/**
 * routes/invoices.mjs — Invoice endpoints (revenue entries as invoices)
 */

function extractCustomer(description) {
  if (!description) return 'Okänd kund';
  const parts = description.split(/[|]/);
  const raw = parts[0].trim();
  return raw.split(' ').map(w => w.charAt(0).toUpperCase() + w.slice(1).toLowerCase()).join(' ');
}

export default function registerInvoices(app, pool) {
  // GET /api/ledger/invoices — hämta verifikat med intäktsposter som "fakturor"
  app.get('/api/ledger/invoices', async (req, res) => {
    const tenant_id   = req.auth?.tenant_id || req.headers['x-tenant-id'] || 'wavult-group';
    const fiscal_year = req.query.fiscal_year ? parseInt(req.query.fiscal_year) : null;
    try {
      const conditions = ['e.tenant_id=$1', "e.status='posted'"];
      const params = [tenant_id];
      if (fiscal_year) { params.push(fiscal_year); conditions.push(`e.fiscal_year=$${params.length}`); }
      const { rows: entries } = await pool.query(`
        SELECT DISTINCT ON (e.id)
          e.id, e.entry_number, e.fiscal_year, e.period, e.entry_date, e.description,
          e.reference, e.status, e.metadata
        FROM ledger_journal_entries e
        JOIN ledger_journal_lines l ON l.entry_id = e.id AND l.tenant_id = e.tenant_id
        WHERE ${conditions.join(' AND ')}
          AND l.account_number LIKE '3%'
          AND l.credit > 0
        ORDER BY e.id, e.entry_date DESC
      `, params);

      const entryIds = entries.map(e => e.id);
      let lines = [];
      if (entryIds.length > 0) {
        const placeholders = entryIds.map((_,i) => `$${i+2}`).join(',');
        const { rows } = await pool.query(
          `SELECT * FROM ledger_journal_lines WHERE tenant_id=$1 AND entry_id IN (${placeholders}) ORDER BY line_number`,
          [tenant_id, ...entryIds]
        );
        lines = rows;
      }

      const invoices = entries.map(e => {
        const entryLines = lines.filter(l => l.entry_id === e.id);
        const revenueLines = entryLines.filter(l => (l.account_number||'').startsWith('3') && parseFloat(l.credit||0) > 0);
        const vatLines     = entryLines.filter(l => ['2611','2614','2615','2616'].includes(l.account_number) && parseFloat(l.credit||0) > 0);
        const receivableLines = entryLines.filter(l => l.account_number === '1510' && parseFloat(l.debit||0) > 0);
        const cashLines    = entryLines.filter(l => /^19[0-9]{2}$/.test(l.account_number||'') && parseFloat(l.debit||0) > 0);
        const amount    = revenueLines.reduce((s,l) => s + parseFloat(l.credit||0), 0);
        const vatAmount = vatLines.reduce((s,l) => s + parseFloat(l.credit||0), 0);
        const total     = amount + vatAmount;
        const isPaid = cashLines.length > 0;
        const isSent = receivableLines.length > 0;
        const date = e.entry_date ? new Date(e.entry_date).toISOString().split('T')[0] : '';
        return {
          id: e.id,
          entry_number: e.entry_number,
          period: e.period,
          date,
          description: e.description,
          reference: e.reference,
          customer: extractCustomer(e.description),
          amount,
          vatAmount,
          total,
          status: isPaid ? 'paid' : isSent ? 'sent' : 'posted',
          lines: entryLines,
          revenueAccounts: revenueLines.map(l => l.account_number).join(', '),
        };
      });

      invoices.sort((a,b) => new Date(b.date) - new Date(a.date));
      res.json({ ok: true, invoices, count: invoices.length });
    } catch (e) {
      res.status(500).json({ ok: false, error: e.message });
    }
  });
}