/**
 * Security: Sensitive Data Masking
 *
 * Verifies the maskSensitiveFields() function from @/lib/audit correctly
 * redacts PII and secrets from audit log payloads.
 *
 * Sensitive fields per SECURITY-GUIDELINES.md §5.2:
 *   email, phone, password, credentials_enc, token
 *
 * Masking format:
 *   - len > 4  →  first 2 chars + "***" + last 2 chars  (e.g. "al***om")
 *   - len ≤ 4  →  "***"
 */
import { describe, expect, it } from 'vitest';
import { maskSensitiveFields } from '@/lib/audit';

// ─────────────────────────────────────────────────────────────────────────────

describe('Sensitive data masking - field detection', () => {
  it('masks "email" field', () => {
    const result = maskSensitiveFields({ email: 'user@example.com' });
    expect(result?.email).not.toBe('user@example.com');
    expect(result?.email).toContain('***');
  });

  it('masks "phone" field', () => {
    const result = maskSensitiveFields({ phone: '+61400000000' });
    expect(result?.phone).not.toBe('+61400000000');
    expect(result?.phone).toContain('***');
  });

  it('masks "password" field', () => {
    const result = maskSensitiveFields({ password: 'MySecretPassword123' });
    expect(result?.password).not.toBe('MySecretPassword123');
    expect(result?.password).toContain('***');
  });

  it('masks "credentials_enc" field', () => {
    const result = maskSensitiveFields({ credentials_enc: 'encrypted-secret-data' });
    expect(result?.credentials_enc).not.toBe('encrypted-secret-data');
    expect(result?.credentials_enc).toContain('***');
  });

  it('masks "token" field', () => {
    const result = maskSensitiveFields({ token: 'eyJhbGciOiJIUzI1NiJ9.test' });
    expect(result?.token).not.toBe('eyJhbGciOiJIUzI1NiJ9.test');
    expect(result?.token).toContain('***');
  });
});

describe('Sensitive data masking - masking format', () => {
  it('long email (len > 4) uses partial mask: first 2 + *** + last 2', () => {
    // 'user@example.com' → 'us***om'
    const result = maskSensitiveFields({ email: 'user@example.com' });
    expect(result?.email).toBe('us***om');
  });

  it('short sensitive value (len ≤ 4) is fully replaced with ***', () => {
    const result = maskSensitiveFields({ email: 'ab' });
    expect(result?.email).toBe('***');
  });

  it('exactly 4-char sensitive value is fully masked', () => {
    const result = maskSensitiveFields({ email: 'abcd' });
    expect(result?.email).toBe('***');
  });

  it('5-char sensitive value uses partial mask', () => {
    // 'abcde' → 'ab***de'
    const result = maskSensitiveFields({ password: 'abcde' });
    expect(result?.password).toBe('ab***de');
  });

  it('single char sensitive value becomes ***', () => {
    const result = maskSensitiveFields({ token: 'x' });
    expect(result?.token).toBe('***');
  });

  it('partial mask exposes only 2 leading and 2 trailing characters', () => {
    const result = maskSensitiveFields({ password: 'SuperSecret2025!' });
    const masked = result?.password as string;
    // 'SuperSecret2025!' → first 2 = 'Su', last 2 = '5!', mask = 'Su***5!'
    expect(masked).toMatch(/^Su\*{3}5!$/);
  });
});

describe('Sensitive data masking - non-sensitive fields', () => {
  it('preserves string non-sensitive fields unchanged', () => {
    const result = maskSensitiveFields({ name: 'John Smith', status: 'active' });
    expect(result?.name).toBe('John Smith');
    expect(result?.status).toBe('active');
  });

  it('preserves numeric non-sensitive fields unchanged', () => {
    const result = maskSensitiveFields({ count: 42, score: 9.5 });
    expect(result?.count).toBe(42);
    expect(result?.score).toBe(9.5);
  });

  it('preserves boolean non-sensitive fields unchanged', () => {
    const result = maskSensitiveFields({ isProxy: true, isActive: false });
    expect(result?.isProxy).toBe(true);
    expect(result?.isActive).toBe(false);
  });

  it('preserves null non-sensitive fields unchanged', () => {
    const result = maskSensitiveFields({ companyName: null });
    expect(result?.companyName).toBeNull();
  });

  it('mixed record: masks sensitive, preserves non-sensitive', () => {
    const result = maskSensitiveFields({
      name: 'John',
      email: 'john@example.com',
      status: 'active',
      password: 'hunter2',
    });
    expect(result?.name).toBe('John');
    expect(result?.status).toBe('active');
    expect(result?.email).toContain('***');
    expect(result?.password).toContain('***');
  });
});

describe('Sensitive data masking - edge cases', () => {
  it('returns undefined for undefined input', () => {
    expect(maskSensitiveFields(undefined)).toBeUndefined();
  });

  it('returns empty object for empty object input', () => {
    const result = maskSensitiveFields({});
    expect(result).toEqual({});
  });

  it('does not mutate the original object', () => {
    const original = { email: 'alice@example.com', name: 'Alice' };
    const originalEmail = original.email;
    maskSensitiveFields(original);
    expect(original.email).toBe(originalEmail);
  });

  it('only masks string values - non-string sensitive fields are left as-is', () => {
    // e.g. if someone stores a number in an "email" field (type error upstream),
    // the masking logic gracefully skips it (typeof check)
    const result = maskSensitiveFields({ email: 12345 as unknown as string });
    // The implementation only masks if typeof === 'string', so a number stays
    expect(result?.email).toBe(12345);
  });
});
