//

 // Copyright (c) 2004, International Decision Systems

 // all rights reserved

 //

 package net.sourceforge.addam.ddlgen.generic;

 import net.sourceforge.addam.ddlgen.Filter;

 import net.sourceforge.addam.ddlgen.Generator;

 import org.apache.velocity.Template;

 import org.apache.velocity.VelocityContext;

 import org.apache.velocity.app.Velocity;

 import org.apache.velocity.exception.ResourceNotFoundException;

 import java.io.BufferedWriter;

 import java.sql.Connection;

 import java.sql.DatabaseMetaData;

 import java.sql.ResultSet;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Properties;

 /**

  * ENTER A DESCRIPTION HERE

  *

  * @author TIM3

  * @since Oct 9, 2005

  */

 public abstract class VelocityGenerator implements Generator {

     public List<String> getObjects(String catalog, String schema, Filter filter,

                                    Connection connection, DatabaseMetaData metadata) throws Exception {

         if (metadata.storesUpperCaseIdentifiers()) {

             catalog = (catalog == null) ? null : catalog.toUpperCase();

             schema = (schema == null) ? null : schema.toUpperCase();

         } else if (metadata.storesLowerCaseIdentifiers()) {

             catalog = (catalog == null) ? null : catalog.toLowerCase();

             schema = (schema == null) ? null : schema.toLowerCase();

         }

         ResultSet tablesRS = metadata.getTables(catalog, schema, "%", new String[]{"TABLE"});

         List<String> objects = new ArrayList<String>();

         while (tablesRS.next()) {

             String dbObject = tablesRS.getString(3);

             if (filter.includes(dbObject)) {

                 objects.add(dbObject);

             }

         }

         return objects;

     }

     public void generate(String catalog, String schema, String object,

                          String vendor, Connection connection, DatabaseMetaData metadata, BufferedWriter writer)

             throws Exception {

         if (metadata.storesUpperCaseIdentifiers()) {

             catalog = (catalog == null) ? null : catalog.toUpperCase();

             schema = (schema == null) ? null : schema.toUpperCase();

         } else if (metadata.storesLowerCaseIdentifiers()) {

             catalog = (catalog == null) ? null : catalog.toLowerCase();

             schema = (schema == null) ? null : schema.toLowerCase();

         }

         if (vendor == null) vendor = metadata.getDatabaseProductName();

         Template template = getTemplate(metadata, vendor);

         VelocityContext context = getContext(catalog, schema, object, connection, metadata);

         template.merge(context, writer);

     }

     protected abstract VelocityContext getContext(String catalog, String schema, String object,

                                                   Connection connection, DatabaseMetaData metadata) throws Exception;

     protected Template getTemplate(DatabaseMetaData metadata, String vendor) throws Exception {

         // this is a lame problem in velocity's design - the init and getTemplate methods are static

         // this creates a thread-safety risk; we have to initialize each time and hope for the best

         Properties props = new Properties();

         props.put("resource.loader", "class");

         props.put("class.resource.loader.class", "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");

         Velocity.init(props);

         Template template;

         try {

             String templateName = this.getTemplateName(vendor);

             template = Velocity.getTemplate(templateName);

         } catch (ResourceNotFoundException e) {

             String templateName = this.getTemplateName("");

             template = Velocity.getTemplate(templateName);

         }

         return template;

     }

     protected String getTemplateName(String vendor) {

         String name = getClass().getName().replace('.', '/');

         int lastIndex = name.lastIndexOf("/");

         String dir = name.substring(0, lastIndex);

         String file = name.substring(lastIndex + 1);

         String suffix = (vendor == null || vendor.length()==0) ? "" : "-" + vendor;

         String templateName = dir + "/" + file + suffix + ".vm";

         templateName = templateName.replace("Generator","");

         return templateName;

     }

 }