/*
 * RHQ Management Platform
 * Copyright (C) 2005-2008 Red Hat, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.rhq.plugins.www.snmp;

import java.util.List;
import java.util.Map;

import org.jetbrains.annotations.NotNull;

/**
 * Generic interface for any version of the SNMP protocol. Use {@link SNMPClient#getSession} to get an instance of a
 * class that implements this interface.
 */
public interface SNMPSession {
    /**
     * Retrieves the variable with the the specified MIB name or OID.
     *
     * @param  mibName the name of the variable to retrieve
     *
     * @return a SNMPValue object representing the value of the variable.
     *
     * @throws SNMPException if an error occurs communicating with the SNMP agent.
     */
    @NotNull
    SNMPValue getSingleValue(String mibName) throws SNMPException;

    /**
     * Retrieve the variable that logically next after the specified MIB name or OID.
     *
     * @param  mibName the name of the MIB variable at which to start looking
     *
     * @return An SNMPValue object representing the value of the specified MIB name, or if not found, the next logical
     *         MIB name.
     *
     * @throws SNMPException if an error occurs communicating with the SNMP agent.
     */
    @NotNull
    SNMPValue getNextValue(String mibName) throws SNMPException;

    /**
     * Retrieves all values from a column of an SNMP table (i.e. returns the subtree of values rooted at the specified
     * MIB name or OID).
     *
     * @param  mibName The name of the column of the SNMP table.
     *
     * @return a List of SNMPValue objects representing the values found in the column.
     *
     * @throws SNMPException if an error occurs communicating with the SNMP agent.
     */
    @NotNull
    List<SNMPValue> getColumn(String mibName) throws SNMPException;

    /**
     * TODO
     *
     * @param  mibName the MIB name of the table
     * @param  index
     *
     * @return
     *
     * @throws SNMPException if an error occurs communicating with the SNMP agent.
     */
    @NotNull
    Map<String, SNMPValue> getTable(String mibName, int index) throws SNMPException;

    /**
     * TODO
     *
     * @param  mibName the MIB name of the starting OID
     *
     * @return
     *
     * @throws SNMPException if an error occurs communicating with the SNMP agent.
     */
    @NotNull
    List<SNMPValue> getBulk(String mibName) throws SNMPException;

    /**
     * Pings the agent associated with this session to see if it is responsive.
     *
     * @return true if the agent responds, or false otherwise
     */
    boolean ping();

    /**
     * Get the timeout value for this session.
     *
     * @return the timeout value for this session
     */
    long getTimeout();

    /**
     * Set the timeout value for this session.
     *
     * @param timeout the timeout value for this session
     */
    void setTimeout(long timeout);

    /**
     * Get the retries value for this session.
     *
     * @return the retries value for this session
     */
    int getRetries();

    /**
     * Set the retries value for this session.
     *
     * @param retries the retries value for this session
     */
    void setRetries(int retries);

    /**
     * Closes the session and all underlying resources.
     */
    void close();
}