daily-notification-plugin/ARCHITECTURE.md

DailyNotification Plugin Architecture

Author: Matthew Raymer
Version: 1.0.0
Date: October 20, 2025
Status: 🎯 ACTIVE - Production-ready architecture

Table of Contents

1. Overview
2. Architecture Principles
3. Core Components
4. Data Architecture
5. Storage Implementation
6. Plugin Integration
7. Security Architecture
8. Performance Architecture
9. Migration Strategy
10. Testing Architecture
11. Deployment Architecture
12. Monitoring & Analytics
13. Future Architecture

Overview

The DailyNotification plugin is a Capacitor-based cross-platform notification system designed for TimeSafari applications. It provides enterprise-grade notification management with offline-first capabilities, exact-time scheduling, and comprehensive analytics.

Key Capabilities

• Exact-Time Scheduling: DST-safe notifications with Doze mode compatibility
• Offline-First Design: Works without network connectivity
• Enterprise Data Management: Room database with encryption and retention policies
• Cross-Platform Support: Android (native) and iOS (planned)
• Comprehensive Analytics: Delivery tracking, user interaction analysis, and performance metrics
• Schema Validation: Runtime validation with Zod for data integrity
• Permission Management: Graceful handling of Android 13+ permissions

Architecture Goals

1. Reliability: 99.9% notification delivery success rate
2. Performance: Sub-100ms response times for critical operations
3. Scalability: Support for 10,000+ notifications per user
4. Security: End-to-end encryption for sensitive data
5. Maintainability: Clean separation of concerns and comprehensive testing

Architecture Principles

1. Plugin-First Design

The plugin operates as a self-contained unit with its own:

• Database schema and storage
• Configuration management
• Analytics and reporting
• Security and encryption
• Lifecycle management

2. Offline-First Architecture

All core functionality works without network connectivity:

• Local notification scheduling
• Cached content delivery
• Offline analytics collection
• Local configuration management

3. Data Integrity First

Schema validation at every boundary:

• TypeScript/Zod validation for JavaScript inputs
• Room database constraints for native data
• Encryption for sensitive information
• Retention policies for data lifecycle

4. Performance by Design

Optimized for mobile constraints:

• Background thread execution
• Efficient database queries with proper indexing
• Work deduplication and idempotence
• Battery-aware operations

5. Security by Default

Defense in depth:

• Encryption at rest for sensitive data
• Secure key management
• Permission-based access control
• Audit logging for all operations

Core Components

Plugin Architecture Overview

graph TB
    subgraph "JavaScript Layer"
        A[Vue3 App] --> B[NotificationService]
        B --> C[ValidationService]
        B --> D[PermissionManager]
        B --> E[Capacitor Bridge]
    end
    
    subgraph "Native Android Layer"
        E --> F[DailyNotificationPlugin]
        F --> G[Scheduler]
        F --> H[StorageRoom]
        F --> I[Worker]
        F --> J[Receiver]
    end
    
    subgraph "Data Layer"
        H --> K[Room Database]
        K --> L[Content Entity]
        K --> M[Delivery Entity]
        K --> N[Config Entity]
    end
    
    subgraph "System Integration"
        G --> O[AlarmManager]
        I --> P[WorkManager]
        J --> Q[NotificationManager]
    end

Component Responsibilities

JavaScript Layer

Component	Responsibility	Key Features
NotificationService	High-level notification operations	Schedule, cancel, query notifications
ValidationService	Runtime data validation	Zod schemas, type safety, error handling
PermissionManager	Permission handling and UX	Android 13+ permissions, user education
Capacitor Bridge	Native communication	Method calls, event handling, error propagation

Native Android Layer

Component	Responsibility	Key Features
DailyNotificationPlugin	Main plugin interface	Capacitor integration, method routing
DailyNotificationScheduler	Time-based scheduling	DST-safe calculations, exact alarms
DailyNotificationStorageRoom	Data persistence	Room database, encryption, analytics
DailyNotificationWorker	Background processing	Work deduplication, retry logic
DailyNotificationReceiver	System event handling	Alarm triggers, notification display

Data Architecture

Database Schema Design

The plugin uses Room database with three main entities:

1. NotificationContentEntity

Purpose: Store notification content and metadata

@Entity(tableName = "notification_content")
public class NotificationContentEntity {
    @PrimaryKey String id;                    // Unique notification ID
    String pluginVersion;                      // Plugin version for migration
    String timesafariDid;                      // TimeSafari user identifier
    String notificationType;                   // Type classification
    String title;                              // Notification title
    String body;                               // Notification body
    long scheduledTime;                         // When to deliver
    String timezone;                           // User timezone
    int priority;                              // Notification priority
    boolean vibrationEnabled;                  // Vibration setting
    boolean soundEnabled;                       // Sound setting
    String mediaUrl;                           // Media attachment URL
    String encryptedContent;                   // Encrypted sensitive data
    String encryptionKeyId;                    // Encryption key identifier
    long createdAt;                           // Creation timestamp
    long updatedAt;                           // Last update timestamp
    long ttlSeconds;                          // Time-to-live
    String deliveryStatus;                     // Current delivery status
    int deliveryAttempts;                     // Number of delivery attempts
    long lastDeliveryAttempt;                 // Last attempt timestamp
    int userInteractionCount;                 // User interaction count
    long lastUserInteraction;                 // Last interaction timestamp
    String metadata;                          // Additional metadata
}

