entity.ConversationEntity;
+import com.saars.chatplatform.data.local.entity.MessageEntity;
+import com.saars.chatplatform.data.remote.ApiService;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/**
+ * Saves API responses to Room for offline; loads from Room first for instant UI.
+ */
+public class SyncHelper {
+    private final AppDatabase db;
+    private final ExecutorService executor = Executors.newSingleThreadExecutor();
+
+    public SyncHelper(Context context) {
+        this.db = AppDatabase.getInstance(context);
+    }
+
+    public void saveConversations(List<ApiService.ConversationItem> items) {
+        executor.execute(() -> {
+            List<ConversationEntity> list = new ArrayList<>();
+            for (ApiService.ConversationItem c : items) {
+                ConversationEntity e = new ConversationEntity();
+                e.id = c.id;
+                e.title = c.title;
+                e.lastMessageAt = c.last_message_at;
+                e.updatedAt = System.currentTimeMillis();
+                list.add(e);
+            }
+            db.conversationDao().insertAll(list);
+        });
+    }
+
+    public void saveMessages(String conversationId, List<ApiService.Message> items) {
+        executor.execute(() -> {
+            db.messageDao().deleteByConversation(conversationId);
+            List<MessageEntity> list = new ArrayList<>();
+            for (ApiService.Message m : items) {
+                MessageEntity e = new MessageEntity();
+                e.id = m.id;
+                e.conversationId = m.conversation_id;
+                e.senderId = m.sender_id;
+                e.content = m.content;
+                e.contentType = m.content_type != null ? m.content_type : "text";
+                e.createdAt = m.created_at;
+                e.pending = false;
+                list.add(e);
+            }
+            db.messageDao().insertAll(list);
+        });
+    }
+
+    public void insertMessage(MessageEntity e) {
+        executor.execute(() -> db.messageDao().insert(e));
+    }
+
+    public List<ConversationEntity> getConversationsFromDb() {
+        return db.conversationDao().getAll();
+    }
+
+    public List<MessageEntity> getMessagesFromDb(String conversationId) {
+        return db.messageDao().getByConversation(conversationId);
+    }
+
+    public void saveSentMessagePending(String conversationId, String localId, String content, String senderId) {
+        MessageEntity e = new MessageEntity();
+        e.id = localId;
+        e.conversationId = conversationId;
+        e.senderId = senderId;
+        e.content = content;
+        e.contentType = "text";
+        e.createdAt = String.valueOf(System.currentTimeMillis());
+        e.pending = true;
+        executor.execute(() -> db.messageDao().insert(e));
+    }
+
+    public void markMessageSynced(String localId, String serverId, String createdAt) {
+        executor.execute(() -> {
+            MessageEntity e = db.messageDao().getById(localId);
+            if (e != null) {
+                db.messageDao().deleteById(localId);
+                e.id = serverId;
+                e.createdAt = createdAt;
+                e.pending = false;
+                db.messageDao().insert(e);
+            }
+        });
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/TokenStore.java

@@ -0,0 +1,42 @@
+package com.saars.chatplatform.data.local;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+/**
+ * Stores JWT token after login.
+ */
+public class TokenStore {
+    private static final String PREFS_NAME = "chat_platform";
+    private static final String KEY_ACCESS_TOKEN = "access_token";
+
+    private final SharedPreferences prefs;
+
+    public TokenStore(Context context) {
+        this.prefs = context.getApplicationContext().getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
+    }
+
+    public void setToken(String token) {
+        prefs.edit().putString(KEY_ACCESS_TOKEN, token).apply();
+    }
+
+    public String getToken() {
+        return prefs.getString(KEY_ACCESS_TOKEN, null);
+    }
+
+    public void clear() {
+        prefs.edit().remove(KEY_ACCESS_TOKEN).apply();
+    }
+
+    public boolean hasToken() {
+        String t = getToken();
+        return t != null && !t.isEmpty();
+    }
+
+    /** "Bearer <token>" for Authorization header */
+    public String getBearerToken() {
+        String t = getToken();
+        if (t == null || t.isEmpty()) return null;
+        return "Bearer " + t;
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/dao/ConversationDao.java

@@ -0,0 +1,28 @@
+package com.saars.chatplatform.data.local.dao;
+
+import androidx.room.Dao;
+import androidx.room.Insert;
+import androidx.room.OnConflictStrategy;
+import androidx.room.Query;
+
+import com.saars.chatplatform.data.local.entity.ConversationEntity;
+
+import java.util.List;
+
+@Dao
+public interface ConversationDao {
+    @Query("SELECT * FROM conversations ORDER BY updatedAt DESC")
+    List<ConversationEntity> getAll();
+
+    @Query("SELECT * FROM conversations WHERE id = :id LIMIT 1")
+    ConversationEntity getById(String id);
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insertAll(List<ConversationEntity> list);
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insert(ConversationEntity e);
+
+    @Query("DELETE FROM conversations")
+    void deleteAll();
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/dao/MessageDao.java

@@ -0,0 +1,34 @@
+package com.saars.chatplatform.data.local.dao;
+
+import androidx.room.Dao;
+import androidx.room.Insert;
+import androidx.room.OnConflictStrategy;
+import androidx.room.Query;
+
+import com.saars.chatplatform.data.local.entity.MessageEntity;
+
+import java.util.List;
+
+@Dao
+public interface MessageDao {
+    @Query("SELECT * FROM messages WHERE conversationId = :conversationId ORDER BY createdAt ASC")
+    List<MessageEntity> getByConversation(String conversationId);
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insert(MessageEntity m);
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insertAll(List<MessageEntity> list);
+
+    @Query("DELETE FROM messages WHERE conversationId = :conversationId")
+    void deleteByConversation(String conversationId);
+
+    @Query("DELETE FROM messages WHERE id = :id")
+    void deleteById(String id);
+
+    @Query("SELECT * FROM messages WHERE id = :id LIMIT 1")
+    MessageEntity getById(String id);
+
+    @Query("DELETE FROM messages")
+    void deleteAll();
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/entity/ConversationEntity.java

