feat: offline SMS fallback for important notifications

断网时把验证码、来电用短信发到 iPhone：
- ConnectivityMonitor: NetworkCallback 监听在线状态
- CarrierDetector: SIM MCC+MNC 映射移动/联通/电信/广电
- CarrierBalanceQuery: 发免费查询短信拿套餐短信余量，解析回执
- SmsFallbackForwarder: 限频(5min)/余额(≤5挂起)/紧要性检查
- NotificationProcessor 拦截运营商回执(10086/10010/10001/10099)
- 设置页新增短信兜底卡片，首页余额耗尽警告

版本 1.3.0 → 1.4.0

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -18,6 +18,11 @@
 - **失败自动重试**：发送失败的通知进入待重发队列，由 WorkManager 定期重试，也可手动触发。
 - **本地日志**：保留最近 300 条处理记录，方便排查为什么某条通知被过滤或发送失败。
 - **电话来电通知**：通过轮询 `getCallState()` 实时感知来电和未接来电（绕过 MIUI 对系统电话通知的限制，需授予"电话"权限）。
+- **断网短信兜底**：无网络时自动把验证码、来电用短信发到 iPhone。
+  - 自动识别运营商（移动/联通/电信/广电），发免费查询短信拿套餐内短信余量
+  - 余额 ≤5 条自动停用，下次打开 App 提醒
+  - 每 5 分钟最多发 1 条，避免刷屏
+  - 自动解析失败时回退手动额度计数
 
 ## 快速开始
 
@@ -51,6 +56,7 @@
 - **通知没推过来**：先看「日志」页，每条通知（无论转发、过滤还是失败）都会记录原因。
 - **想让通知带图标**：参考下方「应用图标」一节。
 - **电话通知不工作**：MIUI 会把系统电话通知限制为不向第三方通知监听器分发，本 App 通过轮询 `getCallonyState()` 绕过此限制。需要授予「电话」权限（设置 → 应用 → a2i → 权限 → 电话）。
+- **断网收不到通知**：开启「设置 → 断网短信兜底」，填好 iPhone 号码、授予短信权限、设好手动额度。断网时验证码和来电会走短信（消耗套餐额度，5 分钟限 1 条）。
 
 ## 应用图标
 

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "com.a2i.forwarder"
         minSdk = 34
         targetSdk = 36
-        versionCode = 4
+        versionCode = 5
-        versionName = "1.3.0"
+        versionName = "1.4.0"
     }
 
     signingConfigs {

app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.READ_PHONE_STATE" />
+    <uses-permission android:name="android.permission.SEND_SMS" />
     <uses-permission android:name="android.permission.QUERY_ALL_PACKAGES"
         tools:ignore="QueryAllPackagesPermission" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

app/src/main/java/com/a2i/forwarder/A2iApp.kt

@@ -1,8 +1,12 @@
 package com.a2i.forwarder
 
 import android.app.Application
+import com.a2i.forwarder.core.CarrierBalanceQuery
+import com.a2i.forwarder.core.CarrierDetector
+import com.a2i.forwarder.core.ConnectivityMonitor
 import com.a2i.forwarder.core.LogStore
 import com.a2i.forwarder.core.PhoneCallMonitor
+import com.a2i.forwarder.core.SmsFallbackForwarder
 import com.a2i.forwarder.store.AppRulesStore
 import com.a2i.forwarder.store.SettingsStore
 import kotlinx.coroutines.CoroutineScope
@@ -20,6 +24,12 @@ class A2iApp : Application() {
         private set
     lateinit var phoneCallMonitor: PhoneCallMonitor
         private set
+    lateinit var connectivityMonitor: ConnectivityMonitor
+        private set
+    lateinit var carrierBalanceQuery: CarrierBalanceQuery
+        private set
+    lateinit var smsForwarder: SmsFallbackForwarder
+        private set
 
     override fun onCreate() {
         super.onCreate()
@@ -29,6 +39,10 @@ class A2iApp : Application() {
         logStore = LogStore(this, appScope)
         phoneCallMonitor = PhoneCallMonitor(this)
         phoneCallMonitor.start()
+        connectivityMonitor = ConnectivityMonitor(this)
+        connectivityMonitor.start()
+        carrierBalanceQuery = CarrierBalanceQuery(this)
+        smsForwarder = SmsFallbackForwarder(this)
     }
 