2. NotificationDeliveryEntity

Purpose: Track delivery events and analytics

@Entity(tableName = "notification_delivery")
public class NotificationDeliveryEntity {
    @PrimaryKey String id;                     // Unique delivery ID
    String notificationId;                      // Reference to notification
    String timesafariDid;                      // TimeSafari user identifier
    long deliveryTimestamp;                    // When delivery occurred
    String deliveryStatus;                     // Success/failure status
    String deliveryMethod;                      // How it was delivered
    int deliveryAttemptNumber;                 // Attempt sequence number
    long deliveryDurationMs;                   // How long delivery took
    String userInteractionType;                // Type of user interaction
    long userInteractionTimestamp;             // When interaction occurred
    long userInteractionDurationMs;            // Interaction duration
    String errorCode;                          // Error classification
    String errorMessage;                       // Detailed error message
    String deviceInfo;                         // Device context
    String networkInfo;                        // Network context
    int batteryLevel;                          // Battery level at delivery
    boolean dozeModeActive;                     // Doze mode status
    boolean exactAlarmPermission;              // Exact alarm permission
    boolean notificationPermission;           // Notification permission
    String metadata;                          // Additional context
}

3. NotificationConfigEntity

Purpose: Store configuration and user preferences

@Entity(tableName = "notification_config")
public class NotificationConfigEntity {
    @PrimaryKey String id;                     // Unique config ID
    String timesafariDid;                      // TimeSafari user identifier
    String configType;                         // Configuration category
    String configKey;                          // Configuration key
    String configValue;                        // Configuration value
    String configDataType;                     // Data type (boolean, int, string, json)
    boolean isEncrypted;                       // Encryption flag
    String encryptionKeyId;                    // Encryption key identifier
    long createdAt;                           // Creation timestamp
    long updatedAt;                           // Last update timestamp
    long ttlSeconds;                          // Time-to-live
    boolean isActive;                          // Active status
    String metadata;                          // Additional metadata
}

Database Relationships

erDiagram
    NotificationContentEntity ||--o{ NotificationDeliveryEntity : "tracks"
    NotificationContentEntity ||--o{ NotificationConfigEntity : "configured by"
    
    NotificationContentEntity {
        string id PK
        string timesafariDid
        string notificationType
        long scheduledTime
        string deliveryStatus
    }
    
    NotificationDeliveryEntity {
        string id PK
        string notificationId FK
        string timesafariDid
        string deliveryStatus
        long deliveryTimestamp
    }
    
    NotificationConfigEntity {
        string id PK
        string timesafariDid
        string configType
        string configKey
        string configValue
    }

Indexing Strategy

Performance-optimized indexes for common query patterns:

-- NotificationContentEntity indexes
CREATE INDEX idx_notification_content_timesafari_did ON notification_content(timesafari_did);
CREATE INDEX idx_notification_content_type ON notification_content(notification_type);
CREATE INDEX idx_notification_content_scheduled_time ON notification_content(scheduled_time);
CREATE INDEX idx_notification_content_created_at ON notification_content(created_at);
CREATE INDEX idx_notification_content_plugin_version ON notification_content(plugin_version);

-- NotificationDeliveryEntity indexes
CREATE INDEX idx_notification_delivery_notification_id ON notification_delivery(notification_id);
CREATE INDEX idx_notification_delivery_timestamp ON notification_delivery(delivery_timestamp);
CREATE INDEX idx_notification_delivery_status ON notification_delivery(delivery_status);
CREATE INDEX idx_notification_delivery_user_interaction ON notification_delivery(user_interaction_type);
CREATE INDEX idx_notification_delivery_timesafari_did ON notification_delivery(timesafari_did);

-- NotificationConfigEntity indexes
CREATE INDEX idx_notification_config_timesafari_did ON notification_config(timesafari_did);
CREATE INDEX idx_notification_config_type ON notification_config(config_type);
CREATE INDEX idx_notification_config_updated_at ON notification_config(updated_at);

Storage Implementation

Room Database Architecture

Database Class

@Database(
    entities = {
        NotificationContentEntity.class,
        NotificationDeliveryEntity.class,
        NotificationConfigEntity.class
    },
    version = 1,
    exportSchema = false
)
public abstract class DailyNotificationDatabase extends RoomDatabase {
    
    private static final String DATABASE_NAME = "daily_notification_plugin.db";
    private static volatile DailyNotificationDatabase INSTANCE;
    
    public abstract NotificationContentDao notificationContentDao();
    public abstract NotificationDeliveryDao notificationDeliveryDao();
    public abstract NotificationConfigDao notificationConfigDao();
    
    public static DailyNotificationDatabase getInstance(Context context) {
        return Room.databaseBuilder(
            context.getApplicationContext(),
            DailyNotificationDatabase.class,
            DATABASE_NAME
        ).build();
    }
}

DAO Pattern Implementation

NotificationContentDao - Comprehensive CRUD operations:

@Dao
public interface NotificationContentDao {
    // Basic CRUD
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void insertNotification(NotificationContentEntity notification);
    
    @Query("SELECT * FROM notification_content WHERE id = :id")
    NotificationContentEntity getNotificationById(String id);
    
    @Update
    void updateNotification(NotificationContentEntity notification);
    
    @Query("DELETE FROM notification_content WHERE id = :id")
    void deleteNotification(String id);
    
    // Plugin-specific queries
    @Query("SELECT * FROM notification_content WHERE timesafari_did = :timesafariDid ORDER BY scheduled_time ASC")
    List<NotificationContentEntity> getNotificationsByTimeSafariDid(String timesafariDid);
    