@@ -0,0 +1,15 @@
+package com.saars.chatplatform.data.local.entity;
+
+import androidx.room.Entity;
+import androidx.room.PrimaryKey;
+
+@Entity(tableName = "conversations")
+public class ConversationEntity {
+    @PrimaryKey
+    public String id;
+    public String title;
+    public String lastMessageAt;
+    public long updatedAt;
+
+    public ConversationEntity() {}
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/local/entity/MessageEntity.java

@@ -0,0 +1,20 @@
+package com.saars.chatplatform.data.local.entity;
+
+import androidx.room.Entity;
+import androidx.room.Index;
+import androidx.room.PrimaryKey;
+
+@Entity(tableName = "messages", indices = {@Index("conversationId")})
+public class MessageEntity {
+    @PrimaryKey
+    public String id;
+    public String conversationId;
+    public String senderId;
+    public String content;
+    public String contentType;
+    public String createdAt;
+    /** true = saved locally, not yet confirmed by server */
+    public boolean pending;
+
+    public MessageEntity() {}
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/remote/ApiService.java

@@ -0,0 +1,133 @@
+package com.saars.chatplatform.data.remote;
+
+import retrofit2.Call;
+import retrofit2.http.Body;
+import retrofit2.http.GET;
+import retrofit2.http.Header;
+import retrofit2.http.POST;
+import retrofit2.http.Path;
+import retrofit2.http.Query;
+
+/**
+ * Retrofit API interface for chat platform backend.
+ */
+public interface ApiService {
+
+    @POST("api/v1/auth/login")
+    Call<LoginResponse> login(@Body LoginRequest request);
+
+    @POST("api/v1/auth/register")
+    Call<LoginResponse> register(@Body RegisterRequest request);
+
+    /** 知你客服 Agent 代理（方式一，Token 由拦截器统一添加） */
+    @POST("api/v1/agent/chat")
+    Call<AgentChatResponse> agentChat(@Body AgentChatRequest body);
+
+    @GET("api/v1/chat/conversations")
+    Call<ConversationListResponse> getConversations(
+            @Header("Authorization") String token,
+            @Query("skip") int skip,
+            @Query("limit") int limit);
+
+    @POST("api/v1/chat/conversations")
+    Call<ConversationItem> createConversation(
+            @Header("Authorization") String token,
+            @Body CreateConversationRequest body);
+
+    @GET("api/v1/chat/conversations/{id}/messages")
+    Call<MessageListResponse> getMessages(
+            @Header("Authorization") String token,
+            @Path("id") String conversationId,
+            @Query("before_id") String beforeId,
+            @Query("limit") int limit);
+
+    @POST("api/v1/chat/conversations/{id}/messages")
+    Call<Message> sendMessage(
+            @Header("Authorization") String token,
+            @Path("id") String conversationId,
+            @Body SendMessageRequest body);
+
+    class LoginRequest {
+        public String email;
+        public String password;
+        public LoginRequest(String email, String password) {
+            this.email = email;
+            this.password = password;
+        }
+    }
+
+    class RegisterRequest {
+        public String email;
+        public String username;
+        public String password;
+        public RegisterRequest(String email, String username, String password) {
+            this.email = email;
+            this.username = username;
+            this.password = password;
+        }
+    }
+
+    class LoginResponse {
+        public String access_token;
+        public String refresh_token;
+        public User user;
+    }
+
+    class User {
+        public String id;
+        public String email;
+        public String username;
+    }
+
+    class ConversationListResponse {
+        public java.util.List<ConversationItem> items;
+    }
+
+    class ConversationItem {
+        public String id;
+        public String title;
+        public String last_message_at;
+    }
+
+    class MessageListResponse {
+        public java.util.List<Message> items;
+    }
+
+    class Message {
+        public String id;
+        public String conversation_id;
+        public String sender_id;
+        public String content;
+        public String content_type;
+        public String created_at;
+    }
+
+    class SendMessageRequest {
+        public String content;
+        public String content_type;
+        public SendMessageRequest(String content) {
+            this.content = content;
+            this.content_type = "text";
+        }
+    }
+
+    class CreateConversationRequest {
+        public String title;
+        public CreateConversationRequest(String title) {
+            this.title = title;
+        }
+    }
+
+    class AgentChatRequest {
+        public String message;
+        public String user_id;
+        public AgentChatRequest(String message, String user_id) {
+            this.message = message;
+            this.user_id = user_id;
+        }
+    }
+
+    class AgentChatResponse {
+        public String reply;
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/remote/RetrofitClient.java

@@ -0,0 +1,67 @@
+package com.saars.chatplatform.data.remote;
+
+import android.content.Context;
+
+import com.saars.chatplatform.BuildConfig;
+import com.saars.chatplatform.data.local.TokenStore;
+
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.logging.HttpLoggingInterceptor;
+import retrofit2.Retrofit;
+import retrofit2.converter.gson.GsonConverterFactory;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Singleton Retrofit client with auth interceptor.
+ */
+public class RetrofitClient {
+    private static volatile ApiService apiService;
+    private static TokenStore tokenStore;
+
+    public static void init(Context context) {
+        if (tokenStore == null) {
+            tokenStore = new TokenStore(context);
+        }
+    }
+
+    public static TokenStore getTokenStore(Context context) {
+        if (tokenStore == null) tokenStore = new TokenStore(context);
+        return tokenStore;
+    }
+
+    public static ApiService getApi() {
+        if (apiService == null) {
+            synchronized (RetrofitClient.class) {
+                if (apiService == null) {
+                    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
+                    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
+                    OkHttpClient.Builder builder = new OkHttpClient.Builder()
+                            .connectTimeout(15, TimeUnit.SECONDS)
+                            .readTimeout(15, TimeUnit.SECONDS)
+                            .writeTimeout(15, TimeUnit.SECONDS);
+                    builder.addInterceptor(chain -> {
+                        Request original = chain.request();
+                        String auth = tokenStore != null ? tokenStore.getBearerToken() : null;
+                        Request.Builder req = original.newBuilder();
+                        if (auth != null) req.header("Authorization", auth);
+                        req.header("Content-Type", "application/json");
+                        return chain.proceed(req.build());
+                    });
+                    builder.addInterceptor(logging);
+
+                    String baseUrl = BuildConfig.API_BASE_URL;
+                    if (baseUrl != null && !baseUrl.endsWith("/")) baseUrl += "/";
+                    Retrofit retrofit = new Retrofit.Builder()
+                            .baseUrl(baseUrl)
+                            .client(builder.build())
+                            .addConverterFactory(GsonConverterFactory.create())
+                            .build();
+                    apiService = retrofit.create(ApiService.class);
+                }
+            }
+        }
+        return apiService;
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/data/remote/SocketManager.java

