<?php

namespace Modules\Maintenance\Services;

use App\Business;
use Modules\Maintenance\Models\Equipment;
use Modules\Maintenance\Models\MaintenanceNotification;
use Modules\Maintenance\Models\PreventiveSchedule;
use Modules\Maintenance\Models\WorkOrder;
use Carbon\Carbon;
use Illuminate\Support\Str;
use Modules\Maintenance\Utils\MaintenanceUtil;

class PreventiveScheduleService
{
    public function __construct(
        protected WorkOrderService $workOrderService,
        protected MaintenanceUtil $maintenanceUtil
    ) {}
    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;
        $settings = $this->maintenanceUtil->getMaintenanceSettings($business->id);
        if (! $this->maintenanceUtil->pmRemindersEnabled($business->id)) {
            return 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) {
            $daysUntil = now()->startOfDay()->diffInDays($schedule->next_due_at->copy()->startOfDay(), false);
            if ($daysUntil > $schedule->reminder_days_before || ! $schedule->assignedUser) {
                continue;
            }

            if ($this->reminderSentToday($business->id, $schedule->assigned_user_id, $schedule->id)) {
                continue;
            }

            $dueLabel = $daysUntil < 0
                ? abs($daysUntil).' روز گذشته'
                : ($daysUntil === 0 ? 'امروز' : $daysUntil.' روز دیگر');

            MaintenanceNotificationService::notify(
                $business,
                $schedule->assignedUser,
                'preventive_due',
                'یادآوری نگهداری پیشگیرانه',
                "نگهداری «{$schedule->title}» برای تجهیز «{$schedule->equipment?->name}» — سررسید: {$dueLabel}.",
                ['schedule_id' => $schedule->id, 'equipment_id' => $schedule->equipment_id]
            );
            $count++;
        }

        return $count;
    }

    public function processBusinessSchedules(Business $business): array
    {
        return [
            'reminders' => $this->checkDueReminders($business),
            'work_orders' => $this->createDueWorkOrders($business),
        ];
    }

    public function createDueWorkOrders(Business $business): int
    {
        if (! $this->maintenanceUtil->pmAutoWorkOrderEnabled($business->id)) {
            return 0;
        }

        $count = 0;
        $schedules = PreventiveSchedule::where('business_id', $business->id)
            ->where('is_active', true)
            ->whereNotNull('next_due_at')
            ->where('next_due_at', '<=', now())
            ->with(['equipment', 'assignedUser'])
            ->get();

        foreach ($schedules as $schedule) {
            if ($this->createWorkOrderFromSchedule($business, $schedule)) {
                $count++;
            }
        }

        return $count;
    }

    public function createWorkOrderFromSchedule(Business $business, PreventiveSchedule $schedule): ?WorkOrder
    {
        $openExists = WorkOrder::where('business_id', $business->id)
            ->where('preventive_schedule_id', $schedule->id)
            ->whereIn('status', ['draft', 'open', 'in_progress', 'on_hold'])
            ->exists();

        if ($openExists || ! $schedule->equipment_id) {
            return null;
        }

        $equipment = $schedule->equipment ?? Equipment::find($schedule->equipment_id);
        if (! $equipment) {
            return null;
        }

        $workOrder = WorkOrder::create([
            'business_id' => $business->id,
            'equipment_id' => $equipment->id,
            'project_id' => $schedule->project_id ?? $equipment->project_id,
            'production_line_id' => $schedule->production_line_id ?? $equipment->production_line_id,
            'preventive_schedule_id' => $schedule->id,
            'work_order_number' => $this->workOrderService->generateNumber($business),
            'assigned_technician_id' => $schedule->assigned_user_id,
            'priority' => 'medium',
            'description' => 'ایجاد خودکار از برنامه نگهداری پیشگیرانه: '.$schedule->title,
            'status' => 'open',
            'scheduled_at' => $schedule->next_due_at ?? now(),
        ]);

        if ($schedule->assignedUser) {
            MaintenanceNotificationService::notify(
                $business,
                $schedule->assignedUser,
                'pm_work_order_created',
                'دستور کار پیشگیرانه',
                "دستور کار «{$workOrder->work_order_number}» برای «{$schedule->title}» ایجاد شد.",
                ['work_order_id' => $workOrder->id, 'schedule_id' => $schedule->id]
            );
        }

        return $workOrder;
    }

    protected function reminderSentToday(int $businessId, int $userId, int $scheduleId): bool
    {
        return MaintenanceNotification::where('business_id', $businessId)
            ->where('user_id', $userId)
            ->where('type', 'preventive_due')
            ->whereDate('created_at', today())
            ->where('data->schedule_id', $scheduleId)
            ->exists();
    }
}