/* A tableau representing an HTML window.

 Copyright (c) 2000-2018 The Regents of the University of California.
 All rights reserved.
 Permission is hereby granted, without written agreement and without
 license or royalty fees, to use, copy, modify, and distribute this
 software and its documentation for any purpose, provided that the above
 copyright notice and the following two paragraphs appear in all copies
 of this software.

 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 ENHANCEMENTS, OR MODIFICATIONS.

 PT_COPYRIGHT_VERSION_2
 COPYRIGHTENDKEY
 */
package ptolemy.actor.gui;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

import ptolemy.kernel.util.Attribute;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.NamedObj;
import ptolemy.kernel.util.Settable;
import ptolemy.kernel.util.StringAttribute;
import ptolemy.util.ClassUtilities;
import ptolemy.util.FileUtilities;
import ptolemy.util.StringUtilities;

///////////////////////////////////////////////////////////////////
//// HTMLViewerTableau

/**
 A tableau representing a rendered HTML view in a toplevel window.
 The URL that is viewed is given by the <i>url</i> parameter, and
 can be either an absolute URL, a system fileName, or a resource that
 can be loaded relative to the classpath.  For more information about how
 the URL is specified, see MoMLApplication.specToURL().
 <p>
 The constructor of this
 class creates the window. The text window itself is an instance
 of HTMLViewer, and can be accessed using the getFrame() method.
 As with other tableaux, this is an entity that is contained by
 an effigy of a model.
 There can be any number of instances of this class in an effigy.

 @author  Steve Neuendorffer and Edward A. Lee
 @version $Id$
 @since Ptolemy II 1.0
 @Pt.ProposedRating Yellow (eal)
 @Pt.AcceptedRating Red (cxh)
 @see Effigy
 @see HTMLViewer
 @see MoMLApplication#specToURL(String)
 */
public class HTMLViewerTableau extends Tableau {
    /** Construct a new tableau for the model represented by the given effigy.
     *  This creates an instance of HTMLViewer.  It does not make the frame
     *  visible.  To do that, call show().
     *  @param container The container.
     *  @param name The name.
     *  @exception IllegalActionException If the container does not accept
     *   this entity (this should not occur).
     *  @exception NameDuplicationException If the name coincides with an
     *   attribute already in the container.
     */
    public HTMLViewerTableau(Effigy container, String name)
            throws IllegalActionException, NameDuplicationException {
        super(container, name);

        url = new StringAttribute(this, "url");
        // Set the tableau so that we can get the Configuration and Kepler icon.
        HTMLViewer frame = new HTMLViewer(this);
        setFrame(frame);
        frame.setTableau(this);

    }

    ///////////////////////////////////////////////////////////////////
    ////                         public parameters                 ////

    /** The URL to display. */
    public StringAttribute url;

    ///////////////////////////////////////////////////////////////////
    ////                         public methods                    ////

    /** If the argument is the <i>url</i> parameter, then open the
     *  specified URL and display its contents.
     *  @param attribute The attribute that changed.
     *  @exception IllegalActionException If the URL cannot be opened,
     *   or if the base class throws it.
     */
    @Override
    public void attributeChanged(Attribute attribute)
            throws IllegalActionException {
        if (attribute == url) {
            String urlSpec = ((Settable) attribute).getExpression();

            try {
                // NOTE: This cannot handle a URL that is relative to the
                // MoML file within which this attribute might be being
                // defined.  Is there any way to do that?
                URL toRead = ConfigurationApplication.specToURL(urlSpec);
                ((HTMLViewer) getFrame()).setPage(toRead);
            } catch (IOException ex) {
                throw new IllegalActionException(this, ex,
                        "Cannot open URL: " + urlSpec);
            }
        } else {
            super.attributeChanged(attribute);
        }
    }

    ///////////////////////////////////////////////////////////////////
    ////                         inner classes                     ////

    /** A factory that creates HTML viewer tableaux for Ptolemy models.
     */
    public static class Factory extends TableauFactory {
        /** Create a factory with the given name and container.
         *  @param container The container.
         *  @param name The name.
         *  @exception IllegalActionException If the container is incompatible
         *   with this attribute.
         *  @exception NameDuplicationException If the name coincides with
         *   an attribute already in the container.
         */
        public Factory(NamedObj container, String name)
                throws IllegalActionException, NameDuplicationException {
            super(container, name);
        }

