/**
 * Unit Tests - MemoryProxy Service v3
 * Tests MongoDB-backed governance rule persistence and retrieval
 */

const { MemoryProxyService } = require('../../src/services/MemoryProxy.service');
const GovernanceRule = require('../../src/models/GovernanceRule.model');
const AuditLog = require('../../src/models/AuditLog.model');
const mongoose = require('mongoose');

// Increase timeout for MongoDB operations
jest.setTimeout(30000);

describe('MemoryProxyService v3 (MongoDB)', () => {
  let memoryProxy;

  // Connect to test database before all tests
  beforeAll(async () => {
    const mongoUri = process.env.MONGODB_URI || 'mongodb://localhost:27017/tractatus_test';
    await mongoose.connect(mongoUri);
  });

  // Disconnect after all tests
  afterAll(async () => {
    await mongoose.disconnect();
  });

  const testRules = [
    {
      id: 'test_inst_001',
      text: 'Test rule 1',
      quadrant: 'STRATEGIC',
      persistence: 'HIGH',
      active: true
    },
    {
      id: 'test_inst_002',
      text: 'Test rule 2',
      quadrant: 'OPERATIONAL',
      persistence: 'HIGH',
      active: true
    },
    {
      id: 'test_inst_003',
      text: 'Test rule 3',
      quadrant: 'SYSTEM',
      persistence: 'MEDIUM',
      active: true
    }
  ];

  beforeEach(async () => {
    // Clear test data from previous tests
    await GovernanceRule.deleteMany({ id: /^test_/ });
    await AuditLog.deleteMany({ sessionId: /^test-/ });

    memoryProxy = new MemoryProxyService({
      cacheEnabled: true,
      cacheTTL: 1000, // 1 second for testing
      anthropicEnabled: false // Disable Anthropic API for tests
    });

    await memoryProxy.initialize();
  });

  afterEach(async () => {
    // Cleanup test data
    await GovernanceRule.deleteMany({ id: /^test_/ });
    await AuditLog.deleteMany({ sessionId: /^test-/ });
  });

  describe('Initialization', () => {
    test('should connect to MongoDB successfully', async () => {
      expect(mongoose.connection.readyState).toBe(1); // 1 = connected
    });

    test('should initialize with correct configuration', () => {
      expect(memoryProxy.cacheEnabled).toBe(true);
      expect(memoryProxy.cacheTTL).toBe(1000);
      expect(memoryProxy.anthropicEnabled).toBe(false);
    });
  });

  describe('persistGovernanceRules', () => {
    test('should persist rules successfully', async () => {
      const result = await memoryProxy.persistGovernanceRules(testRules);

      expect(result.success).toBe(true);
      expect(result.total).toBe(3);
      expect(result.inserted + result.modified).toBe(3);
      expect(result.duration).toBeGreaterThanOrEqual(0);
    });

    test('should store rules in MongoDB', async () => {
      await memoryProxy.persistGovernanceRules(testRules);

      const storedRules = await GovernanceRule.find({ id: /^test_/ }).lean();

      expect(storedRules).toHaveLength(3);
      expect(storedRules[0].text).toBeDefined();
      expect(storedRules[0].quadrant).toBeDefined();
      expect(storedRules[0].persistence).toBeDefined();
    });

    test('should update existing rules on re-persist', async () => {
      // First persist
      await memoryProxy.persistGovernanceRules(testRules);

      // Update and re-persist
      const updatedRules = testRules.map(r => ({
        ...r,
        text: r.text + ' UPDATED'
      }));

      const result = await memoryProxy.persistGovernanceRules(updatedRules);

      expect(result.success).toBe(true);
      expect(result.modified).toBe(3);

      const storedRules = await GovernanceRule.find({ id: /^test_/ }).lean();
      expect(storedRules.every(r => r.text.includes('UPDATED'))).toBe(true);
    });

    test('should reject empty rules array', async () => {
      await expect(memoryProxy.persistGovernanceRules([]))
        .rejects
        .toThrow('Cannot persist empty rules array');
    });

    test('should reject non-array input', async () => {
      await expect(memoryProxy.persistGovernanceRules({ invalid: 'input' }))
        .rejects
        .toThrow('Rules must be an array');
    });

    test('should clear cache after persisting', async () => {
      // Load rules to populate cache
      await memoryProxy.persistGovernanceRules(testRules);
      await memoryProxy.loadGovernanceRules();

      const statsBefore = memoryProxy.getCacheStats();
      expect(statsBefore.entries).toBeGreaterThan(0);

