/*
    * $Id: WarehouseQuerier.java,v 1.6 2004/11/22 14:43:21 jdt Exp $
    *
    * (C) Copyright Astrogrid...
    */
   
   package org.astrogrid.datacenter.queriers.ogsadai;
   
   import java.io.File;
  import java.io.IOException;
  import org.astrogrid.community.Account;
  import org.astrogrid.config.SimpleConfig;
  import org.astrogrid.datacenter.queriers.DatabaseAccessException;
  import org.astrogrid.datacenter.queriers.DefaultPlugin;
  import org.astrogrid.datacenter.queriers.Querier;
  import org.astrogrid.datacenter.queriers.VotableInResults;
  import org.astrogrid.datacenter.queriers.sql.postgres.PostgresSqlMaker;
  import org.astrogrid.datacenter.queriers.status.QuerierQuerying;
  import org.astrogrid.datacenter.query.Query;
  import org.astrogrid.util.Workspace;
  
  /***
   * An AstroGrid datacenter plugin Querier that provides access
   * to the AstroGrid OGSA-DAI Grid Data Warehouse.
   *
   * Due to incompatibilities between vanilla Axis and the customised
   * version of Axis used by OGSA-DAI, this plugin querier does not talk
   * directly to the OGSA-DAI installation.  (This allows us to insulate
   * the datacenter runtime from the customised Axis classes).
   *
   * Instead, it shells out to the command-line and invokes a
   * {@link GdsQueryDelegate} (running in a new JVM) to perform
   * the query.  The results supplied by the OGSA-DAI service
   * in VOTable format.
   *
   * Communication between this <code>WarehouseQuerier</code> and
   * a {@link GdsQueryDelegate} is via process input and output streams.
   * This version of the WarehouseQuerier requests OGSA-DAI to deliver
   * its results to a local file. The implications of this are:
   * <ul>
   * <li> The tomcat instances hosting the OGSA-DAI service and the
   * Datacenter service <strong>must be running on the same host</strong>.
   *
   * <li>The tomcat instances hosting the OGSA-DAI service and the
   * Datacenter service should probably be running as the same user
   * (because the latter must create, and the former must write to,
   * the same temporary file).
   * </ul>
   *
   * Delivery to a GridFTP URL is also supported by the It5 OGSA-DAI client
   * code, but requires additional support at the datacenter end in terms
   * of X.509 authentication etc. It is not explicitly supported in this
   * Iteration 5 version of the WarehouseQuerier, which relies on
   * deliver-to-file instead.
   *
   * @author K Andrews
   * @version 1.1
   * @see GdsQueryDelegate
   */
  public class WarehouseQuerier extends DefaultPlugin {
     
     Workspace workspace = null;
     
  
    /***
     * Performs an actual database query (by shelling out to a
     * GdsQueryDelegate running in a separate JVM).
     *
     * Converts input ADQL query into the SQL expected by the
     * GdsQueryDelegate, using a custom Postgres-flavoured translator.
     *
     * @throws IOException, DatabaseAccessException
     */
     public void askQuery(Account user, Query query, Querier querier) throws IOException {
  
        querier.setStatus(new QuerierQuerying(querier.getStatus()));
  
      //Convert to SQL
      PostgresSqlMaker sqlMaker = new PostgresSqlMaker();
      String sql = escapeXmlSpecialChars(sqlMaker.makeSql(query));
       
      log.debug("Successfully created SQL query from input ADQL");
  
      // Get temp file to pass to Query delegate
      try {
         workspace = new Workspace("Warehouse_"+querier.getId());
      }
      catch (Exception th) {
         log.error(th);
         throw new IOException(
            "Couldn't create temporary workspace: " +
            th.getMessage());
      }
       
      File tempFile = null;
      //Set up outputs
      if (this.workspace != null) {
        try {
          tempFile = workspace.makeWorkFile(TEMP_RESULTS_FILENAME);
       }
       catch (Exception e) { //IOException or FileNotFoundException
         // Couldn't create temporary workspace file, use stdout instead
         String errMess = "Couldn't open temporary workspace file: "
             + e.getMessage();
         log.error(errMess);
         throw new DatabaseAccessException(errMess);
       }
     }
     else {
       log.error("WarehouseQuerier workspace is null");
       throw new IOException("WarehouseQuerier workspace is null");
     }
     doShelledOutQuery(sql, tempFile);
     VotableInResults results = new VotableInResults(querier, tempFile);
     results.send(query.getResultsDef(), querier.getUser());
     workspace.close();
   }
 
    /*** Abort - if this is called, try and kill the query and tidy up.
     * Currently not implemented.  I don't know how we're going to
     * do this using the shelled-out query method, yuk!
     */
    public void abort()  {
       //don't forget to workspace.close();
       // TODO
    }
    