    @Query("SELECT * FROM notification_content WHERE scheduled_time <= :currentTime AND delivery_status != 'delivered' ORDER BY scheduled_time ASC")
    List<NotificationContentEntity> getNotificationsReadyForDelivery(long currentTime);
    
    // Analytics queries
    @Query("SELECT COUNT(*) FROM notification_content WHERE notification_type = :notificationType")
    int getNotificationCountByType(String notificationType);
    
    // Cleanup operations
    @Query("DELETE FROM notification_content WHERE (created_at + (ttl_seconds * 1000)) < :currentTime")
    int deleteExpiredNotifications(long currentTime);
}

Storage Service Architecture

DailyNotificationStorageRoom

High-level storage service with async operations:

public class DailyNotificationStorageRoom {
    private DailyNotificationDatabase database;
    private ExecutorService executorService;
    
    // Async notification operations
    public CompletableFuture<Boolean> saveNotificationContent(NotificationContentEntity content) {
        return CompletableFuture.supplyAsync(() -> {
            content.pluginVersion = PLUGIN_VERSION;
            content.touch();
            contentDao.insertNotification(content);
            return true;
        }, executorService);
    }
    
    // Analytics operations
    public CompletableFuture<DeliveryAnalytics> getDeliveryAnalytics(String timesafariDid) {
        return CompletableFuture.supplyAsync(() -> {
            List<NotificationDeliveryEntity> deliveries = deliveryDao.getDeliveriesByTimeSafariDid(timesafariDid);
            // Calculate analytics...
            return analytics;
        }, executorService);
    }
}

Data Migration Strategy

From SharedPreferences to Room

Migration process for existing data:

public class StorageMigration {
    
    public void migrateFromSharedPreferences(Context context) {
        SharedPreferences prefs = context.getSharedPreferences("DailyNotificationPrefs", Context.MODE_PRIVATE);
        Map<String, ?> allData = prefs.getAll();
        
        for (Map.Entry<String, ?> entry : allData.entrySet()) {
            if (entry.getKey().startsWith("notification_")) {
                // Convert SharedPreferences data to Room entity
                NotificationContentEntity entity = convertToEntity(entry.getValue());
                database.notificationContentDao().insertNotification(entity);
            }
        }
    }
    
    private NotificationContentEntity convertToEntity(Object value) {
        // Conversion logic from SharedPreferences format to Room entity
        // Handles data type conversion, field mapping, and validation
    }
}

Plugin Integration

Capacitor Plugin Architecture

Plugin Registration

Automatic plugin discovery via Capacitor annotation processor:

@CapacitorPlugin(name = "DailyNotification")
public class DailyNotificationPlugin extends Plugin {
    
    private DailyNotificationScheduler scheduler;
    private DailyNotificationStorageRoom storage;
    
    @Override
    public void load() {
        scheduler = new DailyNotificationScheduler(getContext());
        storage = new DailyNotificationStorageRoom(getContext());
    }
    
    @PluginMethod
    public void scheduleDailyNotification(PluginCall call) {
        // Implementation with validation and error handling
    }
}

Method Routing

Centralized method handling with validation:

@PluginMethod
public void scheduleDailyNotification(PluginCall call) {
    try {
        // Validate input with Zod schema
        NotificationOptions options = NotificationValidationService.validateNotificationOptions(call.getData());
        
        // Create notification entity
        NotificationContentEntity entity = new NotificationContentEntity(
            options.id, PLUGIN_VERSION, options.timesafariDid,
            options.type, options.title, options.body,
            options.scheduledTime, options.timezone
        );
        
        // Save to Room database
        storage.saveNotificationContent(entity).thenAccept(success -> {
            if (success) {
                // Schedule with AlarmManager
                scheduler.scheduleExactAlarm(entity);
                call.resolve();
            } else {
                call.reject("Failed to save notification");
            }
        });
        
    } catch (ValidationException e) {
        call.reject("Invalid notification options: " + e.getMessage());
    }
}

JavaScript Integration

Service Layer Architecture

High-level service for Vue3 applications:

export class NotificationService {
    private plugin: ValidatedDailyNotificationPlugin;
    private permissionManager: NotificationPermissionManager;
    
    async scheduleNotification(options: NotificationOptions): Promise<boolean> {
        // Validate permissions
        const hasPermissions = await this.permissionManager.checkPermissions();
        if (!hasPermissions) {
            throw new Error('Notification permissions required');
        }
        
        // Schedule notification
        const result = await this.plugin.scheduleDailyNotification(options);
        return result.success;
    }
    
    async getNotificationStatus(): Promise<NotificationStatus> {
        return await this.plugin.checkStatus();
    }
}

Validation Integration

Schema validation at service boundaries:

export class NotificationValidationService {
    static validateNotificationOptions(data: any): NotificationOptions {
        const result = NotificationOptionsSchema.safeParse(data);
        if (!result.success) {
            throw new ValidationException('Invalid notification options', result.error);
        }
        return result.data;
    }
    
    static validateReminderOptions(data: any): ReminderOptions {
        const result = ReminderOptionsSchema.safeParse(data);
        if (!result.success) {
            throw new ValidationException('Invalid reminder options', result.error);
        }
        return result.data;
    }
}

Security Architecture

Encryption Strategy

At-Rest Encryption

Sensitive data encryption for notification content:

public class NotificationEncryption {
    private static final String ALGORITHM = "AES/GCM/NoPadding";
    private static final int KEY_LENGTH = 256;
    
    public String encryptContent(String content, String keyId) {
        try {
            SecretKey key = getOrCreateKey(keyId);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.ENCRYPT_MODE, key);
            
            byte[] encryptedBytes = cipher.doFinal(content.getBytes(StandardCharsets.UTF_8));
            byte[] iv = cipher.getIV();
            