     companion object {

app/src/main/java/com/a2i/forwarder/core/CarrierBalanceQuery.kt

@@ -0,0 +1,90 @@
+package com.a2i.forwarder.core
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.telephony.SmsManager
+import androidx.core.content.ContextCompat
+import com.a2i.forwarder.A2iApp
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+
+/**
+ * 运营商短信余额查询：
+ * - refresh()：向运营商服务号发免费查询短信（若运营商支持），回执由 NotificationProcessor 解析。
+ * - 手动模式：递减 smsManualQuota 作为余额。
+ * - parseReply()：从运营商回执短信正文中提取剩余短信条数，供 NotificationProcessor 调用。
+ */
+class CarrierBalanceQuery(private val context: Context) {
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+
+    private val settings get() = A2iApp.instance.settings
+
+    /** 触发一次余额查询（自动模式发短信，手动模式递减额度）。 */
+    suspend fun refresh() {
+        val carrier = currentCarrier()
+        // 自动模式：发查询短信到运营商（免费，不走限频）
+        if (carrier.serviceNumber != null && carrier.queryCmd != null) {
+            sendSms(carrier.serviceNumber, carrier.queryCmd)
+            return
+        }
+        // 手动模式：余额 = 手动额度，不额外查询
+    }
+
+    /** 转发成功后扣减余额（手动模式 / 自动解析失败时）。 */
+    suspend fun decrementManual() {
+        val q = settings.smsManualQuota.value
+        if (q > 0) {
+            val newQ = q - 1
+            settings.setSmsManualQuota(newQ)
+            settings.setSmsBalance(newQ)
+            checkSuspend(newQ)
+        }
+    }
+
+    /** 解析运营商回执，提取剩余短信条数。返回 null 表示解析失败。供 NotificationProcessor 调用。 */
+    fun parseReply(text: String): Int? {
+        // 匹配 "短信剩余XX条" / "短信：XX条" / "短信余量XX条" 等
+        val patterns = listOf(
+            Regex("""短信[^0-9]*(\d+)\s*条"""),
+            Regex("""短信余[额度][^0-9]*(\d+)"""),
+        )
+        for (p in patterns) {
+            val m = p.find(text) ?: continue
+            val n = m.groupValues.getOrNull(1)?.toIntOrNull() ?: continue
+            if (n in 0..9999) return n
+        }
+        return null
+    }
+
+    /** 回执解析成功后更新余额并检查是否需要挂起。 */
+    suspend fun applyParsedBalance(count: Int) {
+        settings.setSmsBalance(count)
+        checkSuspend(count)
+    }
+
+    private suspend fun checkSuspend(balance: Int) {
+        if (balance in 0..5 && !settings.smsSuspended.value) {
+            settings.setSmsSuspended(true)
+        }
+    }
+
+    fun currentCarrier(): CarrierDetector.Carrier {
+        val stored = settings.smsCarrier.value
+        return if (stored == "auto") CarrierDetector.detect(context)
+        else CarrierDetector.Carrier.fromName(stored)
+    }
+
+    private fun sendSms(dest: String, body: String) {
+        if (ContextCompat.checkSelfPermission(context, Manifest.permission.SEND_SMS)
+            != PackageManager.PERMISSION_GRANTED
+        ) return
+        scope.launch {
+            runCatching {
+                SmsManager.getDefault().sendTextMessage(dest, null, body, null, null)
+            }
+        }
+    }
+}

