/**
 * Egress-policy helpers for the plugin network guard (#plugins, L1 hardening):
 * SSRF/private-IP blocking, declared-host allowlisting, and connect() arg
 * classification.
 */
import { describe, it, expect } from 'vitest';
import net from 'node:net';
import {
  isBlockedIp, makeHostAllow, classifyConnect, dgramSendTarget, dgramConnectTarget,
} from '../../../src/nest/plugins/runtime/egress-policy';

const isIP = (s: string) => net.isIP(s) !== 0;

describe('isBlockedIp', () => {
  it.each([
    '0.0.0.0', '10.1.2.3', '127.0.0.1', '172.16.0.1', '172.31.255.255',
    '192.168.1.1', '169.254.169.254', '100.64.0.1', '224.0.0.1', '255.255.255.255',
    '::1', '::', 'fe80::1', 'fc00::1', 'fd12:3456::1', '::ffff:127.0.0.1', '::ffff:10.0.0.1',
    // non-canonical IPv6 spellings must be blocked too (canonicalization)
    '0::1', '::ffff:a9fe:a9fe', '::ffff:169.254.169.254', '0:0:0:0:0:0:0:1', 'fD00::1', '::ffff:7f00:1',
  ])('blocks %s', (ip) => {
    expect(isBlockedIp(ip)).toBe(true);
  });

  it.each([
    '8.8.8.8', '1.1.1.1', '140.82.121.3', '172.15.0.1', '172.32.0.1',
    '100.63.0.1', '100.128.0.1', '2606:4700::1111', '::ffff:8.8.8.8',
  ])('allows public %s', (ip) => {
    expect(isBlockedIp(ip)).toBe(false);
  });
});

describe('makeHostAllow', () => {
  it('matches exact hosts and *.suffix wildcards, case-insensitively', () => {
    const allow = makeHostAllow(['api.example.com', '*.aviationstack.com']);
    expect(allow('api.example.com')).toBe(true);
    expect(allow('API.example.com')).toBe(true);
    expect(allow('v2.aviationstack.com')).toBe(true);
    expect(allow('aviationstack.com')).toBe(true); // apex matches *.suffix
    expect(allow('evil.com')).toBe(false);
    expect(allow('notapi.example.com')).toBe(false);
  });

  it('an empty egress list allows nothing', () => {
    const allow = makeHostAllow([]);
    expect(allow('anything.com')).toBe(false);
  });

  it('rejects degenerate wildcards that would be allow-all', () => {
    // `*.` matched any trailing-dot host; `*.com`/`*` are whole-TLD/allow-all.
    expect(makeHostAllow(['*.'])('evil.com')).toBe(false);
    expect(makeHostAllow(['*.'])('evil.com.')).toBe(false);
    expect(makeHostAllow(['*.com'])('evil.com')).toBe(false);
    expect(makeHostAllow(['*'])('evil.com')).toBe(false);
  });

  it('normalizes a trailing dot so an FQDN host cannot dodge an exact match', () => {
    const allow = makeHostAllow(['api.example.com']);
    expect(allow('api.example.com.')).toBe(true); // trailing-dot FQDN still matches
    // and the FQDN trick can't turn a real wildcard into allow-all
    expect(makeHostAllow(['*.example.com'])('sink.attacker.com.')).toBe(false);
  });
});

describe('classifyConnect', () => {
  it('treats a unix-socket path (options.path) as local', () => {
    expect(classifyConnect([{ path: '/tmp/x.sock' }], isIP)).toEqual({ kind: 'local', host: '/tmp/x.sock' });
  });

  it('treats a bare non-numeric string as a local IPC path', () => {
    expect(classifyConnect(['/run/app.sock'], isIP).kind).toBe('local');
  });

  it('classifies an options object with a hostname', () => {
    expect(classifyConnect([{ host: 'api.example.com', port: 443 }], isIP)).toEqual({ kind: 'hostname', host: 'api.example.com' });
  });

  it('classifies an options object with a literal IP', () => {
    expect(classifyConnect([{ host: '10.0.0.5', port: 80 }], isIP)).toEqual({ kind: 'literal-ip', host: '10.0.0.5' });
  });

  it('classifies the (port, host) form', () => {
    expect(classifyConnect([443, 'example.com'], isIP)).toEqual({ kind: 'hostname', host: 'example.com' });
    expect(classifyConnect([80, '127.0.0.1'], isIP)).toEqual({ kind: 'literal-ip', host: '127.0.0.1' });
  });

  it('defaults a port-only connect to localhost', () => {
    expect(classifyConnect([8080], isIP)).toEqual({ kind: 'hostname', host: 'localhost' });
  });
});

describe('dgramSendTarget', () => {
  const msg = Buffer.from('x');
  it('reads the address from send(msg, port, address)', () => {
    expect(dgramSendTarget([msg, 53, 'attacker.com'])).toBe('attacker.com');
  });
  it('reads the address from the send(msg, offset, length, port, address) form', () => {
    expect(dgramSendTarget([msg, 0, 1, 53, 'attacker.com'])).toBe('attacker.com');
  });
  it('is null when no explicit address is given (connected / localhost default)', () => {
    expect(dgramSendTarget([msg, 53])).toBeNull();
    expect(dgramSendTarget([msg])).toBeNull();
    expect(dgramSendTarget([msg, 0, 1, 53])).toBeNull();
  });
  it('ignores a trailing callback in the address slot', () => {
    expect(dgramSendTarget([msg, 53, () => {}])).toBeNull();
  });
});

describe('dgramConnectTarget', () => {
  it('reads the address from connect(port, address)', () => {
    expect(dgramConnectTarget([53, 'attacker.com'])).toBe('attacker.com');
  });
  it('is null for connect(port) or connect(port, cb)', () => {
    expect(dgramConnectTarget([53])).toBeNull();
    expect(dgramConnectTarget([53, () => {}])).toBeNull();
  });
});