<?php

namespace App\Console\Commands;

use Acme\Dhl\Models\DhlShipment;
use App\Models\ShoppingOrder;
use Illuminate\Console\Command;
use Illuminate\Support\Carbon;

/**
 * Traegt das Versanddatum fuer Altbestellungen nach, damit die Absatzauswertung
 * "nach Versand" auch rueckwirkend funktioniert.
 *
 * Quellen, in dieser Reihenfolge:
 * 1. Datum des ersten ausgehenden DHL-Labels – exakt, verfuegbar ab 23.10.2025.
 * 2. `updated_at` der Bestellung – Schaetzung. Gegengeprueft an Bestellungen MIT
 *    Label liegt sie in rund 93 % innerhalb von 24 Stunden und in rund 97 % im
 *    richtigen Monat am tatsaechlichen Versanddatum.
 *
 * Die Quelle wird in `shipped_at_source` festgehalten, damit geschaetzte Monate
 * in der Auswertung als solche ausgewiesen werden koennen.
 */
class BackfillShippedAt extends Command
{
    protected $signature = 'sales:backfill-shipped-at
                            {--fix : Tatsaechlich schreiben (ohne Flag nur Vorschau)}
                            {--since= : Nur Bestellungen ab diesem Datum (Y-m-d)}
                            {--chunk=500 : Bestellungen je Verarbeitungsblock}';

    protected $description = 'Traegt shipped_at fuer bereits versendete Altbestellungen nach (DHL-Label oder Schaetzung)';

    public function handle(): int
    {
        $fix = (bool) $this->option('fix');
        $since = $this->option('since');
        $chunk = max(50, (int) $this->option('chunk'));

        $query = ShoppingOrder::query()
            ->whereIn('shipped', ShoppingOrder::SHIPPED_STATES)
            ->whereNull('shipped_at')
            ->when($since, fn ($q) => $q->where('created_at', '>=', $since))
            ->orderBy('id');

        $total = (clone $query)->count();

        if ($total === 0) {
            $this->info('Keine Bestellungen ohne Versanddatum gefunden.');

            return self::SUCCESS;
        }

        $this->info("Bestellungen ohne Versanddatum: {$total}");

        $counts = [ShoppingOrder::SHIPPED_AT_SOURCE_DHL => 0, ShoppingOrder::SHIPPED_AT_SOURCE_ESTIMATED => 0];
        $byMonth = [];
        $bar = $this->output->createProgressBar($total);

        $query->chunkById($chunk, function ($orders) use ($fix, &$counts, &$byMonth, $bar) {
            $labels = $this->getLabelDates($orders->pluck('id')->all());

            foreach ($orders as $order) {
                $shippedAt = $labels[$order->id] ?? null;
                $source = ShoppingOrder::SHIPPED_AT_SOURCE_DHL;

                if ($shippedAt === null) {
                    $shippedAt = $order->updated_at ?: $order->created_at;
                    $source = ShoppingOrder::SHIPPED_AT_SOURCE_ESTIMATED;
                }

                if ($shippedAt === null) {
                    continue;
                }

                $counts[$source]++;
                $month = $shippedAt->format('Y-m');
                $byMonth[$month][$source] = ($byMonth[$month][$source] ?? 0) + 1;

                if ($fix) {
                    ShoppingOrder::withoutTimestamps(fn () => ShoppingOrder::query()
                        ->whereKey($order->id)
                        ->update(['shipped_at' => $shippedAt, 'shipped_at_source' => $source]));
                }

                $bar->advance();
            }
        });

        $bar->finish();
        $this->newLine(2);

        ksort($byMonth);
        $rows = [];
        foreach ($byMonth as $month => $sources) {
            $dhl = $sources[ShoppingOrder::SHIPPED_AT_SOURCE_DHL] ?? 0;
            $estimated = $sources[ShoppingOrder::SHIPPED_AT_SOURCE_ESTIMATED] ?? 0;
            $sum = $dhl + $estimated;
            $rows[] = [$month, $dhl, $estimated, $sum > 0 ? round($estimated / $sum * 100, 1).' %' : '-'];
        }

        $this->table(['Versandmonat', 'aus DHL-Label', 'geschaetzt', 'Anteil geschaetzt'], $rows);
        $this->info('Exakt aus DHL-Label: '.$counts[ShoppingOrder::SHIPPED_AT_SOURCE_DHL]);
        $this->info('Geschaetzt aus updated_at: '.$counts[ShoppingOrder::SHIPPED_AT_SOURCE_ESTIMATED]);

        if (! $fix) {
            $this->warn('Trockenlauf! Nutze --fix um die Werte zu schreiben.');
        }

        return self::SUCCESS;
    }

    /**
     * Datum des ersten ausgehenden DHL-Labels je Bestellung.
     *
     * @param  array<int, int>  $orderIds
     * @return array<int, Carbon>
     */
    private function getLabelDates(array $orderIds): array
    {
        return DhlShipment::query()
            ->whereIn('order_id', $orderIds)
            ->where('type', 'outbound')
            ->orderBy('created_at')
            ->get(['order_id', 'created_at'])
            ->groupBy('order_id')
            ->map(fn ($shipments) => $shipments->first()->created_at)
            ->all();
    }
}