@@ -0,0 +1,120 @@
+package com.saars.chatplatform.data.remote;
+
+import android.util.Log;
+
+import com.saars.chatplatform.BuildConfig;
+import com.saars.chatplatform.data.local.SyncHelper;
+
+import org.json.JSONObject;
+
+import java.net.URISyntaxException;
+
+import io.socket.client.IO;
+import io.socket.client.Socket;
+import io.socket.emitter.Emitter;
+
+/**
+ * Socket.IO: connect with token, join conversation room, receive new_message.
+ */
+public class SocketManager {
+    private static final String TAG = "SocketManager";
+    private static Socket socket;
+    private static String currentConversationId;
+    private static NewMessageListener newMessageListener;
+    private static SyncHelper syncHelper;
+
+    public interface NewMessageListener {
+        void onNewMessage(String conversationId, String messageId, String content, String senderId, String createdAt);
+    }
+
+    public static void init(SyncHelper helper) {
+        syncHelper = helper;
+    }
+
+    public static void connect(String token) {
+        if (token == null || token.isEmpty()) return;
+        if (socket != null && socket.connected()) return;
+        try {
+            String base = BuildConfig.API_BASE_URL;
+            if (base != null && base.endsWith("/")) base = base.substring(0, base.length() - 1);
+            IO.Options opts = new IO.Options();
+            opts.forceNew = true;
+            opts.reconnection = true;
+            opts.query = "token=" + token;
+            socket = IO.socket(base, opts);
+            socket.on(Socket.EVENT_CONNECT, args -> Log.d(TAG, "Socket connected"));
+            socket.on(Socket.EVENT_DISCONNECT, args -> Log.d(TAG, "Socket disconnected"));
+            socket.on(Socket.EVENT_CONNECT_ERROR, args -> Log.e(TAG, "Socket error: " + (args.length > 0 ? args[0] : "")));
+            socket.on("new_message", onNewMessage);
+            socket.connect();
+        } catch (URISyntaxException e) {
+            Log.e(TAG, "Socket URI error", e);
+        }
+    }
+
+    public static void disconnect() {
+        if (socket != null) {
+            socket.disconnect();
+            socket.off();
+            socket = null;
+        }
+        currentConversationId = null;
+    }
+
+    public static void joinConversation(String conversationId) {
+        currentConversationId = conversationId;
+        if (socket != null && socket.connected()) {
+            JSONObject obj = new JSONObject();
+            try {
+                obj.put("conversation_id", conversationId);
+                socket.emit("join_conversation", obj);
+            } catch (Exception e) {
+                Log.e(TAG, "join_conversation emit error", e);
+            }
+        }
+    }
+
+    public static void leaveConversation() {
+        if (socket != null && socket.connected() && currentConversationId != null) {
+            try {
+                JSONObject obj = new JSONObject();
+                obj.put("conversation_id", currentConversationId);
+                socket.emit("leave_conversation", obj);
+            } catch (Exception e) {
+                Log.e(TAG, "leave_conversation emit error", e);
+            }
+        }
+        currentConversationId = null;
+    }
+
+    public static void setNewMessageListener(NewMessageListener listener) {
+        newMessageListener = listener;
+    }
+
+    private static final Emitter.Listener onNewMessage = args -> {
+        if (args.length == 0) return;
+        try {
+            JSONObject o = (JSONObject) args[0];
+            String conversationId = o.optString("conversation_id");
+            String id = o.optString("id");
+            String content = o.optString("content");
+            String senderId = o.optString("sender_id");
+            String createdAt = o.optString("created_at");
+            if (syncHelper != null) {
+                com.saars.chatplatform.data.local.entity.MessageEntity e = new com.saars.chatplatform.data.local.entity.MessageEntity();
+                e.id = id;
+                e.conversationId = conversationId;
+                e.senderId = senderId;
+                e.content = content;
+                e.createdAt = createdAt;
+                e.pending = false;
+                syncHelper.insertMessage(e);
+            }
+            if (newMessageListener != null) {
+                newMessageListener.onNewMessage(conversationId, id, content, senderId, createdAt);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "onNewMessage parse error", e);
+        }
+    };
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/domain/repository/ChatRepository.java

@@ -0,0 +1,30 @@
+package com.saars.chatplatform.domain.repository;
+
+import java.util.List;
+
+/**
+ * Repository interface for chat: conversations and messages (domain layer).
+ */
+public interface ChatRepository {
+
+    void loadConversations(LoadCallback callback);
+
+    void loadMessages(String conversationId, String beforeId, int limit, LoadMessagesCallback callback);
+
+    void sendMessage(String conversationId, String content, SendCallback callback);
+
+    interface LoadCallback {
+        void onSuccess(List<?> items);
+        void onError(Throwable t);
+    }
+
+    interface LoadMessagesCallback {
+        void onSuccess(List<?> items);
+        void onError(Throwable t);
+    }
+
+    interface SendCallback {
+        void onSuccess(Object message);
+        void onError(Throwable t);
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/fcm/ChatFirebaseMessagingService.java

