<?php

declare(strict_types=1);

namespace Steuerkram\Controllers;

use Steuerkram\Models\Invoice;
use Steuerkram\Models\Customer;
use Steuerkram\Models\Beleg;
use Steuerkram\Models\Booking;
use Steuerkram\Models\Account;
use Steuerkram\Models\Setting;
use Steuerkram\Services\PdfInvoiceService;
use Steuerkram\View;

class InvoiceController
{
    public function index(array $params): void
    {
        $filter   = $_GET;
        $page     = max(1, (int)($_GET['page'] ?? 1));
        $result   = Invoice::all($filter, $page);
        $settings = Setting::get();

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle'     => 'Ausgangsrechnungen',
            'content'       => $this->renderView('invoices/list', [
                'rows'     => $result['rows'],
                'total'    => $result['total'],
                'pages'    => $result['pages'],
                'page'     => $page,
                'filter'   => $filter,
                'settings' => $settings,
            ]),
            'topbarActions' => '<a href="/invoices/new" class="btn btn-primary">+ Rechnung erstellen</a>',
        ]);
    }

    public function create(array $params): void
    {
        $customers = Customer::all();
        $settings  = Setting::get();

        $invoiceDefaults = [
            'rechnungs_datum' => date('Y-m-d'),
        ];

        $preCustomerId = (int)($_GET['customer_id'] ?? 0);
        if ($preCustomerId > 0) {
            $customer = Customer::find($preCustomerId);
            if ($customer) {
                $invoiceDefaults['customer_id']  = $preCustomerId;
                $invoiceDefaults['payment_days'] = $customer['payment_days'];
            }
        }

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Neue Rechnung',
            'content'   => $this->renderView('invoices/form', [
                'invoice'   => $invoiceDefaults,
                'lines'     => [],
                'customers' => $customers,
                'errors'    => [],
                'action'    => '/invoices',
                'settings'  => $settings,
            ]),
        ]);
    }

    public function store(array $params): void
    {
        $data   = $_POST;
        $errors = $this->validate($data);

        if ($errors) {
            $customers = Customer::all();
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Neue Rechnung',
                'content'   => $this->renderView('invoices/form', [
                    'invoice'   => $data,
                    'lines'     => $data['lines'] ?? [],
                    'customers' => $customers,
                    'errors'    => $errors,
                    'action'    => '/invoices',
                    'settings'  => Setting::get(),
                ]),
            ]);
            return;
        }

        $id = Invoice::create($data);
        View::redirect("/invoices/{$id}", 'Rechnung als Entwurf gespeichert.');
    }

    public function show(array $params): void
    {
        $invoice = Invoice::find((int)$params['id']);
        if (!$invoice) { http_response_code(404); return; }

        $lines    = Invoice::lines((int)$params['id']);
        $settings = Setting::get();

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Rechnung ' . ($invoice['rechnungs_nr'] ?? 'Entwurf'),
            'content'   => $this->renderView('invoices/show', [
                'invoice'  => $invoice,
                'lines'    => $lines,
                'settings' => $settings,
            ]),
        ]);
    }

    public function edit(array $params): void
    {
        $invoice = Invoice::find((int)$params['id']);
        if (!$invoice) { http_response_code(404); return; }
        if ($invoice['status'] !== 'Entwurf') {
            View::redirect("/invoices/{$invoice['id']}", 'Nur Entwürfe können bearbeitet werden.', 'error');
            return;
        }

        $lines     = Invoice::lines((int)$params['id']);
        $customers = Customer::all();

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Rechnung bearbeiten',
            'content'   => $this->renderView('invoices/form', [
                'invoice'   => $invoice,
                'lines'     => $lines,
                'customers' => $customers,
                'errors'    => [],
                'action'    => '/invoices/' . $invoice['id'],
                'settings'  => Setting::get(),
            ]),
        ]);
    }

    public function update(array $params): void
    {
        $id      = (int)$params['id'];
        $invoice = Invoice::find($id);
        if (!$invoice) { http_response_code(404); return; }

