/*
 * Microsoft JDBC Driver for SQL Server
 * 
 * Copyright(c) Microsoft Corporation All rights reserved.
 * 
 * This program is made available under the terms of the MIT License. See the LICENSE file in the project root for more information.
 */

package com.microsoft.sqlserver.jdbc;

import static java.nio.charset.StandardCharsets.UTF_8;

import java.text.MessageFormat;
import java.util.concurrent.ConcurrentHashMap;

import javax.xml.bind.DatatypeConverter;

/**
 * Factory for SQLServerAeadAes256CbcHmac256Algorithm
 */
class SQLServerAeadAes256CbcHmac256Factory extends SQLServerEncryptionAlgorithmFactory {
    // In future we can have more
    private byte algorithmVersion = 0x1;
    private ConcurrentHashMap<String, SQLServerAeadAes256CbcHmac256Algorithm> encryptionAlgorithms = new ConcurrentHashMap<String, SQLServerAeadAes256CbcHmac256Algorithm>();

    @Override
    SQLServerEncryptionAlgorithm create(SQLServerSymmetricKey columnEncryptionKey,
            SQLServerEncryptionType encryptionType,
            String encryptionAlgorithm) throws SQLServerException {

        assert (columnEncryptionKey != null);
        if (encryptionType != SQLServerEncryptionType.Deterministic && encryptionType != SQLServerEncryptionType.Randomized) {
            MessageFormat form = new MessageFormat(SQLServerException.getErrString("R_InvalidEncryptionType"));
            Object[] msgArgs = {encryptionType, encryptionAlgorithm,
                    "'" + SQLServerEncryptionType.Deterministic + "," + SQLServerEncryptionType.Randomized + "'"};
            throw new SQLServerException(this, form.format(msgArgs), null, 0, false);

        }
        String factoryKey = "";

        StringBuffer factoryKeyBuilder = new StringBuffer();
        factoryKeyBuilder.append(DatatypeConverter.printBase64Binary(new String(columnEncryptionKey.getRootKey(), UTF_8).getBytes()));

        factoryKeyBuilder.append(":");
        factoryKeyBuilder.append(encryptionType);
        factoryKeyBuilder.append(":");
        factoryKeyBuilder.append(algorithmVersion);

        factoryKey = factoryKeyBuilder.toString();

        SQLServerAeadAes256CbcHmac256Algorithm aesAlgorithm;

        if (!encryptionAlgorithms.containsKey(factoryKey)) {
            SQLServerAeadAes256CbcHmac256EncryptionKey encryptedKey = new SQLServerAeadAes256CbcHmac256EncryptionKey(columnEncryptionKey.getRootKey(),
                    SQLServerAeadAes256CbcHmac256Algorithm.algorithmName);
            aesAlgorithm = new SQLServerAeadAes256CbcHmac256Algorithm(encryptedKey, encryptionType, algorithmVersion);
            encryptionAlgorithms.putIfAbsent(factoryKey, aesAlgorithm);
        }

        return encryptionAlgorithms.get(factoryKey);
    }

}