<?php

namespace App\Models;

use CodeIgniter\Model;

class RememberTokenModel extends Model
{
    public const LIFETIME_SECONDS = 30 * 24 * 60 * 60;

    protected $table         = 'remember_tokens';
    protected $primaryKey    = 'id';
    protected $returnType    = 'array';
    protected $useTimestamps = true;
    protected $allowedFields = ['selector', 'validator_hash', 'expires_at'];

    public function issueToken(): string
    {
        $selector = bin2hex(random_bytes(16));
        $validator = bin2hex(random_bytes(32));

        $this->insert([
            'selector'       => $selector,
            'validator_hash' => hash('sha256', $validator),
            'expires_at'     => date('Y-m-d H:i:s', time() + self::LIFETIME_SECONDS),
        ]);

        return $selector . ':' . $validator;
    }

    public function verifyToken(string $token): bool
    {
        [$selector, $validator] = $this->splitToken($token);
        if ($selector === null) {
            return false;
        }

        $row = $this->where('selector', $selector)->first();
        if (!$row || strtotime($row['expires_at']) <= time()) {
            if ($row) {
                $this->delete($row['id']);
            }

            return false;
        }

        return hash_equals($row['validator_hash'], hash('sha256', $validator));
    }

    public function deleteToken(string $token): void
    {
        [$selector] = $this->splitToken($token);
        if ($selector !== null) {
            $this->where('selector', $selector)->delete();
        }
    }

    public function deleteExpired(): void
    {
        $this->where('expires_at <=', date('Y-m-d H:i:s'))->delete();
    }

    private function splitToken(string $token): array
    {
        $parts = explode(':', $token, 2);
        if (count($parts) !== 2 || !ctype_xdigit($parts[0]) || strlen($parts[0]) !== 32
            || !ctype_xdigit($parts[1]) || strlen($parts[1]) !== 64) {
            return [null, null];
        }

        return $parts;
    }
}