/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
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/*
 * Copyright (c) 1999 by Sun Microsystems, Inc.
 * All rights reserved.
 *
 */

//  UARequester.java: Requester operations for UA.
//  Author:           James Kempf
//  Created On:       Thu Jan  8 15:17:35 1998
//  Last Modified By: James Kempf
//  Last Modified On: Mon Feb 22 13:47:06 1999
//  Update Count:     78
//

package com.sun.slp;

import java.util.*;

/**
 * The URequester class implements the Locator interface.
 * It handles the request for the API.  If any of the parameters
 * are missing, they will be supplied with a default value if
 * possible.  If a cached value may be supplied, it will be.
 * If no DA is present, and convergence is used to gather
 * results, these will be merged into one result.
 *
 * @author Erik Guttman, James Kempf
 */


class UARequester extends Object implements Locator {

    private static SLPConfig config = null;
    private static DATable dat = null;

    private Locale locale;

    UARequester(Locale nlocale) {

        Assert.nonNullParameter(nlocale, "locale");

        if (config == null) {
            config = SLPConfig.getSLPConfig();
        }

        if (dat == null) {
            dat = DATable.getDATable();
        }

        locale = nlocale;
    }

    /**
     * Return the Locator's locale object. All requests are made in
     * this locale.
     *
     * @return The Locale object.
     */

    public Locale getLocale() {
        return locale;

    }

    /**
     * Return an enumeration of known service types for this scope and naming
     * authority.  Unless a proprietary or experimental service is being
     * discovered, the namingAuthority parameter should be the empty
     * string, "".
     *
     * @param NA        The naming authority, "" for default,
     *           '*' for any naming authority.
     * @param scopes    The SLP scopes of the types.
     * @return ServiceLocationEnumeration of ServiceType objects for
     *        the service type names.
     * @exception IllegalArgumentException If any of the parameters are
     *                                    null or syntactically incorrect.
     * @exception ServiceLocationException An exception is thrown if the
     *                                    operation fails.
     */

    public synchronized ServiceLocationEnumeration
        findServiceTypes(String NA, Vector scopes)
        throws ServiceLocationException {

        Assert.nonNullParameter(NA, " NA");
        Assert.nonNullParameter(scopes, "scopes");

        // Formulate and send off messages.

        Vector msgs = createMessages(SrvLocHeader.SrvTypeRqst,
                                     NA,
                                     null,
                                     null,
                                     scopes);

        // Collate results.

        Vector ret = new Vector();
        int i, n = msgs.size();
        int max = config.getMaximumResults();

        for (i = 0; i < n; i++) {
            CSrvTypeMsg msg = (CSrvTypeMsg)msgs.elementAt(i);

            // Check for errors.

            checkForError(msg, msgs);

            Vector serviceTypes = msg.serviceTypes;

            addUnique(serviceTypes, ret, max);

        }

        // Return.

        return new ServiceLocationEnumerator(ret);
    }

    /**
     * Return an enumeration of ServiceURL objects for services matching
     * the query. The services are returned from the locale of the
     * locator.
     *
     * @param type      The type of the service (e.g. printer, etc.).
     * @param scopes    The SLP scopes of the service types.
     * @param query             A string with the SLP query.
     * @return ServiceLocationEnumeration of ServiceURL objects for
     *        services matching the
     *         attributes.
     * @exception ServiceLocationException An exception is returned if the
     *                                    operation fails.
     * @see ServiceURL
     */

    public synchronized ServiceLocationEnumeration
        findServices(ServiceType type, Vector scopes, String query)
        throws ServiceLocationException {

        Assert.nonNullParameter(type, "type");
        Assert.nonNullParameter(scopes, "scopes");
        Assert.nonNullParameter(query, "query");

        // Formulate and send off messages.

        Vector msgs = createMessages(SrvLocHeader.SrvReq,
                                     type,
                                     query,
                                     type,
                                     scopes);

        // Collate results.

        Vector ret = new Vector();
        int i, n = msgs.size();
        int max = config.getMaximumResults();

        for (i = 0; i < n; i++) {
            SrvLocMsg msg = (SrvLocMsg)msgs.elementAt(i);

            // Check for errors.

            checkForError(msg, msgs);

            // Be sure to account for DAAdverts and SAAdverts.