        $data   = $_POST;
        $errors = $this->validate($data);

        if ($errors) {
            $customers = Customer::all();
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Rechnung bearbeiten',
                'content'   => $this->renderView('invoices/form', [
                    'invoice'   => array_merge($invoice, $data),
                    'lines'     => $data['lines'] ?? [],
                    'customers' => $customers,
                    'errors'    => $errors,
                    'action'    => '/invoices/' . $id,
                    'settings'  => Setting::get(),
                ]),
            ]);
            return;
        }

        try {
            Invoice::update($id, $data);
            View::redirect("/invoices/{$id}", 'Rechnung gespeichert.');
        } catch (\PDOException $e) {
            error_log('[Steuerkram] PDO-Fehler in InvoiceController::update(): ' . $e->getMessage());
            View::redirect("/invoices/{$id}", 'Datenbankfehler beim Speichern der Rechnung.', 'error');
        } catch (\Exception $e) {
            View::redirect("/invoices/{$id}", $e->getMessage(), 'error');
        }
    }

    public function finalize(array $params): void
    {
        $id = (int)$params['id'];
        try {
            \Steuerkram\Database::beginTransaction();
            $nr = Invoice::finalize($id);
            $invoice = Invoice::find($id);
            $belegNr = $this->createBeleg($invoice);
            \Steuerkram\Database::commit();
            View::redirect("/invoices/{$id}", "Rechnung {$nr} wurde finalisiert (Beleg {$belegNr}). Bitte Zahlungseingang erfassen.");
        } catch (\PDOException $e) {
            \Steuerkram\Database::rollBack();
            error_log('[Steuerkram] PDO-Fehler in InvoiceController::finalize(): ' . $e->getMessage());
            View::redirect("/invoices/{$id}", 'Datenbankfehler beim Finalisieren der Rechnung.', 'error');
        } catch (\Exception $e) {
            \Steuerkram\Database::rollBack();
            View::redirect("/invoices/{$id}", $e->getMessage(), 'error');
        }
    }

    public function pdf(array $params): void
    {
        $invoice  = Invoice::find((int)$params['id']);
        if (!$invoice) { http_response_code(404); return; }

        $lines    = Invoice::lines((int)$params['id']);
        $settings = Setting::get();

        $svc = new PdfInvoiceService();
        $svc->render($invoice, $lines, $settings);
    }

    public function book(array $params): void
    {
        $id      = (int)$params['id'];
        $invoice = Invoice::find($id);
        if (!$invoice) { http_response_code(404); return; }

        if ($invoice['status'] === 'Entwurf') {
            View::redirect("/invoices/{$id}", 'Rechnung muss zuerst finalisiert werden.', 'error');
            return;
        }
        if (empty($invoice['beleg_id'])) {
            View::redirect("/invoices/{$id}", 'Kein Beleg zugeordnet.', 'error');
            return;
        }

        $bookings    = Booking::forBeleg((int)$invoice['beleg_id']);
        $accounts    = Account::all(['aktiv' => 1]);
        $formErrors  = $_GET['_error'] ?? [];
        $formData    = [];

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Zahlungseingang – ' . ($invoice['rechnungs_nr'] ?? 'Rechnung'),
            'content'   => $this->renderView('invoices/book', [
                'invoice'    => $invoice,
                'bookings'   => $bookings,
                'accounts'   => $accounts,
                'formErrors' => $formErrors,
                'formData'   => $formData,
            ]),
        ]);
    }

    public function storeBooking(array $params): void
    {
        $id      = (int)$params['id'];
        $invoice = Invoice::find($id);
        if (!$invoice) { http_response_code(404); return; }

        $belegId = (int)($invoice['beleg_id'] ?? 0);
        if (!$belegId) {
            View::redirect("/invoices/{$id}", 'Kein Beleg zugeordnet.', 'error');
            return;
        }

        $data   = $_POST;
        $errors = [];

        if (empty($data['kategorie_konto_id']))  $errors['kategorie_konto_id']  = 'Pflichtfeld';
        if (empty($data['zahlungskonto_id']))    $errors['zahlungskonto_id']    = 'Pflichtfeld';
        if (empty($data['buchungs_datum']))       $errors['buchungs_datum']      = 'Pflichtfeld';
        if (!isset($data['betrag_netto']) || $data['betrag_netto'] === '')
            $errors['betrag_netto'] = 'Pflichtfeld';
        if (empty($data['buchungstext']))         $errors['buchungstext']        = 'Pflichtfeld';

        if (empty($errors) && $data['kategorie_konto_id'] === $data['zahlungskonto_id']) {
            $errors['zahlungskonto_id'] = 'Kategorie- und Zahlungskonto dürfen nicht identisch sein.';
        }

        if ($errors) {
            $bookings = Booking::forBeleg($belegId);
            $accounts = Account::all(['aktiv' => 1]);
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Zahlungseingang – ' . ($invoice['rechnungs_nr'] ?? 'Rechnung'),
                'content'   => $this->renderView('invoices/book', [
                    'invoice'    => $invoice,
                    'bookings'   => $bookings,
                    'accounts'   => $accounts,
                    'formErrors' => $errors,
                    'formData'   => $data,
                ]),
            ]);
            return;
        }

