<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Laravelista\Comments\Commentable;
use OwenIt\Auditing\Auditable;
use OwenIt\Auditing\Contracts\Auditable as AuditableContract;
use Illuminate\Support\Facades\DB;

class Lesson extends Model implements AuditableContract
{
    use Commentable, Auditable;

    protected $fillable = ['id', 'course_id', 'name', 'video', 'body'];

    /**
     * Attributes to include in the Audit.
     *
     * @var array
     */
    protected $auditInclude = [
        'name',
        'video',
        'body',
    ];

    public function course()
    {
        return $this->belongsTo('App\Course');
    }

    public function exercises()
    {
        return $this->hasMany('App\Exercise');
    }

    public static function previous($lesson_id, $course_id)
    {
        $previous = Lesson::where('id', '<', $lesson_id)->orderBy('id', 'desc')->where('course_id', $course_id)->first();
        return $previous;
    }

    public static function next($lesson_id, $course_id)
    {
        $next = Lesson::where('id', '>', $lesson_id)->orderBy('id', 'asc')->where('course_id', $course_id)->first();
        return $next;
    }

    public static function isCompleted($id)
    {
        $is_completed = DB::table('lesson_user')
                ->where('user_id', auth()->id())
                ->where('lesson_id', $id)
                ->count() > 0;
        return $is_completed;
    }
}