/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package jdk.javadoc.internal.doclets.toolkit.util;


import java.util.List;
import java.util.Locale;
import java.util.function.Consumer;

import com.sun.source.doctree.AttributeTree;
import com.sun.source.doctree.DocCommentTree;
import com.sun.source.doctree.DocTree;
import com.sun.source.doctree.DocTree.Kind;
import com.sun.source.doctree.StartElementTree;
import com.sun.source.util.DocTreePath;
import com.sun.source.util.DocTreePathScanner;
import com.sun.source.util.TreePath;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;

/**
 * A DocTree scanner to detect use of JavaScript in a doc comment tree.
 */
public class JavaScriptScanner extends DocTreePathScanner<Void, Consumer<DocTreePath>> {

    public Void scan(DocCommentTree tree, TreePath p, Consumer<DocTreePath> f) {
        return scan(new DocTreePath(p, tree), f);
    }

    @Override @DefinedBy(Api.COMPILER_TREE)
    public Void visitStartElement(StartElementTree tree, Consumer<DocTreePath> f) {
        String name = tree.getName().toString();
        if (name.equalsIgnoreCase("script"))
            f.accept(getCurrentPath());
        return super.visitStartElement(tree, f);
    }

    @Override @DefinedBy(Api.COMPILER_TREE)
    public Void visitAttribute(AttributeTree tree, Consumer<DocTreePath> f) {
        String name = tree.getName().toString().toLowerCase(Locale.ENGLISH);
        switch (name) {
            // See https://www.w3.org/TR/html-markup/global-attributes.html#common.attrs.event-handler
            case "onabort":  case "onblur":  case "oncanplay":  case "oncanplaythrough":
            case "onchange":  case "onclick":  case "oncontextmenu":  case "ondblclick":
            case "ondrag":  case "ondragend":  case "ondragenter":  case "ondragleave":
            case "ondragover":  case "ondragstart":  case "ondrop":  case "ondurationchange":
            case "onemptied":  case "onended":  case "onerror":  case "onfocus":  case "oninput":
            case "oninvalid":  case "onkeydown":  case "onkeypress":  case "onkeyup":
            case "onload":  case "onloadeddata":  case "onloadedmetadata":  case "onloadstart":
            case "onmousedown":  case "onmousemove":  case "onmouseout":  case "onmouseover":
            case "onmouseup":  case "onmousewheel":  case "onpause":  case "onplay":
            case "onplaying":  case "onprogress":  case "onratechange":  case "onreadystatechange":
            case "onreset":  case "onscroll":  case "onseeked":  case "onseeking":
            case "onselect":  case "onshow":  case "onstalled":  case "onsubmit":  case "onsuspend":
            case "ontimeupdate":  case "onvolumechange":  case "onwaiting":

            // See https://www.w3.org/TR/html4/sgml/dtd.html
            // Most of the attributes that take a %Script are also defined as event handlers
            // in HTML 5. The one exception is onunload.
            // case "onchange":  case "onclick":   case "ondblclick":  case "onfocus":
            // case "onkeydown":  case "onkeypress":  case "onkeyup":  case "onload":
            // case "onmousedown":  case "onmousemove":  case "onmouseout":  case "onmouseover":
            // case "onmouseup":  case "onreset":  case "onselect":  case "onsubmit":
            case "onunload":
                f.accept(getCurrentPath());
                break;

            // See https://www.w3.org/TR/html4/sgml/dtd.html
            //     https://www.w3.org/TR/html5/
            // These are all the attributes that take a %URI or a valid URL potentially surrounded
            // by spaces
            case "action":  case "cite":  case "classid":  case "codebase":  case "data":
            case "datasrc":  case "for":  case "href":  case "longdesc":  case "profile":
            case "src":  case "usemap":
                List<? extends DocTree> value = tree.getValue();
                if (!value.isEmpty() && value.get(0).getKind() == Kind.TEXT) {
                    String v = value.get(0).toString().trim().toLowerCase(Locale.ENGLISH);
                    if (v.startsWith("javascript:")) {
                        f.accept(getCurrentPath());
                    }
                }
                break;
        }
        return super.visitAttribute(tree, f);
    }

    /**
     * Used to indicate a fault when parsing, typically used in
     * lambda methods.
     */
    public static class Fault extends RuntimeException {
        private static final long serialVersionUID = 0L;
    }
}