/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
* A pure java implementation of WOContext.
*
* @author michael@mpowers.net
* @author $Author: cgruber $
* @version $Revision: 905 $
*/
public class WOContext
{
	private WOSession session;
	private WORequest request;
	private WOResponse response;
    private List elementStack;
	private boolean isInForm;
	private boolean isDistributionEnabled;
    private static final String EMPTY = "";
    private static final String SEP = ".";
    private static final String ZERO = "0";
    private static final String HTTP = "http://";
    private static final String HTTPS = "https://";

	// package access
	WOComponent page;
	WOComponent component;
	StringBuffer elementID;
    
    private static volatile int contextCounter = 0;
    private String contextID;
    
	/**
	* Default constructor performs necessary initialization.
	* Subclassers should override the static factory method below.
	*/
    public WOContext ()
    {
        contextID = null;
    	elementID = new StringBuffer();
        elementStack = new LinkedList();
    }
    
	/**
	* Preferred constructor performs necessary initialization.
	* Subclassers should override this method.
	*/
    public WOContext (WORequest aRequest)
    {
    	this();
	    request = aRequest;
        response = new WOResponse();
    }
    
	/** 
	* Simply calls the preferred constructor.
	* Included for compatibility.
	*/
    public static WOContext contextWithRequest (WORequest aRequest)
    {
        String id = Integer.toString( contextCounter++ );
    	WOContext result = new WOContext( aRequest );
        result.contextID = id;
        return result;
    }
    
	/** 
	* Returns the context id.
	*/
    public String contextID ()
    {
    	return contextID;
    }
    
	/** 
	* Returns the sender id, or null if it doesn't exist.
	*/
    public String senderID ()
    {
    	return request.senderID();
    }
    
	/** 
	* Returns the element id, or null if it doesn't exist.
	*/
    public String elementID ()
    {
    	return elementID.toString();
    }

	/** 
	* Returns this context's application, or null if it doesn't exist.
	*/
    public WOApplication application ()
    {
    	return request.application();
    }
     
	/** 
    * Returns whether a session has been created for the associated request.
	*/
    public boolean hasSession ()
    {
    	return ( session != null );
    }
    
	/** 
	* Returns this context's session, creating one if it doesn't exist.
	*/
    public WOSession session ()
    {
    	if ( session == null )
	    {
            // so far we can't figure out how the direct action handler can avoid creating a session
            throw new RuntimeException( "WOContext.session: Lazy instantiation not yet implemented." );
/*            
            session = application().restoreSessionWithID( 
                request.sessionID(), this );
            if ( session == null )
            {
                session = application().createSessionForRequest( request );
                session.setContext( this );
            }
*/            
	    }
	    return session;
    }
    
    /**
    * Package access only.
    */
    void setSession( WOSession aSession )
    {
        session = aSession;
    }
    
	/** 
	* Returns this context's request.
	*/
    public WORequest request ()
    {
    	return request;
    }
    
	/** 
	* Returns this context's response.
	*/
    public WOResponse response ()
    {
    	return response;
    }
    
	/** 
	* Returns the current page.
	*/
    public WOComponent page ()
    {
        return (WOComponent) elementStack.get( elementStack.size()-1 );
    }
    
	/** 
	* Returns the current component.
	*/
    public WOComponent component ()
    {
        Object o;
    	Iterator i = elementStack.iterator();
        while ( i.hasNext() )
        {
            o = i.next();
            if ( o instanceof WOComponent ) return (WOComponent) o;
        }
        return null;
    }	

    /**
    * Returns the current component's parent.
    */    
    WOComponent parent ()
    {
        Object o;
    	Iterator i = elementStack.iterator();
        if ( i.hasNext() )
        {
            // skip current component
            o = i.next();
        }
        while ( i.hasNext() )
        {
            o = i.next();
            if ( o instanceof WOComponent ) 
            {
                return (WOComponent) o;
            }
        }
        return null;
    }
    
    /**
    * Pushes an element onto the stack.
    * Package access only.
    */
    void pushElement( WOElement aComponent )
    {
        elementStack.add( 0, aComponent );
    }
    
    /**
    * Pops an element off the stack.
    * Package access only.
    */
    WOElement popElement()
    {
        return (WOElement) elementStack.remove(0);
    }
    
	/** 
	* Returns whether the current context is in a form.
	*/
    public boolean isInForm ()
    {
	    return isInForm;
	}
    
	/** 
	* Sets whether the current context is in a WOForm. 
	*/
    public void setInForm (boolean inForm)
    {
    	isInForm = inForm;
    }
    
