// send-invoice.js
const { execSync } = require("child_process");
const nodemailer = require("nodemailer");
const fs = require("fs");
const path = require("path");
const yaml = require("js-yaml");

const args = process.argv.slice(2);
// Usage: node send-invoice.js acme "Website redesign" 4500 1 --send

const [clientSlug, description, rate, quantity, flag] = args;
const send = flag === "--send";

const me = yaml.load(fs.readFileSync("config/me.yml", "utf8"));
const client = yaml.load(fs.readFileSync(`clients/${clientSlug}.yml`, "utf8"));

// Auto-increment invoice number from ledger
const ledgerPath = "ledger.csv";
const ledger = fs.existsSync(ledgerPath)
  ? fs.readFileSync(ledgerPath, "utf8").split("\n").filter(Boolean)
  : [];
const nextNumber = ledger.length + 1001;
const invoiceNumber = `INV-${nextNumber}`;

// Dates
const today = new Date();
const due = new Date(today);
due.setDate(due.getDate() + 30);
const fmt = (d) => d.toISOString().split("T")[0];

// Build and write invoice YAML
const invoiceData = {
  number: invoiceNumber,
  date: fmt(today),
  due_date: fmt(due),
  items: [{ description, rate: parseFloat(rate), quantity: parseFloat(quantity) }],
};

const tmpFile = `/tmp/invoice-${invoiceNumber}.yml`;
fs.writeFileSync(tmpFile, yaml.dump({ ...me, ...client, invoice: invoiceData }));

// Generate PDF
const outputPath = `output/${invoiceNumber}-${clientSlug}.pdf`;
execSync(`invoice generate ${tmpFile} --output ${outputPath}`);
console.log(`Generated: ${outputPath}`);

// Log to ledger
const total = parseFloat(rate) * parseFloat(quantity);
fs.appendFileSync(ledgerPath,
  `${invoiceNumber},${clientSlug},${fmt(today)},${fmt(due)},${total},pending\n`);

// Send email
if (send) {
  const transporter = nodemailer.createTransport({
    host: process.env.SMTP_HOST,
    port: 587,
    auth: { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS },
  });

  transporter.sendMail({
    from: me.business.email,
    to: client.client.email,
    subject: `Invoice ${invoiceNumber} from ${me.business.name}`,
    text: `Hi ${client.client.contact},\n\nPlease find attached invoice ${invoiceNumber} for ${description}.\n\nAmount due: $${total.toFixed(2)}\nDue date: ${fmt(due)}\n\nThank you,\n${me.business.name}`,
    attachments: [{ filename: path.basename(outputPath), path: outputPath }],
  });
  console.log(`Sent to ${client.client.email}`);
}

// tax-config.js
const TAX_RATES = {
  US: { CA: 0.0725, NY: 0.08, TX: 0.0625, OR: 0 },
  EU: { DE: 0.19, FR: 0.20, NL: 0.21 },
  DEFAULT: 0
};

function calculateTax(subtotal, country, state) {
  if (country === 'US') return subtotal * (TAX_RATES.US[state] || 0);
  if (country === 'EU') return subtotal * (TAX_RATES.EU[state] || 0);
  return subtotal * TAX_RATES.DEFAULT;
}

module.exports = { calculateTax, TAX_RATES };

// check-overdue.js
const fs = require("fs");

function getOverdueInvoices() {
  const ledger = fs.readFileSync("ledger.csv", "utf8")
    .split("\n").filter(Boolean);
  const today = new Date();
  const overdue = [];
  for (const line of ledger) {
    const [id, client, issued, due, amount, status] = line.split(",");
    if (status === "pending" && new Date(due) < today) {
      const daysOverdue = Math.floor((today - new Date(due)) / (1000*60*60*24));
      overdue.push({ id, client, due, amount, daysOverdue });
    }
  }
  return overdue;
}

const overdue = getOverdueInvoices();
for (const inv of overdue) {
  console.log(`${inv.id}: ${inv.client} - $${inv.amount} - ${inv.daysOverdue} days overdue`);
  if ([7, 14, 30].includes(inv.daysOverdue)) {
    console.log(`  -> Sending ${inv.daysOverdue}-day reminder`);
  }
}