// Flips past-due 'sent' invoices to 'overdue' and emails the client a payment reminder.
// The email goes out only on the sent→overdue transition, so re-running never double-sends.
// Run daily from the monorepo root (cron / scheduled task): npx tsx scripts/send-overdue-reminders.ts

import path from 'node:path';
import { fileURLToPath } from 'node:url';
import dotenv from 'dotenv';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
dotenv.config({ path: path.resolve(__dirname, '../.env') });

import { and, eq, lt } from 'drizzle-orm';
import { getDb, getPool, invoices, clients, firms } from '@lawdesk/db';
import { sendEmail, invoiceOverdueEmail } from '../apps/api/src/lib/email';

async function main() {
  const db = getDb();
  const now = new Date();

  const due = await db
    .select({
      id: invoices.id,
      number: invoices.number,
      total: invoices.total,
      dueAt: invoices.dueAt,
      clientName: clients.name,
      clientEmail: clients.email,
      firmName: firms.name,
    })
    .from(invoices)
    .innerJoin(clients, eq(invoices.clientId, clients.id))
    .innerJoin(firms, eq(invoices.firmId, firms.id))
    .where(and(eq(invoices.status, 'sent'), lt(invoices.dueAt, now)));

  console.log(`Found ${due.length} past-due invoice(s) to mark overdue.`);

  let flipped = 0;
  let emailed = 0;

  for (const inv of due) {
    // Guard on status='sent' so a concurrent run can't flip (and email) the same invoice twice.
    const [row] = await db
      .update(invoices)
      .set({ status: 'overdue', updatedAt: new Date() })
      .where(and(eq(invoices.id, inv.id), eq(invoices.status, 'sent')))
      .returning({ id: invoices.id });
    if (!row) continue;
    flipped++;

    if (!inv.clientEmail || !inv.dueAt) {
      console.log(`  ${inv.number}: marked overdue, no reminder (missing client email or due date)`);
      continue;
    }

    const totalFmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(
      Number(inv.total),
    );
    const dueDate = inv.dueAt.toLocaleDateString('en-US', {
      year: 'numeric',
      month: 'short',
      day: 'numeric',
    });

    const tpl = invoiceOverdueEmail({
      clientName: inv.clientName,
      firmName: inv.firmName,
      invoiceNumber: inv.number,
      total: totalFmt,
      dueDate,
    });
    const result = await sendEmail({ to: inv.clientEmail, ...tpl });
    if (result.ok && !result.skipped) {
      emailed++;
      console.log(`  ${inv.number}: marked overdue, reminder sent to ${inv.clientEmail}`);
    } else {
      console.log(`  ${inv.number}: marked overdue, reminder ${result.skipped ? 'skipped (no API key)' : `FAILED: ${result.error}`}`);
    }
  }

  console.log(`Done. ${flipped} invoice(s) marked overdue, ${emailed} reminder(s) sent.`);
  await getPool().end();
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});