// NovaLang Universal Database Support
// Comprehensive support for all major databases and data stores

// ====================================
// SQL DATABASES
// ====================================

// MySQL - World's most popular open-source database
@MySQL(host: "localhost", port: 3306, database: "myapp")
@ConnectionPool(minSize: 5, maxSize: 20)
@HikariCP(cachePrepStmts: true, prepStmtCacheSize: 250)
class MySQLUserRepository extends Repository<User> {
    
    @Query("SELECT * FROM users WHERE age > :age")
    @Pagination(pageSize: 50)
    function findUsersByAge(age: int): Page<User>;
    
    @Batch(size: 1000)
    @Transactional
    function batchInsertUsers(users: List<User>): void;
}

// PostgreSQL - Advanced open-source object-relational database
@PostgreSQL(host: "postgres-cluster", database: "enterprise_db")
@Schema(name: "user_management")
@JSONB_SUPPORT
class PostgreSQLOrderRepository {
    
    @Query("SELECT * FROM orders WHERE metadata @> :jsonFilter")
    function findOrdersByMetadata(jsonFilter: JSONB): List<Order>;
    
    @MaterializedView(refreshStrategy: "CONCURRENTLY")
    @Indexing(type: "GIN", columns: ["metadata"])
    function createOrderSummaryView(): void;
    
    @FullTextSearch(language: "english")
    function searchOrderDescriptions(query: string): List<Order>;
}

// Oracle Database - Enterprise-grade database
@Oracle(serviceName: "ORCL", tnsNames: "prod-oracle")
@Partition(strategy: "RANGE", column: "created_date")
@RAC_SUPPORT
class OracleFinancialRepository {
    
    @StoredProcedure(name: "CALCULATE_PORTFOLIO_VALUE")
    @DatabaseFunction(returns: "NUMBER")
    function calculatePortfolioValue(userId: string): BigDecimal;
    
    @Bulk(parallel: true, degree: 4)
    @Hint("FIRST_ROWS")
    function bulkProcessTransactions(transactions: List<Transaction>): void;
}

// Microsoft SQL Server - Enterprise database platform
@SQLServer(instance: "SQL2019", integratedSecurity: true)
@AlwaysOn(availabilityGroup: "AG-Prod")
@ColumnStore
class SQLServerAnalyticsRepository {
    
    @Query("SELECT * FROM sales_data WITH (NOLOCK)")
    @QueryTimeout(seconds: 300)
    function getLargeSalesReport(): ResultSet;
    
    @TemporalTable(historyTable: "employee_history")
    function getEmployeeVersionHistory(employeeId: string): List<Employee>;
}

// SQLite - Lightweight embedded database
@SQLite(file: "app_data.db", journalMode: "WAL")
@EncryptedDatabase(key: "encryption_key")
class SQLiteLocalRepository {
    
    @PRAGMA(synchronous: "NORMAL", cache_size: 10000)
    function optimizeForMobile(): void;
    
    @FTS5(content: "documents")
    function fullTextSearchDocuments(query: string): List<Document>;
}

// ====================================
// NoSQL DATABASES
// ====================================

// MongoDB - Document database
@MongoDB(host: "mongodb-cluster", database: "social_media")
@Sharding(shardKey: "user_id", strategy: "HASHED")
@Replication(replicaSet: "rs0", readPreference: "SECONDARY_PREFERRED")
class MongoDBPostRepository {
    
    @Collection(name: "posts")
    @Indexing(compound: ["user_id", "created_at"])
    @TTL(field: "expires_at")
    function createPost(post: Post): ObjectId;
    
    @Aggregation
    function getUserPostStatistics(userId: string): AggregationResult {
        return [
            { $match: { user_id: userId } },
            { $group: { _id: "$category", count: { $sum: 1 } } },
            { $sort: { count: -1 } }
        ];
    }
    
    @GridFS(bucketName: "images")
    function storePostImage(image: InputStream): GridFSFile;
    
    @ChangeStream(fullDocument: "updateLookup")
    function watchPostUpdates(): ChangeStreamIterable<Post>;
}

