<?php

namespace App\Observers;

use App\Models\RepairOrder;
use App\Models\Vehicle;
use App\Models\Part;
use App\Models\MaintenanceSchedule;
use Carbon\Carbon;
use Illuminate\Support\Str;

class VehicleObserver
{
    /**
     * Handle the Vehicle "creating" event.
     */
    public function creating(Vehicle $vehicle): void
    {
        // Generate fleet number if not provided
        if (empty($vehicle->fleet_number)) {
            $prefix = 'FL-';
            $latest = Vehicle::where('fleet_number', 'like', $prefix . '%')
                ->orderBy('fleet_number', 'desc')
                ->first();

            $number = 1;
            if ($latest) {
                $parts = explode('-', $latest->fleet_number);
                $number = intval(end($parts)) + 1;
            }

            $vehicle->fleet_number = $prefix . str_pad($number, 4, '0', STR_PAD_LEFT);
        }
    }

    /**
     * Handle the Vehicle "created" event.
     */
    public function created(Vehicle $vehicle): void
    {
        // Create default maintenance schedules
        $this->createDefaultMaintenanceSchedules($vehicle);
    }

    /**
     * Handle the Vehicle "updated" event.
     */
    public function updated(Vehicle $vehicle)
    {
        // If mileage updated, check maintenance schedules
        if ($vehicle->isDirty('mileage')) {
            $this->checkMaintenanceSchedules($vehicle);
        }
    }

    /**
     * Create default maintenance schedules for a new vehicle.
     */
    protected function createDefaultMaintenanceSchedules(Vehicle $vehicle)
    {
        // Oil change schedule (every 5,000 miles or 6 months)
        MaintenanceSchedule::create([
            'vehicle_id' => $vehicle->id,
            'name' => 'Oil Change',
            'description' => 'Regular oil and filter change',
            'mileage_interval' => 5000,
            'day_interval' => 180,
            'last_performed' => null,
            'last_mileage' => $vehicle->mileage,
            'next_due_mileage' => $vehicle->mileage + 5000,
            'next_due_date' => Carbon::now()->addDays(180),
            'is_active' => true,
        ]);

        // Tire rotation (every 10,000 miles)
        MaintenanceSchedule::create([
            'vehicle_id' => $vehicle->id,
            'name' => 'Tire Rotation',
            'description' => 'Rotate tires to ensure even wear',
            'mileage_interval' => 10000,
            'day_interval' => null,
            'last_performed' => null,
            'last_mileage' => $vehicle->mileage,
            'next_due_mileage' => $vehicle->mileage + 10000,
            'next_due_date' => null,
            'is_active' => true,
        ]);

        // Full service (every 30,000 miles or yearly)
        MaintenanceSchedule::create([
            'vehicle_id' => $vehicle->id,
            'name' => 'Full Service',
            'description' => 'Complete vehicle inspection and service',
            'mileage_interval' => 30000,
            'day_interval' => 365,
            'last_performed' => null,
            'last_mileage' => $vehicle->mileage,
            'next_due_mileage' => $vehicle->mileage + 30000,
            'next_due_date' => Carbon::now()->addDays(365),
            'is_active' => true,
        ]);
    }

    /**
     * Check and update maintenance schedules.
     */
    protected function checkMaintenanceSchedules(Vehicle $vehicle)
    {
        $schedules = MaintenanceSchedule::where('vehicle_id', $vehicle->id)
            ->where('is_active', true)
            ->get();

        foreach ($schedules as $schedule) {
            // If current mileage exceeds next due mileage, flag for maintenance
            if ($schedule->next_due_mileage && $vehicle->mileage >= $schedule->next_due_mileage) {
                // Could trigger notifications here
            }
        }
    }
}