  /***
    * Shells out to the command line to delegate the query operation to
    * a GdsQueryDelegate running in a separate JVM.
    *
    * The GdsQueryDelegate accepts SQL, performs the actual query via
    * OGSA-DAI, and returns VOTable results.
    *
    * @param sql  String containing the SQL query to be performed
    * @param tempFile  File to hold the GdsQueryDelegate's VOTable results
    * @throws DatabaseAccessException
    */
   protected void doShelledOutQuery(String sql, File tempFile)
       throws DatabaseAccessException {
 
     if (sql == null) {
       String errMess = "Empty sql query string supplied to WarehouseQuerier";
       log.error(errMess);
       throw new DatabaseAccessException(errMess);
     }
     if (tempFile == null) {
       String errMess = "Null results destination supplied to WarehouseQuerier";
       log.error(errMess);
       throw new DatabaseAccessException(errMess);
     }
 
     log.debug("Commencing doShelledOutQuery");
 
     // Configure parameters for external call
     String[] cmdArgs;
     if (tempFile == null) {
       cmdArgs = new String[5];
     }
     else {
       cmdArgs = new String[6];
     }
     cmdArgs[0] = getJavaBinary();
     cmdArgs[1] = "-jar";
     cmdArgs[2] = getExecutableJar();
     cmdArgs[3] = sql;
     cmdArgs[4] = getOgsaDaiRegistryString();
     cmdArgs[5] = "file://" + tempFile.getAbsolutePath();
     // FUTURE: We can use gsiftp urls here too
     //cmdArgs[5] = "gsiftp://" + tempFile.getAbsolutePath();
     log.debug("Command is: " + cmdArgs[0] + " " + cmdArgs[1] +
           " " + cmdArgs[2] + " " + cmdArgs[3] + " " + cmdArgs[4]);
 
     // Use utility helper to perform call
     log.info("Commencing shelled-out query");
     SystemTalker talker = new SystemTalker();
     TalkResult result = talker.talk(cmdArgs, "");
 
     if (result.getErrorCode() != 0) {
       log.error("Shelled-out query failed:" + result.getStderr());
       throw new DatabaseAccessException(
         "External call failed: " + result.getStderr());
     }
     // Finished external call successfully
     log.info("Shelled-out query succeeded");
   }
 
   /***
    * Assembles the URL of the OGSA-DAI registry to be used by the
    * GdsQueryDelegate.
    *
    * @return  String holding full URL of the OGSA-DAI registry
    * @throws DatabaseAccessException
    */
   protected String getOgsaDaiRegistryString() throws DatabaseAccessException {
     String host = SimpleConfig.getProperty("WAREHOUSE_OgsaDaiHostString");
     if (host == null) {
       String errorMessage =
         "Fatal error: Property 'WAREHOUSE_OgsaDaiHostString' not found " +
         " in file 'AstroGridConfig.properties'";
       log.error(errorMessage);
       throw new DatabaseAccessException(errorMessage);
     }
     String registry = SimpleConfig.getProperty("WAREHOUSE_OgsaDaiRegistryString");
     if (registry == null) {
       String errorMessage =
         "Fatal error: Property 'WAREHOUSE_OgsaDaiRegistryString' not found" +
         " in file 'WarehouseQuerier.properties'";
       log.error(errorMessage);
       throw new DatabaseAccessException(errorMessage);
     }
     return host + registry;
   }
 
   /***
    * Assembles the fully-qualified path of the Java JVM to be shelled
    * out to.
    *
    * By default, looks for the environment variable JAVA_HOME and figures
    * out the path from that.
    *
    * If JAVA_HOME is not defined, looks for a local property instead.
    *
    * @return  String holding full path of the Java JVM binary
    * @throws DatabaseAccessException
    */
   protected String getJavaBinary() throws DatabaseAccessException {
     // First, check if user has customised the JVM location
     //  in the WarehouseQuerier.properties file
     String customJVM = SimpleConfig.getProperty("WAREHOUSE_WarehouseJvm");
     if (customJVM != null) {
       return customJVM;  // Use customised JVM if it exists
     }
     else {
       // No custom JVM - use JVM in JAVA_HOME
       String javaHome = System.getProperty("java.home");
       if (javaHome == null) {  //Shouldn't happen
         String errorMessage =
           "Fatal error: System property 'java.home' not defined! "+
              "Please set WAREHOUSE_WarehouseJvm property in " +
              "'AstroGridConfig.properties' file";
         log.error(errorMessage);
         throw new DatabaseAccessException(errorMessage);
       }
       String separator = System.getProperty("file.separator");
       if (separator == null) {
         log.warn("Warning, couldn't get system file.separator, assuming '/'");
         separator = "/";
       }
       // Assume JVM binary is called java and is in bin dir of JAVA_HOME
       String fullPath = javaHome + separator + "bin" + separator + "java";
       File testFile = new File(fullPath);
       if (!(testFile.exists())) {
         //Try looking for a .exe version - might be running under Windows
         testFile = new File(fullPath + ".exe");
         if (!(testFile.exists())) {
           String errorMessage =
             "Fatal error: Java binary '" + fullPath + "[.exe]' not found! "+
                "Please set WAREHOUSE_WarehouseJvm property in " +
                "'AstroGridConfig.properties' file";
           log.error(errorMessage);
           throw new DatabaseAccessException(errorMessage);
         }
         else {
           return fullPath + ".exe";
         }
       }
       return fullPath;
     }
   }
 