      // Persist again (should clear cache)
      await memoryProxy.persistGovernanceRules(testRules);

      const statsAfter = memoryProxy.getCacheStats();
      expect(statsAfter.entries).toBe(0);
    });
  });

  describe('loadGovernanceRules', () => {
    beforeEach(async () => {
      await memoryProxy.persistGovernanceRules(testRules);
    });

    test('should load rules successfully', async () => {
      const allRules = await memoryProxy.loadGovernanceRules();
      const testRulesLoaded = allRules.filter(r => r.id.startsWith('test_'));

      expect(testRulesLoaded).toHaveLength(3);
      expect(testRulesLoaded.find(r => r.id === 'test_inst_001')).toBeDefined();
      expect(testRulesLoaded.find(r => r.id === 'test_inst_002')).toBeDefined();
      expect(testRulesLoaded.find(r => r.id === 'test_inst_003')).toBeDefined();
    });

    test('should load from cache on second call', async () => {
      // First call - from MongoDB
      await memoryProxy.loadGovernanceRules();

      // Second call - from cache (much faster)
      const startTime = Date.now();
      const allRules = await memoryProxy.loadGovernanceRules();
      const duration = Date.now() - startTime;

      const testRulesLoaded = allRules.filter(r => r.id.startsWith('test_'));
      expect(testRulesLoaded).toHaveLength(3);
      expect(duration).toBeLessThan(10); // Cache should be very fast
    });

    test('should bypass cache when skipCache option is true', async () => {
      // Load to populate cache
      await memoryProxy.loadGovernanceRules();

      // Clear cache
      memoryProxy.clearCache();

      // Load with skipCache should work
      const allRules = await memoryProxy.loadGovernanceRules({ skipCache: true });
      const testRulesLoaded = allRules.filter(r => r.id.startsWith('test_'));
      expect(testRulesLoaded).toHaveLength(3);
    });

    test('should return empty array when no test rules exist', async () => {
      // Clear all test rules
      await GovernanceRule.deleteMany({ id: /^test_/ });

      const rules = await memoryProxy.loadGovernanceRules();
      expect(rules.filter(r => r.id.startsWith('test_'))).toEqual([]);
    });

    test('should maintain data integrity across persist/load cycle', async () => {
      const rules = await memoryProxy.loadGovernanceRules();

      for (const testRule of testRules) {
        const loaded = rules.find(r => r.id === testRule.id);
        expect(loaded).toBeDefined();
        expect(loaded.text).toBe(testRule.text);
        expect(loaded.quadrant).toBe(testRule.quadrant);
        expect(loaded.persistence).toBe(testRule.persistence);
      }
    });
  });

  describe('getRule', () => {
    beforeEach(async () => {
      await memoryProxy.persistGovernanceRules(testRules);
    });

    test('should get specific rule by ID', async () => {
      const rule = await memoryProxy.getRule('test_inst_002');

      expect(rule).toBeDefined();
      expect(rule.id).toBe('test_inst_002');
      expect(rule.text).toBe('Test rule 2');
      expect(rule.quadrant).toBe('OPERATIONAL');
    });

    test('should return null for non-existent rule', async () => {
      const rule = await memoryProxy.getRule('test_inst_999');
      expect(rule).toBeNull();
    });
  });

  describe('getRulesByQuadrant', () => {
    beforeEach(async () => {
      await memoryProxy.persistGovernanceRules(testRules);
    });

    test('should filter rules by quadrant', async () => {
      const strategicRules = await memoryProxy.getRulesByQuadrant('STRATEGIC');

      const testStrategicRules = strategicRules.filter(r => r.id.startsWith('test_'));
      expect(testStrategicRules).toHaveLength(1);
      expect(testStrategicRules[0].id).toBe('test_inst_001');
      expect(testStrategicRules[0].quadrant).toBe('STRATEGIC');
    });

    test('should return empty array for non-existent quadrant', async () => {
      const rules = await memoryProxy.getRulesByQuadrant('NONEXISTENT');
      expect(rules.filter(r => r.id.startsWith('test_'))).toEqual([]);
    });
  });