            // Combine IV + encrypted data
            byte[] combined = new byte[iv.length + encryptedBytes.length];
            System.arraycopy(iv, 0, combined, 0, iv.length);
            System.arraycopy(encryptedBytes, 0, combined, iv.length, encryptedBytes.length);
            
            return Base64.encodeToString(combined, Base64.DEFAULT);
        } catch (Exception e) {
            throw new EncryptionException("Failed to encrypt content", e);
        }
    }
}

Key Management

Secure key storage using Android Keystore:

public class NotificationKeyManager {
    private static final String KEY_ALIAS = "DailyNotificationKey";
    private static final String ANDROID_KEYSTORE = "AndroidKeyStore";
    
    public SecretKey getOrCreateKey(String keyId) {
        try {
            KeyStore keyStore = KeyStore.getInstance(ANDROID_KEYSTORE);
            keyStore.load(null);
            
            if (keyStore.containsAlias(KEY_ALIAS)) {
                return (SecretKey) keyStore.getKey(KEY_ALIAS, null);
            } else {
                return createNewKey();
            }
        } catch (Exception e) {
            throw new KeyManagementException("Failed to get encryption key", e);
        }
    }
    
    private SecretKey createNewKey() {
        try {
            KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, ANDROID_KEYSTORE);
            KeyGenParameterSpec keyGenParameterSpec = new KeyGenParameterSpec.Builder(KEY_ALIAS,
                    KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
                    .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                    .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                    .setKeySize(KEY_LENGTH)
                    .build();
            
            keyGenerator.init(keyGenParameterSpec);
            return keyGenerator.generateKey();
        } catch (Exception e) {
            throw new KeyManagementException("Failed to create encryption key", e);
        }
    }
}

Permission Architecture

Android 13+ Permission Handling

Graceful permission management with user education:

export class NotificationPermissionManager {
    async checkPermissions(): Promise<PermissionStatus> {
        const platform = Capacitor.getPlatform();
        if (platform === 'web') {
            return { granted: false, reason: 'Web platform not supported' };
        }
        
        // Check POST_NOTIFICATIONS permission (Android 13+)
        const hasNotificationPermission = await this.checkNotificationPermission();
        
        // Check SCHEDULE_EXACT_ALARM permission (Android 12+)
        const hasExactAlarmPermission = await this.checkExactAlarmPermission();
        
        return {
            granted: hasNotificationPermission && hasExactAlarmPermission,
            notificationPermission: hasNotificationPermission,
            exactAlarmPermission: hasExactAlarmPermission
        };
    }
    
    async requestPermissions(): Promise<boolean> {
        const status = await this.checkPermissions();
        
        if (!status.notificationPermission) {
            await this.requestNotificationPermission();
        }
        
        if (!status.exactAlarmPermission) {
            await this.requestExactAlarmPermission();
        }
        
        return status.granted;
    }
}

Permission UX Flow

User-friendly permission requests with education:

export class PermissionUXManager {
    async showPermissionRationale(): Promise<void> {
        const rationale = `
            Daily notifications help you stay on track with your TimeSafari goals.
            
            We need:
            • Notification permission to show reminders
            • Exact alarm permission for precise timing
            
            You can change these settings later in your device settings.
        `;
        
        await this.showDialog({
            title: 'Enable Notifications',
            message: rationale,
            buttons: [
                { text: 'Not Now', role: 'cancel' },
                { text: 'Enable', handler: () => this.requestPermissions() }
            ]
        });
    }
}

Performance Architecture

Background Processing

WorkManager Integration

Efficient background work with deduplication:

public class DailyNotificationWorker extends Worker {
    private static final ConcurrentHashMap<String, AtomicBoolean> activeWork = new ConcurrentHashMap<>();
    private static final ConcurrentHashMap<String, Long> workTimestamps = new ConcurrentHashMap<>();
    
    @Override
    public Result doWork() {
        String workKey = createWorkKey(notificationId, action);
        
        // Prevent duplicate work execution
        if (!acquireWorkLock(workKey)) {
            Log.d(TAG, "Skipping duplicate work: " + workKey);
            return Result.success();
        }
        
        try {
            // Check if work already completed
            if (isWorkAlreadyCompleted(workKey)) {
                Log.d(TAG, "Work already completed: " + workKey);
                return Result.success();
            }
            
            // Execute actual work
            Result result = executeWork();
            
            // Mark as completed if successful
            if (result == Result.success()) {
                markWorkAsCompleted(workKey);
            }
            
            return result;
        } finally {
            releaseWorkLock(workKey);
        }
    }
}

Work Deduplication Strategy

Atomic locks prevent race conditions:

private boolean acquireWorkLock(String workKey) {
    AtomicBoolean lock = activeWork.computeIfAbsent(workKey, k -> new AtomicBoolean(false));
    boolean acquired = lock.compareAndSet(false, true);
    
    if (acquired) {
        workTimestamps.put(workKey, System.currentTimeMillis());
        Log.d(TAG, "Acquired work lock: " + workKey);
    }
    
    return acquired;
}

private void releaseWorkLock(String workKey) {
    AtomicBoolean lock = activeWork.remove(workKey);
    workTimestamps.remove(workKey);
    
    if (lock != null) {
        lock.set(false);
        Log.d(TAG, "Released work lock: " + workKey);
    }
}

Database Performance

Query Optimization

Efficient queries with proper indexing:

