construprogress/app/Models/Comment.php

<?php

namespace App\Models;

use App\Notifications\TaskCommentNotification;
use App\Traits\LogsActivity;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\MorphTo;

class Comment extends Model
{
    use HasFactory, LogsActivity;

    protected $fillable = [
        'commentable_type',
        'commentable_id',
        'user_id',
        'body',
        'parent_id',
    ];

    protected $casts = [
        'body' => 'string',
    ];

    // ============================================================
    // Events / Observers
    // ============================================================

    protected static function booted(): void
    {
        static::created(function (Comment $comment) {
            // Notify if comment is on a Task
            if ($comment->commentable_type === Task::class) {
                $task = $comment->commentable;
                if ($task) {
                    // Notify creator and assignee (except the commenter)
                    $usersToNotify = collect([$task->creator, $task->assignee])
                        ->unique('id')
                        ->filter(fn ($u) => $u && $u->id !== $comment->user_id);

                    foreach ($usersToNotify as $user) {
                        $user->notify(new TaskCommentNotification($task, $comment));
                    }
                }
            }
        });
    }

    // ============================================================
    // Relationships
    // ============================================================

    public function commentable(): MorphTo
    {
        return $this->morphTo();
    }

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    public function parent(): BelongsTo
    {
        return $this->belongsTo(Comment::class, 'parent_id');
    }

    public function replies(): HasMany
    {
        return $this->hasMany(Comment::class, 'parent_id')->orderBy('created_at');
    }

    // ============================================================
    // Scopes
    // ============================================================

    public function scopeTopLevel($query)
    {
        return $query->whereNull('parent_id');
    }

    public function scopeWithReplies($query)
    {
        return $query->with('replies.user');
    }

    // ============================================================
    // Accessors
    // ============================================================

    public function getExcerptAttribute(): string
    {
        return strlen($this->body) > 150
            ? substr($this->body, 0, 150).'...'
            : $this->body;
    }
}