require('dotenv').config();
const path = require('path');
const express = require('express');
const { savePayment, listPayments, countPayments } = require('./db');
const { createPaymentLink } = require('./payment-api');

const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

function toNumber(v) {
  const n = parseFloat(v);
  return Number.isFinite(n) ? n : 0;
}

const ALLOWED_CURRENCIES = ['USD', 'AUD'];

// --- Create payment link ---------------------------------------------------
app.post('/api/payments', async (req, res) => {
  const { customerName, email, phone, address, currency, items } = req.body || {};

  // All customer fields are required.
  const customerFields = { customerName, email, phone, address };
  const CUSTOMER_LABELS = {
    customerName: 'Customer name',
    email: 'Email',
    phone: 'Phone number',
    address: 'Address',
  };
  const missingCustomer = Object.keys(CUSTOMER_LABELS).filter(
    (k) => !customerFields[k] || !String(customerFields[k]).trim()
  );
  if (missingCustomer.length) {
    return res.status(400).json({
      error: `Missing required field(s): ${missingCustomer.map((k) => CUSTOMER_LABELS[k]).join(', ')}.`,
    });
  }

  const cleanItems = Array.isArray(items) ? items : [];
  if (cleanItems.length === 0) {
    return res.status(400).json({ error: 'At least one item is required.' });
  }
  const cleanCurrency = ALLOWED_CURRENCIES.includes(currency) ? currency : 'AUD';

  const normItems = cleanItems.map((it) => ({
    sku: (it.sku || '').trim(),
    name: (it.name || '').trim(),
    price: toNumber(it.price),
    quantity: toNumber(it.quantity),
    condition: (it.condition || '').trim(),
  }));

  // Each item requires SKU, a positive price, a positive quantity and a condition.
  for (let i = 0; i < normItems.length; i++) {
    const it = normItems[i];
    const missing = [];
    if (!it.sku) missing.push('SKU');
    if (!(it.price > 0)) missing.push('price');
    if (!(it.quantity > 0)) missing.push('quantity');
    if (!it.condition) missing.push('condition');
    if (missing.length) {
      return res
        .status(400)
        .json({ error: `Item ${i + 1} is missing required field(s): ${missing.join(', ')}.` });
    }
  }

  const total = normItems.reduce((sum, it) => sum + it.price * it.quantity, 0);

  // Sequential quote number based on how many payments already exist:
  // first ever -> QT000001, when history already has 9 -> QT000010.
  const quoteNumber = `QT${String(countPayments() + 1).padStart(6, '0')}`;

  try {
    const dataPayment = await createPaymentLink({
      customerName,
      email,
      phone,
      address,
      currency: cleanCurrency,
      quoteNumber,
      items: normItems,
      total,
    });

    const saved = savePayment({
      customer_name: customerName,
      email: email || '',
      phone: phone || '',
      address: address || '',
      items_json: JSON.stringify(normItems),
      total,
      currency: cleanCurrency,
      payment_link: dataPayment.link,
      status: 'created',
    });

    res.json({ ok: true, payment: saved, link: dataPayment.link, raw: dataPayment.raw });
  } catch (err) {
    console.error('createPaymentLink error:', err);
    res.status(502).json({ error: err.message || 'Failed to create payment link.' });
  }
});

// --- History ---------------------------------------------------------------
app.get('/api/payments', (_req, res) => {
  res.json({ ok: true, payments: listPayments() });
});

app.listen(PORT, () => {
  console.log(`Quick Payment server running: http://localhost:${PORT}`);
});