   /***
    * Assembles the fully-qualified path of the Java executable jar
    * containing the OGSA-DAI GdsQueryDelegate.
    *
    * The location and name of the jar can be customised for a given
    * installation in the WarehouseQuerier.properties file.
    *
    * @return  String holding full path of the GdsQueryDelegate executable jar
    * @throws DatabaseAccessException
    */
   protected String getExecutableJar() throws DatabaseAccessException {
     // Extract path to directory containing executable jar
     String jarPath = SimpleConfig.getProperty("WAREHOUSE_ExecutableJarPath");
     if (jarPath == null) {
       String errorMessage = "Property 'WAREHOUSE_ExecutableJarPath' not set" +
       " in properties file 'AstroGridConfig.properties'";
       log.error(errorMessage);
       throw new DatabaseAccessException(errorMessage);
     }
     String sep = System.getProperty("file.separator");
     if (sep == null) {
       log.warn("Warning, couldn't get system file.separator, assuming " +
           "WAREHOUSE_ExecutableJarPath is properly terminated " +
           "with file separator");
     }
     else {
       int pathlen = jarPath.length();
       // If last char in path not separator, add separator
       if (!(jarPath.substring(pathlen-1,pathlen).equalsIgnoreCase(sep))) {
         jarPath = jarPath + sep;
       }
     }
     // Extract name of executable jar
     String jarName = SimpleConfig.getProperty("WAREHOUSE_ExecutableJarName");
     if (jarName == null) {
       String errorMessage =
           "Property 'WAREHOUSE_ExecutableJarName' not set in " +
           "properties file 'AstroGridConfig.properties'";
       log.error(errorMessage);
       throw new DatabaseAccessException(errorMessage);
     }
     return jarPath + jarName;
   }
 
 
   /***
    * Adjust input string (SQL query) to escape XML special characters
    * likely to cause problems.
    * @return  Version of string with escaped XML special characters
    */
   protected String escapeXmlSpecialChars(String inString) {
     String outString = "";
     for (int i = 0; i < inString.length(); i++) {
       char c = inString.charAt(i);
       if (c == '<') {
         outString = outString + "&lt;";
       }
       else if (c == '>') {
         outString = outString + "&gt;";
       }
       else if (c == '&') {
         outString = outString + "&amp;";
       }
       else {
         outString = outString + c;
       }
     }
     return outString;
   }
 
    /*** Returns just the number of matches rather than the list of matches */
    public long getCount(Account user, Query query, Querier querier) throws IOException {
             throw new UnsupportedOperationException("Not done yet");
    }
   // ----------------------------------------------------------
   // Fallback defaults for values that should be configured on a
   // per-installation basis in the WarehouseServiceImpl.properties
   private final String DEFAULT_WAREHOUSE_JVM = "/usr/bin/java";
 
   private final String TEMP_RESULTS_FILENAME = "warehouseResults.xml";
 //================================================================
 
    /*** Returns the formats that this plugin can provide.  Asks the results class; override in subclasse if nec */
    public String[] getFormats() {
       return VotableInResults.getFormats();
    }
    
    
    
 }
 /*
 $Log: WarehouseQuerier.java,v $
 Revision 1.6  2004/11/22 14:43:21  jdt
 Restored Martin's changes from PAL_MCHJDT_705
 
 Revision 1.4  2004/11/12 13:49:12  mch
 Fix where keyword maker might not have had keywords made
 
 Revision 1.3  2004/11/03 00:17:56  mch
 PAL_MCH Candidate 2 merge
 
 Revision 1.2.6.1  2004/10/27 00:43:39  mch
 Started adding getCount, some resource fixes, some jsps
 
 Revision 1.2  2004/10/18 13:11:30  mch
 Lumpy Merge
 
 Revision 1.1.6.1  2004/10/15 19:59:06  mch
 Lots of changes during trip to CDS to improve int test pass rate
 
 Revision 1.1  2004/09/28 15:02:13  mch
 Merged PAL and server packages
 
 Revision 1.14  2004/09/07 00:54:20  mch
 Tidied up Querier/Plugin/Results, and removed deprecated SPI-visitor-SQL-translator
 
 Revision 1.13  2004/04/01 17:10:31  mch
 Removed unused import
 
 Revision 1.12  2004/04/01 10:10:09  eca
 Replaced PostgresAdqlQueryTranslator with ogsadai.AdqlQueryTranslator.
 
