/**
 * Practical Usage Examples for Multi-Database MongoDB Client
 *
 * This file demonstrates real-world usage patterns for the enhanced MongoDB client
 * with multiple database support.
 */

import { getCurrentDatabase, MongoDBClient, setDefaultDatabase } from '@stock-bot/mongodb-client';

// Example 1: Using different databases for different data types
export class DataServiceExample {
  private mongoClient = MongoDBClient.getInstance();

  async initialize() {
    await this.mongoClient.connect();

    // Set stock as default database for most operations
    setDefaultDatabase('stock');
    console.log(`Default database: ${getCurrentDatabase()}`);
  }

  // Stock market data goes to 'stock' database (default)
  async saveStockData(symbols: any[], exchanges: any[]) {
    // These use the default 'stock' database
    await this.mongoClient.batchUpsert('symbols', symbols, 'symbol');
    await this.mongoClient.batchUpsert('exchanges', exchanges, 'exchange_id');

    // Or use convenience method (explicitly targets 'stock' database)
    await this.mongoClient.batchUpsertStock('prices', symbols, 'symbol');
  }

  // Analytics and metrics go to 'analytics' database
  async saveAnalyticsData(performanceData: any[], metrics: any[]) {
    // Override database for specific operations
    await this.mongoClient.batchUpsert('performance', performanceData, 'date', {
      database: 'analytics',
    });

    // Or use convenience method
    await this.mongoClient.batchUpsertAnalytics('metrics', metrics, 'metric_name');
  }

  // Trading documents and logs go to 'trading_documents' database
  async saveTradingData(orders: any[], transactions: any[]) {
    // Use convenience method for trading data
    await this.mongoClient.batchUpsertTrading('orders', orders, 'order_id');
    await this.mongoClient.batchUpsertTrading('transactions', transactions, 'transaction_id');
  }

  // Example of switching default database dynamically
  async switchToAnalyticsMode() {
    console.log(`Current default: ${getCurrentDatabase()}`);

    // Switch to analytics database for a series of operations
    setDefaultDatabase('analytics');
    console.log(`New default: ${getCurrentDatabase()}`);

    // Now all operations without explicit database parameter go to 'analytics'
    await this.mongoClient.batchUpsert('daily_reports', [], 'date');
    await this.mongoClient.batchUpsert('portfolio_performance', [], 'portfolio_id');

    // Switch back to stock database
    setDefaultDatabase('stock');
  }

  // Example of working with multiple databases simultaneously
  async crossDatabaseAnalysis() {
    // Get direct access to different databases
    const stockDb = this.mongoClient.getDatabase('stock');
    const analyticsDb = this.mongoClient.getDatabase('analytics');
    const tradingDb = this.mongoClient.getDatabase('trading_documents');

    // Perform operations on multiple databases
    const stockSymbols = await stockDb.collection('symbols').find({}).toArray();
    const performance = await analyticsDb.collection('performance').find({}).toArray();
    const orders = await tradingDb.collection('orders').find({}).toArray();

    console.log('Cross-database analysis:', {
      symbolsCount: stockSymbols.length,
      performanceRecords: performance.length,
      ordersCount: orders.length,
    });
  }
}

// Example 2: Data Migration Between Databases
export class DataMigrationExample {
  private mongoClient = MongoDBClient.getInstance();

  async migrateHistoricalData() {
    await this.mongoClient.connect();

    // Get collections from different databases
    const stockCollection = this.mongoClient.getCollection('historical_prices', 'stock');
    const analyticsCollection = this.mongoClient.getCollection('price_analysis', 'analytics');

    // Read from stock database
    const historicalPrices = await stockCollection
      .find({
        date: { $gte: new Date('2024-01-01') },
      })
      .toArray();

    console.log(`Found ${historicalPrices.length} historical price records`);

    // Transform and save to analytics database
    const analysisData = historicalPrices.map(price => ({
      symbol: price.symbol,
      date: price.date,
      price_change: price.close - price.open,
      volume_normalized: price.volume / 1000000,
      created_at: new Date(),
      updated_at: new Date(),
    }));

    // Save to analytics database
    await this.mongoClient.batchUpsert('price_analysis', analysisData, ['symbol', 'date'], {
      database: 'analytics',
    });

    console.log(`Migrated ${analysisData.length} records to analytics database`);
  }
}

// Example 3: Service-Specific Database Usage
export class TradingServiceExample {
  private mongoClient = MongoDBClient.getInstance();

  async initialize() {
    await this.mongoClient.connect();
    // Trading service primarily works with trading_documents database
    setDefaultDatabase('trading_documents');
  }

  async processTradeOrders(orders: any[]) {
    // Default database is 'trading_documents', so no need to specify
    await this.mongoClient.batchUpsert('orders', orders, 'order_id');

    // Log to analytics database for monitoring
    const orderMetrics = orders.map(order => ({
      metric_name: `order_${order.type}`,
      value: order.quantity,
      timestamp: new Date(),
    }));

    await this.mongoClient.batchUpsert(
      'trading_metrics',
      orderMetrics,
      ['metric_name', 'timestamp'],
      { database: 'analytics' }
    );
  }

  async getOrderHistory(symbolFilter?: string) {
    // Get collection from default database (trading_documents)
    const ordersCollection = this.mongoClient.getCollection('orders');

    const filter = symbolFilter ? { symbol: symbolFilter } : {};
    return await ordersCollection.find(filter).sort({ created_at: -1 }).limit(100).toArray();
  }
}

// Example 4: Configuration-Based Database Routing
export class ConfigurableDatabaseRouter {
  private mongoClient = MongoDBClient.getInstance();

  // Configuration mapping data types to databases
  private databaseConfig = {
    market_data: 'stock',
    user_data: 'trading_documents',
    analytics: 'analytics',
    logs: 'trading_documents',
    cache: 'analytics',
  };

  async saveData(
    dataType: keyof typeof this.databaseConfig,
    collection: string,
    data: any[],
    uniqueKeys: string[]
  ) {
    const targetDatabase = this.databaseConfig[dataType];

    console.log(`Saving ${data.length} records to ${targetDatabase}.${collection}`);

    return await this.mongoClient.batchUpsert(collection, data, uniqueKeys, {
      database: targetDatabase,
    });
  }

  async saveMarketData(data: any[]) {
    return this.saveData('market_data', 'realtime_prices', data, 'symbol');
  }

  async saveUserActivity(data: any[]) {
    return this.saveData('user_data', 'user_actions', data, 'user_id');
  }

  async saveAnalytics(data: any[]) {
    return this.saveData('analytics', 'performance_metrics', data, 'metric_id');
  }
}

// Usage example for your data service
export async function exampleUsage() {
  const dataService = new DataServiceExample();

  await dataService.initialize();

  // Save different types of data to appropriate databases
  await dataService.saveStockData(
    [{ symbol: 'AAPL', price: 150.25, volume: 1000000 }],
    [{ exchange_id: 'NYSE', name: 'New York Stock Exchange' }]
  );

  await dataService.saveAnalyticsData(
    [{ date: new Date(), portfolio_return: 0.15 }],
    [{ metric_name: 'sharpe_ratio', value: 1.25 }]
  );

  await dataService.saveTradingData(
    [{ order_id: 'ORD001', symbol: 'AAPL', quantity: 100 }],
    [{ transaction_id: 'TXN001', amount: 15025 }]
  );

  // Perform cross-database analysis
  await dataService.crossDatabaseAnalysis();

  console.log('Multi-database operations completed successfully!');
}