@@ -0,0 +1,75 @@
+package com.saars.chatplatform.fcm;
+
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.Intent;
+import android.os.Build;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.core.app.NotificationCompat;
+
+import com.google.firebase.messaging.FirebaseMessagingService;
+import com.google.firebase.messaging.RemoteMessage;
+import com.saars.chatplatform.presentation.MainActivity;
+
+import java.util.Map;
+
+/**
+ * FCM: receive data/notification messages, show notification when app in background.
+ */
+public class ChatFirebaseMessagingService extends FirebaseMessagingService {
+
+    private static final String TAG = "ChatFCM";
+    private static final String CHANNEL_ID = "chat_messages";
+
+    @Override
+    public void onNewToken(@NonNull String token) {
+        Log.d(TAG, "FCM token: " + token);
+        // Optional: send token to backend POST /api/v1/users/me/fcm_token
+    }
+
+    @Override
+    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
+        Map<String, String> data = remoteMessage.getData();
+        if (data != null && !data.isEmpty()) {
+            String title = data.get("title");
+            String body = data.get("body");
+            String conversationId = data.get("conversation_id");
+            showNotification(title != null ? title : "新消息", body != null ? body : "", conversationId);
+            return;
+        }
+        RemoteMessage.Notification notif = remoteMessage.getNotification();
+        if (notif != null) {
+            showNotification(notif.getTitle(), notif.getBody(), null);
+        }
+    }
+
+    private void showNotification(String title, String body, String conversationId) {
+        createChannel();
+        Intent intent = new Intent(this, MainActivity.class);
+        if (conversationId != null) {
+            intent.putExtra("open_conversation_id", conversationId);
+        }
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        PendingIntent pi = PendingIntent.getActivity(this, 0, intent,
+                PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_IMMUTABLE);
+        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
+                .setSmallIcon(android.R.drawable.ic_dialog_email)
+                .setContentTitle(title)
+                .setContentText(body)
+                .setAutoCancel(true)
+                .setContentIntent(pi);
+        NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+        if (nm != null) nm.notify((int) System.currentTimeMillis(), builder.build());
+    }
+
+    private void createChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            NotificationChannel ch = new NotificationChannel(CHANNEL_ID, "聊天消息", NotificationManager.IMPORTANCE_DEFAULT);
+            NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+            if (nm != null) nm.createNotificationChannel(ch);
+        }
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/ConversationListAdapter.java

@@ -0,0 +1,59 @@
+package com.saars.chatplatform.presentation;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.saars.chatplatform.R;
+import com.saars.chatplatform.data.remote.ApiService;
+
+import java.util.List;
+
+public class ConversationListAdapter extends RecyclerView.Adapter<ConversationListAdapter.VH> {
+
+    private final List<ApiService.ConversationItem> items;
+    private final OnItemClickListener listener;
+
+    public interface OnItemClickListener {
+        void onItemClick(ApiService.ConversationItem item);
+    }
+
+    public ConversationListAdapter(List<ApiService.ConversationItem> items, OnItemClickListener listener) {
+        this.items = items;
+        this.listener = listener;
+    }
+
+    @NonNull
+    @Override
+    public VH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_conversation, parent, false);
+        return new VH(v);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull VH holder, int position) {
+        ApiService.ConversationItem item = items.get(position);
+        holder.tvTitle.setText(item.title != null ? item.title : "对话");
+        holder.tvTime.setText(item.last_message_at != null ? item.last_message_at : "");
+        holder.itemView.setOnClickListener(v -> listener.onItemClick(item));
+    }
+
+    @Override
+    public int getItemCount() {
+        return items.size();
+    }
+
+    static class VH extends RecyclerView.ViewHolder {
+        TextView tvTitle, tvTime;
+
+        VH(View itemView) {
+            super(itemView);
+            tvTitle = itemView.findViewById(R.id.tvTitle);
+            tvTime = itemView.findViewById(R.id.tvTime);
+        }
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/MainActivity.java

@@ -0,0 +1,147 @@
+package com.saars.chatplatform.presentation;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.saars.chatplatform.data.local.entity.ConversationEntity;
+import com.saars.chatplatform.data.local.SyncHelper;
+import com.saars.chatplatform.data.local.TokenStore;
+import com.saars.chatplatform.data.remote.ApiService;
+import com.saars.chatplatform.data.remote.RetrofitClient;
+import com.saars.chatplatform.data.remote.SocketManager;
+import com.saars.chatplatform.databinding.ActivityMainBinding;
+import com.saars.chatplatform.presentation.agent.AgentChatActivity;
+import com.saars.chatplatform.presentation.chat.ChatActivity;
+import com.saars.chatplatform.presentation.login.LoginActivity;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class MainActivity extends AppCompatActivity {
+
+    private ActivityMainBinding binding;
+    private TokenStore tokenStore;
+    private SyncHelper syncHelper;
+    private final List<ApiService.ConversationItem> items = new ArrayList<>();
+    private ConversationListAdapter adapter;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        tokenStore = RetrofitClient.getTokenStore(this);
+        if (!tokenStore.hasToken()) {
+            startActivity(new Intent(this, LoginActivity.class));
+            finish();
+            return;
+        }
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+        setSupportActionBar(binding.toolbar);
+
+        adapter = new ConversationListAdapter(items, item -> {
+            Intent i = new Intent(MainActivity.this, ChatActivity.class);
+            i.putExtra(ChatActivity.EXTRA_CONVERSATION_ID, item.id);
+            i.putExtra(ChatActivity.EXTRA_TITLE, item.title != null ? item.title : "对话");
+            startActivity(i);
+        });
+        binding.recycler.setLayoutManager(new LinearLayoutManager(this));
+        binding.recycler.setAdapter(adapter);
+
+        binding.fabNew.setOnClickListener(v -> createConversation());
+        binding.fabAgent.setOnClickListener(v -> startActivity(new Intent(this, AgentChatActivity.class)));
+        syncHelper = new SyncHelper(this);
+        loadFromDbThenApi();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        if (tokenStore.hasToken()) {
+            SocketManager.connect(tokenStore.getToken());
+            loadFromDbThenApi();
+        }
+    }
+
+    private void applyConversationsToUi(List<ConversationEntity> list) {
+        items.clear();
+        for (ConversationEntity e : list) {
+            ApiService.ConversationItem c = new ApiService.ConversationItem();
+            c.id = e.id;
+            c.title = e.title;
+            c.last_message_at = e.lastMessageAt;
+            items.add(c);
+        }
+        adapter.notifyDataSetChanged();
+    }
+
+    private void loadFromDbThenApi() {
+        binding.progress.setVisibility(View.VISIBLE);
+        new Thread(() -> {
+            List<ConversationEntity> fromDb = syncHelper.getConversationsFromDb();
+            runOnUiThread(() -> {
+                applyConversationsToUi(fromDb);
+                binding.progress.setVisibility(View.GONE);
+            });
+        }).start();
+        RetrofitClient.getApi().getConversations(tokenStore.getBearerToken(), 0, 50)
+                .enqueue(new Callback<ApiService.ConversationListResponse>() {
+                    @Override
+                    public void onResponse(Call<ApiService.ConversationListResponse> call,
+                                           Response<ApiService.ConversationListResponse> response) {
+                        if (response.isSuccessful() && response.body() != null && response.body().items != null) {
+                            syncHelper.saveConversations(response.body().items);
+                            new Thread(() -> {
+                                List<ConversationEntity> fromDb = syncHelper.getConversationsFromDb();
+                                runOnUiThread(() -> applyConversationsToUi(fromDb));
+                            }).start();
+                        }
+                        binding.progress.setVisibility(View.GONE);
+                    }
+
+                    @Override
+                    public void onFailure(Call<ApiService.ConversationListResponse> call, Throwable t) {
+                        binding.progress.setVisibility(View.GONE);
+                        Toast.makeText(MainActivity.this, "加载失败: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+                    }
+                });
+    }
+
+    private void createConversation() {
+        binding.fabNew.setEnabled(false);
+        ApiService.CreateConversationRequest req = new ApiService.CreateConversationRequest("新对话");
+        RetrofitClient.getApi().createConversation(tokenStore.getBearerToken(), req)
+                .enqueue(new Callback<ApiService.ConversationItem>() {
+                    @Override
+                    public void onResponse(Call<ApiService.ConversationItem> call,
+                                           Response<ApiService.ConversationItem> response) {
+                        binding.fabNew.setEnabled(true);
+                        if (response.isSuccessful() && response.body() != null) {
+                            items.add(0, response.body());
+                            adapter.notifyItemInserted(0);
+                            Intent i = new Intent(MainActivity.this, ChatActivity.class);
+                            i.putExtra(ChatActivity.EXTRA_CONVERSATION_ID, response.body().id);
+                            i.putExtra(ChatActivity.EXTRA_TITLE, "新对话");
+                            startActivity(i);
+                        } else {
+                            Toast.makeText(MainActivity.this, "创建失败", Toast.LENGTH_SHORT).show();
+                        }
+                    }
+
+                    @Override
+                    public void onFailure(Call<ApiService.ConversationItem> call, Throwable t) {
+                        binding.fabNew.setEnabled(true);
+                        Toast.makeText(MainActivity.this, "创建失败: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+                    }
+                });
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/agent/AgentChatActivity.java

