/*
 * Copyright 2016-2018 shardingsphere.io.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * </p>
 */

package io.shardingsphere.proxy.transport.mysql.constant;

import lombok.Getter;
import lombok.RequiredArgsConstructor;

/**
 * Capability flag.
 * @see <a href="https://dev.mysql.com/doc/internals/en/capability-flags.html#packet-Protocol::CapabilityFlags">CapabilityFlags</a>
 * 
 * @author zhangliang
 */
@RequiredArgsConstructor
@Getter
public enum CapabilityFlag {
    
    CLIENT_LONG_PASSWORD(0x00000001),
    
    CLIENT_FOUND_ROWS(0x00000002),
    
    CLIENT_LONG_FLAG(0x00000004),
    
    CLIENT_CONNECT_WITH_DB(0x00000008),
    
    CLIENT_NO_SCHEMA(0x00000010),
    
    CLIENT_COMPRESS(0x00000020),
    
    CLIENT_ODBC(0x00000040),
    
    CLIENT_LOCAL_FILES(0x00000080),
    
    CLIENT_IGNORE_SPACE(0x00000100),
    
    CLIENT_PROTOCOL_41(0x00000200),
    
    CLIENT_INTERACTIVE(0x00000400),
    
    CLIENT_SSL(0x00000800),
    
    CLIENT_IGNORE_SIGPIPE(0x00001000),
    
    CLIENT_TRANSACTIONS(0x00002000),
    
    CLIENT_RESERVED(0x00004000),
    
    CLIENT_SECURE_CONNECTION(0x00008000),
    
    CLIENT_MULTI_STATEMENTS(0x00010000),
    
    CLIENT_MULTI_RESULTS(0x00020000),
    
    CLIENT_PS_MULTI_RESULTS(0x00040000),
    
    CLIENT_PLUGIN_AUTH(0x00080000),
    
    CLIENT_CONNECT_ATTRS(0x00100000),
    
    CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA(0x00200000),
    
    CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS(0x00400000),
    
    CLIENT_SESSION_TRACK(0x00800000),
    
    CLIENT_DEPRECATE_EOF(0x01000000);
    
    private final int value;
    
    /**
     * Get handshake capability flags lower bit.
     * 
     * @return handshake capability flags lower bit
     */
    public static int calculateHandshakeCapabilityFlagsLower() {
        return calculateCapabilityFlags(CLIENT_LONG_PASSWORD, CLIENT_FOUND_ROWS, CLIENT_LONG_FLAG, CLIENT_CONNECT_WITH_DB, CLIENT_ODBC, CLIENT_IGNORE_SPACE,
                CLIENT_PROTOCOL_41, CLIENT_INTERACTIVE, CLIENT_IGNORE_SIGPIPE, CLIENT_TRANSACTIONS, CLIENT_SECURE_CONNECTION);
    }
    
    /**
     * Get handshake capability flags upper bit.
     *
     * @return handshake capability flags upper bit
     */
    public static int calculateHandshakeCapabilityFlagsUpper() {
        return 0;
    }
    
    // TODO use xor to calculate lower and upper
    private static int calculateCapabilityFlags(final CapabilityFlag... capabilities) {
        int result = 0;
        for (CapabilityFlag each : capabilities) {
            result |= each.value;
        }
        return result;
    }
}