// Optimized query for ready notifications
@Query("SELECT * FROM notification_content WHERE scheduled_time <= :currentTime AND delivery_status != 'delivered' ORDER BY scheduled_time ASC LIMIT 50")
List<NotificationContentEntity> getNotificationsReadyForDelivery(long currentTime);

// Optimized query for user notifications
@Query("SELECT * FROM notification_content WHERE timesafari_did = :timesafariDid AND created_at > :sinceTime ORDER BY scheduled_time ASC")
List<NotificationContentEntity> getRecentNotificationsByUser(String timesafariDid, long sinceTime);

// Optimized analytics query
@Query("SELECT notification_type, COUNT(*) as count FROM notification_content GROUP BY notification_type")
List<NotificationTypeCount> getNotificationCountsByType();

Background Thread Execution

Non-blocking operations for UI responsiveness:

public class DailyNotificationStorageRoom {
    private final ExecutorService executorService = Executors.newFixedThreadPool(4);
    
    public CompletableFuture<Boolean> saveNotificationContent(NotificationContentEntity content) {
        return CompletableFuture.supplyAsync(() -> {
            try {
                contentDao.insertNotification(content);
                return true;
            } catch (Exception e) {
                Log.e(TAG, "Failed to save notification", e);
                return false;
            }
        }, executorService);
    }
    
    public CompletableFuture<List<NotificationContentEntity>> getNotificationsReadyForDelivery() {
        return CompletableFuture.supplyAsync(() -> {
            long currentTime = System.currentTimeMillis();
            return contentDao.getNotificationsReadyForDelivery(currentTime);
        }, executorService);
    }
}

Memory Management

Efficient Data Structures

Memory-conscious data handling:

public class NotificationContentEntity {
    // Use primitive types where possible
    private long scheduledTime;        // Instead of Date object
    private int priority;              // Instead of enum
    private boolean vibrationEnabled;  // Instead of Boolean
    
    // Lazy loading for large fields
    private String encryptedContent;   // Load only when needed
    private String metadata;           // Parse only when accessed
    
    // Efficient string operations
    public boolean isExpired() {
        long expirationTime = createdAt + (ttlSeconds * 1000);
        return System.currentTimeMillis() > expirationTime;
    }
}

Migration Strategy

From SharedPreferences to Room

Migration Process

Step-by-step migration from legacy storage:

public class StorageMigrationManager {
    
    public void migrateToRoom(Context context) {
        Log.d(TAG, "Starting migration from SharedPreferences to Room");
        
        // 1. Export existing data
        Map<String, Object> legacyData = exportSharedPreferencesData(context);
        
        // 2. Transform to Room entities
        List<NotificationContentEntity> entities = transformToRoomEntities(legacyData);
        
        // 3. Import to Room database
        importToRoomDatabase(entities);
        
        // 4. Verify migration
        boolean success = verifyMigration(entities.size());
        
        // 5. Clean up legacy data
        if (success) {
            cleanupLegacyData(context);
            Log.d(TAG, "Migration completed successfully");
        } else {
            Log.e(TAG, "Migration failed, keeping legacy data");
        }
    }
    
    private Map<String, Object> exportSharedPreferencesData(Context context) {
        SharedPreferences prefs = context.getSharedPreferences("DailyNotificationPrefs", Context.MODE_PRIVATE);
        Map<String, ?> allData = prefs.getAll();
        
        Map<String, Object> exportedData = new HashMap<>();
        for (Map.Entry<String, ?> entry : allData.entrySet()) {
            if (entry.getKey().startsWith("notification_")) {
                exportedData.put(entry.getKey(), entry.getValue());
            }
        }
        
        return exportedData;
    }
}

Data Transformation

Convert legacy format to Room entities:

private List<NotificationContentEntity> transformToRoomEntities(Map<String, Object> legacyData) {
    List<NotificationContentEntity> entities = new ArrayList<>();
    
    for (Map.Entry<String, Object> entry : legacyData.entrySet()) {
        try {
            // Parse legacy JSON format
            String jsonString = (String) entry.getValue();
            JsonObject jsonObject = JsonParser.parseString(jsonString).getAsJsonObject();
            
            // Create Room entity
            NotificationContentEntity entity = new NotificationContentEntity();
            entity.id = jsonObject.get("id").getAsString();
            entity.title = jsonObject.get("title").getAsString();
            entity.body = jsonObject.get("body").getAsString();
            entity.scheduledTime = jsonObject.get("scheduledTime").getAsLong();
            entity.timezone = jsonObject.get("timezone").getAsString();
            entity.pluginVersion = PLUGIN_VERSION; // Set current version
            entity.createdAt = System.currentTimeMillis();
            entity.updatedAt = System.currentTimeMillis();
            
            entities.add(entity);
            
        } catch (Exception e) {
            Log.w(TAG, "Failed to transform legacy data: " + entry.getKey(), e);
        }
    }
    
    return entities;
}

Schema Evolution

Version Management

Database versioning for schema changes:

@Database(
    entities = {
        NotificationContentEntity.class,
        NotificationDeliveryEntity.class,
        NotificationConfigEntity.class
    },
    version = 1,  // Increment for schema changes
    exportSchema = false
)
public abstract class DailyNotificationDatabase extends RoomDatabase {
    
    // Migration from version 1 to 2
    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
            // Add new columns
            database.execSQL("ALTER TABLE notification_content ADD COLUMN analytics_data TEXT");
            database.execSQL("ALTER TABLE notification_content ADD COLUMN priority_level INTEGER DEFAULT 0");
            
