<?php

declare(strict_types=1);

namespace Steuerkram\Controllers;

use Steuerkram\Models\Beleg;
use Steuerkram\Models\Booking;
use Steuerkram\Models\Account;
use Steuerkram\Models\Asset;
use Steuerkram\Models\Supplier;
use Steuerkram\View;
use Steuerkram\Services\ImageCropService;
use Steuerkram\Services\KontierungsvorschlagService;

class BelegController
{
    private const ALLOWED_MIME = [
        'application/pdf'  => 'pdf',
        'image/png'        => 'png',
        'image/jpeg'       => 'jpg',
        'image/tiff'       => 'tif',
        'application/xml'  => 'xml',
        'text/xml'         => 'xml',
    ];

    public function index(array $params): void
    {
        $filter = $_GET;
        if (!isset($filter['year']))  $filter['year']  = (string)date('Y');
        if (!isset($filter['month'])) $filter['month'] = (string)date('n');
        $page     = max(1, (int)($_GET['page'] ?? 1));
        $result   = Beleg::all($filter, $page);
        $totalAll = Beleg::all([], 1, 1)['total'];

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle'     => 'Belege',
            'content'       => $this->renderView('belege/list', [
                'rows'     => $result['rows'],
                'total'    => $result['total'],
                'totalAll' => $totalAll,
                'pages'    => $result['pages'],
                'page'     => $page,
                'filter'   => $filter,
            ]),
            'topbarActions' => '<a href="/belege/export?' . http_build_query($filter) . '" class="btn btn-secondary">CSV Export</a> <a href="/belege/upload" class="btn btn-primary">+ Beleg hochladen</a>',
        ]);
    }

    public function export(array $params): void
    {
        $filter = $_GET;
        unset($filter['page']);
        $result = Beleg::all($filter, 1, 99999);

        header('Content-Type: text/csv; charset=utf-8');
        header('Content-Disposition: attachment; filename="belegliste-' . date('Ymd') . '.csv"');

        $out = fopen('php://output', 'w');
        fprintf($out, chr(0xEF) . chr(0xBB) . chr(0xBF)); // UTF-8 BOM for Excel

        fputcsv($out, [
            'Belegnr.', 'Belegdatum', 'Belegart', 'Lieferant', 'Rechnungsnr.',
            'Dateiname', 'Geschäftsjahr', 'Notizen',
            'Bewirtungsgrund', 'Teilnehmerliste',
            'Brutto (€)', 'Status',
        ], ';');

        foreach ($result['rows'] as $row) {
            if ($row['locked']) {
                $status = 'Gesperrt';
            } elseif ($row['booked']) {
                $status = 'Gebucht';
            } else {
                $status = 'Offen';
            }

            fputcsv($out, [
                $this->csvSanitize((string)($row['beleg_nr'] ?? '')),
                $row['beleg_datum'] ?? '',
                $row['belegtyp'] ?? '',
                $this->csvSanitize((string)($row['supplier_name'] ?? '')),
                $this->csvSanitize((string)($row['rechnungs_nr'] ?? '')),
                $this->csvSanitize((string)($row['filename'] ?? '')),
                (string)($row['fiscal_year_nr'] ?? ''),
                $this->csvSanitize((string)($row['notes'] ?? '')),
                $this->csvSanitize((string)($row['bewirtungsgrund'] ?? '')),
                $this->csvSanitize((string)($row['teilnehmerliste'] ?? '')),
                $row['betrag_brutto'] !== null
                    ? number_format((float)$row['betrag_brutto'], 2, ',', '')
                    : '',
                $status,
            ], ';');
        }
        fclose($out);
    }

    public function uploadForm(array $params): void
    {
        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Beleg hochladen',
            'content'   => $this->renderView('belege/upload', ['errors' => []]),
        ]);
    }

    public function upload(array $params): void
    {
        $errors = [];

        if (empty($_FILES['beleg_file']) || $_FILES['beleg_file']['error'] !== UPLOAD_ERR_OK) {
            $errors['file'] = 'Keine gültige Datei übermittelt.';
        } else {
            $file     = $_FILES['beleg_file'];
            $mime     = mime_content_type($file['tmp_name']);
            $mimeKey  = strtolower($mime);

            if (!isset(self::ALLOWED_MIME[$mimeKey])) {
                $errors['file'] = 'Nicht erlaubter Dateityp. Erlaubt: PDF, PNG, JPEG, TIFF, XML.';
            }
        }

        if ($errors) {
            if (($_SERVER['HTTP_X_REQUESTED_WITH'] ?? '') === 'XMLHttpRequest') {
                http_response_code(422);
                header('Content-Type: application/json');
                echo json_encode(['error' => implode(' ', $errors)]);
                return;
            }
            $view = new View();
            $view->render('layout/base.php', [
                'pageTitle' => 'Beleg hochladen',
                'content'   => $this->renderView('belege/upload', [
                    'errors' => $errors,
                    'old'    => $_POST,
                ]),
            ]);
            return;
        }

