<?php

namespace App\Http\Controllers;

use App\Models\DatevExport;
use App\Models\DatevExportLine;
use App\Services\DatevExportService;
use App\Services\HTMLHelper;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;

class PaymentTaxAdvisorController extends Controller
{
    private DatevExportService $datevService;

    public function __construct(DatevExportService $datevService)
    {
        $this->middleware('admin');
        $this->datevService = $datevService;
    }

    /**
     * Hauptseite: Periodenauswahl + Export-Übersicht
     */
    public function index(Request $request)
    {
        $this->setFilterVars($request);

        $month = intval(session('payment_taxadvisor_filter_month'));
        $year = intval(session('payment_taxadvisor_filter_year'));

        // Letzter Export für diese Periode
        $currentExport = DatevExport::forPeriod($month, $year)
            ->generated()
            ->latest()
            ->first();

        // Letzte 10 Exports für die Historie
        $recentExports = DatevExport::generated()
            ->latest()
            ->limit(10)
            ->get();

        $data = [
            'filter_months' => HTMLHelper::getTransMonths(),
            'filter_years' => HTMLHelper::getYearRange(2023),
            'current_month' => $month,
            'current_year' => $year,
            'current_export' => $currentExport,
            'recent_exports' => $recentExports,
        ];

        return view('admin.payment.taxadvisor', $data);
    }

    /**
     * AJAX: Vorschau der Daten für die gewählte Periode.
     */
    public function preview(Request $request)
    {
        $month = intval($request->get('month', session('payment_taxadvisor_filter_month')));
        $year = intval($request->get('year', session('payment_taxadvisor_filter_year')));

        try {
            $preview = $this->datevService->getPreview($month, $year);

            return response()->json([
                'success' => true,
                'data' => $preview,
            ]);
        } catch (\Exception $e) {
            return response()->json([
                'success' => false,
                'message' => 'Fehler bei der Vorschau: '.$e->getMessage(),
            ], 500);
        }
    }

    /**
     * Export generieren und speichern.
     */
    public function generate(Request $request)
    {
        $month = intval($request->get('month', session('payment_taxadvisor_filter_month')));
        $year = intval($request->get('year', session('payment_taxadvisor_filter_year')));

        try {
            $export = $this->datevService->generateExport($month, $year);

            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('success', "DATEV-Export für {$month}/{$year} erfolgreich generiert. {$export->total_lines} Buchungszeilen erstellt.");
        } catch (\RuntimeException $e) {
            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('error', $e->getMessage());
        } catch (\Exception $e) {
            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('error', 'Fehler beim Generieren: '.$e->getMessage());
        }
    }

    /**
     * CSV-Datei herunterladen.
     */
    public function download($id)
    {
        $export = DatevExport::findOrFail($id);

        if (! $export->isGenerated()) {
            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('error', 'Export wurde noch nicht generiert.');
        }

        $disk = config('datev.storage_disk', 'local');
        $path = $export->file_path;

        if (! Storage::disk($disk)->exists($path)) {
            // CSV neu generieren falls Datei nicht mehr vorhanden
            $csvContent = $this->datevService->buildCsv($export);
            Storage::disk($disk)->makeDirectory($export->getStoragePath());
            Storage::disk($disk)->put($path, $csvContent);
        }

        // Status auf "heruntergeladen" setzen
        $export->markAsDownloaded();

        return Storage::disk($disk)->download($path, $export->filename, [
            'Content-Type' => 'text/csv; charset=utf-8',
        ]);
    }

    /**
     * DataTable: Export-Lines eines bestimmten Exports.
     */
    public function datatable(Request $request)
    {
        $exportId = $request->get('export_id');

        $query = DatevExportLine::select('datev_export_lines.*');

        if ($exportId) {
            $query->where('datev_export_id', $exportId);
        } else {
            // Fallback: Lines des aktuellen Perioden-Exports
            $month = intval(session('payment_taxadvisor_filter_month', date('m')));
            $year = intval(session('payment_taxadvisor_filter_year', date('Y')));

