<?php

namespace App\Services;

use App\Models\Equipment;
use App\Models\User;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

class EquipmentWarehouseRequests
{
    /** Read-only projection; consumers must not insert rows into the paginator.
     * @return LengthAwarePaginator<int,covariant array<string,mixed>>|null
     */
    public function page(User $actor, Equipment $equipment): ?LengthAwarePaginator
    {
        $canRead = $actor->hasFunctions(['admin', 'warehouse_request_read', 'warehouse_request_prepare'])
            || ($actor->hasFunctions(['warehouse_request_review']) && $actor->department_id !== null)
            || ($actor->hasFunctions(['warehouse_request_deliver']) && $actor->hasFunctions(['warehouse']));
        if (! $canRead || ! Schema::hasTable('warehouse_requests')) {
            return null;
        }
        $query = app(WarehouseWorkdesk::class)->visible($actor);
        if (DB::getDriverName() === 'pgsql') {
            $query->whereRaw("EXISTS (SELECT 1 FROM json_array_elements(warehouse_requests.snapshot->'lines') AS line(value) WHERE line.value->'equipment'->>'id' = ?)", [(string) $equipment->id]);
        } elseif (DB::getDriverName() === 'sqlite') {
            $query->whereRaw("EXISTS (SELECT 1 FROM json_each(json_extract(warehouse_requests.snapshot, '$.lines')) AS line WHERE json_extract(line.value, '$.equipment.id') = ?)", [$equipment->id]);
        } else {
            return null;
        }

        return $query->oldest('id')->paginate(15, ['id', 'snapshot'], 'requests_page')->withQueryString()->through(function ($record) use ($equipment) {
            $p = app(WarehouseFulfilment::class)->progress($record);
            $lines = [];
            foreach ($record->snapshot['lines'] as $index => $line) {
                if (($line['equipment']['id'] ?? null) !== $equipment->id) {
                    continue;
                }
                $lines[] = ['line' => $index + 1, 'item' => $line['item'], 'destination' => $line['destination'],
                    'requested_milli' => $line['quantity_milli'], 'reserved_milli' => $p['reserved'][$index],
                    'delivered_milli' => $p['delivered'][$index], 'remaining_milli' => $p['remaining'][$index], 'cancelled_milli' => $p['cancelled'][$index]];
            }

            return ['id' => $record->id, 'state' => $p['state'], 'version' => $p['version'],
                'reservation_ready' => $p['reservation_ready'], 'lines' => $lines];
        });
    }
}