// 能力检测层（伪代码）
sealed interface BackgroundCapability {
    data class Android(
        val ignoreBatteryOptimization: Boolean,
        val exactAlarmGranted: Boolean,
        val foregroundServiceTypes: Set<Int>
    ) : BackgroundCapability
    data class IOS(
        val backgroundModes: Set<String>,
        val backgroundAppRefreshEnabled: Boolean
    ) : BackgroundCapability
}

// 策略路由层
class KeepAliveStrategyResolver @Inject constructor(
    private val androidChecker: AndroidCapabilityChecker,
    private val iosChecker: IOSCapabilityChecker
) {
    fun resolve(): KeepAlivePlan = when (Platform.current) {
        Platform.ANDROID -> androidPlan()
        Platform.IOS -> iosPlan()
    }

    private fun androidPlan(): KeepAlivePlan = buildPlan {
        // 优先级 1：用户已授权白名单 → 精确闹钟 + 前台服务 dataSync
        if (androidChecker.exactAlarmGranted && androidChecker.ignoreBatteryOptimization) {
            add(ExactAlarmHeartbeat(intervalMs = 5 * 60 * 1000))
            add(ForegroundDataSyncService::class.java)
        }
        // 优先级 2：仅忽略电池优化 → WorkManager 周期性任务（≥15 min）
        else if (androidChecker.ignoreBatteryOptimization) {
            add(PeriodicWorkRequestBuilder<SyncWorker>(15, TimeUnit.MINUTES).build())
        }
        // 优先级 3：无任何权限 → 依赖 FCM 高优先级推送唤醒 + 本地缓存合并
        else {
            add(FCMHighPriorityPushHandler())
            add(LocalCacheMergeStrategy())
        }
    }

    private fun iosPlan(): KeepAlivePlan = buildPlan {
        // 仅能声明能力，运行时由系统决定
        if (iosChecker.backgroundModes.contains("remote-notification")) {
            add(SilentPushHandler(maxProcessTimeSec = 25))
        }
        if (iosChecker.backgroundAppRefreshEnabled) {
            add(BGAppRefreshTaskScheduler(minIntervalSec = 15 * 60)) // 系统最终决定
        }
        // 兜底：前台恢复时增量同步
        add(ForegroundIncrementalSync())
    }
}

// 事件：background_task_result
{
  "event": "background_task_result",
  "platform": "android",
  "task_type": "periodic_sync",
  "trigger_source": "workmanager",          // alarm / workmanager / fcm / manual
  "white_list_status": "granted",           // granted / denied / not_requested
  "execution_latency_ms": 12400,
  "result": "success",                      // success / timeout / network_error / permission_revoked
  "battery_level_pct": 68,
  "network_type": "wifi",
  "app_version": "3.2.1",
  "os_version": "14"
}

// lib/background/background_strategy.dart
abstract class BackgroundStrategy {
  Future<bool> initialize();           // 原生初始化
  Future<void> startHeartbeat(Duration interval); // 启动心跳
  Future<void> stopHeartbeat();        // 停止心跳
  Future<PermissionStatus> requestWhitelist();    // 请求白名单
  Stream<BackgroundEvent> get events;  // 统一事件总线
}

// 原生实现通过 Pigeon 生成代码，保证类型安全
// android/src/main/kotlin/.../BackgroundStrategyImpl.kt
// ios/Classes/BackgroundStrategyImpl.swift

graph TD
    A[业务事件触发] --> B{用户在线状态?}
    B -->|在线/前台| C[WebSocket/长连接直接下发]
    B -->|离线/后台| D{消息优先级}
    D -->|P0 即时通讯/VoIP| E[厂商通道/APNs 高优先级<br/>priority=10 / FCM high]
    D -->|P1 业务通知/营销| F[厂商通道/APNs 标准优先级<br/>priority=5 / FCM normal]
    D -->|P2 静默同步/日志| G[Silent Push / BG Task<br/>content-available=1 / FCM data-only]
    E & F & G --> H[统一下发网关<br/>重试/限流/去重]
    H --> I[客户端收到 → 上报送达/点击回执]

// 伪代码：基于网络质量与电量动态调整
fun calculateNextInterval(
    lastRttMs: Long,
    batteryLevel: Int,
    isCharging: Boolean,
    networkType: NetworkType
): Duration {
    var base = when (networkType) {
        NetworkType.WIFI -> 5.minutes
        NetworkType.MOBILE_4G -> 3.minutes
        NetworkType.MOBILE_5G -> 2.minutes
        else -> 10.minutes
    }
    // RTT 补偿
    base *= maxOf(1.0, lastRttMs / 200.0)
    // 电量保护
    if (!isCharging && batteryLevel < 20) base *= 2.0
    if (!isCharging && batteryLevel < 10) base *= 4.0
    // 抖动 ±10% 防止惊群
    return (base * (0.9 + Random.nextDouble() * 0.2)).toLong().milliseconds
}

# .github/workflows/privacy-scan.yml
jobs:
  privacy-lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Run Privacy Lint (Android)
        run: |
          ./gradlew :app:lintVitalRelease -Dlint.check=PermissionUsage,HardwareIds,UserData
      - name: Run Privacy Lint (iOS)
        run: |
          # 使用 xcodebuild + 静态分析规则检查 Info.plist 与代码一致性
          python scripts/ios_privacy_audit.py --plist Info.plist --source .
      - name: Upload Report
        uses: actions/upload-artifact@v4
        with:
          name: privacy-report
          path: build/reports/lint-results*.html

# 后台任务成功率（按机型/OS版本/网络分层）
sum(rate(background_task_success_total[5m])) by (model, os_version, network_type)
/
sum(rate(background_task_total[5m])) by (model, os_version, network_type)

# 白名单授权转化漏斗
whitelist_request_total → whitelist_granted_total → task_execution_success_total

# 电量异常预警
avg_over_time(app_battery_pct_per_hour[1h]) > 3

// utils/PermissionDeepLink.kt
object PermissionDeepLink {
    private val VENDOR_INTENTS = mapOf(
        "xiaomi" to Intent().apply { setClassName("com.miui.securitycenter", "com.miui.permcenter.autostart.AutoStartManagementActivity") },
        "huawei" to Intent().apply { setClassName("com.huawei.systemmanager", "com.huawei.systemmanager.optimize.process.ProtectActivity") },
        "oppo"   to Intent().apply { setClassName("com.coloros.safecenter", "com.coloros.safecenter.permission.startup.StartupAppListActivity") },
        "vivo"   to Intent().apply { setClassName("com.vivo.permissionmanager", "com.vivo.permissionmanager.activity.BgStartUpManagerActivity") },
        "samsung" to Intent().apply { action = "android.settings.APPLICATION_DETAILS_SETTINGS"; data = Uri.parse("package:$packageName") },
        "default" to Intent(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS).apply { data = Uri.parse("package:$packageName") }
    )

    fun jumpToWhitelistSetting(context: Context) {
        val vendor = Build.MANUFACTURER.lowercase()
        val intent = VENDOR_INTENTS.entries.firstOrNull { vendor.contains(it.key) }?.value
            ?: VENDOR_INTENTS["default"]!!
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
        try { context.startActivity(intent) } catch (e: ActivityNotFoundException) {
            // 兜底：应用详情页
            Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS).apply {
                data = Uri.parse("package:$packageName")
                addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
            }.also { context.startActivity(it) }
        }
    }
}