<?php

namespace App\Services\Packages;

use App\Models\Event;
use App\Models\EventPackage;
use App\Models\Tenant;

class PackageLimitEvaluator
{
    public function assessEventCreation(Tenant $tenant): ?array
    {
        if ($tenant->hasEventAllowance()) {
            return null;
        }

        $package = $tenant->getActiveResellerPackage();

        if ($package) {
            $limit = $package->package->max_events_per_year ?? 0;

            return [
                'code' => 'event_limit_exceeded',
                'title' => 'Event quota reached',
                'message' => 'Your current package has no remaining event slots. Please upgrade or renew your subscription.',
                'status' => 402,
                'meta' => [
                    'scope' => 'events',
                    'used' => (int) $package->used_events,
                    'limit' => $limit,
                    'remaining' => max(0, $limit - $package->used_events),
                    'tenant_package_id' => $package->id,
                    'package_id' => $package->package_id,
                ],
            ];
        }

        return [
            'code' => 'event_credits_exhausted',
            'title' => 'No event credits remaining',
            'message' => 'You have no event credits remaining. Purchase additional credits or a package to create new events.',
            'status' => 402,
            'meta' => [
                'scope' => 'credits',
                'balance' => (int) ($tenant->event_credits_balance ?? 0),
            ],
        ];
    }

    public function assessPhotoUpload(Tenant $tenant, int $eventId, ?Event $preloadedEvent = null): ?array
    {
        [$event, $eventPackage] = $this->resolveEventAndPackage($tenant, $eventId, $preloadedEvent);

        if (! $event) {
            return [
                'code' => 'event_not_found',
                'title' => 'Event not accessible',
                'message' => 'The selected event could not be found or belongs to another tenant.',
                'status' => 404,
                'meta' => [
                    'scope' => 'photos',
                    'event_id' => $eventId,
                ],
            ];
        }

        if (! $eventPackage || ! $eventPackage->package) {
            return [
                'code' => 'event_package_missing',
                'title' => 'Event package missing',
                'message' => 'No package is attached to this event. Assign a package to enable uploads.',
                'status' => 409,
                'meta' => [
                    'scope' => 'photos',
                    'event_id' => $event->id,
                ],
            ];
        }

        $maxPhotos = $eventPackage->package->max_photos;

        if ($maxPhotos === null) {
            return null;
        }

        if ($eventPackage->used_photos >= $maxPhotos) {
            return [
                'code' => 'photo_limit_exceeded',
                'title' => 'Photo upload limit reached',
                'message' => 'This event has reached its photo allowance. Upgrade the event package to accept more uploads.',
                'status' => 402,
                'meta' => [
                    'scope' => 'photos',
                    'used' => (int) $eventPackage->used_photos,
                    'limit' => (int) $maxPhotos,
                    'remaining' => 0,
                    'event_id' => $event->id,
                    'package_id' => $eventPackage->package_id,
                ],
            ];
        }

        return null;
    }

    public function resolveEventPackageForPhotoUpload(
        Tenant $tenant,
        int $eventId,
        ?Event $preloadedEvent = null
    ): ?EventPackage {
        [, $eventPackage] = $this->resolveEventAndPackage($tenant, $eventId, $preloadedEvent);

        return $eventPackage;
    }

    /**
     * @return array{0: ?Event, 1: ?\App\Models\EventPackage}
     */
    private function resolveEventAndPackage(
        Tenant $tenant,
        int $eventId,
        ?Event $preloadedEvent = null
    ): array {
        $event = $preloadedEvent;

        if (! $event) {
            $event = Event::with(['eventPackage.package', 'eventPackages.package'])
                ->find($eventId);
        }

        if (! $event || $event->tenant_id !== $tenant->id) {
            return [null, null];
        }

        $eventPackage = $event->eventPackage;

        if (! $eventPackage && method_exists($event, 'eventPackages')) {
            $eventPackage = $event->eventPackages()
                ->with('package')
                ->orderByDesc('purchased_at')
                ->orderByDesc('created_at')
                ->first();
        }

        if ($eventPackage && ! $eventPackage->relationLoaded('package')) {
            $eventPackage->load('package');
        }

        return [$event, $eventPackage];
    }
}