        ///////////////////////////////////////////////////////////////////
        ////                         public methods                    ////

        /** If the specified effigy already contains a tableau named
         *  "htmlTableau", then return that tableau; otherwise, create
         *  a new instance of HTMLViewerTableau in the specified
         *  effigy, and name it "htmlTableau".  If the specified
         *  effigy is not an instance of HTMLEffigy, then do not
         *  create a tableau and return null.  It is the
         *  responsibility of callers of this method to check the
         *  return value and call show().
         *  <p>If the URL contains $CLASSPATH, then we look in the
         *  classpath for the URL.
         *  @param effigy The effigy.
         *  @return A HTML viewer tableau, or null if one cannot be
         *    found or created.
         *  @exception Exception If the factory should be able to create a
         *   tableau for the effigy, but something goes wrong.
         */
        @Override
        public Tableau createTableau(Effigy effigy) throws Exception {
            if (effigy instanceof HTMLEffigy) {
                // Indicate to the effigy that this factory contains effigies
                // offering multiple views of the effigy data.
                effigy.setTableauFactory(this);

                // First see whether the effigy already contains an
                // HTMLViewerTableau.
                HTMLViewerTableau tableau = (HTMLViewerTableau) effigy
                        .getEntity("htmlTableau");

                if (tableau == null) {
                    tableau = new HTMLViewerTableau(effigy, "htmlTableau");
                }

                // Unfortunately, if we have a jar url, (for example
                // jar:file:/C:/foo.jar!/intro.htm
                // then the java.net.URI toURL() method will return
                // a URL like jar:, which is missing the file: part
                // This breaks Ptolemy II under WebStart.
                URL pageURL = new URL(effigy.uri.getURI().toString());

                try {
                    ((HTMLViewer) tableau.getFrame()).setPage(pageURL);
                } catch (IOException io) {
                    // setPage() throws an IOException if the page can't
                    // be found.  If we are under Web Start, it could be
                    // that we are looking in the wrong Jar file, so
                    // we try again.
                    String urlString = effigy.uri.getURI().toString();
                    URL anotherURL = ClassUtilities
                            .jarURLEntryResource(urlString);

                    if (anotherURL == null && urlString.indexOf("#") != -1) {
                        anotherURL = _entryResourceWithoutFragment(urlString);
                    }

                    if (anotherURL == null) {
                        try {
                            // Search relative to to $PTII in a jar URL
                            anotherURL = _absolutePTIIURLToJarURL(urlString);
                        } catch (Throwable throwable) {
                            // Ignore: failed
                        }
                    }

                    if (anotherURL == null
                            && urlString.indexOf("$CLASSPATH") != -1) {
                        // The URL contains $CLASSPATH
                        String classpathString = urlString
                                .substring(urlString.indexOf("$CLASSPATH"));
                        anotherURL = FileUtilities.nameToURL(classpathString,
                                null, null);
                    }

                    if (anotherURL == null) {
                        IOException io2 = new IOException("---");
                        io2.initCause(io);
                        throw io2;
                    }

                    // Try to set the title bar?
                    try {
                        effigy.uri.setURI(new URI(anotherURL.toString()));
                        tableau.setTitle(anotherURL.toString());
                    } catch (Exception ex) {
                        try {
                            // URI's can't deal with spaces, so we
                            // convert to %20
                            URL canonicalizedURL = JNLPUtilities
                                    .canonicalizeJarURL(anotherURL);
                            effigy.uri.setURI(
                                    new URI(canonicalizedURL.toString()));
                            tableau.setTitle(canonicalizedURL.toString());
                        } catch (Throwable ex2) {
                            throw ex;
                        }
                    }

                    ((HTMLViewer) tableau.getFrame()).setPage(anotherURL);
                }

                // Don't call show() here.  If show() is called here,
                // then you can't set the size of the window after
                // createTableau() returns.  This will affect how
                // centering works.
                return tableau;
            } else {
                return null;
            }
        }
    }

    ///////////////////////////////////////////////////////////////////
    ////                         private methods                   ////

    /** If possible convert an absolute URL that refers to a file inside
     *  the $PTII tree to a jar URL.
     *  <p>For example, if doc/codeDoc.jar is in the classpath, but
     *  the contents of codeDoc/ do not exist as files, then calling
     *  this method with:
     *  file:/C:/ptII/doc/codeDoc/ptolemy/util/package-summary.html#package_description]
     *  will return:
     *  jar:file:/C:/cxh/ptII/doc/codeDoc.jar!/doc/codeDoc/ptolemy/kernel/package-summary.html#package_description