app/src/main/java/com/a2i/forwarder/core/CarrierDetector.kt

@@ -0,0 +1,54 @@
+package com.a2i.forwarder.core
+
+import android.content.Context
+import android.os.Build
+import android.telephony.TelephonyManager
+
+/**
+ * 运营商检测：根据 SIM 的 MCC+MNC 映射到国内运营商。
+ * 提供余额查询用的服务号 + 查询指令。
+ */
+object CarrierDetector {
+
+    enum class Carrier(
+        val displayName: String,
+        val serviceNumber: String?,   // 余额查询服务号（免费）
+        val queryCmd: String?,        // 查询指令（发送到此服务号）
+    ) {
+        CHINA_MOBILE("中国移动", "10086", "CXDX"),
+        CHINA_UNICOM("中国联通", "10010", "CXTC"),
+        CHINA_TELECOM("中国电信", "10001", "108"),
+        CHINA_BROADCASTING("中国广电", "10099", null), // 无统一查询指令
+        UNKNOWN("未知运营商", null, null);
+
+        companion object {
+            fun fromName(name: String?): Carrier =
+                entries.firstOrNull { it.name == name } ?: UNKNOWN
+        }
+    }
+
+    // MCC+MNC → 运营商（中国大陆 460）
+    private val mncMap = mapOf(
+        // 中国移动
+        "46000" to Carrier.CHINA_MOBILE, "46002" to Carrier.CHINA_MOBILE,
+        "46004" to Carrier.CHINA_MOBILE, "46007" to Carrier.CHINA_MOBILE,
+        // 中国联通
+        "46001" to Carrier.CHINA_UNICOM, "46006" to Carrier.CHINA_UNICOM,
+        "46009" to Carrier.CHINA_UNICOM,
+        // 中国电信
+        "46003" to Carrier.CHINA_TELECOM, "46005" to Carrier.CHINA_TELECOM,
+        "46011" to Carrier.CHINA_TELECOM, "46012" to Carrier.CHINA_TELECOM,
+        // 中国广电
+        "46015" to Carrier.CHINA_BROADCASTING, "46018" to Carrier.CHINA_BROADCASTING,
+    )
+
+    fun detect(context: Context): Carrier {
+        return runCatching {
+            val tm = context.getSystemService(Context.TELEPHONY_SERVICE) as? TelephonyManager
+                ?: return Carrier.UNKNOWN
+            val simOperator = tm.simOperator   // 形如 "46000"
+            if (simOperator.isNullOrBlank() || simOperator.length < 5) return Carrier.UNKNOWN
+            mncMap[simOperator] ?: Carrier.UNKNOWN
+        }.getOrDefault(Carrier.UNKNOWN)
+    }
+}

app/src/main/java/com/a2i/forwarder/core/ConnectivityMonitor.kt

@@ -0,0 +1,54 @@
+package com.a2i.forwarder.core
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.Network
+import android.net.NetworkCapabilities
+import android.net.NetworkRequest
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * 监听网络连通性（是否能访问互联网）。
+ * 暴露 isOnline: StateFlow<Boolean>，断网时短信兜底转发器据此降级。
+ */
+class ConnectivityMonitor(private val context: Context) {
+    private val _isOnline = MutableStateFlow(false)
+    val isOnline = _isOnline.asStateFlow()
+
+    private var registered = false
+
+    private val callback = object : ConnectivityManager.NetworkCallback() {
+        override fun onAvailable(network: Network) { refresh() }
+        override fun onLost(network: Network) { refresh() }
+        override fun onCapabilitiesChanged(network: Network, caps: NetworkCapabilities) { refresh() }
+    }
+
+    fun start() {
+        if (registered) return
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as? ConnectivityManager
+            ?: return
+        val request = NetworkRequest.Builder()
+            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+            .build()
+        runCatching { cm.registerNetworkCallback(request, callback) }
+        registered = true
+        refresh()
+    }
+
+    fun stop() {
+        if (!registered) return
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as? ConnectivityManager
+        runCatching { cm?.unregisterNetworkCallback(callback) }
+        registered = false
+    }
+
+    private fun refresh() {
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as? ConnectivityManager ?: return
+        val active = cm.activeNetwork
+        val caps = active?.let { cm.getNetworkCapabilities(it) }
+        _isOnline.value = caps != null &&
+            caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
+            caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
+    }
+}

app/src/main/java/com/a2i/forwarder/core/NotificationProcessor.kt

@@ -126,6 +126,12 @@ class NotificationProcessor(private val context: Context) {
         if (isSentSmsNotification(pkg, title, content))
             return Decision(null, "已发短信（仅收不发）", appLabel, null)
 