            // Create new indexes
            database.execSQL("CREATE INDEX idx_notification_content_priority ON notification_content(priority_level)");
        }
    };
}

Backward Compatibility

Graceful handling of schema changes:

public class SchemaCompatibilityManager {
    
    public void ensureSchemaCompatibility() {
        int currentVersion = getCurrentSchemaVersion();
        int targetVersion = getTargetSchemaVersion();
        
        if (currentVersion < targetVersion) {
            Log.d(TAG, "Upgrading schema from version " + currentVersion + " to " + targetVersion);
            performSchemaUpgrade(currentVersion, targetVersion);
        }
    }
    
    private void performSchemaUpgrade(int fromVersion, int toVersion) {
        for (int version = fromVersion + 1; version <= toVersion; version++) {
            Migration migration = getMigration(version - 1, version);
            if (migration != null) {
                migration.migrate(database.getOpenHelper().getWritableDatabase());
                Log.d(TAG, "Applied migration " + (version - 1) + " -> " + version);
            }
        }
    }
}

Testing Architecture

Unit Testing Strategy

Entity Testing

Comprehensive entity validation:

@RunWith(AndroidJUnit4.class)
public class NotificationContentEntityTest {
    
    @Test
    public void testEntityCreation() {
        NotificationContentEntity entity = new NotificationContentEntity(
            "test-id", "1.0.0", "test-did", "reminder",
            "Test Title", "Test Body", System.currentTimeMillis(), "UTC"
        );
        
        assertNotNull(entity.id);
        assertEquals("test-id", entity.id);
        assertEquals("1.0.0", entity.pluginVersion);
        assertTrue(entity.isActive());
    }
    
    @Test
    public void testExpirationLogic() {
        NotificationContentEntity entity = new NotificationContentEntity();
        entity.createdAt = System.currentTimeMillis() - (8 * 24 * 60 * 60 * 1000); // 8 days ago
        entity.ttlSeconds = 7 * 24 * 60 * 60; // 7 days TTL
        
        assertTrue(entity.isExpired());
    }
    
    @Test
    public void testDeliveryReadiness() {
        NotificationContentEntity entity = new NotificationContentEntity();
        entity.scheduledTime = System.currentTimeMillis() - 1000; // 1 second ago
        entity.deliveryStatus = "pending";
        
        assertTrue(entity.isReadyForDelivery());
    }
}

DAO Testing

Database operation testing:

@RunWith(AndroidJUnit4.class)
public class NotificationContentDaoTest {
    
    private DailyNotificationDatabase database;
    private NotificationContentDao dao;
    
    @Before
    public void createDatabase() {
        Context context = InstrumentationRegistry.getInstrumentation().getTargetContext();
        database = Room.inMemoryDatabaseBuilder(context, DailyNotificationDatabase.class).build();
        dao = database.notificationContentDao();
    }
    
    @After
    public void closeDatabase() {
        database.close();
    }
    
    @Test
    public void testInsertAndRetrieve() {
        NotificationContentEntity entity = createTestEntity();
        
        dao.insertNotification(entity);
        NotificationContentEntity retrieved = dao.getNotificationById(entity.id);
        
        assertNotNull(retrieved);
        assertEquals(entity.id, retrieved.id);
        assertEquals(entity.title, retrieved.title);
    }
    
    @Test
    public void testQueryByTimeSafariDid() {
        NotificationContentEntity entity1 = createTestEntity("did1");
        NotificationContentEntity entity2 = createTestEntity("did2");
        
        dao.insertNotification(entity1);
        dao.insertNotification(entity2);
        
        List<NotificationContentEntity> did1Notifications = dao.getNotificationsByTimeSafariDid("did1");
        assertEquals(1, did1Notifications.size());
        assertEquals("did1", did1Notifications.get(0).timesafariDid);
    }
}

Integration Testing

Plugin Integration Tests

End-to-end plugin testing:

@RunWith(AndroidJUnit4.class)
public class DailyNotificationPluginIntegrationTest {
    
    private DailyNotificationPlugin plugin;
    private Context context;
    
    @Before
    public void setup() {
        context = InstrumentationRegistry.getInstrumentation().getTargetContext();
        plugin = new DailyNotificationPlugin();
        plugin.load();
    }
    
    @Test
    public void testScheduleNotification() throws Exception {
        JSObject options = new JSObject();
        options.put("id", "test-notification");
        options.put("title", "Test Notification");
        options.put("body", "Test Body");
        options.put("scheduledTime", System.currentTimeMillis() + 60000); // 1 minute from now
        
        PluginCall call = new PluginCall(options, null, null);
        
        plugin.scheduleDailyNotification(call);
        
        // Verify notification was scheduled
        assertTrue(call.getData().has("success"));
    }
    
    @Test
    public void testCheckStatus() throws Exception {
        PluginCall call = new PluginCall(new JSObject(), null, null);
        
        plugin.checkStatus(call);
        
        // Verify status response
        JSObject result = call.getData();
        assertTrue(result.has("enabled"));
        assertTrue(result.has("permissions"));
    }
}

Performance Testing

Database Performance Tests

Query performance validation:

@RunWith(AndroidJUnit4.class)
public class DatabasePerformanceTest {
    
    @Test
    public void testBulkInsertPerformance() {
        List<NotificationContentEntity> entities = createBulkTestData(1000);
        
        long startTime = System.currentTimeMillis();
        dao.insertNotifications(entities);
        long endTime = System.currentTimeMillis();
        
        long duration = endTime - startTime;
        assertTrue("Bulk insert took too long: " + duration + "ms", duration < 5000);
    }
    
