/* ======================================================================
   Parts Copyright 2006 University of Leeds, Oxford University, University of the Highlands and Islands.

   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.

====================================================================== */

package org.bodington.server.resources;

import org.bodington.database.*;
import org.bodington.sqldatabase.*;

public class UploadedFileIndexKey
    implements IndexKey
    {
    PrimaryKey resource_id;
    PrimaryKey parent_uploaded_file_id;
    String name;

    UploadedFileIndexKey()
        {
	resource_id = null;
	parent_uploaded_file_id = null;
	name = null;
        }
        
    public boolean cacheNull()
        {
        return false;
        }
        
    public String whereClause()
        {
        StringBuffer where = new StringBuffer();
        
        where.append( "resource_id " );
        if ( resource_id == null )
            where.append( "IS NULL" );
        else
	    {
	    where.append( "= " );
            where.append( resource_id.toString() );
	    }
	
        if ( parent_uploaded_file_id == null )
        {
            // it is logical that when parent_uploaded_file_id is null
            // that left_index = 0 and vice versa so this is valid
            // alternative, and in MS SQL the query runs much much
            // faster because it uses a better scheme for loading
            // records from the objects table.
            where.append( " AND left_index = 0 " );
        }
        else
	    {
            where.append( " AND parent_uploaded_file_id " );
	    where.append( "= " );
            where.append( parent_uploaded_file_id.toString() );

	    where.append( " AND name " );
	    if ( name == null )
		where.append( "IS NULL" );
	    else
		{
		where.append( "= " );
		where.append( SqlDatabase.quotedSQL( name ) );
		}
	    }
        return where.toString();
        }
    
    void setResourceId( PrimaryKey id )
        {
        resource_id = id;
        }
    PrimaryKey getResourceId()
        {
        return resource_id;
        }
    
    void setParentUploadedFileId( PrimaryKey id )
        {
        parent_uploaded_file_id = id;
        }
    PrimaryKey getParentUploadedFileId()
        {
        return parent_uploaded_file_id;
        }
    
    void setName( String u )
        {
        name = u;
        }
    String getName()
        {
        return name;
        }
    
    public boolean equals(Object obj)
        {
        if ( !(obj instanceof UploadedFileIndexKey) )
            return false;

        UploadedFileIndexKey other = (UploadedFileIndexKey)obj;
        
        if ( other.name==null || this.name==null )
            return false;
        
	
	if (	!((other.resource_id == null && 
		   this.resource_id == null)      ||
		  (other.resource_id !=null && 
		   this.resource_id != null &&
		   other.resource_id.equals( this.resource_id ) ) ) )
	    return false;

	// for root folders ignore names
	if (	other.parent_uploaded_file_id == null && 
		  this.parent_uploaded_file_id == null   )
	    return true;

	// not equal if one is root and one isn't
	if (	other.parent_uploaded_file_id == null ||
		  this.parent_uploaded_file_id == null  )
	    return false;
	
	// not equal if not siblings
	if ( !other.parent_uploaded_file_id.equals( this.parent_uploaded_file_id ) )
	    return false;
	
	// equal if neither have names
	if ( (this.name == null || this.name.length()==0) && 
		(other.name == null || other.name.length()==0) )
	    return true;
	
	// not equal if one has a name and the other hasn't
	if ( (this.name == null || this.name.length()==0) || 
		(other.name == null || other.name.length()==0) )
	    return false;

	// equal if both have the same name
	// This is case sensitive which means that two apparently different
	// keys may map to the same database record depending on the case
	// insensitivity of the database.  Problem is that the equalsIgnoreCase
	// may ignore case for more alphabets than the database comparison.
	// It's better to have two keys onto one record than have a key
	// return a record in cache that wouldn't have been found by a 
	// database query.
	return other.name.equals( this.name );
        }

    public int hashCode()
        {
	if ( parent_uploaded_file_id != null )
	    return parent_uploaded_file_id.intValue();
	if ( resource_id != null )
	    return resource_id.intValue();
        if ( name==null )
	    return 0;
        return name.hashCode();
        }

    }