        $file    = $_FILES['beleg_file'];
        $mime    = mime_content_type($file['tmp_name']);
        $ext     = self::ALLOWED_MIME[strtolower($mime)];
        $belegNr = Beleg::generateBelegNr();
        $year    = !empty($_POST['beleg_datum'])
            ? date('Y', strtotime($_POST['beleg_datum']))
            : date('Y');

        // Store under uploads/{year}/{belegNr}/original.{ext}
        $relDir  = "static/uploads/{$year}/{$belegNr}";
        $absDir  = dirname(__DIR__, 2) . "/public/{$relDir}";
        if (!is_dir($absDir)) mkdir($absDir, 0755, true);

        $filename    = pathinfo($file['name'], PATHINFO_BASENAME);
        $filenameWithoutExt = pathinfo($file['name'], PATHINFO_FILENAME);
        $storagePath = "{$relDir}/original.{$ext}";
        $absPath     = dirname(__DIR__, 2) . "/public/{$storagePath}";

        move_uploaded_file($file['tmp_name'], $absPath);

        // Weißen Rand bei JPEG/PNG automatisch wegschneiden
        if (in_array($mime, ['image/jpeg', 'image/png'], true)) {
            (new ImageCropService())->cropWhitespace($absPath);
        }

        // Hash nach potenziellem Crop berechnen (reflektiert den tatsächlich gespeicherten Inhalt)
        $hash = hash_file('sha256', $absPath);

        $id = Beleg::create([
            'beleg_nr'      => $belegNr,
            'filename'      => $filename,
            'storage_path'  => $storagePath,
            'mime_type'     => $mime,
            'file_hash'     => $hash,
            'beleg_datum'   => $_POST['beleg_datum'] ?? null,
            'rechnungs_nr'  => $filenameWithoutExt,
            'betrag_brutto' => null,
            'belegtyp'      => $_POST['belegtyp'] ?? 'Eingangsrechnung',
            'notes'         => $_POST['notes'] ?? null,
        ]);

        if (($_SERVER['HTTP_X_REQUESTED_WITH'] ?? '') === 'XMLHttpRequest') {
            header('Content-Type: application/json');
            echo json_encode(['id' => $id, 'beleg_nr' => $belegNr]);
            return;
        }

        View::redirect("/belege/{$id}", "Beleg {$belegNr} erfolgreich hochgeladen.");
    }

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

        $bookings  = Booking::forBeleg((int)$params['id']);
        $integrity = Beleg::verifyIntegrity((int)$params['id']);
        $accounts  = Account::all(['aktiv' => 1]);
        $suppliers = Supplier::all();
        $assets    = Asset::all();

        $svc         = new KontierungsvorschlagService();
        $kiAktiv     = $svc->isEnabled();
        $kiVorschlag = $beleg['ki_vorschlag'] !== null
            ? json_decode($beleg['ki_vorschlag'], true)
            : null;
        // KI-Sektion anzeigen wenn Ergebnis vorhanden ODER LLM gerade verfügbar
        $kiSektion   = $kiAktiv || $kiVorschlag !== null;

        $view = new View();
        $view->render('layout/base.php', [
            'pageTitle' => 'Beleg ' . $beleg['beleg_nr'],
            'content'   => $this->renderView('belege/detail', [
                'beleg'       => $beleg,
                'suppliers'   => $suppliers,
                'bookings'    => $bookings,
                'integrity'   => $integrity,
                'accounts'    => $accounts,
                'assets'      => $assets,
                'kiAktiv'     => $kiAktiv,
                'kiSektion'   => $kiSektion,
                'kiVorschlag' => $kiVorschlag,
            ]),
        ]);
    }

