<?php

namespace App\Modules\Maintenance\Services;

use App\Business;
use App\Modules\Maintenance\Models\Equipment;
use App\Modules\Maintenance\Models\PreventiveSchedule;
use Carbon\Carbon;
use Illuminate\Support\Str;

class PreventiveScheduleService
{
    public function calculateNextDue(PreventiveSchedule $schedule): ?Carbon
    {
        $base = $schedule->last_performed_at ?? now();

        return match ($schedule->frequency_type) {
            'daily' => $base->copy()->addDays($schedule->frequency_value),
            'weekly' => $base->copy()->addWeeks($schedule->frequency_value),
            'monthly' => $base->copy()->addMonths($schedule->frequency_value),
            'quarterly' => $base->copy()->addMonths(3 * $schedule->frequency_value),
            'semi_annual' => $base->copy()->addMonths(6 * $schedule->frequency_value),
            'annual' => $base->copy()->addYears($schedule->frequency_value),
            default => null,
        };
    }

    public function updateNextDue(PreventiveSchedule $schedule): void
    {
        $next = $this->calculateNextDue($schedule);
        if ($next) {
            $schedule->update(['next_due_at' => $next]);
        }
    }

    public function generateEquipmentQrCode(Business $business, Equipment $equipment): string
    {
        $code = $equipment->qr_code ?: 'EQ-'.$business->id.'-'.$equipment->id.'-'.Str::upper(Str::random(6));
        if (! $equipment->qr_code) {
            $equipment->update(['qr_code' => $code]);
        }

        return $code;
    }

    public function checkDueReminders(Business $business): int
    {
        $count = 0;
        $schedules = PreventiveSchedule::where('business_id', $business->id)
            ->where('is_active', true)
            ->whereNotNull('next_due_at')
            ->whereNotNull('assigned_user_id')
            ->with('assignedUser', 'equipment')
            ->get();

        foreach ($schedules as $schedule) {
            $daysUntil = now()->diffInDays($schedule->next_due_at, false);
            if ($daysUntil <= $schedule->reminder_days_before && $schedule->assignedUser) {
                MaintenanceNotificationService::notify(
                    $business,
                    $schedule->assignedUser,
                    'preventive_due',
                    'یادآوری نگهداری پیشگیرانه',
                    "نگهداری «{$schedule->title}» برای تجهیز «{$schedule->equipment?->name}» تا {$daysUntil} روز دیگر سررسید می‌شود.",
                    ['schedule_id' => $schedule->id, 'equipment_id' => $schedule->equipment_id]
                );
                $count++;
            }
        }

        return $count;
    }
}