package org.apache.ojb.broker.metadata;

 /* Copyright 2003-2005 The Apache Software Foundation

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 import org.apache.commons.lang.builder.ToStringBuilder;

 import org.apache.commons.lang.builder.ToStringStyle;

 import org.apache.ojb.broker.accesslayer.conversions.FieldConversion;

 import java.io.Serializable;

 /**

  * An ArgumentDescriptor contains information that defines a single argument

  * that is passed to a procedure/function.

  * <br>

  * Note: Be careful when use ArgumentDescriptor variables or caching

  * ArgumentDescriptor instances, because instances could become invalid

  * during runtime (see {@link MetadataManager}).

  *

  * @author <a href="mailto:rongallagher@bellsouth.net">Ron Gallagher<a>

  * @version $Id: ArgumentDescriptor.java,v 1.1 2007-08-24 22:17:29 ewestfal Exp $

  */

 public final class ArgumentDescriptor extends DescriptorBase implements XmlCapable, Serializable

 {

         private static final long serialVersionUID = 5205304260023247711L;

     private static final int SOURCE_NULL = 0;

     private static final int SOURCE_FIELD = 1;

     private static final int SOURCE_VALUE = 2;

     private int fieldSource = SOURCE_NULL;

     private String constantValue = null;

     private String fieldRefName = null;

     private boolean returnedByProcedure = false;

     //---------------------------------------------------------------

     /**

      * The procedure descriptor that this object is related to.

      */

     private ProcedureDescriptor procedureDescriptor;

     //---------------------------------------------------------------

     /**

      * Constructor declaration.  By default, this object will be configured

      * so that the value returned by {@link #fieldSource} will be null.  To

      * change this, call either version of the setValue method.

      *

      * @see #setValue()

      * @see #setValue(String)

      * @see #setValue(String,boolean)

      */

     public ArgumentDescriptor(ProcedureDescriptor procedureDescriptor)

     {

         this.procedureDescriptor = procedureDescriptor;

         this.setValue();

     }

     /**

      * Sets up this object to represent a null value.

      */

     public void setValue()

     {

         this.fieldSource = SOURCE_NULL;

         this.fieldRefName = null;

         this.returnedByProcedure = false;

         this.constantValue = null;

     }

     /**

      * Sets up this object to represent a value that is derived from a field

      * in the corresponding class-descriptor.

      * <p>

      * If the value of <code>fieldRefName</code> is blank or refers to an

      * invalid field reference, then the value of the corresponding argument

      * will be set to null. In this case, {@link #getIsReturnedByProcedure}

      * will be set to <code>false</code>, regardless of the value of the

      * <code>returnedByProcedure</code> argument.

      *

      * @param fieldRefName the name of the field reference that provides the

      *          value of this argument.

      * @param returnedByProcedure indicates that the value of the argument

      *          is returned by the procedure that is invoked.

      */

     public void setValue(String fieldRefName, boolean returnedByProcedure)

     {

         this.fieldSource = SOURCE_FIELD;

         this.fieldRefName = fieldRefName;

         this.returnedByProcedure = returnedByProcedure;

         this.constantValue = null;

         // If the field reference is not valid, then disregard the value

         // of the returnedByProcedure argument.

         if (this.getFieldRef() == null)

         {

             this.returnedByProcedure = false;

         }

         // If the field reference is not valid, then disregard the value

         // of the returnedByProcedure argument.

         if (this.getFieldRef() == null)

         {

             this.returnedByProcedure = false;

         }

     }

     /**

      * Sets up this object to represent an argument that will be set to a

      * constant value.

      *

      * @param constantValue the constant value.