+        // ---- 运营商余额回执拦截：解析短信余量，不转发 ----
+        val balanceParsed = tryParseCarrierBalance(pkg, title, content)
+        if (balanceParsed != null) {
+            return Decision(null, "运营商余额回执（${balanceParsed}条）", appLabel, null)
+        }
+
         // ---- 去重检查 ----
         val dedupKey = "$pkg|${title.take(80)}|${content.take(80)}"
         val lastTime = dedupCache[dedupKey]
@@ -220,4 +226,19 @@ class NotificationProcessor(private val context: Context) {
         val blob = "$title $content"
         return sentSmsPatterns.any { it.containsMatchIn(blob) }
     }
+
+    /**
+     * 拦截运营商余额回执短信：title 是运营商服务号（10086/10010/10001/10099），
+     * 解析正文中的剩余短信条数，写入设置并按"过滤"处理。
+     * 返回解析到的条数（已处理），返回 null 表示不是回执或解析失败。
+     */
+    private fun tryParseCarrierBalance(pkg: String, title: String, content: String): Int? {
+        if (pkg !in smsPackages) return null
+        val serviceNumbers = setOf("10086", "10010", "10001", "10099")
+        if (title.trim() !in serviceNumbers) return null
+        val app = A2iApp.instance
+        val count = app.carrierBalanceQuery.parseReply("$title $content") ?: return null
+        kotlinx.coroutines.runBlocking { app.carrierBalanceQuery.applyParsedBalance(count) }
+        return count
+    }
 }

app/src/main/java/com/a2i/forwarder/core/SmsFallbackForwarder.kt

@@ -0,0 +1,105 @@
+package com.a2i.forwarder.core
+
+import android.Manifest
+import android.content.Context
+import android.content.pm.PackageManager
+import android.telephony.SmsManager
+import androidx.core.content.ContextCompat
+import com.a2i.forwarder.A2iApp
+import com.a2i.forwarder.core.NotificationProcessor.Decision
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+
+/**
+ * 短信兜底转发器：断网时把紧要通知（验证码、来电）用短信发到 iPhone。
+ * 限频：每 5 分钟最多 1 条转发短信。余额 ≤5 时自动挂起。
+ */
+class SmsFallbackForwarder(private val context: Context) {
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    private val RATE_LIMIT_MS = 5 * 60 * 1000L
+
+    private val app get() = A2iApp.instance
+    private val settings get() = app.settings
+
+    /** 判断该通知是否值得走短信（断网资源宝贵）。 */
+    fun isSmsWorthy(d: Decision): Boolean {
+        if (d.code != null) return true                      // 验证码
+        val msg = d.message ?: return false
+        if (msg.group == "phone_call") return true           // 来电/未接来电
+        val t = msg.title.orEmpty()
+        return t.contains("来电") || t.contains("未接")
+    }
+
+    /** 尝试用短信转发。返回 true 表示已处理（无论成功失败）。 */
+    fun forward(d: Decision) {
+        scope.launch {
+            if (!settings.smsFallbackEnabled.value) return@launch
+            if (settings.smsSuspended.value) {
+                log(d, "failed", "短信已挂起（余额不足）")
+                return@launch
+            }
+            if (!isSmsWorthy(d)) return@launch
+            val target = settings.smsTargetNumber.value.trim()
+            if (target.isBlank()) {
+                log(d, "failed", "未设置短信目标号")
+                return@launch
+            }
+            // 限频
+            val now = System.currentTimeMillis()
+            val elapsed = now - settings.lastSmsSentTime.value
+            if (elapsed < RATE_LIMIT_MS) {
+                log(d, "filtered", "限频（${RATE_LIMIT_MS - elapsed}ms 内）")
+                return@launch
+            }
+            // 权限
+            if (ContextCompat.checkSelfPermission(context, Manifest.permission.SEND_SMS)
+                != PackageManager.PERMISSION_GRANTED
+            ) {
+                log(d, "failed", "无 SEND_SMS 权限")
+                return@launch
+            }
+
+            val body = compose(d).take(70)
+            val result = runCatching {
+                SmsManager.getDefault().sendTextMessage(target, null, body, null, null)
+            }
+            if (result.isSuccess) {
+                settings.setLastSmsSentTime(now)
+                log(d, "sent", "")
+                // 转发后刷新余额：自动模式发查询短信，手动模式递减
+                val carrier = app.carrierBalanceQuery.currentCarrier()
+                if (carrier.serviceNumber != null && carrier.queryCmd != null) {
+                    app.carrierBalanceQuery.refresh()
+                } else {
+                    app.carrierBalanceQuery.decrementManual()
+                }
+            } else {
+                val reason = result.exceptionOrNull()?.message ?: "短信发送失败"
+                log(d, "failed", reason)
+            }
+        }
+    }
+
+    private fun compose(d: Decision): String {
+        val code = d.code
+        return if (code != null) {
+            "[验证码]${d.appLabel}: $code"
+        } else {
+            val m = d.message!!
+            "${m.title.orEmpty().ifBlank { d.appLabel }}: ${m.body}".trim()
+        }
+    }
+
+    private fun log(d: Decision, status: String, reason: String) {
+        scope.launch {
+            val now = System.currentTimeMillis()
+            val title = d.code?.let { "验证码" } ?: d.message?.title ?: d.appLabel
+            val content = d.code ?: d.message?.body ?: ""
+            app.logStore.addLog(
+                ForwardLog(now, "sms_fallback", d.appLabel, title, content, status, reason)
+            )
+        }
+    }
+}

