There is a regex for email validation in java that works perfectly in android. Can someone help me convert it to swift?

Question

The regex in kotlin does not allow white spaces, emojis etc. I want this regex to be used in swift but the regex does not work exactly and needs to be converted. I have tried but I am unable to achieve proper conversion. Help would be appreciated

Code tested in online kotlin playground

Kotlin Playground code:

import java.util.regex.*

fun main() {

    println(isValidEmailAddress(" abc@gmail.com"))
    // returns false
    println(isValidEmailAddress("abc@gmail.com"))
    // returns false

}

val EMAIL_PATTERN = Pattern.compile("[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
            "\\@" +
            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
            "(" +
                "\\." +
                "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
            ")+")

public fun isValidEmailAddress(email: String): Boolean {
        return EMAIL_PATTERN.matcher(email).matches()
    }

Code tested in online swift playground

Swift Playground code:

import Foundation

extension String {
    func isValidEmail() -> Bool {
        let regex = try! NSRegularExpression(pattern: "[a-zA-Z0-9+._%-+]{1,256}@[a-zA-Z0-9][a-zA-Z0-9-]{0,64}+\\.[a-zA-Z0-9][a-zA-Z0-9-]{0,25}+", options: .caseInsensitive)
        return regex.firstMatch(in: self, options: [], range: NSRange(location: 0, length: count)) != nil
    }
}

var str = " abc@gmail.com".isValidEmail()
print(str)
// returns true
str = "abc@gmail.com".isValidEmail()
print(str)
// returns true

Answer after following suggested changes:

import Foundation

extension String {
    func isValidEmail() -> Bool {
        let regex = try! NSRegularExpression(pattern: "^[a-zA-Z0-9+._%-]{1,256}@[a-zA-Z0-9][a-zA-Z0-9-]{0,64}+(\\.[a-zA-Z0-9][a-zA-Z0-9-]{0,25})+$", options: .caseInsensitive)
        return regex.firstMatch(in: self, options: [], range: NSRange(location: 0, length: self.utf16.count)) != nil
    }
}

var str = " abcgmail.com".isValidEmail()
print(str)
// returns false
str = "ac@gmail.com".isValidEmail()
print(str)
// returns false