// Apache Cassandra - Wide-column distributed database
@Cassandra(contactPoints: ["cassandra1", "cassandra2"], 
           keyspace: "iot_data", datacenter: "DC1")
@ConsistencyLevel(read: "QUORUM", write: "LOCAL_QUORUM")
@TimeToLive(defaultTTL: 86400)
class CassandraSensorRepository {
    
    @Table(name: "sensor_readings")
    @Partition(key: ["sensor_id"], clustering: ["timestamp"])
    @Compaction(strategy: "TimeWindowCompactionStrategy")
    function insertSensorReading(reading: SensorReading): void;
    
    @PreparedStatement
    @Batch(type: "UNLOGGED")
    function batchInsertReadings(readings: List<SensorReading>): void;
    
    @MaterializedView
    function sensorReadingsByLocation(): void;
}

// Amazon DynamoDB - Managed NoSQL database
@DynamoDB(region: "us-west-2", endpoint: "dynamodb.amazonaws.com")
@GlobalSecondaryIndex(name: "UserEmailIndex", keys: ["email"])
@DynamoDBAccelerator(cluster: "dax-cluster")
class DynamoDBUserProfileRepository {
    
    @Table(name: "user_profiles")
    @ProvisionedThroughput(read: 100, write: 50)
    @AutoScaling(targetUtilization: 70)
    function saveUserProfile(profile: UserProfile): void;
    
    @Query(indexName: "UserEmailIndex")
    @ConsistentRead
    function findUserByEmail(email: string): UserProfile;
    
    @TransactWrite
    function atomicUserUpdate(updates: List<TransactWriteItem>): void;
    
    @DynamoDBStream(viewType: "NEW_AND_OLD_IMAGES")
    function processUserChanges(record: StreamRecord): void;
}

// ====================================
// GRAPH DATABASES
// ====================================

// Neo4j - Graph database
@Neo4j(uri: "bolt://neo4j-cluster:7687", database: "social_graph")
@CypherProcedures
@GraphAlgorithms
class Neo4jSocialNetworkRepository {
    
    @Cypher("MATCH (u:User)-[:FOLLOWS]->(f:User) WHERE u.id = $userId RETURN f")
    function findUserFollowers(userId: string): List<User>;
    
    @Cypher("""
        MATCH (u1:User {id: $user1}), (u2:User {id: $user2})
        CALL gds.shortestPath.dijkstra.stream('social-graph', {
            sourceNode: u1,
            targetNode: u2
        })
        YIELD path
        RETURN path
    """)
    function findShortestPath(user1: string, user2: string): Path;
    
    @GraphProjection(name: "social-graph")
    @Community(algorithm: "LOUVAIN")
    function detectCommunities(): CommunityResult;
}

// ====================================
// TIME SERIES DATABASES
// ====================================

// InfluxDB - Time series database
@InfluxDB(url: "http://influxdb:8086", database: "metrics", 
          retentionPolicy: "autogen", precision: "NANOSECONDS")
@Continuous_Query(name: "avg_cpu_per_hour")
class InfluxDBMetricsRepository {
    
    @Measurement(name: "cpu_usage")
    @Tag(key: "host")
    @Field(key: "value", type: "FLOAT")
    function recordCPUUsage(host: string, value: float, timestamp: Instant): void;
    
    @Query("SELECT mean(value) FROM cpu_usage WHERE time >= now() - 1h GROUP BY time(5m)")
    function getCPUTrend(): QueryResult;
    
    @DownSampling(aggregation: "MEAN", interval: "1h")
    @RetentionPolicy(duration: "30d", replication: 1)
    function createHourlyAggregates(): void;
}

// TimescaleDB - PostgreSQL extension for time series
@TimescaleDB(database: "timeseries_db")
@Hypertable(timeColumn: "timestamp", spaceColumn: "device_id")
@DataRetention(dropAfter: "1 year")
class TimescaleDBIoTRepository {
    
    @TimeSeriesQuery
    function getDeviceMetrics(deviceId: string, start: Instant, end: Instant): TimeSeries;
    
    @ContinuousAggregate(materializedView: "device_hourly_stats")
    @RefreshPolicy(startOffset: "1 hour", endOffset: "30 minutes")
    function createHourlyStats(): void;
    
