/*

 * Copyright (c) 2012, 2013, 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 com.sun.tools.doclint;

import java.util.Set;

import java.util.LinkedHashSet;

import javax.lang.model.element.Element;

import javax.lang.model.element.ElementKind;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.Modifier;

import javax.lang.model.type.TypeMirror;

import javax.lang.model.util.Elements;

import javax.lang.model.util.Types;

import com.sun.source.doctree.DocCommentTree;

import com.sun.source.util.DocTrees;

import com.sun.source.util.JavacTask;

import com.sun.source.util.SourcePositions;

import com.sun.source.util.TreePath;

import com.sun.tools.javac.model.JavacTypes;

import com.sun.tools.javac.tree.JCTree;

import com.sun.tools.javac.util.StringUtils;

/**

 * Utility container for current execution environment,

 * providing the current declaration and its doc comment.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own

 * risk.  This code and its internal interfaces are subject to change

 * or deletion without notice.</b></p>

 */

public class Env {

    /**

     * Access kinds for declarations.

     */

    public enum AccessKind {

        PRIVATE,

        PACKAGE,

        PROTECTED,

        PUBLIC;

        static boolean accepts(String opt) {

            for (AccessKind g: values())

                if (opt.equals(StringUtils.toLowerCase(g.name()))) return true;

            return false;

        }

        static AccessKind of(Set<Modifier> mods) {

            if (mods.contains(Modifier.PUBLIC))

                return AccessKind.PUBLIC;

            else if (mods.contains(Modifier.PROTECTED))

                return AccessKind.PROTECTED;

            else if (mods.contains(Modifier.PRIVATE))

                return AccessKind.PRIVATE;

            else

                return AccessKind.PACKAGE;

        }

    /** Message handler. */

    final Messages messages;

    int implicitHeaderLevel = 0;

    Set<String> customTags;

    // Utility classes

    DocTrees trees;

    Elements elements;

    Types types;

    // Types used when analysing doc comments.

    TypeMirror java_lang_Error;

    TypeMirror java_lang_RuntimeException;

    TypeMirror java_lang_Throwable;

    TypeMirror java_lang_Void;

    /** The path for the declaration containing the comment currently being analyzed. */

    TreePath currPath;

    /** The element for the declaration containing the comment currently being analyzed. */

    Element currElement;

    /** The comment current being analyzed. */

    DocCommentTree currDocComment;

    /**

     * The access kind of the declaration containing the comment currently being analyzed.

     * This is the minimum (most restrictive) access kind of the declaration itself

     * and that of its containers. For example, a public method in a private class is

     * noted as private.

     */

    AccessKind currAccess;

    /** The set of methods, if any, that the current declaration overrides. */

    Set<? extends ExecutableElement> currOverriddenMethods;

    Env() {

        messages = new Messages(this);

    }

    void init(JavacTask task) {

        init(DocTrees.instance(task), task.getElements(), task.getTypes());

    }

    void init(DocTrees trees, Elements elements, Types types) {

        this.trees = trees;

        this.elements = elements;

        this.types = types;

        java_lang_Error = elements.getTypeElement("java.lang.Error").asType();

        java_lang_RuntimeException = elements.getTypeElement("java.lang.RuntimeException").asType();

        java_lang_Throwable = elements.getTypeElement("java.lang.Throwable").asType();

        java_lang_Void = elements.getTypeElement("java.lang.Void").asType();

    }

    void setImplicitHeaders(int n) {

        implicitHeaderLevel = n;

    }

    void setCustomTags(String cTags) {

        for (String s : cTags.split(DocLint.TAGS_SEPARATOR)) {

            if (!s.isEmpty())

                customTags.add(s);

        }

    }

    /** Set the current declaration and its doc comment. */

    void setCurrent(TreePath path, DocCommentTree comment) {

        currPath = path;

        currDocComment = comment;

        currElement = trees.getElement(currPath);

        currOverriddenMethods = ((JavacTypes) types).getOverriddenMethods(currElement);

        AccessKind ak = AccessKind.PUBLIC;

        for (TreePath p = path; p != null; p = p.getParentPath()) {

            Element e = trees.getElement(p);

            if (e != null && e.getKind() != ElementKind.PACKAGE) {

                ak = min(ak, AccessKind.of(e.getModifiers()));

            }

        }

        currAccess = ak;

    }

    AccessKind getAccessKind() {

        return currAccess;

    }

    long getPos(TreePath p) {

        return ((JCTree) p.getLeaf()).pos;

    }

    long getStartPos(TreePath p) {

        SourcePositions sp = trees.getSourcePositions();

        return sp.getStartPosition(p.getCompilationUnit(), p.getLeaf());

    }

    private <T extends Comparable<T>> T min(T item1, T item2) {

        return (item1 == null) ? item2

                : (item2 == null) ? item1

                : item1.compareTo(item2) <= 0 ? item1 : item2;

    }

}