<?php

/**
 * User OTP Model
 * Manages email-based one-time passwords for two-factor authentication
 */
class UserOtp_model
{
    protected static string $tablename = "user_otp_codes";

    /**
     * Generate and store a new OTP code for a user
     * @param int $userId User ID
     * @param int $expiryMinutes Expiry time in minutes (default 10)
     * @return string The generated OTP code
     */
    public static function generateOTP($userId, $expiryMinutes = 10)
    {
        $db = \Config\Database::connect();

        // Generate 6-digit OTP
        $otpCode = str_pad(random_int(0, 999999), 6, '0', STR_PAD_LEFT);

        // Calculate expiry time
        $expiresAt = date('Y-m-d H:i:s', strtotime("+{$expiryMinutes} minutes"));

        // Store OTP in database
        $data = [
            'user_id' => $userId,
            'otp_code' => $otpCode,
            'expires_at' => $expiresAt,
            'used' => 'F',
            'created_at' => date('Y-m-d H:i:s')
        ];

        $db->table(self::$tablename)->insert($data);

        return $otpCode;
    }

    /**
     * Verify an OTP code for a user
     * @param int $userId User ID
     * @param string $otpCode The OTP code to verify
     * @return bool True if valid, false otherwise
     */
    public static function verifyOTP($userId, $otpCode)
    {
        $db = \Config\Database::connect();

        // Get the most recent unused OTP for this user
        $result = $db->table(self::$tablename)
            ->where('user_id', $userId)
            ->where('otp_code', $otpCode)
            ->where('used', 'F')
            ->where('expires_at >', date('Y-m-d H:i:s'))
            ->orderBy('created_at', 'DESC')
            ->limit(1)
            ->get()
            ->getRow();

        if (!$result) {
            return false;
        }

        // Mark OTP as used
        $db->table(self::$tablename)
            ->where('id', $result->id)
            ->update(['used' => 'T']);

        return true;
    }

    /**
     * Clean up expired OTP codes
     * @return int Number of deleted records
     */
    public static function cleanupExpiredOTPs()
    {
        $db = \Config\Database::connect();

        $db->table(self::$tablename)
            ->where('expires_at <', date('Y-m-d H:i:s'))
            ->orWhere('used', 'T')
            ->delete();

        return $db->affectedRows();
    }

    /**
     * Delete all OTP codes for a user
     * @param int $userId User ID
     */
    public static function deleteUserOTPs($userId)
    {
        $db = \Config\Database::connect();

        $db->table(self::$tablename)
            ->where('user_id', $userId)
            ->delete();
    }
}