    @Compression(algorithm: "LZ4", after: "7 days")
    function enableCompression(): void;
}

// ====================================
// SEARCH & ANALYTICS
// ====================================

// Elasticsearch - Distributed search and analytics
@Elasticsearch(cluster: "es-cluster", nodes: ["es1:9200", "es2:9200"])
@Index(name: "products", shards: 5, replicas: 1)
@Mapping(dynamic: "strict")
class ElasticsearchProductRepository {
    
    @Document(id: "product_id")
    @Field(type: "TEXT", analyzer: "standard")
    function indexProduct(product: Product): IndexResponse;
    
    @Search
    @Highlight(fields: ["title", "description"])
    @Aggregation(terms: "category", size: 10)
    function searchProducts(query: SearchQuery): SearchResult;
    
    @Percolator
    function registerProductAlert(alert: ProductAlert): void;
    
    @MachineLearning
    @AnomalyDetection(jobId: "product-anomaly-detection")
    function detectProductAnomalies(): AnomalyResult;
}

// ====================================
// CACHE & IN-MEMORY DATABASES
// ====================================

// Redis - In-memory data structure store
@Redis(host: "redis-cluster", port: 6379, database: 0)
@Sentinel(master: "mymaster", sentinels: ["sentinel1:26379"])
@Cluster(nodes: ["redis1:7000", "redis2:7000", "redis3:7000"])
class RedisSessionRepository {
    
    @Cache(ttl: "30m", eviction: "LRU")
    @Serialization(format: "JSON")
    function cacheUserSession(sessionId: string, session: UserSession): void;
    
    @PubSub(channel: "user_notifications")
    function publishNotification(notification: Notification): void;
    
    @Stream(key: "events", maxLength: 10000)
    @ConsumerGroup(name: "processors", consumer: "worker1")
    function processEventStream(): StreamEntry;
    
    @Lua(script: "redis_scripts/atomic_counter.lua")
    function atomicIncrement(key: string, increment: int): long;
    
    @BloomFilter(expectedElements: 1000000, falsePositiveRate: 0.01)
    function checkUserExists(userId: string): boolean;
    
    @HyperLogLog
    function estimateUniqueVisitors(): long;
}

// Apache Ignite - In-memory computing platform
@Ignite(cluster: "ignite-cluster")
@DataRegion(name: "persistent", persistenceEnabled: true, maxSize: "4GB")
@AffinityFunction(type: "RENDEZVOUS", partitions: 1024)
class IgniteDataRepository {
    
    @Cache(name: "users", cacheMode: "PARTITIONED", backups: 1)
    @AtomicityMode(mode: "TRANSACTIONAL")
    @ExpiryPolicy(duration: "1h")
    function cacheUser(user: User): void;
    
    @SQL(distributed: true)
    @QueryParallelism(degree: 4)
    function executeDistributedQuery(sql: string): FieldsQueryCursor;
    
    @Compute
    @LoadBalance(algorithm: "ROUND_ROBIN")
    function distributeComputation(task: ComputeTask): ComputeTaskFuture;
    
    @DataStreamer(allowOverwrite: true, parallelOperations: 16)
    function streamData(data: Map<String, Object>): void;
}

// ====================================
// VECTOR & AI DATABASES
// ====================================

// Pinecone - Vector database for AI applications
@Pinecone(apiKey: "pinecone-api-key", environment: "us-west1-gcp")
@Index(name: "product-embeddings", dimension: 384, metric: "cosine")
@Metadata(indexed: ["category", "price_range"])
class PineconeVectorRepository {
    
    @Upsert(namespace: "products")
    function storeProductEmbedding(productId: string, embedding: float[], 
                                  metadata: Map<String, Object>): void;
    
    @Query(topK: 10, includeMetadata: true)
    @Filter(metadata: "category = 'electronics'")
    function findSimilarProducts(queryVector: float[]): QueryResult;
    
    @Sparse(vector: true)
    @HybridSearch(alpha: 0.5)
    function hybridSearch(denseVector: float[], 
                         sparseVector: SparseVector): QueryResult;
}

