<?php

declare(strict_types=1);

namespace App\Observers;

use App\Exceptions\Artist\CrossTenantEngagementException;
use App\Models\ArtistEngagement;
use App\Models\Scopes\OrganisationScope;

/**
 * Observer for ArtistEngagement.
 *
 * On `creating`: denormalises `organisation_id` from the parent Artist
 * (RFC v0.2 D10) and asserts artist.organisation_id === event.organisation_id.
 *
 * On `deleted` (soft delete): cascade soft-delete to child Performance
 * rows; hard-delete child AdvanceSection rows (per RFC §5.4 — sections
 * have no soft delete). AdvanceSubmission rows remain in the table with
 * `advance_section_id = NULL` (FK is `nullOnDelete`) per RFC §5.4
 * audit-immutability — orphaned but preserved for retention compliance.
 */
final class ArtistEngagementObserver
{
    public function creating(ArtistEngagement $engagement): void
    {
        $artist = $engagement->artist()->withoutGlobalScope(OrganisationScope::class)->first();
        $event = $engagement->event()->withoutGlobalScope(OrganisationScope::class)->first();

        if ($artist === null || $event === null) {
            return;
        }

        if ($engagement->organisation_id === null) {
            $engagement->organisation_id = $artist->organisation_id;
        }

        if ($artist->organisation_id !== $event->organisation_id) {
            $engagement->setRelation('artist', $artist);
            $engagement->setRelation('event', $event);
            throw CrossTenantEngagementException::forEngagement($engagement);
        }
    }

    /**
     * Reserved for Session 2 state-machine validation when
     * `booking_status` transitions land. No-op for now.
     */
    public function saving(ArtistEngagement $engagement): void
    {
        // intentionally empty — see class docblock
    }

    public function deleted(ArtistEngagement $engagement): void
    {
        if (! $engagement->isForceDeleting() && $engagement->trashed()) {
            $engagement->performances()->delete();
            $engagement->advanceSections()->delete();
        }
    }
}