            Vector serviceURLs = null;

            if (msg instanceof CSrvMsg) {
                serviceURLs = ((CSrvMsg)msg).serviceURLs;

            } else if (msg instanceof CSAAdvert) {
                serviceURLs = new Vector();
                serviceURLs.addElement(((CSAAdvert)msg).URL);

            } else if (msg instanceof CDAAdvert) {
                serviceURLs = new Vector();
                serviceURLs.addElement(((CDAAdvert)msg).URL);

            }

            addUnique(serviceURLs, ret, max);

        }

        // Return.

        return new ServiceLocationEnumerator(ret);
    }

    /**
     * Return the attributes for the service URL, using the locale
     * of the locator.
     *
     * @param URL       The service URL.
     * @param scopes    The SLP scopes of the service.
     * @param attributeIds A vector of strings identifying the desired
     *                    attributes. A null value means return all
     *                    the attributes.  <b>Partial id strings</b> may
     *                     begin with '*' to match all ids which end with
     *                     the given suffix, or end with '*' to match all
     *                     ids which begin with a given prefix, or begin
     *                     and end with '*' to do substring matching for
     *                     ids containing the given partial id.
     * @return ServiceLocationEnumeration of ServiceLocationAttribute
     *         objects matching the ids.
     * @exception ServiceLocationException An exception is returned if the
     *                                    operation fails.
     * @exception IllegalArgumentException If any of the parameters are
     *                                    null or syntactically incorrect.
     * @see ServiceLocationAttribute
     *
     */

    public synchronized ServiceLocationEnumeration
        findAttributes(ServiceURL URL, Vector scopes, Vector attributeIds)
        throws ServiceLocationException {

        Assert.nonNullParameter(URL, "URL");
        Assert.nonNullParameter(scopes, "scopes");
        Assert.nonNullParameter(attributeIds, "attributeIds");

        Vector msgs = createMessages(SrvLocHeader.AttrRqst,
                                     URL,
                                     attributeIds,
                                     URL.getServiceType(),
                                     scopes);

        // Check results.

        Vector ret = new Vector();
        int i, n = msgs.size();
        int max = config.getMaximumResults();

        // We only take the first message that came back and is OK.

        for (i = 0; i < n; i++) {
            SrvLocMsg msg = (SrvLocMsg)msgs.elementAt(i);

            // Check for errors.

            checkForError(msg, msgs);

            // Select out attribute list.

            if (msg instanceof CAttrMsg) {
                ret = ((CAttrMsg)msg).attrList;

            } else if (msg instanceof CSAAdvert) {

                // Need to check that URL matches.

                CSAAdvert smsg = (CSAAdvert)msg;

                if (!URL.equals(smsg.URL)) {
                    continue;

                }

                ret = smsg.attrs;

            } else if (msg instanceof CDAAdvert) {

                // Need to check that URL matches.

                CDAAdvert smsg = (CDAAdvert)msg;

                if (!URL.equals(smsg.URL)) {
                    continue;

                }

                ret = smsg.attrs;
            }

            // Truncate, if return is larger than maximum.

            if (ret.size() > max) {
                ret.setSize(max);

            }

            // Break out, we only need one.

            break;

        }

        // Return.

        return new ServiceLocationEnumerator(ret);
    }

    /**
     * Return all attributes for all service URL's having this
     * service type in the locale of the Locator.
     *
     * @param type The service type.
     * @param scopes    The SLP scopes of the service type.
     * @param attributeIds A vector of strings identifying the desired
     *                    attributes. A null value means return all
     *                    the attributes.  <b>Partial id strings</b> may
     *                     begin with '*' to match all ids which end with
     *                     the given suffix, or end with '*' to match all
     *                     ids which begin with a given prefix, or begin
     *                     and end with '*' to do substring matching for
     *                     ids containing the given partial id.
     * @return ServiceLocationEnumeration of ServiceLocationAttribute
     *         objects matching the ids.
     * @exception ServiceLocationException An exception is returned if the
     *                                    operation fails.
     * @exception IllegalArgumentException If any of the parameters are
     *                                    null or syntactically incorrect.
     * @see ServiceLocationAttribute
     *
     */

    public synchronized ServiceLocationEnumeration
        findAttributes(ServiceType type, Vector scopes, Vector attributeIds)
        throws ServiceLocationException {

        Assert.nonNullParameter(type, "URL");
        Assert.nonNullParameter(scopes, "scopes");
        Assert.nonNullParameter(attributeIds, "attributeIds");

        // Formulate and send off messages.

        Vector msgs = createMessages(SrvLocHeader.AttrRqst,
                                     type,
                                     attributeIds,
                                     type,
                                     scopes);
        // Collate results.

        Vector ret = new Vector();
        int i, n = msgs.size();
        int max = config.getMaximumResults();
        Hashtable ht = new Hashtable();

        for (i = 0; i < n && ret.size() < max; i++) {
            SrvLocMsg msg = (SrvLocMsg)msgs.elementAt(i);

            // Check for errors.

            checkForError(msg, msgs);

            Vector attrList = null;

            // Get the instance variable.

            if (msg instanceof CAttrMsg) {
                attrList = ((CAttrMsg)msg).attrList;

            } else if (msg instanceof CSAAdvert) {
                attrList = ((CSAAdvert)msg).attrs;

            } else if (msg instanceof CDAAdvert) {
                attrList = ((CDAAdvert)msg).attrs;

            }

            // Merge any duplicates.

            int j, m = attrList.size();

            for (j = 0; j < m; j++) {
                ServiceLocationAttribute attr =
                    (ServiceLocationAttribute)attrList.elementAt(j);

                ServiceLocationAttribute.mergeDuplicateAttributes(attr,
                                                                  ht,
                                                                  ret,
                                                                  true);

                if (ret.size() >= max) {
                    break;

                }
            }
        }

        // Return.

        return new ServiceLocationEnumerator(ret);
    }

    // Execute the message request, returning messages.

    private Vector
        createMessages(int msgType,
                       Object t1,
                       Object t2,
                       ServiceType type,
                       Vector scopes)
        throws ServiceLocationException {

        // Validate, lower case scopes.

