<?php
require_once __DIR__ . '/../src/config.php';
require_once __DIR__ . '/../src/auth.php';
require_once __DIR__ . '/../src/invoice_functions.php';
require_once __DIR__ . '/../src/customer_functions.php';
require_once __DIR__ . '/../src/db.php';
require_once __DIR__ . '/../src/pdf_functions.php';
require_once __DIR__ . '/../src/icons.php';
require_login();

$pdo = get_db();
$settings = get_settings();
$customers = get_customers();
$error = '';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $customer_id  = (int)($_POST['customer_id'] ?? 0);
    $invoice_date = $_POST['invoice_date'] ?: date('Y-m-d');
    $service_date = $_POST['service_date'] ?: null;
    $notes_internal = $_POST['notes_internal'] ?? '';

    if ($customer_id <= 0) {
        $error = 'Bitte einen Kunden auswählen.';
    } else {
        $vat_mode = $settings['vat_mode'] ?? 'klein';
        $vat_rate = (float)($settings['default_vat_rate'] ?? 19.0);

        $items = [];
        $total_net = 0.0;
        $count = isset($_POST['item_desc']) ? count($_POST['item_desc']) : 0;

        for ($i = 0; $i < $count; $i++) {
            $desc = trim($_POST['item_desc'][$i] ?? '');
            $qty  = (float)($_POST['item_qty'][$i] ?? 0);
            $price= (float)($_POST['item_price'][$i] ?? 0);
            if ($desc !== '' && $qty > 0 && $price >= 0) {
                $line_net = $qty * $price;
                $total_net += $line_net;
                $items[] = [
                    'position_no' => count($items) + 1,
                    'description' => $desc,
                    'quantity'    => $qty,
                    'unit_price'  => $price,
                ];
            }
        }

        if (empty($items)) {
            $error = 'Bitte mindestens eine Position ausfüllen.';
        } else {
            if ($vat_mode === 'normal') {
                $total_vat = round($total_net * $vat_rate / 100, 2);
            } else {
                $total_vat = 0.0;
            }
            $total_gross = $total_net + $total_vat;

            $pdo->beginTransaction();
            try {
                $invoice_number = generate_invoice_number();
                $stmt = $pdo->prepare("INSERT INTO invoices
                    (invoice_number, customer_id, invoice_date, service_date, vat_mode, vat_rate,
                     payment_terms, notes_internal, total_net, total_vat, total_gross, paid)
                     VALUES (:in, :cid, :idate, :sdate, :vm, :vr, :pt, :ni, :tn, :tv, :tg, FALSE)
                     RETURNING id");
                $stmt->execute([
                    ':in'   => $invoice_number,
                    ':cid'  => $customer_id,
                    ':idate'=> $invoice_date,
                    ':sdate'=> $service_date,
                    ':vm'   => $vat_mode,
                    ':vr'   => $vat_rate,
                    ':pt'   => $settings['payment_terms'] ?? null,
                    ':ni'   => $notes_internal,
                    ':tn'   => $total_net,
                    ':tv'   => $total_vat,
                    ':tg'   => $total_gross,
                ]);
                $invoice_id = $stmt->fetchColumn();

                $stmtItem = $pdo->prepare("INSERT INTO invoice_items
                    (invoice_id, position_no, description, quantity, unit_price, vat_rate)
                    VALUES (:iid, :pn, :d, :q, :up, :vr)");
                foreach ($items as $it) {
                    $stmtItem->execute([
                        ':iid' => $invoice_id,
                        ':pn'  => $it['position_no'],
                        ':d'   => $it['description'],
                        ':q'   => $it['quantity'],
                        ':up'  => $it['unit_price'],
                        ':vr'  => $vat_rate,
                    ]);
                }

                $pdo->commit();

                // PDF sofort archivieren (GoBD-konform)
                archive_invoice_pdf($invoice_id);

                header('Location: ' . url_for('invoice_pdf.php?id=' . $invoice_id));
                exit;
            } catch (Exception $e) {
                $pdo->rollBack();
                $error = 'Fehler beim Speichern der Rechnung: ' . $e->getMessage();
            }
        }
    }
}
?>
<!doctype html>
<html lang="de">
<head>
    <meta charset="utf-8">
    <title>Neue Rechnung</title>
    <link rel="stylesheet" href="assets/style.css">
    <script>
        function addRow() {
            const tbody = document.getElementById('items-body');
            const index = tbody.children.length;
            const tr = document.createElement('tr');
            tr.innerHTML = `
                <td>${index+1}</td>
                <td><input type="text" name="item_desc[${index}]" size="40"></td>
                <td><input type="number" step="0.01" name="item_qty[${index}]" value="1"></td>
                <td><input type="number" step="0.01" name="item_price[${index}]" value="0.00"></td>
            `;
            tbody.appendChild(tr);
        }