 
 
 01/04/04 ElizabethAuden
 
 Revision 1.11  2004/03/26 15:52:47  eca
 datacenter.queriers.ogsadai.AdqlQueryTranslator now updated for
 1) optimized for Postgres
 2) conforms to ADQLSchemav06
 
 Also, imported new AdqlQueryTranslator in WarehouseQuerier
 
 25/03/04 Elizabeth Auden
 
 Revision 1.10  2004/03/24 15:57:31  kea
 Updated Javadocs etc.
 
 Revision 1.9  2004/03/17 18:24:15  kea
 Integrating new javaapp using del-to-file, del-to-gridftp.
 
 Revision 1.8  2004/03/17 15:48:33  kea
 Tidying method sigs.
 
 Revision 1.7  2004/03/17 13:53:29  mch
 MCH botch to compile
 
 Revision 1.6  2004/03/17 12:20:54  kea
 Removing XSLT rowset->VOTable conversions, now done in OGSA-DAI.
 Interim checkin, end-to-end not working yet.
 
 Revision 1.5  2004/03/15 17:11:14  mch
 'botch' fix for duplicate Workspace id
 
 Revision 1.4  2004/03/12 20:04:57  mch
 It05 Refactor (Client)
 
 Revision 1.3  2004/03/12 04:45:26  mch
 It05 MCH Refactor
 
 Revision 1.2  2004/01/24 20:44:25  gtr
 Merged from GDW-integration branch.
 
 Revision 1.1.2.3  2004/01/24 20:37:33  gtr
 Merged from GDW-integration branch.
 
 Revision 1.1.2.2  2004/01/24 17:38:00  gtr
 Datacenter client has changed the Query class back to _query.
 
 Revision 1.1.2.1  2004/01/22 14:56:32  gtr
 Transfered from astrogrid/warehouse, with package name changed to be in
 org.astrogrid.datacenter.*.
 
 Revision 1.18  2004/01/21 15:59:40  gtr
 _query class is changed to Query.
 
 Revision 1.17  2004/01/19 12:47:54  kea
 Giving proper WAREHOUSE_ prefix to toplevel warehouse config properties
 in AstroGridConfig.properties file.
 
 Revision 1.16  2004/01/16 12:19:09  kea
 Fixing broken Javadoc comments.
 
 Revision 1.15  2004/01/15 18:36:57  kea
 Now looks for properties in toplevel AstroGridConfig.properties,
 using SimpleConfig initialised by datacenter infrastructure.
 
 Revision 1.14  2004/01/08 21:41:34  kea
 Horrid kludge to convert datacenter "t.DEC" to "t.decl" for warehouse tables.
 
 Revision 1.13  2004/01/08 20:00:42  kea
 Added XML special char escaping to sql strings returned by datacenter
 ADQL->SQL conversion (otherwise OGSA-DAI perform docs get broken).
 
 Revision 1.12  2003/12/15 15:45:35  kea
 Correcting misleading error message.
 
 Revision 1.11  2003/12/12 14:42:03  gtr
 Unused import statements were removed.
 
 Revision 1.10  2003/12/11 13:14:48  kea
 Moved OGSA-DAI host and registry location into WarehouseQuerier properties
 file so they can be edited more easily in a tomcat inst.
 
 Revision 1.9  2003/12/10 12:27:56  kea
 Finding JVM to shell out to from JAVA_HOME.
 
 Revision 1.8  2003/12/09 12:19:34  kea
 Changed shelling-out to use executable jar (including adjustments
 to properties file).
 
 Revision 1.7  2003/12/08 20:16:54  kea
 Added JavaDoc.  Changed properties to use Java-style capitalisation.
 Misc. small tidyings.
 
 Revision 1.6  2003/12/04 18:54:56  kea
 Minimal logging added - more to follow.
 
 Revision 1.5  2003/12/02 16:22:13  kea
 Moved ogsa-dai functionality out into GdsQuerierDelegate.
 Misc. changes to accommodate changes in datacenter codebase.
 
 Revision 1.2  2003/11/26 19:46:19  kea
 Basic datacenter-style querier, now fully integrated so it should
 when invoked via datacenter framework.
 Needs a lot of cleaning up and documentation added.
 May need revision to meet forthcoming datacenter codebase changes.
 
 Revision 1.1  2003/11/19 17:33:40  kea
 Initial Querier functionality for integration with the database.
 This compiles and sort-of runs at the command-line;  however, we
 currently have no means of getting the OGSA-DAI results into the
 format expected by the datacenter.  (They currently get dumped to
 /tmp/WS_OGSA_OUTPUT).
 */