<?php

namespace App\Services;

use PDO;
use RuntimeException;

final class RfidService
{
    public function __construct(
        private readonly PDO $pdo,
        private readonly AuditService $audit
    ) {
    }

    public function createDevice(int $tenantId, string $name, ?string $location, int $actorUserId): string
    {
        if (trim($name) === '') {
            throw new RuntimeException('Bitte einen Geraetenamen angeben.');
        }

        $token = bin2hex(random_bytes(20));
        $statement = $this->pdo->prepare(
            'INSERT INTO rfid_devices (tenant_id, name, location_label, device_token, status)
             VALUES (:tenant_id, :name, :location_label, :device_token, "planned")'
        );
        $statement->execute([
            'tenant_id' => $tenantId,
            'name' => trim($name),
            'location_label' => $location,
            'device_token' => $token,
        ]);
        $deviceId = (int) $this->pdo->lastInsertId();

        $this->audit->log($tenantId, $actorUserId, 'rfid.device_created', 'rfid_device', $deviceId, 'success');

        return $token;
    }

    public function assignTag(int $tenantId, int $memberId, string $uid, ?string $label, int $actorUserId): void
    {
        if (trim($uid) === '') {
            throw new RuntimeException('Die Karten-UID darf nicht leer sein.');
        }

        $statement = $this->pdo->prepare(
            'INSERT INTO rfid_tags (tenant_id, member_id, uid_hash, label, status)
             VALUES (:tenant_id, :member_id, :uid_hash, :label, "active")'
        );
        $statement->execute([
            'tenant_id' => $tenantId,
            'member_id' => $memberId,
            'uid_hash' => hash('sha256', trim($uid)),
            'label' => $label,
        ]);

        $this->audit->log($tenantId, $actorUserId, 'rfid.tag_assigned', 'rfid_tag', (int) $this->pdo->lastInsertId(), 'success');
    }

    public function ingest(array $payload): void
    {
        $deviceToken = trim((string) ($payload['device_token'] ?? ''));
        $uid = trim((string) ($payload['uid'] ?? ''));
        $externalEventId = trim((string) ($payload['event_id'] ?? ''));

        if ($deviceToken === '' || $uid === '') {
            throw new RuntimeException('device_token und uid sind Pflichtfelder.');
        }

        $deviceStatement = $this->pdo->prepare(
            'SELECT d.id, d.tenant_id, d.status
             FROM rfid_devices d
             WHERE d.device_token = :device_token
             LIMIT 1'
        );
        $deviceStatement->execute(['device_token' => $deviceToken]);
        $device = $deviceStatement->fetch();

        if (!$device) {
            throw new RuntimeException('Das RFID-Geraet ist unbekannt.');
        }

        $status = 'received';
        $tagStatement = $this->pdo->prepare(
            'SELECT id FROM rfid_tags WHERE tenant_id = :tenant_id AND uid_hash = :uid_hash LIMIT 1'
        );
        $tagStatement->execute([
            'tenant_id' => $device['tenant_id'],
            'uid_hash' => hash('sha256', $uid),
        ]);

        if ($tagStatement->fetch()) {
            $status = 'linked';
        }

        $statement = $this->pdo->prepare(
            'INSERT INTO rfid_events (
                tenant_id,
                device_id,
                external_event_id,
                uid_hash,
                payload_json,
                status,
                received_at
            ) VALUES (
                :tenant_id,
                :device_id,
                :external_event_id,
                :uid_hash,
                :payload_json,
                :status,
                :received_at
            )'
        );
        $statement->execute([
            'tenant_id' => $device['tenant_id'],
            'device_id' => $device['id'],
            'external_event_id' => $externalEventId !== '' ? $externalEventId : null,
            'uid_hash' => hash('sha256', $uid),
            'payload_json' => json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
            'status' => $status,
            'received_at' => gmdate('Y-m-d H:i:s'),
        ]);

        $this->audit->log((int) $device['tenant_id'], null, 'rfid.event_received', 'rfid_event', (int) $this->pdo->lastInsertId(), 'success', [
            'status' => $status,
            'device_id' => (int) $device['id'],
        ]);
    }
}