@@ -0,0 +1,158 @@
+package com.saars.chatplatform.presentation.agent;
+
+import android.os.Bundle;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.saars.chatplatform.data.local.SyncHelper;
+import com.saars.chatplatform.data.local.TokenStore;
+import com.saars.chatplatform.data.remote.ApiService;
+import com.saars.chatplatform.data.remote.RetrofitClient;
+import com.saars.chatplatform.databinding.ActivityAgentChatBinding;
+import com.saars.chatplatform.presentation.chat.MessageListAdapter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+/**
+ * 知你客服 Agent 对话页（方式一：通过 SAARS 后端代理调用平台执行 API）
+ */
+public class AgentChatActivity extends AppCompatActivity {
+
+    /** 固定会话 ID，用于 Room 存储历史 */
+    public static final String AGENT_CONVERSATION_ID = "agent_知你客服";
+
+    private ActivityAgentChatBinding binding;
+    private TokenStore tokenStore;
+    private SyncHelper syncHelper;
+    private final List<ApiService.Message> messages = new ArrayList<>();
+    private MessageListAdapter adapter;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        binding = ActivityAgentChatBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        tokenStore = RetrofitClient.getTokenStore(this);
+        syncHelper = new SyncHelper(this);
+        setSupportActionBar(binding.toolbar);
+        if (getSupportActionBar() != null) {
+            getSupportActionBar().setTitle("知你客服");
+            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+        }
+        binding.toolbar.setNavigationOnClickListener(v -> finish());
+
+        adapter = new MessageListAdapter(messages);
+        binding.recycler.setLayoutManager(new LinearLayoutManager(this));
+        binding.recycler.setAdapter(adapter);
+
+        binding.btnSend.setOnClickListener(v -> sendToAgent());
+        loadHistoryFromDb();
+    }
+
+    private void loadHistoryFromDb() {
+        new Thread(() -> {
+            List<com.saars.chatplatform.data.local.entity.MessageEntity> fromDb =
+                    syncHelper.getMessagesFromDb(AGENT_CONVERSATION_ID);
+            runOnUiThread(() -> {
+                messages.clear();
+                for (com.saars.chatplatform.data.local.entity.MessageEntity e : fromDb) {
+                    ApiService.Message m = new ApiService.Message();
+                    m.id = e.id;
+                    m.conversation_id = e.conversationId;
+                    m.sender_id = e.senderId;
+                    m.content = e.content;
+                    m.created_at = e.createdAt;
+                    messages.add(m);
+                }
+                adapter.notifyDataSetChanged();
+                scrollToBottom();
+            });
+        }).start();
+    }
+
+    private void sendToAgent() {
+        String content = binding.etInput.getText().toString().trim();
+        if (content.isEmpty()) return;
+        binding.etInput.setText("");
+        binding.btnSend.setEnabled(false);
+
+        // user_id 不传时后端使用 JWT 的 sub 作为知你客服多轮记忆的 user_id
+        ApiService.AgentChatRequest req = new ApiService.AgentChatRequest(content, null);
+        RetrofitClient.getApi().agentChat(req).enqueue(new Callback<ApiService.AgentChatResponse>() {
+            @Override
+            public void onResponse(Call<ApiService.AgentChatResponse> call, Response<ApiService.AgentChatResponse> response) {
+                binding.btnSend.setEnabled(true);
+                if (response.isSuccessful() && response.body() != null) {
+                    String reply = response.body().reply != null ? response.body().reply : "";
+                    appendUserMessage(content);
+                    appendBotMessage(reply);
+                    scrollToBottom();
+                } else {
+                    Toast.makeText(AgentChatActivity.this, "请求失败: " + response.message(), Toast.LENGTH_SHORT).show();
+                }
+            }
+
+            @Override
+            public void onFailure(Call<ApiService.AgentChatResponse> call, Throwable t) {
+                binding.btnSend.setEnabled(true);
+                Toast.makeText(AgentChatActivity.this, "请求失败: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+            }
+        });
+    }
+
+    private void appendUserMessage(String content) {
+        ApiService.Message m = new ApiService.Message();
+        m.id = "local_u_" + System.currentTimeMillis();
+        m.conversation_id = AGENT_CONVERSATION_ID;
+        m.sender_id = "user";
+        m.content = content;
+        m.created_at = String.valueOf(System.currentTimeMillis());
+        messages.add(m);
+        adapter.notifyItemInserted(messages.size() - 1);
+        saveMessageToRoom(m);
+    }
+
+    private void appendBotMessage(String content) {
+        ApiService.Message m = new ApiService.Message();
+        m.id = "local_b_" + System.currentTimeMillis();
+        m.conversation_id = AGENT_CONVERSATION_ID;
+        m.sender_id = "agent";
+        m.content = content;
+        m.created_at = String.valueOf(System.currentTimeMillis());
+        messages.add(m);
+        adapter.notifyItemInserted(messages.size() - 1);
+        com.saars.chatplatform.data.local.entity.MessageEntity e = new com.saars.chatplatform.data.local.entity.MessageEntity();
+        e.id = m.id;
+        e.conversationId = m.conversation_id;
+        e.senderId = m.sender_id;
+        e.content = m.content;
+        e.createdAt = m.created_at;
+        e.pending = false;
+        syncHelper.insertMessage(e);
+    }
+
+    private void saveMessageToRoom(ApiService.Message m) {
+        com.saars.chatplatform.data.local.entity.MessageEntity e = new com.saars.chatplatform.data.local.entity.MessageEntity();
+        e.id = m.id;
+        e.conversationId = m.conversation_id;
+        e.senderId = m.sender_id;
+        e.content = m.content;
+        e.createdAt = m.created_at;
+        e.pending = false;
+        syncHelper.insertMessage(e);
+    }
+
+    private void scrollToBottom() {
+        if (messages.isEmpty()) return;
+        binding.recycler.smoothScrollToPosition(messages.size() - 1);
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/chat/ChatActivity.java