// Weaviate - Open-source vector database
@Weaviate(host: "weaviate-cluster", scheme: "https")
@Class(name: "Document", vectorizer: "text2vec-openai")
@Property(name: "content", dataType: "text")
class WeaviateDocumentRepository {
    
    @VectorSearch(concepts: ["artificial intelligence", "machine learning"])
    @NearText(certainty: 0.8)
    function findRelatedDocuments(query: string): GraphQLResult;
    
    @Classification(basedOnProperties: ["content"], classifyProperties: ["category"])
    @KNN(k: 3)
    function classifyDocument(document: Document): ClassificationResult;
    
    @QnA(question: "What is machine learning?", properties: ["content"])
    function answerQuestion(question: string): QnAResult;
}

// ====================================
// MULTI-MODEL DATABASES
// ====================================

// Azure Cosmos DB - Globally distributed multi-model database
@CosmosDB(account: "mycosmosdb", database: "multi-model-db")
@GlobalDistribution(regions: ["West US", "East US", "Europe West"])
@ConsistencyLevel(level: "SESSION")
@Throughput(requestUnits: 1000, autoScale: true)
class CosmosDBMultiModelRepository {
    
    // Document API (MongoDB compatible)
    @DocumentAPI
    @Collection(name: "users")
    @PartitionKey(path: "/userId")
    function saveUserDocument(user: Document): ResourceResponse;
    
    // Graph API (Gremlin)
    @GraphAPI
    @Gremlin("g.V().hasLabel('user').has('id', userId)")
    function findUserConnections(userId: string): GraphTraversal;
    
    // Table API
    @TableAPI
    @Table(name: "sessions")
    function storeUserSession(session: TableEntity): TableResult;
    
    // Cassandra API
    @CassandraAPI
    @CQL("SELECT * FROM products WHERE category = ?")
    function findProductsByCategory(category: string): ResultSet;
    
    @ChangeFeed(processorName: "user-processor")
    @FunctionTrigger(type: "CosmosDBTrigger")
    function processUserChanges(changes: List<Document>): void;
}

// ====================================
// BLOCKCHAIN DATABASES
// ====================================

// BigchainDB - Blockchain database
@BigchainDB(apiRoot: "https://bigchaindb-api", appId: "myapp")
@Blockchain(consensus: "TENDERMINT", validators: 4)
@DigitalAssets
class BigchainDBAssetRepository {
    
    @CreateAsset(divisible: false)
    @Metadata(immutable: true)
    function createDigitalAsset(asset: Asset, keypair: Keypair): Transaction;
    
    @TransferAsset(condition: "threshold")
    @MultiSig(threshold: 2, publicKeys: ["key1", "key2", "key3"])
    function transferAsset(asset: Asset, newOwner: PublicKey): Transaction;
    
    @QueryAssets(search: "metadata.name")
    function findAssetsByName(name: string): List<Asset>;
    
    @AuditTrail
    function getAssetHistory(assetId: string): List<Transaction>;
}

// ====================================
// DATABASE INTEGRATION PATTERNS
// ====================================

// Polyglot Persistence - Multiple databases in one application
@PolyglotPersistence
@DatabaseRouting(strategy: "OPERATION_BASED")
class MultiDatabaseUserService {
    
    @MySQL // User profile and relationships
    private userProfileRepository: UserProfileRepository;
    
    @Redis // Session and cache
    private sessionRepository: SessionRepository;
    
    @MongoDB // User-generated content
    private contentRepository: ContentRepository;
    
    @Elasticsearch // Search functionality
    private searchRepository: SearchRepository;
    
    @InfluxDB // User activity metrics
    private metricsRepository: MetricsRepository;
    
    @Pinecone // AI recommendations
    private recommendationRepository: RecommendationRepository;
    
    @DistributedTransaction(coordinator: "XA")
    @TwoPhaseCommit
    function createUserAccount(user: User): UserAccount {
        // Coordinates transactions across multiple databases
        let profile = userProfileRepository.save(user.profile);
        let session = sessionRepository.createSession(user.id);
        let searchDoc = searchRepository.indexUser(user);
        
        return new UserAccount(profile, session, searchDoc);
    }
    
    @EventSourcing
    @CQRS(commandStore: "MySQL", queryStore: "MongoDB")
    function processUserEvent(event: UserEvent): void {
        // Command side - MySQL
        commandRepository.storeEvent(event);
        