        try {
            $data['beleg_id']    = $belegId;
            $data['buchungstyp'] = 'Einnahme';
            Booking::create($data);
            View::redirect("/invoices/{$id}/book", 'Buchung erfasst.');
        } catch (\PDOException $e) {
            error_log('[Steuerkram] PDO-Fehler in InvoiceController::storeBooking(): ' . $e->getMessage());
            $bookings = Booking::forBeleg($belegId);
            $accounts = Account::all(['aktiv' => 1]);
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Zahlungseingang – ' . ($invoice['rechnungs_nr'] ?? 'Rechnung'),
                'content'   => $this->renderView('invoices/book', [
                    'invoice'    => $invoice,
                    'bookings'   => $bookings,
                    'accounts'   => $accounts,
                    'formErrors' => ['_exception' => 'Datenbankfehler beim Speichern der Buchung.'],
                    'formData'   => $data,
                ]),
            ]);
        } catch (\Exception $e) {
            $bookings = Booking::forBeleg($belegId);
            $accounts = Account::all(['aktiv' => 1]);
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Zahlungseingang – ' . ($invoice['rechnungs_nr'] ?? 'Rechnung'),
                'content'   => $this->renderView('invoices/book', [
                    'invoice'    => $invoice,
                    'bookings'   => $bookings,
                    'accounts'   => $accounts,
                    'formErrors' => ['_exception' => $e->getMessage()],
                    'formData'   => $data,
                ]),
            ]);
        }
    }

    private function createBeleg(array $invoice): string
    {
        $id = (int)$invoice['id'];

        $belegNr = Beleg::generateBelegNr();
        $belegId = Beleg::create([
            'beleg_nr'       => $belegNr,
            'filename'       => $invoice['rechnungs_nr'] . '.pdf',
            'storage_path'   => '',
            'mime_type'      => 'application/pdf',
            'file_hash'      => hash('sha256', $invoice['rechnungs_nr']),
            'beleg_datum'    => $invoice['rechnungs_datum'],
            'rechnungs_nr'   => $invoice['rechnungs_nr'],
            'betrag_brutto'  => $invoice['betrag_brutto'],
            'belegtyp'       => 'Ausgangsrechnung',
            'notes'          => 'Automatisch erstellt aus Rechnung ' . $invoice['rechnungs_nr'],
        ]);

        \Steuerkram\Database::execute(
            'UPDATE invoices SET beleg_id=? WHERE id=?', [$belegId, $id]
        );

        return $belegNr;
    }

    public function destroy(array $params): void
    {
        if (!Setting::isTestMode()) {
            View::redirect('/invoices', 'Löschen ist nur im Testmodus erlaubt.', 'error');
            return;
        }
        $id = (int)$params['id'];
        Invoice::delete($id);
        View::redirect('/invoices', 'Rechnung gelöscht.');
    }

    public function markPaid(array $params): void
    {
        Invoice::markPaid((int)$params['id']);
        View::redirect('/invoices/' . $params['id'], 'Rechnung als bezahlt markiert.');
    }

    public function cancel(array $params): void
    {
        Invoice::cancel((int)$params['id']);
        View::redirect('/invoices/' . $params['id'], 'Rechnung storniert.');
    }

    public function addLine(array $params): void
    {
        // This is handled client-side via JS; redirect back
        View::redirect('/invoices/' . $params['id'] . '/edit');
    }

    public function deleteLine(array $params): void
    {
        \Steuerkram\Database::execute(
            'DELETE FROM invoice_lines WHERE id=? AND invoice_id=?',
            [(int)$params['line_id'], (int)$params['id']]
        );
        View::redirect('/invoices/' . $params['id'] . '/edit', 'Position gelöscht.');
    }

    private function validate(array $data): array
    {
        $errors = [];
        if (empty($data['customer_id']))    $errors['customer_id']    = 'Pflichtfeld';
        if (empty($data['betreff']))        $errors['betreff']        = 'Pflichtfeld';
        if (empty($data['rechnungs_datum'])) $errors['rechnungs_datum'] = 'Pflichtfeld';
        if (empty($data['lines'])) {
            $errors['lines'] = 'Mindestens eine Position erforderlich.';
        }
        return $errors;
    }

    private function renderView(string $template, array $data): string
    {
        extract($data, EXTR_SKIP);
        ob_start();
        include dirname(__DIR__) . '/Views/' . $template . '.php';
        return ob_get_clean();
    }
}