     *
     *  @param urlName The absolute URL to be converted.
     *  @return The jar url that refers to a file if the file can be found
     *  as a resource or null if the file cannot be found.
     *  @exception URISyntaxException If there are problems creating a URI.
     *  @exception MalformedURLException If there are problems creating a URL.
     */
    public static URL _absolutePTIIURLToJarURL(String urlName)
            throws java.net.URISyntaxException, java.net.MalformedURLException {
        // Try looking up the URL as a resource relative to $PTII.
        String ptIIDirAsURLName = StringUtilities
                .getProperty("ptolemy.ptII.dirAsURL");

        // FIXME: This is an ugly hack.
        // If the user has a Windows installation that includes the
        // source jar file, then when they open whatsNew4.0.htm
        // and click on a javadoc link that is in codeDoc.jar but
        // not a separate file, then the file will come up missing
        // because ptolemy.ptII.dirAsURL refers to ptsupport.jar
        // The hack is to strip that out.
        String ptsupportPath = "/ptolemy/ptsupport.jar";

        if (ptIIDirAsURLName.endsWith(ptsupportPath)) {
            ptIIDirAsURLName = ptIIDirAsURLName.substring(0,
                    ptIIDirAsURLName.length() - ptsupportPath.length());
        }

        String relativePath = null;

        if (urlName.startsWith(ptIIDirAsURLName)) {
            relativePath = urlName.substring(ptIIDirAsURLName.length());
        } else {
            // If we click on a link, it might be:
            // "file:/C:/ptII/doc/codeDoc/"
            // but ptolemy.ptII.dirAsURL might be
            // "file:/c:/ptII"
            // URL.sameFile() will not work here, so we use URI.relativize()
            URI uri = new URI(urlName);
            URI ptIIDirAsURI;

            try {
                ptIIDirAsURI = new URI(ptIIDirAsURLName);
            } catch (java.net.URISyntaxException ex) {
                // If the ptIIDirAsURLName has a space in it, then it is
                // not a legitimate URI, so we substitute in %20
                ptIIDirAsURI = new URI(StringUtilities
                        .substitute(ptIIDirAsURLName, " ", "%20"));
            }

            URI relativeURI = uri.relativize(ptIIDirAsURI);

            if (relativeURI.toURL().sameFile(ptIIDirAsURI.toURL())) {
                int offset = 0;

                if (urlName.startsWith("jar:")) {
                    offset = 4;
                }

                // Hmm, should this be
                relativePath = uri.toString()
                        .substring(ptIIDirAsURI.toString().length() + offset);

                //relativePath = urlName.substring(ptIIDirAsURLName.length());
            }
        }

        if (relativePath == null) {
            return null;
        } else {
            if (relativePath.startsWith("/")) {
                relativePath = relativePath.substring(1);
            }

            URL anotherURL = ClassUtilities.getResource(relativePath);

            if (anotherURL == null && relativePath.indexOf('#') != -1) {
                // getResource does not work on paths that look like:
                // "package-summary.html#package_description"
                // So, we get the resource without the
                // trailing # and then append it
                try {
                    anotherURL = _entryResourceWithoutFragment(relativePath);
                } catch (IOException ex) {
                    // Ignored
                }
            }

            return anotherURL;
        }
    }

    // Given a string that contains a URL that has a # character signifiying
    // a fragment, strip the fragment off and look up the URL as a resource.
    // getResource() does not work on paths that look like:
    // "package-summary.html#package_description"
    // So, we get the resource without the
    // trailing # and then append it.  If the resource cannot be found,
    // we return null
    // @param urlString A string representing a jar URL or a relative URL.
    private static URL _entryResourceWithoutFragment(String urlString)
            throws IOException, MalformedURLException {
        String urlStringBase = urlString.substring(0,
                urlString.lastIndexOf("#"));

        URL anotherURL = null;

        if (urlStringBase.startsWith("jar:")) {
            anotherURL = ClassUtilities.jarURLEntryResource(urlStringBase);
        } else {
            anotherURL = ClassUtilities.getResource(urlStringBase);
        }

        if (anotherURL != null) {
            anotherURL = new URL(anotherURL.toString()
                    + urlString.substring(urlString.lastIndexOf("#")));
        }

        return anotherURL;
    }
}