@@ -0,0 +1,178 @@
+package com.saars.chatplatform.presentation.chat;
+
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.saars.chatplatform.data.local.SyncHelper;
+import com.saars.chatplatform.data.local.TokenStore;
+import com.saars.chatplatform.data.local.entity.MessageEntity;
+import com.saars.chatplatform.data.remote.ApiService;
+import com.saars.chatplatform.data.remote.RetrofitClient;
+import com.saars.chatplatform.data.remote.SocketManager;
+import com.saars.chatplatform.databinding.ActivityChatBinding;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class ChatActivity extends AppCompatActivity {
+
+    public static final String EXTRA_CONVERSATION_ID = "conversation_id";
+    public static final String EXTRA_TITLE = "title";
+
+    private ActivityChatBinding binding;
+    private TokenStore tokenStore;
+    private SyncHelper syncHelper;
+    private String conversationId;
+    private final List<ApiService.Message> messages = new ArrayList<>();
+    private MessageListAdapter adapter;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        binding = ActivityChatBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        conversationId = getIntent().getStringExtra(EXTRA_CONVERSATION_ID);
+        String title = getIntent().getStringExtra(EXTRA_TITLE);
+        if (conversationId == null) {
+            finish();
+            return;
+        }
+        tokenStore = RetrofitClient.getTokenStore(this);
+        syncHelper = new SyncHelper(this);
+        setSupportActionBar(binding.toolbar);
+        if (getSupportActionBar() != null) {
+            getSupportActionBar().setTitle(title != null ? title : "对话");
+            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+        }
+        binding.toolbar.setNavigationOnClickListener(v -> finish());
+
+        adapter = new MessageListAdapter(messages);
+        binding.recycler.setLayoutManager(new LinearLayoutManager(this));
+        binding.recycler.setAdapter(adapter);
+
+        binding.btnSend.setOnClickListener(v -> sendMessage());
+        loadFromDbThenApi();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        SocketManager.joinConversation(conversationId);
+        SocketManager.setNewMessageListener((convId, msgId, content, senderId, createdAt) -> {
+            if (!convId.equals(conversationId)) return;
+            runOnUiThread(() -> {
+                ApiService.Message m = new ApiService.Message();
+                m.id = msgId;
+                m.conversation_id = convId;
+                m.sender_id = senderId;
+                m.content = content;
+                m.created_at = createdAt;
+                messages.add(m);
+                adapter.notifyItemInserted(messages.size() - 1);
+                scrollToBottom();
+            });
+        });
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        SocketManager.leaveConversation();
+        SocketManager.setNewMessageListener(null);
+    }
+
+    private void applyMessagesToUi(List<MessageEntity> list) {
+        messages.clear();
+        for (MessageEntity e : list) {
+            ApiService.Message m = new ApiService.Message();
+            m.id = e.id;
+            m.conversation_id = e.conversationId;
+            m.sender_id = e.senderId;
+            m.content = e.content;
+            m.created_at = e.createdAt;
+            messages.add(m);
+        }
+        adapter.notifyDataSetChanged();
+        scrollToBottom();
+    }
+
+    private void loadFromDbThenApi() {
+        new Thread(() -> {
+            List<MessageEntity> fromDb = syncHelper.getMessagesFromDb(conversationId);
+            runOnUiThread(() -> applyMessagesToUi(fromDb));
+        }).start();
+        RetrofitClient.getApi().getMessages(tokenStore.getBearerToken(), conversationId, null, 50)
+                .enqueue(new Callback<ApiService.MessageListResponse>() {
+                    @Override
+                    public void onResponse(Call<ApiService.MessageListResponse> call,
+                                           Response<ApiService.MessageListResponse> response) {
+                        if (response.isSuccessful() && response.body() != null && response.body().items != null) {
+                            syncHelper.saveMessages(conversationId, response.body().items);
+                            new Thread(() -> {
+                                List<MessageEntity> fromDb = syncHelper.getMessagesFromDb(conversationId);
+                                runOnUiThread(() -> applyMessagesToUi(fromDb));
+                            }).start();
+                        }
+                    }
+
+                    @Override
+                    public void onFailure(Call<ApiService.MessageListResponse> call, Throwable t) {
+                        Toast.makeText(ChatActivity.this, "加载消息失败: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+                    }
+                });
+    }
+
+    private void sendMessage() {
+        String content = binding.etInput.getText().toString().trim();
+        if (content.isEmpty()) return;
+        binding.etInput.setText("");
+        binding.btnSend.setEnabled(false);
+
+        ApiService.SendMessageRequest req = new ApiService.SendMessageRequest(content);
+        RetrofitClient.getApi().sendMessage(tokenStore.getBearerToken(), conversationId, req)
+                .enqueue(new Callback<ApiService.Message>() {
+                    @Override
+                    public void onResponse(Call<ApiService.Message> call, Response<ApiService.Message> response) {
+                        binding.btnSend.setEnabled(true);
+                        if (response.isSuccessful() && response.body() != null) {
+                            ApiService.Message msg = response.body();
+                            messages.add(msg);
+                            adapter.notifyItemInserted(messages.size() - 1);
+                            scrollToBottom();
+                            MessageEntity e = new MessageEntity();
+                            e.id = msg.id;
+                            e.conversationId = msg.conversation_id;
+                            e.senderId = msg.sender_id;
+                            e.content = msg.content;
+                            e.contentType = msg.content_type != null ? msg.content_type : "text";
+                            e.createdAt = msg.created_at;
+                            e.pending = false;
+                            syncHelper.insertMessage(e);
+                        } else {
+                            Toast.makeText(ChatActivity.this, "发送失败: " + response.message(), Toast.LENGTH_SHORT).show();
+                        }
+                    }
+
+                    @Override
+                    public void onFailure(Call<ApiService.Message> call, Throwable t) {
+                        binding.btnSend.setEnabled(true);
+                        Toast.makeText(ChatActivity.this, "发送失败: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+                    }
+                });
+    }
+
+    private void scrollToBottom() {
+        if (messages.isEmpty()) return;
+        binding.recycler.smoothScrollToPosition(messages.size() - 1);
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/chat/MessageListAdapter.java

