import DatabaseService from '../../../src/services/DatabaseService';

describe('DatabaseService', () => {
  let databaseService: DatabaseService;

  beforeEach(() => {
    databaseService = new DatabaseService();

    // Mock console methods to reduce test noise
    jest.spyOn(console, 'log').mockImplementation(() => {});
    jest.spyOn(console, 'error').mockImplementation(() => {});
  });

  afterEach(() => {
    jest.clearAllMocks();
    jest.restoreAllMocks();
    try {
      databaseService.close();
    } catch {
      // Ignore close errors in tests
    }
  });

  describe('initial state', () => {
    it('should have null database connections initially', () => {
      expect(databaseService.getMainDb()).toBeNull();
      expect(databaseService.getProfanityDb()).toBeNull();
    });

    it('should throw error when accessing models before initialization', () => {
      expect(() => databaseService.getLocationModel()).toThrow('Database not initialized. Call initialize() first.');
      expect(() => databaseService.getProfanityWordModel()).toThrow('Database not initialized. Call initialize() first.');
    });
  });

  describe('close method', () => {
    it('should handle close when not initialized', () => {
      expect(() => databaseService.close()).not.toThrow();
    });

    it('should be callable multiple times', () => {
      expect(() => {
        databaseService.close();
        databaseService.close();
        databaseService.close();
      }).not.toThrow();
    });
  });

  describe('type safety', () => {
    it('should have correct method signatures', () => {
      expect(typeof databaseService.initialize).toBe('function');
      expect(typeof databaseService.initializeMainDatabase).toBe('function');
      expect(typeof databaseService.initializeProfanityDatabase).toBe('function');
      expect(typeof databaseService.getLocationModel).toBe('function');
      expect(typeof databaseService.getProfanityWordModel).toBe('function');
      expect(typeof databaseService.getMainDb).toBe('function');
      expect(typeof databaseService.getProfanityDb).toBe('function');
      expect(typeof databaseService.close).toBe('function');
    });

    it('should return correct types', () => {
      expect(databaseService.getMainDb()).toBeNull();
      expect(databaseService.getProfanityDb()).toBeNull();
    });
  });

  describe('error handling', () => {
    it('should handle method calls on uninitialized service', () => {
      expect(() => databaseService.getLocationModel()).toThrow();
      expect(() => databaseService.getProfanityWordModel()).toThrow();
    });

    it('should provide meaningful error messages', () => {
      expect(() => databaseService.getLocationModel()).toThrow('Database not initialized. Call initialize() first.');
      expect(() => databaseService.getProfanityWordModel()).toThrow('Database not initialized. Call initialize() first.');
    });
  });

  describe('service instantiation', () => {
    it('should create a new instance successfully', () => {
      const newService = new DatabaseService();
      expect(newService).toBeInstanceOf(DatabaseService);
      expect(newService.getMainDb()).toBeNull();
      expect(newService.getProfanityDb()).toBeNull();
    });

    it('should allow multiple instances', () => {
      const service1 = new DatabaseService();
      const service2 = new DatabaseService();

      expect(service1).toBeInstanceOf(DatabaseService);
      expect(service2).toBeInstanceOf(DatabaseService);
      expect(service1).not.toBe(service2);
    });
  });
});