/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2000 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.execution;

import java.io.*;
import java.net.*;
import java.util.*;

import org.openide.ErrorManager;
import org.openide.util.NbBundle;

/** Stream handler for internal resource-based URLs.
 * @author Jesse Glick
 */
class NbResourceStreamHandler extends URLStreamHandler {

    public static final String PROTOCOL_BOOT_RESOURCE = "nbresboot"; // NOI18N
    public static final String PROTOCOL_CURRENT_RESOURCE = "nbrescurr"; // NOI18N
    public static final String PROTOCOL_LOCALIZED_BOOT_RESOURCE = "nbresbootloc"; // NOI18N
    public static final String PROTOCOL_LOCALIZED_CURRENT_RESOURCE = "nbrescurrloc"; // NOI18N

    public URLConnection openConnection (URL u) throws IOException {
        if (u.getProtocol ().equals (PROTOCOL_BOOT_RESOURCE)) {
            return new Connection (u, 0, false);
        } else if (u.getProtocol ().equals (PROTOCOL_CURRENT_RESOURCE)) {
            return new Connection (u, 2, false);
        } else if (u.getProtocol ().equals (PROTOCOL_LOCALIZED_BOOT_RESOURCE)) {
            return new Connection (u, 0, true);
        } else if (u.getProtocol ().equals (PROTOCOL_LOCALIZED_CURRENT_RESOURCE)) {
            return new Connection (u, 2, true);
        } else {
            throw new IOException (NbBundle.getMessage (NbResourceStreamHandler.class, "EXC_UnrecognizedProtocol"));
        }
    }

    private static class Connection extends URLConnection {

	private final boolean localized;
        private final int current; // 0 = boot, 1 = system, 2 = current

	// A real connection to delegate to. Non-null if successfully connected.
	private URLConnection real;
        
        private IOException exception = null;
        
        private static final Set warnedURLs = new HashSet(); // Set

	public Connection (URL u, int current, boolean localized) {
	    super (u);
	    this.current = current;
	    this.localized = localized;
            if (current == 0 && warnedURLs.add(u.toExternalForm())) {
                ErrorManager.getDefault().log(ErrorManager.WARNING, "Warning: in " + u.toExternalForm() + ", the " + u.getProtocol() + " URL protocol has been deprecated in favor of nbres/nbresloc which is less implementation-dependent.");
            } else if (current == 2 && warnedURLs.add(u.toExternalForm())) {
                ErrorManager.getDefault().log(ErrorManager.WARNING, "Warning: in " + u.toExternalForm() + ", the " + u.getProtocol() + " URL protocol has been deprecated as it assumes Filesystems == classpath.");
            }
	}

	/** Tries to get a URL from this resource from the proper classloader,
	 * localizing first if requested.
	 * Also opens the URL to make a connection; this connection, real,
	 * will be delegated to for all operations.
	 */
	public synchronized void connect () throws IOException {
            if (exception != null) {
                // See tryToConnect().
                IOException e = exception;
                exception = null;
                throw e;
            }
	    if (! connected) {
		String resource = url.getFile ();
		if (resource.startsWith ("/")) resource = resource.substring (1); //NOI18N
		ClassLoader loader;
                switch (current) {
                case 2:
                    throw new IOException("No longer works!"); // NOI18N
                    /*
                    loader = new NbClassLoader();
                    break;
                     */
                case 0:
                    loader = NbResourceStreamHandler.class.getClassLoader ();
                    break;
                default:
                    throw new InternalError ();
                }
		URL target;
		if (localized) {
                    String ext, basename;
		    int index = resource.lastIndexOf ('.');
		    if (index != -1) {
                        ext = resource.substring (index + 1);
                        basename = resource.substring (0, index).replace ('/', '.');
                    } else {
                        ext = null;
                        basename = resource.replace ('/', '.');
                    }
                    try {
                        target = NbBundle.getLocalizedFile (basename, ext, Locale.getDefault (), loader);
                    } catch (MissingResourceException mre) {
                        throw (IOException) ErrorManager.getDefault ().annotate
			    (new IOException (NbBundle.getMessage (NbResourceStreamHandler.class, "EXC_nbres_cannot_connect", url)), mre);
                    }
		} else {
		    target = loader.getResource (resource);
                    if (target == null) throw new IOException
                        (NbBundle.getMessage (NbResourceStreamHandler.class, "EXC_nbres_cannot_connect", url));
		}
		real = target.openConnection ();
                real.connect ();
		connected = true;
	    }
	}
        
        /** Try to connect; but if it does not work, oh well.
         * Ideally this would be quite unnecessary.
         * Unfortunately much code, inclduing the Swing editor kits,
         * gets header fields and so on without ever calling connect().
         * These methods cannot even throw exceptions so it is a mess.
         * E.g. if you display a nbres: URL in the ICE browser, it is fine:
         * it calls connect() according to the specification, then
         * getContentType() produces text/html as expected.
         * But using the SwingBrowser default implementation, it goes
         * ahead and calls getContentType() immediately. So we have
         * to try to connect and get the right content type then too.
         * This complicated the timing of error reporting.
         */
        private void tryToConnect () {
            if (connected || exception != null) return;
            try {
                connect ();
            } catch (IOException ioe) {
                exception = ioe;
            }
        }

	public String getHeaderField (int n) {
            tryToConnect ();
	    if (connected)
		return real.getHeaderField (n);
	    else
		return null;
	}

	public String getHeaderFieldKey (int n) {
            tryToConnect ();
	    if (connected)
		return real.getHeaderFieldKey (n);
	    else
		return null;
	}

	public String getHeaderField (String key) {
            tryToConnect ();
	    if (connected)
		return real.getHeaderField (key);
	    else
		return null;
	}

	public InputStream getInputStream () throws IOException {
            connect ();
            return real.getInputStream ();
	}

	public OutputStream getOutputStream () throws IOException {
            connect ();
            return real.getOutputStream ();
	}
        
        // Should not be required, but they are:
        
        public String getContentType () {
            tryToConnect ();
            if (connected)
                return real.getContentType ();
            else
                return "application/octet-stream"; // NOI18N
        }
        
        public int getContentLength () {
            tryToConnect ();
            if (connected)
                return real.getContentLength ();
            else
                return 0;
        }

	// [PENDING] might be some more methods it would be useful to delegate, possibly

    }

}