/**
 * Integration test for order pair execution
 * Tests the complete flow of executing coordinated buy/sell order pairs
 */

import { describe, it, expect, beforeAll, afterAll, beforeEach } from '@jest/globals';
import { HedgingManager } from '../../src/core/HedgingManager';
import { OrderCoordinator } from '../../src/core/OrderCoordinator';
import { HedgingOrder, OrderDetails } from '../../src/types/hedging';

describe('Order Pair Execution Integration', () => {
  let hedgingManager: HedgingManager;
  let orderCoordinator: OrderCoordinator;
  let testSessionId: string;

  beforeAll(async () => {
    // Initialize hedging manager
    hedgingManager = new HedgingManager({
      accounts: './config/accounts.json',
      hedging: './config/hedging-config.json',
      marketData: './config/market-data-config.json'
    });

    // Initialize order coordinator
    orderCoordinator = new OrderCoordinator({
      maxConcurrentOrders: 20,
      orderTimeout: 30000,
      retryAttempts: 3,
      retryDelay: 1000,
      atomicExecution: true
    });

    await hedgingManager.initialize();
    await orderCoordinator.initialize();
  });

  afterAll(async () => {
    if (hedgingManager) {
      await hedgingManager.shutdown();
    }
    if (orderCoordinator) {
      await orderCoordinator.shutdown();
    }
  });

  beforeEach(async () => {
    // Create a test session for each test
    const sessionRequest = {
      name: 'Order Pair Test Session',
      accountIds: ['account-1', 'account-2'],
      volumeTarget: 10000,
      strategy: {
        symbol: 'ETH/USD',
        volumeDistribution: 'equal' as const,
        priceRange: { min: 0.001, max: 0.01 },
        timing: { minInterval: 30, maxInterval: 120, orderSize: { min: 100, max: 500 } },
        riskLimits: { maxPositionSize: 0.1, stopLossThreshold: 0.05, maxSlippage: 0.02 },
        orderTypes: { primary: 'limit' as const, fallback: 'market' as const }
      }
    };

    try {
      const session = await hedgingManager.createSession(sessionRequest);
      testSessionId = session.id;
    } catch (error) {
      testSessionId = 'mock-session-id';
    }
  });

  describe('Order Pair Creation', () => {
    it('should create a coordinated buy/sell order pair', async () => {
      const orderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        const orderPair = await orderCoordinator.createOrderPair(orderPairRequest);
        
        expect(orderPair).toBeDefined();
        expect(orderPair.id).toBeDefined();
        expect(orderPair.sessionId).toBe(testSessionId);
        expect(orderPair.status).toBe('pending');
        expect(orderPair.volume).toBe(100);
        expect(orderPair.price).toBe(2500);
        
        // Verify order pair structure
        expect(orderPair.orderPair).toBeDefined();
        expect(orderPair.orderPair.buyOrder).toBeDefined();
        expect(orderPair.orderPair.sellOrder).toBeDefined();
        
        // Verify buy order
        const buyOrder: OrderDetails = orderPair.orderPair.buyOrder;
        expect(buyOrder.accountId).toBe('account-1');
        expect(buyOrder.side).toBe('buy');
        expect(buyOrder.type).toBe('limit');
        expect(buyOrder.size).toBe(100);
        expect(buyOrder.price).toBe(2500);
        expect(buyOrder.status).toBe('pending');
        
        // Verify sell order
        const sellOrder: OrderDetails = orderPair.orderPair.sellOrder;
        expect(sellOrder.accountId).toBe('account-2');
        expect(sellOrder.side).toBe('sell');
        expect(sellOrder.type).toBe('limit');
        expect(sellOrder.size).toBe(100);
        expect(sellOrder.price).toBe(2500);
        expect(sellOrder.status).toBe('pending');
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should validate order pair neutrality', async () => {
      const orderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        const orderPair = await orderCoordinator.createOrderPair(orderPairRequest);
        
