import { describe, expect, it } from 'vitest';
import { HDKey } from '@scure/bip32';
import { buildInvoiceOption } from '../src/option';

const seed = new Uint8Array(64).fill(9);
const xpub = HDKey.fromMasterSeed(seed).derive("m/44'/60'/0'").publicExtendedKey;

describe('buildInvoiceOption', () => {
  it('xpub mode: derives a fresh address at the wallet next index, exact pegged amount, no dust', () => {
    const built = buildInvoiceOption({
      chain: 'base',
      fiatAmount: '100',
      rateUnits: 1_000000n,
      wallet: { kind: 'xpub', xpub, nextIndex: 4 },
    });
    expect(built.asset).toBe('USDC');
    expect(built.cryptoAmount).toBe(100_000000n);
    expect(built.derivationIndex).toBe(4);
    expect(built.dustApplied).toBe(false);
    expect(built.address).toMatch(/^0x/);
  });

  it('static mode: keeps the merchant address and applies a unique cent-dust suffix', () => {
    const built = buildInvoiceOption({
      chain: 'tron',
      fiatAmount: '100',
      rateUnits: 1_000000n,
      wallet: { kind: 'static', staticAddress: 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t', nextIndex: 0 },
    });
    expect(built.asset).toBe('USDT');
    expect(built.address).toBe('TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t');
    expect(built.derivationIndex).toBeNull();
    expect(built.dustApplied).toBe(true);
    expect(built.cryptoAmount).toBeGreaterThan(100_000000n);
    expect(built.cryptoAmount).toBeLessThanOrEqual(100_099900n);
  });

  it('lazily creating per selection means differing rates peg per option (each call pegs its own)', () => {
    const early = buildInvoiceOption({
      chain: 'base',
      fiatAmount: '100',
      rateUnits: 1_000000n,
      wallet: { kind: 'xpub', xpub, nextIndex: 0 },
    });
    const later = buildInvoiceOption({
      chain: 'base',
      fiatAmount: '100',
      rateUnits: 999700n,
      wallet: { kind: 'xpub', xpub, nextIndex: 1 },
    });
    expect(early.cryptoAmount).toBe(100_000000n);
    expect(later.cryptoAmount).toBe(100_030010n);
  });

  it('rejects misconfigured wallets', () => {
    expect(() =>
      buildInvoiceOption({ chain: 'base', fiatAmount: '1', rateUnits: 1_000000n, wallet: { kind: 'xpub', nextIndex: 0 } }),
    ).toThrow(/missing/);
    expect(() =>
      buildInvoiceOption({ chain: 'tron', fiatAmount: '1', rateUnits: 1_000000n, wallet: { kind: 'static', nextIndex: 0 } }),
    ).toThrow(/missing/);
  });
});