	/** 
	* Appends the specified string to the end of the element id.
	* For example, if the element id is "0.1", sending "Test" 
	* changes the element id to "0.1.Test".
	*/
    public void appendElementIDComponent (String aString)
    {
        if ( elementID.length() > 0 )
        {
    	    elementID.append( SEP );
        }
        elementID.append( aString );
    }
    
	/** 
	* Appends a zero to the element id to represent the first
	* new child component.  For example, if the element id is "0.1",
	* calling this changes the element id to "0.1.0".
	*/
    public void appendZeroElementIDComponent ()
    {
        if ( elementID.length() > 0 )
        {
            elementID.append( SEP );
        }
        elementID.append( ZERO );
    }
    
	/** 
	* Increments the last component of the element id.
	* For example, if the element id is "0.1", calling this
	* changes the element id to "0.2".
	*/
    public void incrementLastElementIDComponent ()
    {        
	    String last;
        String id = elementID.toString();
        int index = id.lastIndexOf( SEP );
	    if ( index == -1 )
        {
            last = id;
        }
        else
        {
            last = id.substring( index + 1 );
        }
        
        deleteLastElementIDComponent();
        
        try
        {
            appendElementIDComponent( 
                Integer.toString( Integer.parseInt( last ) + 1 ) );
        }
        catch ( Exception exc )
        {
            System.err.println( "Error parsing id: " + last );
            appendZeroElementIDComponent();
        }
        //System.out.println( "WOContext: " + elementID );        
    }
    
	/** 
	* Deletes the last component of the element id.
	* For example, if the element id is "0.1", callling this
	* changes the element id to "0".
	*/
    public void deleteLastElementIDComponent ()
    {
	    int index = elementID.toString().lastIndexOf( SEP );
	    if ( index == -1 )
        {
            elementID.setLength( 0 );   
        }
        else
        {
            elementID.setLength( index );
        }
    }
    
	/** 
	* Deletes all components of the element id.
	* This makes the element id an empty string.
	*/
    public void deleteAllElementIDComponents ()
    {
    	elementID.setLength( 0 );
    }
    
	/** 
	* Returns a URL for the named action with query parameters
	* as specified by the dictionary.
	*/
    public String directActionURLForActionNamed (
    	String anActionName, Map aQueryDict)
    {
    	StringBuffer query = new StringBuffer();
        
        try
        {
            String key;
            Iterator i = aQueryDict.keySet().iterator();
            while ( i.hasNext() )
            {
                key = i.next().toString();
                query.append( URI.encode( key, 
                    URI.allowed_within_query ) );
                query.append( '=' );
                query.append( URI.encode( aQueryDict.get( key ).toString(), 
                    URI.allowed_within_query ) );
                if ( i.hasNext() )
                {
                    query.append( '&' );
                }
            }
        } 
        catch ( IOException exc )
        {
            // report error
            System.err.println( 
                "directActionURLForActionNamed: " + anActionName + " : " + aQueryDict );
            System.err.println( exc );
            
            // delete query string
            query = new StringBuffer();
        }
        
        return urlWithRequestHandlerKey(
            WOApplication.directActionRequestHandlerKey(), 
            anActionName, query.toString() );
    }
    
	/** 
	* Returns the complete URL for the current component action.
	*/
    public String componentActionURL ()
    {
        StringBuffer buffer = new StringBuffer();
        buffer.append( request().applicationName() );
        buffer.append( '/' );
        buffer.append( WOApplication.application().componentRequestHandlerKey() );
        buffer.append( '/' );
        buffer.append( page().name() );
        buffer.append( '/' );
        buffer.append( contextID );
        buffer.append( '/' );
        buffer.append( elementID );
    	return buffer.toString();
    }
    
	/** 
	* Returns a URL relative to the servlet for the specified 
	* request handler, action, and query string.
	*/
    public String urlWithRequestHandlerKey (
    	String aRequestHandlerKey, String aPath, String aQueryString)
    {
        StringBuffer buffer = new StringBuffer();
        buffer.append( request().applicationName() );
        buffer.append( '/' );
        buffer.append( aRequestHandlerKey );
        buffer.append( '/' );
        buffer.append( aPath );
        if ( aQueryString != null && aQueryString.trim().length() > 0 )
        {
            buffer.append( '?' );
            buffer.append( aQueryString );
        }
    	return buffer.toString();
    }
    