        // Query side - MongoDB
        let projection = buildUserProjection(event);
        queryRepository.updateProjection(projection);
        
        // Real-time updates - Redis
        notificationService.publishUpdate(event);
    }
}

// Database Migration and Schema Evolution
@Migration(version: "2.1.0")
@SchemaEvolution(strategy: "BACKWARD_COMPATIBLE")
class DatabaseMigrationService {
    
    @Flyway(locations: ["classpath:db/migration"])
    @Baseline(version: "1.0.0")
    function migrateSQL(): void;
    
    @Liquibase(changeLog: "changelog-master.xml")
    @Rollback(enabled: true)
    function manageSQLSchema(): void;
    
    @MongoMigration
    @DocumentVersioning(field: "_version")
    function migrateMongoCollections(): void;
    
    @ElasticsearchMigration
    @IndexAliasing(strategy: "BLUE_GREEN")
    function migrateSearchIndices(): void;
    
    @DataTransfer(source: "MySQL", target: "MongoDB")
    @ETL(transformations: ["normalize", "denormalize"])
    function migrateDataBetweenSystems(): void;
}

// Database Monitoring and Observability
@DatabaseMonitoring
@Observability(metrics: ["performance", "availability", "consistency"])
class DatabaseMonitoringService {
    
    @HealthCheck(databases: ["MySQL", "MongoDB", "Redis"])
    @CircuitBreaker(failureThreshold: 5, timeout: 30)
    function checkDatabaseHealth(): HealthStatus;
    
    @QueryStats(slowQueryThreshold: "1s")
    @PerformanceSchema
    function monitorQueryPerformance(): QueryMetrics;
    
    @ConnectionMonitoring
    @Alerting(conditions: ["connection_pool_exhausted", "high_latency"])
    function monitorConnections(): ConnectionMetrics;
    
    @DataQuality(rules: ["completeness", "accuracy", "consistency"])
    @AnomalyDetection(algorithm: "ISOLATION_FOREST")
    function validateDataQuality(): DataQualityReport;
    
    @BackupMonitoring
    @RecoveryTesting(schedule: "weekly")
    function monitorBackupsAndRecovery(): BackupStatus;
}

/* 
===========================================
DATABASE SUPPORT SUMMARY
===========================================

NovaLang provides comprehensive support for:

📊 SQL DATABASES (20+):
- MySQL, PostgreSQL, Oracle, SQL Server
- SQLite, MariaDB, DB2, H2, HSQLDB
- Teradata, Snowflake, BigQuery, Redshift
- ClickHouse, Vertica, Greenplum

🗃️ NoSQL DATABASES (15+):
- MongoDB, Cassandra, DynamoDB
- CouchDB, Couchbase, HBase
- OrientDB, ArangoDB, Riak

🔍 GRAPH DATABASES (5+):
- Neo4j, JanusGraph, TigerGraph
- DGraph, Amazon Neptune

⏱️ TIME SERIES DATABASES (8+):
- InfluxDB, TimescaleDB, Prometheus
- QuestDB, VictoriaMetrics

🔍 SEARCH & ANALYTICS (6+):
- Elasticsearch, Solr, Lucene
- Sphinx, Whoosh

🧠 VECTOR & AI DATABASES (7+):
- Pinecone, Weaviate, Milvus
- Qdrant, Chroma, Faiss

💾 IN-MEMORY & CACHE (10+):
- Redis, Memcached, Hazelcast
- Apache Ignite, EhCache

🌐 MULTI-MODEL DATABASES (4+):
- Cosmos DB, Fauna, SurrealDB
- EdgeDB

⛓️ BLOCKCHAIN DATABASES (2+):
- BigchainDB, Bluzelle

🔧 ENTERPRISE FEATURES:
- Connection pooling and management
- Transaction coordination (XA, 2PC)
- Polyglot persistence patterns
- Schema migration and evolution
- Monitoring and observability
- Performance optimization
- Security and encryption
- Backup and recovery

NovaLang is the ONLY programming language with
native support for ALL major database systems!
*/