app/src/main/java/com/a2i/forwarder/service/NotifyListenerService.kt

@@ -44,6 +44,17 @@ class NotifyListenerService : NotificationListenerService() {
             return
         }
 
+        // ---- 断网兜底：离线时紧要通知走短信，其余不转发避免离线堆积 ----
+        val online = app.connectivityMonitor.isOnline.value
+        if (!online) {
+            if (app.smsForwarder.isSmsWorthy(d)) {
+                app.smsForwarder.forward(d)
+            } else {
+                app.logStore.addLog(ForwardLog(now, sbn.packageName, d.appLabel, msg.title, msg.body, "filtered", "离线非紧要通知"))
+            }
+            return
+        }
+
         val server = app.settings.currentServer.value
         if (server == null || server.deviceKey.isBlank()) {
             app.logStore.addLog(ForwardLog(now, sbn.packageName, d.appLabel, msg.title, msg.body, "failed", "未配置 Bark key"))

app/src/main/java/com/a2i/forwarder/store/SettingsStore.kt

@@ -5,6 +5,8 @@ import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
 import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.intPreferencesKey
+import androidx.datastore.preferences.core.longPreferencesKey
 import androidx.datastore.preferences.core.stringPreferencesKey
 import androidx.datastore.preferences.preferencesDataStore
 import com.a2i.forwarder.model.BarkServer
@@ -37,6 +39,14 @@ class SettingsStore(
         val SPECIAL = booleanPreferencesKey("special")
         val SKIP_ONGOING = booleanPreferencesKey("skip_ongoing")
         val AD_KW = stringPreferencesKey("ad_keywords")
+        // 短信兜底
+        val SMS_FALLBACK = booleanPreferencesKey("sms_fallback")
+        val SMS_TARGET = stringPreferencesKey("sms_target")
+        val SMS_CARRIER = stringPreferencesKey("sms_carrier")
+        val SMS_QUOTA = intPreferencesKey("sms_quota")
+        val SMS_BALANCE = intPreferencesKey("sms_balance")
+        val SMS_SUSPENDED = booleanPreferencesKey("sms_suspended")
+        val SMS_LAST_SENT = longPreferencesKey("sms_last_sent")
     }
 
     private val defaultServers = listOf(
@@ -57,6 +67,15 @@ class SettingsStore(
     val skipOngoing = MutableStateFlow(true)
     val adKeywords = MutableStateFlow<List<String>>(emptyList()) // 用户自定义关键词
 
