Future<Map?> encrypt(List<int> data, List<int> key)

this method returns Map of {
    encrypted: List<int>,
    tag: List<int>,
    nonce: List<int> 
}

// tag: authentication tag or MAC (message authentication code), the algorithm uses it to verify whether or not the ciphertext (encrypted data) and/or associated data have been modified.

// nonce: (or "initialization vector", "IV", "salt") is a unique non-secret sequence of data required by most cipher (encryption) algorithms, making the ciphertext (encrypted data) unique despite the same key

Future<Map?> encryptString(String string, String key, String keyEncoding, String outputEncoding)

this method takes inputs of UTF8 string, key in base64 or hex encoding string depending on keyEncoding

this method returns Map of {
    encrypted: String (in base64 or hex encoded string depending on outputEncoding),
    tag: String (in base64 or hex encoded string depending on outputEncoding),
    nonce: String (in base64 or hex encoded string depending on outputEncoding) 
}

Future<List<int>?>decrypt(List<int> encrypted, List<int> key, List<int> nonce, List<int> tag)

this method returns List<int>

Future<String?>decryptString(String inputEncoding, String encryptedString, String key, String nonce, String tag)

this method takes inputs in base64 or hex encoding string depending on inputEncoding

this method returns String in UTF8

try {
    final key =
    await FlutterKeyGenerator.generateSymmetricKey(256);

    print("256 bit key: ${key}");
    // new unique key will be generated every time generateSymmetricKey is run
    // [116, 89, 78, 246, 24, 145, 69, 153, 89, 21, 182, 39, 208, 83, 28, 190, 10, 254, 168, 181, 192, 9, 37, 129, 186, 197, 78, 107, 111, 196, 119, 250]

    if (key != null) {
    /*
    / Data in bytes encryption:
    */
    print("=================================================================================================================================================");
    print("Data in bytes encryption:");
    final data = [1, 2, 3];
    final sealedBox = await FlutterChacha20Poly1305.encrypt(data, key);

    print("Encrypted: ${sealedBox}");
    // Data in this object will be unique every time FlutterChacha20Poly1305.encrypt(data, key); is run
    // {
    //   encrypted: [48, 140, 193],
    //   tag: [2, 233, 22, 168, 82, 89, 110, 176, 158, 180, 147, 83, 250, 56, 15, 97],
    //   nonce: [186, 194, 249, 80, 235, 2, 210, 108, 23, 3, 133, 172] 
    // }

    final encrypted = [48, 140, 193];
    final uniqueKey = [116, 89, 78, 246, 24, 145, 69, 153, 89, 21, 182, 39, 208, 83, 28, 190, 10, 254, 168, 181, 192, 9, 37, 129, 186, 197, 78, 107, 111, 196, 119, 250];
    final nonce = [186, 194, 249, 80, 235, 2, 210, 108, 23, 3, 133, 172];
    final tag = [2, 233, 22, 168, 82, 89, 110, 176, 158, 180, 147, 83, 250, 56, 15, 97];

    final decryptedData = await FlutterChacha20Poly1305.decrypt(encrypted, uniqueKey, nonce, tag);
    print("Decrypted bytes: ${decryptedData} \n\n");
    // Decrypted bytes: [1, 2, 3]

    /*
    / Data in string encryption with key, nonce, tag in base64 or hex encoding
    */

    print("=================================================================================================================================================");
    print("Data in string encryption with key, nonce, tag in base64 or hex encoding:");

    final jsonString = "{ x: 1, y: 2, z: 3 }";
    final keyInBase64 = "LAnIp48R+r525MH9kme671+2Z2sta+yRGGmA783KBl8=";
    final keyEncoding = "base64";
    final outputEncoding = "base64"; // or "hex"

    final encryptStringObject = await FlutterChacha20Poly1305.encryptString(jsonString, keyInBase64, keyEncoding, outputEncoding);
    print("String encrypted object: ${encryptStringObject}");
    // Data in this object will be unique every time FlutterChacha20Poly1305.encryptString(jsonString, keyInBase64, keyEncoding, outputEncoding) is run
    // {
    //   tag: T/dbBWayYCdN+yvOvGU61Q==,
    //   encrypted: +OxmNIVA6gvwOCoQJAalHQS4Baw=,
    //   nonce: j43/wSHX6Dh6jIAF
    // }

    final inputEncoding = "base64"; // all the params below must be in base64 encoded string
    final encryptedString = "+OxmNIVA6gvwOCoQJAalHQS4Baw=";
    final tagBase64 = "T/dbBWayYCdN+yvOvGU61Q==";
    final nonceBase64 = "j43/wSHX6Dh6jIAF";

    final decryptedJSONString = await FlutterChacha20Poly1305.decryptString(inputEncoding, encryptedString, keyInBase64, nonceBase64, tagBase64);
    print("Decrypted JSON string: ${decryptedJSONString}");
    // { x: 1, y: 2, z: 3 }
    }
} catch (e) {
    print(e);
}