    @Test
    public void testQueryPerformance() {
        // Insert test data
        insertTestData(1000);
        
        long startTime = System.currentTimeMillis();
        List<NotificationContentEntity> results = dao.getNotificationsReadyForDelivery(System.currentTimeMillis());
        long endTime = System.currentTimeMillis();
        
        long duration = endTime - startTime;
        assertTrue("Query took too long: " + duration + "ms", duration < 1000);
    }
}

Deployment Architecture

Build Configuration

Gradle Configuration

Optimized build setup for production:

android {
    compileSdkVersion 34
    buildToolsVersion "34.0.0"
    
    defaultConfig {
        minSdkVersion 21
        targetSdkVersion 34
        
        // Plugin-specific configuration
        buildConfigField "String", "PLUGIN_VERSION", "\"1.0.0\""
        buildConfigField "boolean", "ENABLE_ANALYTICS", "true"
        buildConfigField "boolean", "ENABLE_ENCRYPTION", "true"
    }
    
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
            
            // Production-specific settings
            buildConfigField "boolean", "DEBUG_MODE", "false"
            buildConfigField "int", "MAX_NOTIFICATIONS", "10000"
        }
        
        debug {
            minifyEnabled false
            buildConfigField "boolean", "DEBUG_MODE", "true"
            buildConfigField "int", "MAX_NOTIFICATIONS", "100"
        }
    }
}

dependencies {
    // Room database
    implementation "androidx.room:room-runtime:2.6.1"
    annotationProcessor "androidx.room:room-compiler:2.6.1"
    
    // WorkManager
    implementation "androidx.work:work-runtime:2.9.0"
    
    // Encryption
    implementation "androidx.security:security-crypto:1.1.0-alpha06"
    
    // Testing
    testImplementation "junit:junit:4.13.2"
    androidTestImplementation "androidx.test.ext:junit:1.1.5"
    androidTestImplementation "androidx.test.espresso:espresso-core:3.5.1"
}

ProGuard Configuration

Code obfuscation for production builds:

# Room database
-keep class * extends androidx.room.RoomDatabase
-keep @androidx.room.Entity class *
-keep @androidx.room.Dao class *

# Plugin classes
-keep class com.timesafari.dailynotification.** { *; }

# Capacitor plugin
-keep class com.timesafari.dailynotification.DailyNotificationPlugin { *; }

# Encryption
-keep class javax.crypto.** { *; }
-keep class java.security.** { *; }

# WorkManager
-keep class androidx.work.** { *; }

Plugin Distribution

Capacitor Plugin Structure

Standard plugin structure for distribution:

daily-notification-plugin/
├── android/
│   └── plugin/
│       ├── build.gradle
│       └── src/main/java/com/timesafari/dailynotification/
│           ├── DailyNotificationPlugin.java
│           ├── entities/
│           ├── dao/
│           ├── database/
│           └── storage/
├── src/
│   ├── definitions/
│   ├── web/
│   └── services/
├── package.json
├── capacitor.config.ts
└── README.md

Package Configuration

Plugin package metadata:

{
  "name": "@timesafari/daily-notification",
  "version": "1.0.0",
  "description": "Enterprise-grade daily notification plugin for TimeSafari",
  "main": "dist/plugin.cjs.js",
  "module": "dist/esm/index.js",
  "types": "dist/esm/index.d.ts",
  "capacitor": {
    "platforms": {
      "android": {
        "src": "android"
      },
      "ios": {
        "src": "ios"
      }
    }
  },
  "keywords": [
    "capacitor",
    "plugin",
    "notifications",
    "timesafari",
    "android",
    "ios"
  ],
  "author": "Matthew Raymer",
  "license": "MIT"
}

Monitoring & Analytics

Analytics Architecture

Delivery Analytics

Comprehensive delivery tracking:

public class DeliveryAnalyticsManager {
    
    public DeliveryAnalytics calculateAnalytics(String timesafariDid) {
        List<NotificationDeliveryEntity> deliveries = deliveryDao.getDeliveriesByTimeSafariDid(timesafariDid);
        
        int totalDeliveries = deliveries.size();
        int successfulDeliveries = 0;
        int failedDeliveries = 0;
        long totalDuration = 0;
        int userInteractions = 0;
        
        for (NotificationDeliveryEntity delivery : deliveries) {
            if (delivery.isSuccessful()) {
                successfulDeliveries++;
                totalDuration += delivery.deliveryDurationMs;
            } else {
                failedDeliveries++;
            }
            
            if (delivery.hasUserInteraction()) {
                userInteractions++;
            }
        }
        
        double successRate = totalDeliveries > 0 ? (double) successfulDeliveries / totalDeliveries : 0.0;
        double averageDuration = successfulDeliveries > 0 ? (double) totalDuration / successfulDeliveries : 0.0;
        double interactionRate = totalDeliveries > 0 ? (double) userInteractions / totalDeliveries : 0.0;
        
        return new DeliveryAnalytics(
            totalDeliveries, successfulDeliveries, failedDeliveries,
            successRate, averageDuration, userInteractions, interactionRate
        );
    }
}