        DATable.validateScopes(scopes, locale);

        SrvLocMsg multiMsg = null;
        SrvLocMsg uniMsg = null;
        Vector daAddresses = null;
        Vector multiCastScopes = null;

        // Get the hashtable of unicast DA addresses and multicast scopes.

        Hashtable daRecords = dat.findDAScopes(scopes);

        // Get multicast scopes and DA addresses.

        multiCastScopes =
            (Vector)daRecords.get(DATable.MULTICAST_KEY);

        daAddresses =
            (Vector)daRecords.get(DATable.UNICAST_KEY);

        // Special case for service request and attribute request
        //  if the user is looking for a special SLP type.

        if (((msgType == SrvLocHeader.SrvReq) ||
            (msgType == SrvLocHeader.AttrRqst)) &&
            (type.equals(Defaults.DA_SERVICE_TYPE) ||
            type.equals(Defaults.SA_SERVICE_TYPE))) {

            multiCastScopes = scopes;
            daAddresses = null;

            // Get query. If an attribute request, then the user
            //  needs to sort out the attributes.

            String query = "";

            if (msgType == SrvLocHeader.SrvReq) {
                query = (String)t2;

            }

            multiMsg = new CSrvMsg(locale, type, multiCastScopes, query);

        } else {

            // Handle a regular message.

            // Multicast scopes are all scopes not supported by any DA.

            if (multiCastScopes != null) {

                switch (msgType) {

                case SrvLocHeader.SrvTypeRqst:
                    multiMsg =
                        new CSrvTypeMsg(locale, (String)t1, multiCastScopes);
                    break;

                case SrvLocHeader.SrvReq:
                    multiMsg =
                        new CSrvMsg(locale, type, multiCastScopes, (String)t2);
                    break;

                case SrvLocHeader.AttrRqst:

                    if (t1 instanceof ServiceURL) {
                        multiMsg =
                            new CAttrMsg(locale,
                                         (ServiceURL)t1,
                                         multiCastScopes,
                                         (Vector)t2);

                    } else {
                        multiMsg =
                            new CAttrMsg(locale,
                                         type,
                                         multiCastScopes,
                                         (Vector)t2);

                    }
                }
            }

            // Unicast only requires a single message because the DAs will
            //  ignore any scopes they do not support, just as long as
            //  they support one of them.

            if (daAddresses != null) {
                switch (msgType) {

                case SrvLocHeader.SrvTypeRqst:
                    uniMsg =
                        new CSrvTypeMsg(locale, (String)t1, scopes);
                    break;

                case SrvLocHeader.SrvReq:
                    uniMsg =
                        new CSrvMsg(locale, type, scopes, (String)t2);
                    break;

                case SrvLocHeader.AttrRqst:

                    if (t1 instanceof ServiceURL) {
                        uniMsg =
                            new CAttrMsg(locale,
                                         (ServiceURL)t1,
                                         scopes,
                                         (Vector)t2);

                    } else {
                        uniMsg =
                            new CAttrMsg(locale,
                                         type,
                                         scopes,
                                         (Vector)t2);

                    }

                }
            }
        }

        // Send off messages, return results.

        return Transact.transactUA(daAddresses,
                                   uniMsg,
                                   multiMsg,
                                   config.getMulticastAddress());
    }

    // Check message for error code.

    private static void
        checkForError(SrvLocMsg msg, Vector v)
        throws ServiceLocationException {
        int err = msg.getErrorCode();

        if (err != ServiceLocationException.OK) {
            if (v.size() == 1) {
                config.writeLog("single_exception",
                                new Object[] {
                    Integer.valueOf(err)});
                throw
                    new ServiceLocationException((short)err,
                                                 "remote_error",
                                                 new Object[] {});
            } else {
                config.writeLog("multiple_exception",
                                new Object[] {
                    Integer.valueOf(err)});
            }
        }
    }

    // Process the incoming vector, adding any unique returns.

    private static void addUnique(Vector incoming, Vector returns, int max) {

        int i, n = incoming.size();

        for (i = 0; i < n; i++) {
            Object o = incoming.elementAt(i);

            if (!returns.contains(o) && returns.size() < max) {
                returns.addElement(o);

            }
        }
    }

}