servicedesk/src/app/Models/TicketMessage.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Attributes\Fillable;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\HasOne;
use Illuminate\Database\Eloquent\Relations\HasOneThrough;

#[Fillable(['ticket_id', 'author_name', 'internal', 'body', 'edited', 'api_client_id', 'source', 'created_at', 'updated_at'])]
class TicketMessage extends Model
{
    protected function casts(): array
    {
        return [
            'internal' => 'boolean',
            'edited' => 'boolean',
        ];
    }

    /**
     * "role" and "author_id" are read-only virtual attributes derived from
     * authorLink (see below) — neither is a real column anymore, so this
     * keeps every existing `$message->role`/`$message->author_id` read
     * working unchanged. Write via attachAuthor() instead.
     */
    public function getAttribute($key)
    {
        if ($key === 'role') {
            return $this->authorLink?->role?->key ?? 'system';
        }

        if ($key === 'author_id') {
            return $this->authorLink?->user_id;
        }

        return parent::getAttribute($key);
    }

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

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

    /**
     * Who wrote this message and in what role — replaces the old flat
     * author_id/role columns. A message with no row here is a
     * system-generated entry (no author, no role).
     */
    public function authorLink(): HasOne
    {
        return $this->hasOne(TicketMessageAuthor::class);
    }

    public function author(): HasOneThrough
    {
        return $this->hasOneThrough(User::class, TicketMessageAuthor::class, 'ticket_message_id', 'id', 'id', 'user_id');
    }

    /**
     * Links this message to the given author + role (or does nothing for a
     * system message, i.e. $roleKey === null) — the write-side counterpart
     * to the role/author_id reads above, since neither is a plain column
     * anymore.
     */
    public function attachAuthor(?int $userId, ?string $roleKey): void
    {
        if ($roleKey === null) {
            return;
        }

        $this->authorLink()->create([
            'user_id' => $userId,
            'role_id' => Role::query()->where('key', $roleKey)->value('id'),
        ]);
    }

    public function attachments(): HasMany
    {
        return $this->hasMany(TicketAttachment::class, 'message_id');
    }
}