Performance Metrics

System performance monitoring:

public class PerformanceMetricsManager {
    
    public PerformanceMetrics collectMetrics() {
        return new PerformanceMetrics(
            getDatabaseSize(),
            getQueryPerformanceMetrics(),
            getMemoryUsageMetrics(),
            getBatteryImpactMetrics()
        );
    }
    
    private DatabaseSizeMetrics getDatabaseSize() {
        return new DatabaseSizeMetrics(
            contentDao.getTotalNotificationCount(),
            deliveryDao.getTotalDeliveryCount(),
            configDao.getTotalConfigCount()
        );
    }
    
    private QueryPerformanceMetrics getQueryPerformanceMetrics() {
        long startTime = System.currentTimeMillis();
        List<NotificationContentEntity> results = contentDao.getNotificationsReadyForDelivery(System.currentTimeMillis());
        long endTime = System.currentTimeMillis();
        
        return new QueryPerformanceMetrics(
            results.size(),
            endTime - startTime
        );
    }
}

Logging Architecture

Structured Logging

Comprehensive logging for debugging and monitoring:

public class NotificationLogger {
    private static final String TAG = "DailyNotification";
    
    public static void logNotificationScheduled(String notificationId, long scheduledTime) {
        Log.d(TAG, String.format("DN|SCHEDULE notification_id=%s scheduled_time=%d", 
                notificationId, scheduledTime));
    }
    
    public static void logNotificationDelivered(String notificationId, long durationMs) {
        Log.d(TAG, String.format("DN|DELIVERED notification_id=%s duration_ms=%d", 
                notificationId, durationMs));
    }
    
    public static void logNotificationFailed(String notificationId, String errorCode, String errorMessage) {
        Log.e(TAG, String.format("DN|FAILED notification_id=%s error_code=%s error_message=%s", 
                notificationId, errorCode, errorMessage));
    }
    
    public static void logUserInteraction(String notificationId, String interactionType) {
        Log.d(TAG, String.format("DN|INTERACTION notification_id=%s interaction_type=%s", 
                notificationId, interactionType));
    }
}

Error Tracking

Comprehensive error tracking for debugging:

public class ErrorTrackingManager {
    
    public void trackError(String errorCode, String errorMessage, Exception exception) {
        ErrorReport report = new ErrorReport(
            errorCode,
            errorMessage,
            exception != null ? exception.getMessage() : null,
            System.currentTimeMillis(),
            getDeviceContext(),
            getPluginContext()
        );
        
        // Store error report
        storeErrorReport(report);
        
        // Log error
        Log.e(TAG, "Error tracked: " + errorCode + " - " + errorMessage, exception);
    }
    
    private DeviceContext getDeviceContext() {
        return new DeviceContext(
            Build.VERSION.SDK_INT,
            Build.MANUFACTURER,
            Build.MODEL,
            getBatteryLevel(),
            isDozeModeActive()
        );
    }
}

Future Architecture

Planned Enhancements

iOS Implementation

Cross-platform parity with iOS:

// Planned iOS implementation
@objc(DailyNotificationPlugin)
public class DailyNotificationPlugin: CAPPlugin {
    
    private var scheduler: DailyNotificationScheduler?
    private var storage: DailyNotificationStorageRoom?
    
    @objc func scheduleDailyNotification(_ call: CAPPluginCall) {
        // iOS-specific implementation
        // - UNUserNotificationCenter integration
        // - BGTaskScheduler for background work
        // - Core Data for persistence
    }
}

Advanced Features

Enterprise-grade enhancements:

1. Push Notification Integration

   • FCM/APNs integration
   • Server-side notification management
   • Real-time delivery status

2. Advanced Analytics

   • Machine learning insights
   • User behavior analysis
   • Performance optimization recommendations

3. Multi-User Support

   • Shared notification management
   • Team collaboration features
   • Admin dashboard integration

4. Cloud Synchronization

   • Cross-device notification sync
   • Backup and restore
   • Conflict resolution

Scalability Considerations

Horizontal Scaling

Multi-instance support for high-volume applications:

public class MultiInstanceManager {
    
    public void initializeInstance(String instanceId) {
        // Create instance-specific database
        String databaseName = "daily_notification_" + instanceId + ".db";
        DailyNotificationDatabase instanceDb = Room.databaseBuilder(
            context, DailyNotificationDatabase.class, databaseName
        ).build();
        
        // Initialize instance-specific services
        initializeInstanceServices(instanceId, instanceDb);
    }
}

Performance Optimization

Advanced performance features:

1. Database Sharding

   • User-based sharding
   • Time-based partitioning
   • Load balancing

2. Caching Strategy

   • Redis integration
   • In-memory caching
   • Cache invalidation

3. Background Processing

   • Distributed work queues
   • Priority-based processing
   • Resource management

---

Conclusion

The DailyNotification plugin architecture provides a robust, scalable, and maintainable foundation for enterprise-grade notification management. With its Room database integration, comprehensive analytics, security-first design, and performance optimization, it delivers reliable notification services for TimeSafari applications.

Key Architectural Strengths

1. Data Integrity: Schema validation and encryption ensure data security
2. Performance: Optimized queries and background processing for responsiveness
3. Reliability: Work deduplication and retry logic for consistent operation
4. Scalability: Modular design supports future enhancements
5. Maintainability: Clean separation of concerns and comprehensive testing

Next Steps

1. Complete Room Migration: Finish migration from SharedPreferences to Room database
2. iOS Implementation: Port Android architecture to iOS platform
3. Advanced Analytics: Implement machine learning insights
4. Cloud Integration: Add server-side synchronization capabilities
5. Performance Optimization: Implement advanced caching and sharding

This architecture provides a solid foundation for building reliable, scalable notification services that meet enterprise requirements while maintaining excellent user experience.

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Document Version: 1.0.0
Last Updated: October 20, 2025
Next Review: November 20, 2025