@@ -0,0 +1,45 @@
+package com.saars.chatplatform.presentation.chat;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+import com.saars.chatplatform.R;
+import com.saars.chatplatform.data.remote.ApiService;
+import java.util.List;
+
+public class MessageListAdapter extends RecyclerView.Adapter<MessageListAdapter.VH> {
+    private final List<ApiService.Message> items;
+
+    public MessageListAdapter(List<ApiService.Message> items) {
+        this.items = items;
+    }
+
+    @NonNull
+    @Override
+    public VH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_message, parent, false);
+        return new VH(v);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull VH holder, int position) {
+        ApiService.Message m = items.get(position);
+        holder.tvMessage.setText(m.content != null ? m.content : "");
+    }
+
+    @Override
+    public int getItemCount() {
+        return items.size();
+    }
+
+    static class VH extends RecyclerView.ViewHolder {
+        TextView tvMessage;
+        VH(View itemView) {
+            super(itemView);
+            tvMessage = itemView.findViewById(R.id.tvMessage);
+        }
+    }
+}

saars/android-app/app/src/main/java/com/saars/chatplatform/presentation/login/LoginActivity.java

@@ -0,0 +1,98 @@
+package com.saars.chatplatform.presentation.login;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import com.saars.chatplatform.data.local.TokenStore;
+import com.saars.chatplatform.data.remote.ApiService;
+import com.saars.chatplatform.data.remote.RetrofitClient;
+import com.saars.chatplatform.databinding.ActivityLoginBinding;
+import com.saars.chatplatform.presentation.MainActivity;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class LoginActivity extends AppCompatActivity {
+
+    private ActivityLoginBinding binding;
+    private TokenStore tokenStore;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        binding = ActivityLoginBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+        tokenStore = RetrofitClient.getTokenStore(this);
+
+        binding.btnLogin.setOnClickListener(v -> doLogin());
+        binding.btnRegister.setOnClickListener(v -> doRegister());
+    }
+
+    private void doLogin() {
+        String email = binding.etEmail.getText().toString().trim();
+        String password = binding.etPassword.getText().toString();
+        if (email.isEmpty() || password.isEmpty()) {
+            Toast.makeText(this, "请输入邮箱和密码", Toast.LENGTH_SHORT).show();
+            return;
+        }
+        binding.btnLogin.setEnabled(false);
+        ApiService.LoginRequest req = new ApiService.LoginRequest(email, password);
+        RetrofitClient.getApi().login(req).enqueue(new Callback<ApiService.LoginResponse>() {
+            @Override
+            public void onResponse(Call<ApiService.LoginResponse> call, Response<ApiService.LoginResponse> response) {
+                binding.btnLogin.setEnabled(true);
+                if (response.isSuccessful() && response.body() != null) {
+                    tokenStore.setToken(response.body().access_token);
+                    com.saars.chatplatform.data.remote.SocketManager.connect(response.body().access_token);
+                    startActivity(new Intent(LoginActivity.this, MainActivity.class));
+                    finish();
+                } else {
+                    Toast.makeText(LoginActivity.this, "登录失败: " + (response.message()), Toast.LENGTH_SHORT).show();
+                }
+            }
+
+            @Override
+            public void onFailure(Call<ApiService.LoginResponse> call, Throwable t) {
+                binding.btnLogin.setEnabled(true);
+                Toast.makeText(LoginActivity.this, "网络错误: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+            }
+        });
+    }
+
+    private void doRegister() {
+        String email = binding.etEmail.getText().toString().trim();
+        String username = binding.etUsername.getText().toString().trim();
+        String password = binding.etPassword.getText().toString();
+        if (email.isEmpty() || username.isEmpty() || password.isEmpty()) {
+            Toast.makeText(this, "请输入邮箱、用户名和密码", Toast.LENGTH_SHORT).show();
+            return;
+        }
+        binding.btnRegister.setEnabled(false);
+        ApiService.RegisterRequest req = new ApiService.RegisterRequest(email, username, password);
+        RetrofitClient.getApi().register(req).enqueue(new Callback<ApiService.LoginResponse>() {
+            @Override
+            public void onResponse(Call<ApiService.LoginResponse> call, Response<ApiService.LoginResponse> response) {
+                binding.btnRegister.setEnabled(true);
+                if (response.isSuccessful() && response.body() != null) {
+                    tokenStore.setToken(response.body().access_token);
+                    com.saars.chatplatform.data.remote.SocketManager.connect(response.body().access_token);
+                    Toast.makeText(LoginActivity.this, "注册成功", Toast.LENGTH_SHORT).show();
+                    startActivity(new Intent(LoginActivity.this, MainActivity.class));
+                    finish();
+                } else {
+                    Toast.makeText(LoginActivity.this, "注册失败: " + response.message(), Toast.LENGTH_SHORT).show();
+                }
+            }
+
+            @Override
+            public void onFailure(Call<ApiService.LoginResponse> call, Throwable t) {
+                binding.btnRegister.setEnabled(true);
+                Toast.makeText(LoginActivity.this, "网络错误: " + t.getMessage(), Toast.LENGTH_SHORT).show();
+            }
+        });
+    }
+}