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

        $absPath = dirname(__DIR__, 2) . '/public/' . $beleg['storage_path'];
        if (!file_exists($absPath)) { http_response_code(404); return; }

        header('Content-Type: ' . $beleg['mime_type']);
        header('Content-Disposition: inline; filename="' . $beleg['filename'] . '"');
        header('Content-Length: ' . filesize($absPath));
        readfile($absPath);
    }

    public function updateMeta(array $params): void
    {
        $isAjax = ($_SERVER['HTTP_X_REQUESTED_WITH'] ?? '') === 'XMLHttpRequest';
        $id     = (int)$params['id'];
        $beleg  = Beleg::find($id);

        if (!$beleg) {
            if ($isAjax) { http_response_code(404); header('Content-Type: application/json'); echo json_encode(['error' => 'Nicht gefunden.']); return; }
            http_response_code(404); return;
        }
        if ($beleg['locked']) {
            if ($isAjax) { http_response_code(403); header('Content-Type: application/json'); echo json_encode(['error' => 'GoBD: Gesperrter Beleg.']); return; }
            View::redirect("/belege/{$id}", 'GoBD: Gesperrter Beleg kann nicht geändert werden.', 'error');
            return;
        }

        // Lieferant: Name → ID (ggf. neu anlegen)
        $supplierId = null;
        $supplierName = trim($_POST['supplier_name'] ?? '');
        if ($supplierName !== '') {
            $supplierId = Supplier::findOrCreate($supplierName);
        }

        Beleg::updateMeta($id, [
            'rechnungs_nr'  => trim($_POST['rechnungs_nr'] ?? ''),
            'belegtyp'      => $_POST['belegtyp'] ?? $beleg['belegtyp'],
            'beleg_datum'   => $_POST['beleg_datum'] ?: null,
            'supplier_id'   => $supplierId,
        ]);

        if ($isAjax) {
            header('Content-Type: application/json');
            echo json_encode(['ok' => true]);
            return;
        }

        View::redirect("/belege/{$id}", 'Metadaten gespeichert.');
    }

    public function generateVorschlag(array $params): void
    {
        header('Content-Type: application/json');
        $id    = (int)$params['id'];
        $beleg = Beleg::find($id);
        if (!$beleg) {
            echo json_encode(['error' => 'Beleg nicht gefunden']);
            return;
        }

        $svc       = new KontierungsvorschlagService();
        $vorschlag = $svc->generateForBeleg($beleg);
        Beleg::saveKiVorschlag($id, $vorschlag);
        echo json_encode($vorschlag ?? ['error' => 'Kein Vorschlag generiert']);
    }

    public function resetVorschlag(array $params): void
    {
        header('Content-Type: application/json');
        Beleg::saveKiVorschlag((int)$params['id'], null);
        echo json_encode(['ok' => true]);
    }

    public function destroy(array $params): void
    {
        $id = (int)$params['id'];
        if (!Beleg::delete($id)) {
            View::redirect('/belege', 'Beleg kann nicht gelöscht werden (gesperrt oder enthält Buchungen).', 'error');
            return;
        }
        View::redirect('/belege', 'Beleg gelöscht.');
    }

    public function cropImage(array $params): void
    {
        header('Content-Type: application/json');
        $id    = (int)$params['id'];
        $beleg = Beleg::find($id);

        if (!$beleg) {
            http_response_code(404);
            echo json_encode(['error' => 'Beleg nicht gefunden.']);
            return;
        }
        if ($beleg['locked']) {
            http_response_code(403);
            echo json_encode(['error' => 'GoBD: Gesperrter Beleg kann nicht verändert werden.']);
            return;
        }
        if (!in_array($beleg['mime_type'], ['image/jpeg', 'image/png'], true)) {
            http_response_code(422);
            echo json_encode(['error' => 'Zuschneiden nur für JPEG und PNG möglich.']);
            return;
        }

        $body = json_decode(file_get_contents('php://input'), true) ?? [];
        $x    = (int)($body['x'] ?? 0);
        $y    = (int)($body['y'] ?? 0);
        $w    = (int)($body['w'] ?? 0);
        $h    = (int)($body['h'] ?? 0);

        if ($w < 10 || $h < 10) {
            http_response_code(422);
            echo json_encode(['error' => 'Auswahlbereich zu klein (mindestens 10×10 Pixel).']);
            return;
        }

        $absPath = dirname(__DIR__, 2) . '/public/' . $beleg['storage_path'];
        if (!file_exists($absPath)) {
            http_response_code(404);
            echo json_encode(['error' => 'Datei nicht gefunden.']);
            return;
        }

        $svc = new ImageCropService();
        if (!$svc->cropToRect($absPath, $x, $y, $w, $h)) {
            http_response_code(500);
            echo json_encode(['error' => 'Zuschnitt fehlgeschlagen.']);
            return;
        }

        Beleg::updateHash($id, hash_file('sha256', $absPath));
        echo json_encode(['ok' => true]);
    }

    private function csvSanitize(string $value): string
    {
        if ($value !== '' && in_array($value[0], ['=', '+', '-', '@'], true)) {
            return "'" . $value;
        }
        return $value;
    }

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