import { describe, expect, test } from 'bun:test';
import {
  addCIDR,
  generateIPsInSubnet,
  isIPInRange,
  isInSubnet,
  parseSubnet,
  stripCIDR,
} from './subnet-parser';

describe('Subnet Parser', () => {
  describe('parseSubnet', () => {
    test('should parse valid /24 subnet', () => {
      const result = parseSubnet('10.0.10.0/24');

      expect(result.network).toBe('10.0.10.0');
      expect(result.maskBits).toBe(24);
      expect(result.octets).toEqual([10, 0, 10, 0]);
      expect(result.firstUsableIp).toBe('10.0.10.10');
      expect(result.lastUsableIp).toBe('10.0.10.254');
    });

    test('should reject invalid subnet format', () => {
      expect(() => parseSubnet('invalid')).toThrow('Invalid subnet format');
      expect(() => parseSubnet('10.0.10.0')).toThrow('Invalid subnet format');
      expect(() => parseSubnet('10.0.10.0/abc')).toThrow('Invalid subnet format');
    });

    test('should reject invalid IP address', () => {
      expect(() => parseSubnet('256.0.10.0/24')).toThrow('Invalid IP address');
      expect(() => parseSubnet('10.0.10/24')).toThrow('Invalid IP address');
    });

    test('should reject subnets smaller than /24', () => {
      expect(() => parseSubnet('10.0.10.0/25')).toThrow('Subnet too small');
      expect(() => parseSubnet('10.0.10.0/30')).toThrow('Subnet too small');
    });
  });

  describe('stripCIDR', () => {
    test('should strip CIDR mask', () => {
      expect(stripCIDR('10.0.10.10/24')).toBe('10.0.10.10');
      expect(stripCIDR('192.168.1.1/16')).toBe('192.168.1.1');
    });

    test('should return IP unchanged if no mask', () => {
      expect(stripCIDR('10.0.10.10')).toBe('10.0.10.10');
    });
  });

  describe('addCIDR', () => {
    test('should add CIDR mask', () => {
      expect(addCIDR('10.0.10.10', 24)).toBe('10.0.10.10/24');
      expect(addCIDR('192.168.1.1', 16)).toBe('192.168.1.1/16');
    });
  });

  describe('isInSubnet', () => {
    test('should return true for IP in subnet', () => {
      expect(isInSubnet('10.0.10.50/24', '10.0.10.0/24')).toBe(true);
      expect(isInSubnet('10.0.10.10/24', '10.0.10.0/24')).toBe(true);
      expect(isInSubnet('10.0.10.254/24', '10.0.10.0/24')).toBe(true);
    });

    test('should return false for IP outside subnet', () => {
      expect(isInSubnet('10.0.11.50/24', '10.0.10.0/24')).toBe(false);
      expect(isInSubnet('10.0.20.10/24', '10.0.10.0/24')).toBe(false);
      expect(isInSubnet('192.168.1.1/24', '10.0.10.0/24')).toBe(false);
    });
  });

  describe('generateIPsInSubnet', () => {
    test('should generate IPs from .10 to .254', () => {
      const ips = Array.from(generateIPsInSubnet('10.0.10.0/24'));

      expect(ips[0]).toBe('10.0.10.10/24'); // First usable (reserve .1-.9)
      expect(ips[ips.length - 1]).toBe('10.0.10.254/24'); // Last usable
      expect(ips.length).toBe(245); // 254 - 10 + 1 = 245 IPs
    });

    test('should generate correct IPs for different subnet', () => {
      const ips = Array.from(generateIPsInSubnet('192.168.1.0/24'));

      expect(ips[0]).toBe('192.168.1.10/24');
      expect(ips[ips.length - 1]).toBe('192.168.1.254/24');
    });
  });

  describe('isIPInRange', () => {
    test('should match single IP reservation', () => {
      expect(isIPInRange('10.0.10.50', '10.0.10.50', null)).toBe(true);
      expect(isIPInRange('10.0.10.51', '10.0.10.50', null)).toBe(false);
    });

    test('should match IP range reservation', () => {
      expect(isIPInRange('10.0.10.50', '10.0.10.50', '10.0.10.60')).toBe(true);
      expect(isIPInRange('10.0.10.55', '10.0.10.50', '10.0.10.60')).toBe(true);
      expect(isIPInRange('10.0.10.60', '10.0.10.50', '10.0.10.60')).toBe(true);
      expect(isIPInRange('10.0.10.49', '10.0.10.50', '10.0.10.60')).toBe(false);
      expect(isIPInRange('10.0.10.61', '10.0.10.50', '10.0.10.60')).toBe(false);
    });

    test('should handle IPs with CIDR notation', () => {
      expect(isIPInRange('10.0.10.50/24', '10.0.10.50', '10.0.10.60')).toBe(true);
    });
  });
});