/*
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.
 *
 *
 */