        // Verify position neutrality
        expect(orderPair.orderPair.buyOrder.size).toBe(orderPair.orderPair.sellOrder.size);
        expect(orderPair.orderPair.buyOrder.price).toBe(orderPair.orderPair.sellOrder.price);
        expect(orderPair.orderPair.buyOrder.side).not.toBe(orderPair.orderPair.sellOrder.side);
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should reject order pair with same account for buy and sell', async () => {
      const invalidOrderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-1', // Same account for both sides
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        await orderCoordinator.createOrderPair(invalidOrderPairRequest);
        fail('Should have rejected order pair with same account');
      } catch (error) {
        expect(error.message).toContain('same account');
      }
    });

    it('should reject order pair with different sizes', async () => {
      const invalidOrderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        buySize: 100,
        sellSize: 150, // Different sizes
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        await orderCoordinator.createOrderPair(invalidOrderPairRequest);
        fail('Should have rejected order pair with different sizes');
      } catch (error) {
        expect(error.message).toContain('size');
      }
    });
  });

  describe('Order Pair Execution', () => {
    let testOrderPairId: string;

    beforeEach(async () => {
      const orderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        const orderPair = await orderCoordinator.createOrderPair(orderPairRequest);
        testOrderPairId = orderPair.id;
      } catch (error) {
        testOrderPairId = 'mock-order-pair-id';
      }
    });

    it('should execute order pair atomically', async () => {
      try {
        const result = await orderCoordinator.executeOrderPair(testOrderPairId);
        
        expect(result).toBeDefined();
        expect(result.success).toBe(true);
        expect(result.orderPairId).toBe(testOrderPairId);
        expect(result.executionTime).toBeDefined();
        expect(result.executionTime).toBeGreaterThan(0);
        
        // Verify both orders were executed
        const orderPair = await orderCoordinator.getOrderPair(testOrderPairId);
        expect(orderPair.status).toBe('filled');
        expect(orderPair.orderPair.buyOrder.status).toBe('filled');
        expect(orderPair.orderPair.sellOrder.status).toBe('filled');
        expect(orderPair.executedAt).toBeDefined();
        expect(orderPair.completedAt).toBeDefined();
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should handle partial fills correctly', async () => {
      try {
        // Mock partial fill scenario
        const result = await orderCoordinator.executeOrderPair(testOrderPairId);
        
        if (result.partialFill) {
          const orderPair = await orderCoordinator.getOrderPair(testOrderPairId);
          expect(orderPair.status).toBe('partial');
          expect(orderPair.orderPair.buyOrder.fillSize).toBeLessThan(orderPair.orderPair.buyOrder.size);
          expect(orderPair.orderPair.sellOrder.fillSize).toBeLessThan(orderPair.orderPair.sellOrder.size);
        }
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should handle execution failures gracefully', async () => {
      try {
        // Mock execution failure scenario
        const result = await orderCoordinator.executeOrderPair(testOrderPairId);
        
        if (!result.success) {
          const orderPair = await orderCoordinator.getOrderPair(testOrderPairId);
          expect(orderPair.status).toBe('failed');
          expect(result.error).toBeDefined();
          expect(result.error.message).toBeDefined();
        }
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should retry failed orders according to configuration', async () => {
      try {
        const result = await orderCoordinator.executeOrderPair(testOrderPairId);
        
        if (!result.success && result.retryCount) {
          expect(result.retryCount).toBeGreaterThan(0);
          expect(result.retryCount).toBeLessThanOrEqual(3); // Max retry attempts
        }
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });
  });

  describe('Order Pair Monitoring', () => {
    let testOrderPairId: string;

    beforeEach(async () => {
      const orderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        const orderPair = await orderCoordinator.createOrderPair(orderPairRequest);
        testOrderPairId = orderPair.id;
      } catch (error) {
        testOrderPairId = 'mock-order-pair-id';
      }
    });

    it('should track order pair status changes', async () => {
      try {
        const initialOrderPair = await orderCoordinator.getOrderPair(testOrderPairId);
        expect(initialOrderPair.status).toBe('pending');
        
        // Execute the order pair
        await orderCoordinator.executeOrderPair(testOrderPairId);
        
        const executedOrderPair = await orderCoordinator.getOrderPair(testOrderPairId);
        expect(executedOrderPair.status).toBe('submitted');
        
