public enum ConnectionStatus {
    IDLE(0),
    CONNECTED(1),
    DISCONNECTED(2),
    CONNECTING(3),
    FAILURE(4);
}

public enum ConversationType {
    UNKNOWN(0),
    /// private chat
    PRIVATE(1),
    /// group
    GROUP(2),
    /// chatroom
    CHATROOM(3),
    /// system conversation
    SYSTEM(4);
}

public enum PullDirection {
    NEWER, OLDER
}

public enum MessageDirection {
    SEND(1),
    RECEIVE(2);
}

public enum MessageState {
    UNKNOWN(0),
    SENDING(1),
    SENT(2),
    FAIL(3),
    UPLOADING(4);
}

public enum CallStatus {
    // no active call
    IDLE(0),
    // incoming call
    INCOMING(1),
    // outgoing call
    OUTGOING(2),
    // connecting
    CONNECTING(3),
    // connected
    CONNECTED(4),
    // joined proactively
    JOIN(5);
}

public enum CallMediaType {
    // audio call
    VOICE(0),
    // video call
    VIDEO(1);
}

public enum CallFinishReason {
        /// unknown reason
        UNKNOWN(0),
        /// current user hung up an active call
        HANGUP(1),
        /// current user rejected the incoming call
        DECLINE(2),
        /// current user was busy
        BUSY(3),
        /// current user did not answer
        NO_RESPONSE(4),
        /// current user canceled the call
        CANCEL(5),
        /// remote user hung up an active call
        OTHER_SIDE_HANGUP(6),
        /// remote user rejected the incoming call
        OTHER_SIDE_DECLINE(7),
        /// remote user was busy
        OTHER_SIDE_BUSY(8),
        /// remote user did not answer
        OTHER_SIDE_NO_RESPONSE(9),
        /// remote user canceled the call
        OTHER_SIDE_CANCEL(10),
        /// room was destroyed
        ROOM_DESTROY(11),
        /// network error
        NETWORK_ERROR(12),
        /// current user answered the call on another device
        ACCEPT_ON_OTHER_CLIENT(13),
        /// current user hung up the call on another device
        HANGUP_ON_OTHER_CLIENT(14);
}