  describe('getRulesByPersistence', () => {
    beforeEach(async () => {
      await memoryProxy.persistGovernanceRules(testRules);
    });

    test('should filter rules by persistence level', async () => {
      const highRules = await memoryProxy.getRulesByPersistence('HIGH');

      const testHighRules = highRules.filter(r => r.id.startsWith('test_'));
      expect(testHighRules).toHaveLength(2);
      expect(testHighRules.every(r => r.persistence === 'HIGH')).toBe(true);
    });

    test('should return empty array for non-existent persistence level', async () => {
      const rules = await memoryProxy.getRulesByPersistence('LOW');
      expect(rules.filter(r => r.id.startsWith('test_'))).toEqual([]);
    });
  });

  describe('auditDecision', () => {
    test('should audit decision successfully', async () => {
      const decision = {
        sessionId: 'test-session-001',
        action: 'blog_post_generation',
        rulesChecked: ['inst_016', 'inst_017'],
        violations: [],
        allowed: true,
        metadata: {
          user: 'test-user',
          timestamp: new Date().toISOString()
        }
      };

      const result = await memoryProxy.auditDecision(decision);

      expect(result.success).toBe(true);
      expect(result.audited).toBe(true);
      expect(result.auditId).toBeDefined();
      expect(result.duration).toBeGreaterThanOrEqual(0);
    });

    test('should create audit log in MongoDB', async () => {
      const decision = {
        sessionId: 'test-session-002',
        action: 'test_action',
        allowed: true
      };

      const result = await memoryProxy.auditDecision(decision);

      const storedLog = await AuditLog.findById(result.auditId).lean();

      expect(storedLog).toBeDefined();
      expect(storedLog.sessionId).toBe('test-session-002');
      expect(storedLog.action).toBe('test_action');
      expect(storedLog.allowed).toBe(true);
      expect(storedLog.timestamp).toBeDefined();
    });

    test('should store multiple audit entries', async () => {
      const decision1 = { sessionId: 'test-session-multi-1', action: 'action-1', allowed: true };
      const decision2 = { sessionId: 'test-session-multi-2', action: 'action-2', allowed: false };

      await memoryProxy.auditDecision(decision1);
      await memoryProxy.auditDecision(decision2);

      const logs = await AuditLog.find({
        sessionId: { $in: ['test-session-multi-1', 'test-session-multi-2'] }
      }).lean();

      expect(logs).toHaveLength(2);
    });

    test('should reject decision without required fields', async () => {
      const invalidDecision = { sessionId: 'test', /* missing action */ };

      await expect(memoryProxy.auditDecision(invalidDecision))
        .rejects
        .toThrow('Decision must include sessionId and action');
    });
  });

  describe('Cache Management', () => {
    test('should clear cache', async () => {
      await memoryProxy.persistGovernanceRules(testRules);

      // Load rules to populate cache
      await memoryProxy.loadGovernanceRules();

      expect(memoryProxy.getCacheStats().entries).toBeGreaterThan(0);

      memoryProxy.clearCache();

      expect(memoryProxy.getCacheStats().entries).toBe(0);
    });

    test('should expire cache after TTL', async () => {
      // Create proxy with 100ms TTL
      const shortTTLProxy = new MemoryProxyService({
        cacheEnabled: true,
        cacheTTL: 100,
        anthropicEnabled: false
      });
      await shortTTLProxy.initialize();

      await shortTTLProxy.persistGovernanceRules(testRules);

      // Load to populate cache
      await shortTTLProxy.loadGovernanceRules();

      // Wait for cache to expire
      await new Promise(resolve => setTimeout(resolve, 150));

      // Should reload from MongoDB (cache expired)
      const allRules = await shortTTLProxy.loadGovernanceRules();
      const testRulesLoaded = allRules.filter(r => r.id.startsWith('test_'));
      expect(testRulesLoaded).toHaveLength(3);
    });

    test('should get cache statistics', () => {
      const stats = memoryProxy.getCacheStats();

      expect(stats.enabled).toBe(true);
      expect(stats.ttl).toBe(1000);
      expect(stats.entries).toBeGreaterThanOrEqual(0);
      expect(stats.keys).toBeDefined();
    });
  });
});