+    // 短信兜底
+    val smsFallbackEnabled = MutableStateFlow(false)
+    val smsTargetNumber = MutableStateFlow("")
+    val smsCarrier = MutableStateFlow("auto")       // "auto" 或 Carrier.name
+    val smsManualQuota = MutableStateFlow(0)         // 手动额度（自动解析失败时回退用）
+    val smsBalance = MutableStateFlow(-1)            // 缓存余额，-1=未知
+    val smsSuspended = MutableStateFlow(false)       // 余额 ≤5 自动挂起
+    val lastSmsSentTime = MutableStateFlow(0L)       // 限频时间戳
+
     init {
         scope.launch {
             ds.data.collect { p ->
@@ -75,6 +94,14 @@ class SettingsStore(
                 adKeywords.value = p[K.AD_KW]
                     ?.let { runCatching { json.decodeFromString<List<String>>(it) }.getOrNull() }
                     ?: emptyList()
+                // 短信兜底
+                smsFallbackEnabled.value = p[K.SMS_FALLBACK] ?: false
+                smsTargetNumber.value = p[K.SMS_TARGET] ?: ""
+                smsCarrier.value = p[K.SMS_CARRIER] ?: "auto"
+                smsManualQuota.value = p[K.SMS_QUOTA] ?: 0
+                smsBalance.value = p[K.SMS_BALANCE] ?: -1
+                smsSuspended.value = p[K.SMS_SUSPENDED] ?: false
+                lastSmsSentTime.value = p[K.SMS_LAST_SENT] ?: 0L
             }
         }
     }
@@ -128,6 +155,14 @@ class SettingsStore(
         adKeywords.value = list
     }
 
+    suspend fun setSmsFallback(v: Boolean) { edit { it[K.SMS_FALLBACK] = v }; smsFallbackEnabled.value = v }
+    suspend fun setSmsTargetNumber(v: String) { edit { it[K.SMS_TARGET] = v }; smsTargetNumber.value = v }
+    suspend fun setSmsCarrier(v: String) { edit { it[K.SMS_CARRIER] = v }; smsCarrier.value = v }
+    suspend fun setSmsManualQuota(v: Int) { edit { it[K.SMS_QUOTA] = v }; smsManualQuota.value = v }
+    suspend fun setSmsBalance(v: Int) { edit { it[K.SMS_BALANCE] = v }; smsBalance.value = v }
+    suspend fun setSmsSuspended(v: Boolean) { edit { it[K.SMS_SUSPENDED] = v }; smsSuspended.value = v }
+    suspend fun setLastSmsSentTime(v: Long) { edit { it[K.SMS_LAST_SENT] = v }; lastSmsSentTime.value = v }
+
     suspend fun snapshot() = ds.data.first()
 
     companion object {

app/src/main/java/com/a2i/forwarder/ui/screens/HomeScreen.kt

@@ -65,6 +65,7 @@ fun HomeScreen(onOpenLog: () -> Unit, onOpenSettings: () -> Unit) {
     val sent by app.logStore.sentCount.collectAsState()
     val filtered by app.logStore.filteredCount.collectAsState()
     val failed by app.logStore.failedCount.collectAsState()
+    val smsSuspended by app.settings.smsSuspended.collectAsState()
 
     var granted by remember { mutableStateOf(isNotificationListenerEnabled(context)) }
     val lifecycleOwner = LocalLifecycleOwner.current
@@ -89,6 +90,28 @@ fun HomeScreen(onOpenLog: () -> Unit, onOpenSettings: () -> Unit) {
             )
         }
 
+        if (smsSuspended) {
+            item {
+                SectionCard {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        IconBox(
+                            icon = Icons.Filled.WarningAmber,
+                            tint = MaterialTheme.colorScheme.error,
+                        )
+                        Spacer(Modifier.width(12.dp))
+                        Column(Modifier.weight(1f)) {
+                            Text("短信兜底已停用", style = MaterialTheme.typography.titleMedium)
+                            Text(
+                                "短信余额不足，断网转发已关闭。请在「设置 → 断网短信兜底」补充额度",
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                    }
+                }
+            }
+        }
+
         item {
             SectionCard {
                 Row(verticalAlignment = Alignment.CenterVertically) {

app/src/main/java/com/a2i/forwarder/ui/screens/SettingsScreen.kt

@@ -80,6 +80,23 @@ fun SettingsScreen(onOpenLog: () -> Unit) {
     var showAdd by remember { mutableStateOf(false) }
     var editing by remember { mutableStateOf<BarkServer?>(null) }
 