        // Enter springt zum nächsten Feld statt Formular abzuschicken
        document.addEventListener('DOMContentLoaded', function() {
            const form = document.querySelector('form');

            form.addEventListener('keydown', function(e) {
                if (e.key === 'Enter' && e.target.tagName !== 'TEXTAREA' && e.target.type !== 'submit') {
                    e.preventDefault();

                    const inputs = Array.from(form.querySelectorAll('input, select, textarea, button[type="submit"]'));
                    const currentIndex = inputs.indexOf(e.target);

                    if (currentIndex > -1 && currentIndex < inputs.length - 1) {
                        inputs[currentIndex + 1].focus();
                    }
                }
            });
        });
    </script>
</head>
<body>
<header>
    <h1>PIRP</h1>
    <nav>
        <a href="<?= url_for('index.php') ?>"><?= icon_dashboard() ?>Dashboard</a>
        <a href="<?= url_for('invoices.php') ?>" class="active"><?= icon_invoices() ?>Rechnungen</a>
        <a href="<?= url_for('customers.php') ?>"><?= icon_customers() ?>Kunden</a>
        <a href="<?= url_for('expenses.php') ?>"><?= icon_expenses() ?>Ausgaben</a>
        <a href="<?= url_for('belegarchiv.php') ?>"><?= icon_archive() ?>Belege</a>
        <a href="<?= url_for('journal.php') ?>"><?= icon_journal() ?>Journal</a>
        <a href="<?= url_for('euer.php') ?>"><?= icon_euer() ?>EÜR</a>
        <a href="<?= url_for('settings.php') ?>"><?= icon_settings() ?>Einstellungen</a>
        <a href="<?= url_for('logout.php') ?>"><?= icon_logout() ?>Logout (<?= htmlspecialchars($_SESSION['username'] ?? '') ?>)</a>
        <span class="cmd-k-hint" onclick="document.dispatchEvent(new KeyboardEvent('keydown',{key:'k',ctrlKey:true}))"><kbd>Ctrl+K</kbd></span>
    </nav>
</header>
<main>
    <div class="module-subnav">
        <a href="<?= url_for('invoices.php') ?>">Übersicht</a>
        <a href="<?= url_for('invoice_new.php') ?>" class="active">Neue Rechnung</a>
        <a href="<?= url_for('recurring.php') ?>">Abo-Rechnungen</a>
            </div>
    <?php if ($error): ?><p class="error"><?= htmlspecialchars($error) ?></p><?php endif; ?>

    <form method="post">
        <label>Kunde:
            <select name="customer_id" required>
                <option value="">-- wählen --</option>
                <?php foreach ($customers as $c): ?>
                    <option value="<?= $c['id'] ?>"><?= htmlspecialchars($c['name']) ?></option>
                <?php endforeach; ?>
            </select>
        </label>

        <div class="flex-row">
            <label>Rechnungsdatum:
                <input type="date" name="invoice_date" value="<?= htmlspecialchars(date('Y-m-d')) ?>">
            </label>
            <label>Leistungsdatum:
                <input type="date" name="service_date">
            </label>
        </div>

        <h2>Positionen</h2>
        <table class="list">
            <thead>
            <tr>
                <th>Pos.</th>
                <th>Beschreibung</th>
                <th>Menge</th>
                <th>Einzelpreis (netto)</th>
            </tr>
            </thead>
            <tbody id="items-body">
            <?php for ($i = 0; $i < 3; $i++): ?>
                <tr>
                    <td><?= $i+1 ?></td>
                    <td><input type="text" name="item_desc[<?= $i ?>]" size="40"></td>
                    <td><input type="number" step="0.01" name="item_qty[<?= $i ?>]" value="1"></td>
                    <td><input type="number" step="0.01" name="item_price[<?= $i ?>]" value="0.00"></td>
                </tr>
            <?php endfor; ?>
            </tbody>
        </table>
        <button type="button" onclick="addRow()">Position hinzufügen</button>

        <label>Interne Notizen (nicht auf Rechnung):
            <textarea name="notes_internal" rows="3"></textarea>
        </label>

        <button type="submit">Rechnung speichern &amp; PDF anzeigen</button>
    </form>
</main>
<script src="assets/command-palette.js"></script>
</body>
</html>