saars/android-app/app/src/main/res/layout/activity_agent_chat.xml

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+    <com.google.android.material.appbar.MaterialToolbar
+        android:id="@+id/toolbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        app:navigationIcon="@android:drawable/ic_menu_revert"
+        app:title="知你客服" />
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recycler"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:padding="8dp" />
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:padding="8dp">
+        <EditText
+            android:id="@+id/etInput"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:hint="输入消息，与知你客服对话"
+            android:inputType="text"
+            android:minHeight="48dp" />
+        <Button
+            android:id="@+id/btnSend"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="发送"
+            android:layout_marginStart="8dp" />
+    </LinearLayout>
+</LinearLayout>

saars/android-app/app/src/main/res/layout/activity_chat.xml

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+    <com.google.android.material.appbar.MaterialToolbar
+        android:id="@+id/toolbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        app:navigationIcon="@android:drawable/ic_menu_revert"
+        app:title="对话" />
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recycler"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:padding="8dp" />
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:padding="8dp">
+        <EditText
+            android:id="@+id/etInput"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:hint="输入消息"
+            android:inputType="text"
+            android:minHeight="48dp" />
+        <Button
+            android:id="@+id/btnSend"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="发送"
+            android:layout_marginStart="8dp" />
+    </LinearLayout>
+</LinearLayout>

saars/android-app/app/src/main/res/layout/activity_login.xml

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:padding="24dp">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:gravity="center">
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="聊天平台"
+            android:textSize="24sp"
+            android:layout_marginTop="48dp"
+            android:layout_marginBottom="32dp" />
+
+        <com.google.android.material.textfield.TextInputLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="邮箱"
+            style="@style/Widget.Material3.TextInputLayout.OutlinedBox">
+
+            <com.google.android.material.textfield.TextInputEditText
+                android:id="@+id/etEmail"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:inputType="textEmailAddress" />
+        </com.google.android.material.textfield.TextInputLayout>
+
+        <com.google.android.material.textfield.TextInputLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="用户名（注册时填）"
+            style="@style/Widget.Material3.TextInputLayout.OutlinedBox"
+            android:layout_marginTop="16dp">
+
+            <com.google.android.material.textfield.TextInputEditText
+                android:id="@+id/etUsername"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:inputType="text" />
+        </com.google.android.material.textfield.TextInputLayout>
+
+        <com.google.android.material.textfield.TextInputLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="密码"
+            style="@style/Widget.Material3.TextInputLayout.OutlinedBox"
+            android:layout_marginTop="16dp">
+
+            <com.google.android.material.textfield.TextInputEditText
+                android:id="@+id/etPassword"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:inputType="textPassword" />
+        </com.google.android.material.textfield.TextInputLayout>
+
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/btnLogin"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="登录"
+            android:layout_marginTop="24dp" />
+
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/btnRegister"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="注册"
+            style="@style/Widget.Material3.Button.TextButton"
+            android:layout_marginTop="8dp" />
+    </LinearLayout>
+</ScrollView>

saars/android-app/app/src/main/res/layout/activity_main.xml

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+        <com.google.android.material.appbar.MaterialToolbar
+            android:id="@+id/toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="?attr/actionBarSize"
+            android:title="会话列表" />
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior">
+
+        <ProgressBar
+            android:id="@+id/progress"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:visibility="gone" />
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/recycler"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:clipToPadding="false" />
+    </FrameLayout>
+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fabAgent"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|end"
+        android:layout_marginEnd="16dp"
+        android:layout_marginBottom="88dp"
+        android:contentDescription="知你客服"
+        app:srcCompat="@android:drawable/ic_menu_send" />
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fabNew"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="16dp"
+        android:contentDescription="新对话"
+        app:srcCompat="@android:drawable/ic_input_add" />
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

saars/android-app/app/src/main/res/layout/item_conversation.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="16dp"
+    android:background="?attr/selectableItemBackground">
+
+    <TextView
+        android:id="@+id/tvTitle"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:textSize="16sp"
+        android:textStyle="bold"
+        android:maxLines="1"
+        android:ellipsize="end" />
+
+    <TextView
+        android:id="@+id/tvTime"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:textSize="12sp"
+        android:textColor="?android:attr/textColorSecondary"
+        android:layout_marginTop="4dp" />
+</LinearLayout>

saars/android-app/app/src/main/res/layout/item_message.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:padding="8dp">
+    <TextView
+        android:id="@+id/tvMessage"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:maxWidth="280dp"
+        android:padding="12dp"
+        android:textSize="15sp" />
+</FrameLayout>

saars/android-app/app/src/main/res/values/colors.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="primary">#6750A4</color>
+</resources>

saars/android-app/app/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Chat Platform</string>
+</resources>

saars/android-app/app/src/main/res/values/themes.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="Theme.ChatPlatform" parent="Theme.Material3.DayNight.NoActionBar">
+        <item name="colorPrimary">@color/primary</item>
+    </style>
+</resources>