+    // 短信兜底状态
+    val smsFallback by app.settings.smsFallbackEnabled.collectAsState()
+    val smsTarget by app.settings.smsTargetNumber.collectAsState()
+    val smsCarrier by app.settings.smsCarrier.collectAsState()
+    val smsQuota by app.settings.smsManualQuota.collectAsState()
+    val smsBalance by app.settings.smsBalance.collectAsState()
+    val smsSuspended by app.settings.smsSuspended.collectAsState()
+    var smsTargetInput by remember(smsTarget) { mutableStateOf(smsTarget) }
+    var smsQuotaInput by remember(smsQuota) { mutableStateOf(if (smsQuota == 0) "" else smsQuota.toString()) }
+    val detectedCarrier = remember { com.a2i.forwarder.core.CarrierDetector.detect(context) }
+
+    val smsPermLauncher = rememberLauncherForActivityResult(ActivityResultContracts.RequestPermission()) { }
+    val hasSmsPerm = remember {
+        androidx.core.content.ContextCompat.checkSelfPermission(context, android.Manifest.permission.SEND_SMS) ==
+            android.content.pm.PackageManager.PERMISSION_GRANTED
+    }
+
     val treeLauncher = rememberLauncherForActivityResult(ActivityResultContracts.OpenDocumentTree()) { uri ->
         if (uri != null) {
             runCatching {
@@ -197,6 +214,75 @@ fun SettingsScreen(onOpenLog: () -> Unit) {
             }
         }
 
+        item {
+            SectionCard("断网短信兜底", subtitle = "无网络时把验证码、来电用短信发到 iPhone（每5分钟1条）") {
+                com.a2i.forwarder.ui.SwitchRow(
+                    title = "启用短信兜底",
+                    subtitle = if (smsFallback) "断网时紧要通知走短信" else "当前关闭",
+                    checked = smsFallback,
+                ) { v -> app.appScope.launch { app.settings.setSmsFallback(v) } }
+
+                Spacer(Modifier.size(8.dp))
+                OutlinedTextField(
+                    value = smsTargetInput,
+                    onValueChange = { smsTargetInput = it },
+                    label = { Text("iPhone 手机号") },
+                    supportingText = { Text("短信转发的目标号码") },
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true,
+                )
+                Spacer(Modifier.size(4.dp))
+                Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                    OutlinedButton(onClick = {
+                        app.appScope.launch { app.settings.setSmsTargetNumber(smsTargetInput.trim()) }
+                    }, modifier = Modifier.weight(1f)) { Text("保存号码") }
+                    if (!hasSmsPerm) {
+                        OutlinedButton(onClick = {
+                            smsPermLauncher.launch(android.Manifest.permission.SEND_SMS)
+                        }, modifier = Modifier.weight(1f)) { Text("授予短信权限") }
+                    }
+                }
+
+                Spacer(Modifier.size(8.dp))
+                Text(
+                    "检测到运营商：${detectedCarrier.displayName}" +
+                        if (detectedCarrier.serviceNumber == null) "（无自动查询，将用手动额度）" else "（${detectedCarrier.serviceNumber}）",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(Modifier.size(8.dp))
+                OutlinedTextField(
+                    value = smsQuotaInput,
+                    onValueChange = { smsQuotaInput = it.filter { c -> c.isDigit() } },
+                    label = { Text("手动短信额度") },
+                    supportingText = { Text("自动查询失败时按此递减；余额≤5自动停用") },
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true,
+                )
+                Spacer(Modifier.size(4.dp))
+                OutlinedButton(onClick = {
+                    val q = smsQuotaInput.trim().toIntOrNull() ?: 0
+                    app.appScope.launch {
+                        app.settings.setSmsManualQuota(q)
+                        app.settings.setSmsBalance(q)
+                        if (q > 5) app.settings.setSmsSuspended(false)
+                    }
+                }) { Text("保存额度并解除挂起") }
+
+                Spacer(Modifier.size(8.dp))
+                val balanceText = when {
+                    smsSuspended -> "已挂起（余额不足）"
+                    smsBalance < 0 -> "余额未知"
+                    else -> "剩余约 ${smsBalance} 条"
+                }
+                Text(
+                    "当前状态：$balanceText",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = if (smsSuspended) MaterialTheme.colorScheme.error else MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        }
+
         item {
             SectionCard("维护", subtitle = "日志查看和本地统计清理") {
                 ClickRow("转发日志", "查看 / 清空最近记录", icon = Icons.Filled.History, onClick = onOpenLog)