        // Wait for execution to complete
        await new Promise(resolve => setTimeout(resolve, 100));
        
        const completedOrderPair = await orderCoordinator.getOrderPair(testOrderPairId);
        expect(['filled', 'failed', 'partial']).toContain(completedOrderPair.status);
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should calculate execution metrics', async () => {
      try {
        const result = await orderCoordinator.executeOrderPair(testOrderPairId);
        
        if (result.success) {
          expect(result.executionTime).toBeDefined();
          expect(result.slippage).toBeDefined();
          expect(result.fees).toBeDefined();
          expect(result.executionTime).toBeGreaterThan(0);
        }
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should emit order pair events', async () => {
      const events: string[] = [];
      
      try {
        orderCoordinator.on('orderPairCreated', (orderPair) => {
          events.push('orderPairCreated');
          expect(orderPair.id).toBe(testOrderPairId);
        });
        
        orderCoordinator.on('orderPairExecuted', (orderPair) => {
          events.push('orderPairExecuted');
          expect(orderPair.id).toBe(testOrderPairId);
        });
        
        orderCoordinator.on('orderPairCompleted', (orderPair) => {
          events.push('orderPairCompleted');
          expect(orderPair.id).toBe(testOrderPairId);
        });
        
        await orderCoordinator.executeOrderPair(testOrderPairId);
        
        expect(events).toContain('orderPairCreated');
        expect(events).toContain('orderPairExecuted');
        expect(events).toContain('orderPairCompleted');
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });
  });

  describe('Concurrent Order Execution', () => {
    it('should handle multiple concurrent order pairs', async () => {
      const orderPairRequests = [
        {
          sessionId: testSessionId,
          buyAccountId: 'account-1',
          sellAccountId: 'account-2',
          symbol: 'ETH/USD',
          size: 100,
          price: 2500,
          orderType: 'limit' as const
        },
        {
          sessionId: testSessionId,
          buyAccountId: 'account-2',
          sellAccountId: 'account-1',
          symbol: 'ETH/USD',
          size: 150,
          price: 2501,
          orderType: 'limit' as const
        }
      ];

      try {
        const orderPairs = await Promise.all(
          orderPairRequests.map(request => orderCoordinator.createOrderPair(request))
        );
        
        expect(orderPairs).toHaveLength(2);
        expect(orderPairs[0].id).not.toBe(orderPairs[1].id);
        
        // Execute both order pairs concurrently
        const results = await Promise.all(
          orderPairs.map(orderPair => orderCoordinator.executeOrderPair(orderPair.id))
        );
        
        expect(results).toHaveLength(2);
        results.forEach(result => {
          expect(result).toBeDefined();
          expect(result.orderPairId).toBeDefined();
        });
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });

    it('should respect maximum concurrent orders limit', async () => {
      const orderPairRequests = Array(25).fill(null).map((_, index) => ({
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500 + index,
        orderType: 'limit' as const
      }));

      try {
        const orderPairs = await Promise.all(
          orderPairRequests.map(request => orderCoordinator.createOrderPair(request))
        );
        
        // Try to execute all order pairs
        const results = await Promise.allSettled(
          orderPairs.map(orderPair => orderCoordinator.executeOrderPair(orderPair.id))
        );
        
        // Some should succeed, some should be rejected due to concurrency limit
        const successful = results.filter(r => r.status === 'fulfilled');
        const rejected = results.filter(r => r.status === 'rejected');
        
        expect(successful.length + rejected.length).toBe(25);
        expect(successful.length).toBeLessThanOrEqual(20); // Max concurrent orders
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });
  });

  describe('Error Handling', () => {
    it('should handle non-existent order pair operations gracefully', async () => {
      const nonExistentOrderPairId = 'non-existent-order-pair-id';
      
      try {
        await orderCoordinator.getOrderPair(nonExistentOrderPairId);
        fail('Should have thrown error for non-existent order pair');
      } catch (error) {
        expect(error.message).toContain('not found');
      }
    });

    it('should handle execution timeout', async () => {
      const orderPairRequest = {
        sessionId: testSessionId,
        buyAccountId: 'account-1',
        sellAccountId: 'account-2',
        symbol: 'ETH/USD',
        size: 100,
        price: 2500,
        orderType: 'limit' as const
      };

      try {
        const orderPair = await orderCoordinator.createOrderPair(orderPairRequest);
        
        // Mock timeout scenario
        const result = await orderCoordinator.executeOrderPair(orderPair.id);
        
        if (!result.success && result.timeout) {
          expect(result.error.message).toContain('timeout');
        }
      } catch (error) {
        // This test should fail initially since OrderCoordinator doesn't exist yet
        expect(error.message).toContain('OrderCoordinator');
      }
    });
  });
});