      */

     public void setValue(String constantValue)

     {

         this.fieldSource = SOURCE_VALUE;

         this.fieldRefName = null;

         this.returnedByProcedure = false;

         this.constantValue = constantValue;

     }

     public boolean getIsReturnedByProcedure()

     {

         return this.returnedByProcedure;

     }

     public Object getValue(Object objekt)

     {

         switch (this.fieldSource)

         {

             case SOURCE_FIELD :

                 if (objekt == null)

                 {

                     return null;

                 }

                 else

                 {

                     FieldDescriptor fd = this.getFieldRef();

                     Object value = null;

                     FieldConversion conversion = null;

                     if (fd != null)

                     {

                         conversion = fd.getFieldConversion();

                         value = fd.getPersistentField().get(objekt);

                         if (conversion != null)

                         {

                             value = conversion.javaToSql(value);

                         }

                     }

                     return value;

                 }

             case SOURCE_VALUE :

                 return this.constantValue;

             case SOURCE_NULL :

                 return null;

             default :

                 return null;

         }

     }

     public void saveValue(Object objekt, Object value)

     {

         if ((this.fieldSource == SOURCE_FIELD) && (this.returnedByProcedure))

         {

             FieldDescriptor fd = this.getFieldRef();

             FieldConversion conversion = null;

             if (fd != null)

             {

                 conversion = fd.getFieldConversion();

                 if (conversion == null)

                 {

                     fd.getPersistentField().set(objekt, value);

                 }

                 else

                 {

                     fd.getPersistentField().set(objekt, conversion.sqlToJava(value));

                 }

             }

         }

     }

     //---------------------------------------------------------------

     /**

      * Retrieve the field descriptor that this argument is related to.

      * <p>

      * This reference can only be set via the {@link #setValue(String,boolean)}

      * method.

      * @return The current value

      */

     public final FieldDescriptor getFieldRef()

     {

         if (this.fieldSource == SOURCE_FIELD)

         {

             return this.getProcedureDescriptor().getClassDescriptor().getFieldDescriptorByName(

                 this.fieldRefName);

         }

         else

         {

             return null;

         }

     }

     /**

      * Retrieve the jdbc type for the field descriptor that is related

      * to this argument.

      */

     public final int getJdbcType()

     {

         switch (this.fieldSource)

         {

             case SOURCE_FIELD :

                 return this.getFieldRef().getJdbcType().getType();

             case SOURCE_NULL :

                 return java.sql.Types.NULL;

             case SOURCE_VALUE :

                 return java.sql.Types.VARCHAR;

             default :

                 return java.sql.Types.NULL;

         }

     }

     //---------------------------------------------------------------

     /**

      * Retrieve the procedure descriptor that this object is related to.

      *

      * @return The current value

      */

     public final ProcedureDescriptor getProcedureDescriptor()

     {

         return this.procedureDescriptor;

     }

     /*

      * @see XmlCapable#toXML()

      */

     public String toXML()

     {

         String eol = System.getProperty("line.separator");

         RepositoryTags tags = RepositoryTags.getInstance();

         // The result

         String result = "     ";

         switch (this.fieldSource)

         {

             case SOURCE_FIELD :

                 result += " " + tags.getOpeningTagNonClosingById(RUNTIME_ARGUMENT);

                 result += " " + tags.getAttribute(FIELD_REF, this.fieldRefName);

                 result += " " + tags.getAttribute(RETURN, String.valueOf(this.returnedByProcedure));

                 result += "/>";

                 break;

             case SOURCE_VALUE :

                 result += " " + tags.getOpeningTagNonClosingById(CONSTANT_ARGUMENT);

                 result += " " + tags.getAttribute(VALUE, this.constantValue);

                 result += "/>";

                 break;

             case SOURCE_NULL :

                 result += " " + tags.getOpeningTagNonClosingById(RUNTIME_ARGUMENT);

                 result += "/>";

                 break;

             default :

                 break;

         }

         // Return the result.

         return (result + eol);

     }

     //---------------------------------------------------------------

     /**

      * Provide a string representation of this object

      *

      * @return a string representation of this object

      */

     public String toString()

     {

         ToStringBuilder buf = new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE);

         switch (this.fieldSource)

         {

             case SOURCE_FIELD :

                 {

                     buf.append("fieldRefName", this.fieldRefName);

                     buf.append("returnedByProcedure", this.returnedByProcedure);

                     break;

                 }

             case SOURCE_NULL :

                 {

                     break;

                 }

             case SOURCE_VALUE :

                 {

                     buf.append("constantValue", this.constantValue);

                     break;

                 }

         }

         return buf.toString();

     }

 }