	/** 
	* Returns the complete URL for the specified request handler,
	* path, and query string.  isSecure determines the protocol:
	* http or https.  port is appended to the protocol, if zero,
	* the port is omitted from the URL.
	*/
    public String completeURLWithRequestHandlerKey (     
    	String aRequestHandlerKey, String aPath, String aQueryString,
		boolean isSecure, int port)
    {
    	StringBuffer buffer = new StringBuffer();
        
        if ( isSecure )
        {
            buffer.append( HTTPS );
        }
        else
        {
            buffer.append( HTTP );
        }
        
        buffer.append( request.applicationHost() );
        
        if ( port != 0 && port != 80 )
        {
            buffer.append( ':' );
            buffer.append( Integer.toString( port ) );
        }
        
        buffer.append( urlWithRequestHandlerKey( 
            aRequestHandlerKey, aPath, aQueryString ) );
        
        return buffer.toString();
    }
    
	/** 
	* Sets whether distribution is enabled.
	*/
    public void setDistributionEnabled (boolean distributionEnabled)
    {
    	isDistributionEnabled = distributionEnabled;
    }
    
	/** 
	* Returns whether distribution is enabled.
	*/
    public boolean isDistributionEnabled ()
    {
    	return isDistributionEnabled;
    }
    
	/** 
	* This method is not included in the WOContext specification.
    * This implementation returns "" since only cookie ids are 
    * currently supported.
	*/
    String urlSessionPrefix ()
    {
    	return EMPTY; // "/" + sessionid;
    }
    
	/** 
	* Returns the relative URL for the current page.
	*/
    String url ()
    {
    	throw new RuntimeException( "Not implemented yet." );
    }
    
    public String toString()
    {
        return "[WOContext@"+Integer.toHexString(System.identityHashCode(this))
            +":id=" + contextID +":page=" + page + ":component=" + component + ":element=" + elementID + "]";
    }
}

/*
 * $Log$
 * Revision 1.2  2006/02/19 01:44:02  cgruber
 * Add xmlrpc files
 * Remove jclark and replace with dom4j and javax.xml.sax stuff
 * Re-work dependencies and imports so it all compiles.
 *
 * Revision 1.1  2006/02/16 13:22:22  cgruber
 * Check in all sources in eclipse-friendly maven-enabled packages.
 *
 * Revision 1.19  2003/08/07 00:15:15  chochos
 * general cleanup (mostly removing unused imports)
 *
 * Revision 1.18  2003/02/21 16:40:23  mpowers
 * Now reading port and smtp host from system properties.
 * Implemented WOApplication.main.
 *
 * Revision 1.17  2003/01/24 20:12:54  mpowers
 * Better parent determination.
 *
 * Revision 1.16  2003/01/21 22:27:02  mpowers
 * Corrected context id usage.
 * Implemented backtracking.
 *
 * Revision 1.15  2003/01/17 20:58:19  mpowers
 * Fixed up WOHyperlink.
 *
 * Revision 1.14  2003/01/17 20:34:57  mpowers
 * Better handling for components and parents in the context's element stack.
 *
 * Revision 1.13  2003/01/14 19:48:36  mpowers
 *  - fixes to property synchronization
 *    - forms now pass takeValuesFromRequest to children
 *  - fixes to action invocation
 *    - now supporting multipleSubmit in forms
 *
 * Revision 1.12  2003/01/13 22:24:44  mpowers
 * Request-response cycle is working with session and page persistence.
 *
 * Revision 1.11  2003/01/10 20:17:41  mpowers
 * Component action urls are now working.
 *
 * Revision 1.8  2003/01/09 21:16:48  mpowers
 * Bringing request-response cycle more into conformance.
 *
 * Revision 1.7  2003/01/09 16:13:59  mpowers
 * Implemented WOComponentRequestHandler:
 * Bringing the request-response cycle more into conformance.
 *
 * Revision 1.4  2002/12/20 22:56:33  mpowers
 * Reimplemented the template parsing again.
 * Nested components are now correctly parsed.
 * ElementID numbering is now working.
 *
 * Revision 1.3  2002/12/18 14:12:38  mpowers
 * Support for differentiated request handlers.
 * Support url generation for WOContext and WORequest.
 *
 * Revision 1.2  2002/12/17 14:57:42  mpowers
 * Minor corrections to WORequests's parsing, and updated javadocs.
 *
 * Revision 1.1.1.1  2000/12/21 15:53:04  mpowers
 * Contributing wotonomy.
 *
 * Revision 1.3  2000/12/20 16:25:49  michael
 * Added log to all files.
 *
 *
 */