            $export = DatevExport::forPeriod($month, $year)
                ->generated()
                ->latest()
                ->first();

            if ($export) {
                $query->where('datev_export_id', $export->id);
            } else {
                $query->where('datev_export_id', 0); // Leere Ergebnismenge
            }
        }

        return \DataTables::eloquent($query)
            ->editColumn('line_number', function (DatevExportLine $line) {
                return $line->line_number;
            })
            ->addColumn('source_type_label', function (DatevExportLine $line) {
                return $line->source_type_label;
            })
            ->addColumn('amount_display', function (DatevExportLine $line) {
                return '<span class="no-line-break">'.$line->formatted_amount.'</span>';
            })
            ->editColumn('soll_haben', function (DatevExportLine $line) {
                $badge = $line->soll_haben === 'H' ? 'success' : 'warning';

                return '<span class="badge badge-'.$badge.'">'.$line->soll_haben.'</span>';
            })
            ->editColumn('konto', function (DatevExportLine $line) {
                return $line->konto;
            })
            ->editColumn('gegenkonto', function (DatevExportLine $line) {
                return $line->gegenkonto;
            })
            ->editColumn('bu_schluessel', function (DatevExportLine $line) {
                return $line->bu_schluessel;
            })
            ->addColumn('belegdatum_display', function (DatevExportLine $line) {
                return $line->formatted_belegdatum;
            })
            ->editColumn('belegfeld1', function (DatevExportLine $line) {
                return $line->belegfeld1;
            })
            ->editColumn('buchungstext', function (DatevExportLine $line) {
                return $line->buchungstext;
            })
            ->editColumn('eu_ustid', function (DatevExportLine $line) {
                return $line->eu_ustid ?: '-';
            })
            ->filterColumn('source_type_label', function ($query, $keyword) {
                $typeMap = ['rechnung' => 'invoice', 'gutschrift' => 'credit', 'storno' => 'cancellation'];
                foreach ($typeMap as $label => $type) {
                    if (stripos($label, $keyword) !== false) {
                        $query->where('source_type', $type);

                        return;
                    }
                }
                $query->where('source_type', 'like', "%{$keyword}%");
            })
            ->orderColumn('line_number', 'line_number $1')
            ->rawColumns(['amount_display', 'soll_haben'])
            ->make(true);
    }

    /**
     * Export sperren (Lock).
     */
    public function lock($id)
    {
        $export = DatevExport::findOrFail($id);

        if ($export->isLocked()) {
            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('info', 'Export ist bereits gesperrt.');
        }

        $export->lock();

        return redirect()
            ->route('admin_payments_taxadvisor')
            ->with('success', "Export {$export->period_label} wurde gesperrt.");
    }

    /**
     * Export löschen (soft delete).
     */
    public function destroy($id)
    {
        $export = DatevExport::findOrFail($id);

        if ($export->isLocked()) {
            return redirect()
                ->route('admin_payments_taxadvisor')
                ->with('error', 'Gesperrte Exports können nicht gelöscht werden.');
        }

        $export->delete();

        return redirect()
            ->route('admin_payments_taxadvisor')
            ->with('success', "Export {$export->period_label} wurde gelöscht.");
    }

    /*
    |--------------------------------------------------------------------------
    | Private Hilfsmethoden
    |--------------------------------------------------------------------------
    */

    private function setFilterVars(Request $request): void
    {
        if (! session('payment_taxadvisor_filter_month')) {
            session(['payment_taxadvisor_filter_month' => intval(date('m'))]);
        }
        if (! session('payment_taxadvisor_filter_year')) {
            session(['payment_taxadvisor_filter_year' => intval(date('Y'))]);
        }

        if ($request->get('payment_taxadvisor_filter_month')) {
            session(['payment_taxadvisor_filter_month' => $request->get('payment_taxadvisor_filter_month')]);
        }
        if ($request->get('payment_taxadvisor_filter_year')) {
            session(['payment_taxadvisor_filter_year' => $request->get('payment_taxadvisor_filter_year')]);
        }
    }
}