// background/steps/fill-paypal-payment.js — Step 9: Fill PayPal checkout payment form
(function attachBackgroundStep14(root, factory) {
  root.MultiPageBackgroundStep14 = factory();
})(typeof self !== 'undefined' ? self : globalThis, function createBackgroundStep14Module() {
  function createStep14Executor(deps = {}) {
    const {
      addLog,
      fetchCheckoutAddress,
      generateRandomEmail,
      sendToContentScriptResilient,
    } = deps;

    async function executeStep14(state = {}) {
      await addLog('步骤 9：正在准备 PayPal 付款信息...');

      const card = generateLuhnVisaTestCard();
      await addLog(`已生成测试 VISA 卡号（Luhn）：尾号 ${card.Credit_Card_Number.slice(-4)} 有效期 ${card.Expires}`);

      // Fetch random US address
      const addr = await fetchCheckoutAddress();
      await addLog(`已获取地址: ${addr.street}, ${addr.city}, ${addr.state} ${addr.zip}`);

      // Generate random credentials
      const email = generateRandomEmail();
      const password = generateRandomPassword();

      // The checkout-paypal content script is still active after step 8's PayPal login.
      // After PayPal login form submission, the tab has redirected to the checkout page.
      await addLog('正在向 PayPal 页面发送填表指令...');

      await sendToContentScriptResilient('checkout-paypal', {
        type: 'EXECUTE_STEP',
        step: 9,
        source: 'background',
        payload: {
          card,
          address: addr,
          email,
          password,
          phone: normalizePaypalPhoneForInput(state.paypalPhone || state.checkoutPhone || '+15822201173'),
          paypalPhone: state.paypalPhone || state.checkoutPhone || '+15822201173',
          paypalSmsApiUrl: state.paypalSmsApiUrl || 'http://a.62-us.com/api/get_sms?key=a5d3262e05efaba982aba7cfae20b8bc',
        },
      });
    }

    return { executeStep14 };
  }

  function generateRandomPassword() {
    const L = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    const D = '0123456789';
    const S = '!@#$%^';
    const A = L + D + S;
    let p = L[Math.floor(Math.random() * 26)]
      + L[26 + Math.floor(Math.random() * 26)]
      + D[Math.floor(Math.random() * 10)]
      + S[Math.floor(Math.random() * 6)];
    for (let i = 4; i < 14; i++) p += A[Math.floor(Math.random() * A.length)];
    return p.split('').sort(() => Math.random() - 0.5).join('');
  }

  function normalizePaypalPhoneForInput(value = '') {
    const raw = String(value || '').trim();
    const digits = raw.replace(/\D+/g, '');
    if (digits.length === 11 && digits.startsWith('1')) {
      return digits.slice(1);
    }
    return digits || raw;
  }

  function generateLuhnVisaTestCard() {
    return {
      Credit_Card_Type: 'Visa',
      Credit_Card_Number: generateVisaLuhnCardNumber(),
      Expires: generateFutureExpiry(),
      CVV2: generateNumericString(3),
    };
  }

  function generateVisaLuhnCardNumber() {
    const body = `4${generateNumericString(14)}`;
    return `${body}${computeLuhnCheckDigit(body)}`;
  }

  function computeLuhnCheckDigit(body) {
    const sumWithZero = luhnSum(`${body}0`);
    return String((10 - (sumWithZero % 10)) % 10);
  }

  function luhnSum(value) {
    let sum = 0;
    let shouldDouble = false;
    for (let index = String(value).length - 1; index >= 0; index -= 1) {
      let digit = Number(String(value)[index]);
      if (!Number.isFinite(digit)) digit = 0;
      if (shouldDouble) {
        digit *= 2;
        if (digit > 9) digit -= 9;
      }
      sum += digit;
      shouldDouble = !shouldDouble;
    }
    return sum;
  }

  function generateFutureExpiry() {
    const now = new Date();
    const month = String(Math.floor(Math.random() * 12) + 1).padStart(2, '0');
    const year = String((now.getFullYear() + 3 + Math.floor(Math.random() * 4)) % 100).padStart(2, '0');
    return `${month}/${year}`;
  }

  function generateNumericString(length) {
    let value = '';
    for (let index = 0; index < length; index += 1) {
      value += String(Math.floor(Math.random() * 10));
    }
    return value;
  }

  return { createStep14Executor };
});