/*

 * Copyright (c) 2003, 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.*;

import javax.lang.model.element.Element;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.TypeElement;

import javax.lang.model.type.TypeMirror;

import com.sun.source.doctree.DocTree;

import jdk.javadoc.internal.doclets.toolkit.Configuration;

import jdk.javadoc.internal.doclets.toolkit.taglets.InheritableTaglet;

/**

 * Search for the requested documentation.  Inherit documentation if necessary.

 *

 *  <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>

 *

 * @author Jamie Ho

 */

public class DocFinder {

    public static final class DocTreeInfo {

        public final DocTree docTree;

        public final Element element;

        public DocTreeInfo() {

            this.docTree = null;

            this.element = null;

        }

        public DocTreeInfo(DocTree docTree, Element baseElement) {

            this.docTree = docTree;

            this.element = baseElement;

        }

        @Override

        public String toString() {

            return "DocTreeInfo{" + "docTree=" + docTree + ", element=" + element + '}';

        }

    }

    /**

     * The class that encapsulates the input.

     */

    public static class Input {

        /**

         * The element to search documentation from.

         */

        public Element element;

        /**

         * The taglet to search for documentation on behalf of. Null if we want

         * to search for overall documentation.

         */

        public InheritableTaglet taglet = null;

        /**

         * The id of the tag to retrieve documentation for.

         */

        public String tagId = null;

        /**

         * The tag to retrieve documentation for.  This is only used for the

         * inheritDoc tag.

         */

        public final DocTreeInfo docTreeInfo;

        /**

         * True if we only want to search for the first sentence.

         */

        public boolean isFirstSentence = false;

        /**

         * True if we are looking for documentation to replace the inheritDocTag.

         */

        public boolean isInheritDocTag = false;

        /**

         * Used to distinguish between type variable param tags and regular

         * param tags.

         */

        public boolean isTypeVariableParamTag = false;

        public final Utils utils;

        public Input(Utils utils, Element element, InheritableTaglet taglet, DocTreeInfo dtInfo,

                boolean isFirstSentence, boolean isInheritDocTag) {

            this.utils = utils;

            this.element = element;

            this.taglet = taglet;

            this.isFirstSentence = isFirstSentence;

            this.isInheritDocTag = isInheritDocTag;

            this.docTreeInfo = dtInfo;

        }

        public Input(Utils utils, Element element, InheritableTaglet taglet, String tagId) {

            this(utils, element);

            this.taglet = taglet;

            this.tagId = tagId;

        }

        public Input(Utils utils, Element element, InheritableTaglet taglet, String tagId,

            boolean isTypeVariableParamTag) {

            this(utils, element);

            this.taglet = taglet;

            this.tagId = tagId;

            this.isTypeVariableParamTag = isTypeVariableParamTag;

        }

        public Input(Utils utils, Element element, InheritableTaglet taglet) {

            this(utils, element);

            this.taglet = taglet;

        }

        public Input(Utils utils, Element element) {

            if (element == null)

                throw new NullPointerException();

            this.element = element;

            this.utils = utils;

            this.docTreeInfo = new DocTreeInfo();

        }

        public Input(Utils utils, Element element, boolean isFirstSentence) {

            this(utils, element);

            this.isFirstSentence = isFirstSentence;

        }

        public Input copy(Utils utils) {

            if (this.element == null) {

                throw new NullPointerException();

            }

            Input clone = new Input(utils, this.element, this.taglet, this.docTreeInfo,

                    this.isFirstSentence, this.isInheritDocTag);

            clone.tagId = this.tagId;

            clone.isTypeVariableParamTag = this.isTypeVariableParamTag;

            return clone;

        }

        /**

         * For debugging purposes

         * @return string representation

         */

        @Override

        public String toString() {

            String encl = element == null ? "" : element.getEnclosingElement().toString() + "::";

            return "Input{" + "element=" + encl + element

                    + ", taglet=" + taglet

                    + ", tagId=" + tagId + ", tag=" + docTreeInfo

                    + ", isFirstSentence=" + isFirstSentence

                    + ", isInheritDocTag=" + isInheritDocTag

                    + ", isTypeVariableParamTag=" + isTypeVariableParamTag

                    + ", utils=" + utils + '}';

        }

    }

    /**

     * The class that encapsulates the output.

     */

    public static class Output {

        /**

         * The tag that holds the documentation.  Null if documentation

         * is not held by a tag.

         */

        public DocTree holderTag;

        /**

         * The Doc object that holds the documentation.

         */

        public Element holder;

        /**

         * The inherited documentation.

         */

        public List<? extends DocTree> inlineTags = Collections.emptyList();

        /**

         * False if documentation could not be inherited.

         */

        public boolean isValidInheritDocTag = true;

        /**

         * When automatically inheriting throws tags, you sometime must inherit

         * more than one tag.  For example if the element declares that it throws

         * IOException and the overridden element has throws tags for IOException and

         * ZipException, both tags would be inherited because ZipException is a

         * subclass of IOException.  This subclass of DocFinder.Output allows

         * multiple tag inheritence.

         */

        public List<DocTree> tagList  = new ArrayList<>();

        /**

         * Returns a string representation for debugging purposes

         * @return string

         */

        @Override

        public String toString() {

            String encl = holder == null ? "" : holder.getEnclosingElement().toString() + "::";

            return "Output{" + "holderTag=" + holderTag

                    + ", holder=" + encl + holder

                    + ", inlineTags=" + inlineTags

                    + ", isValidInheritDocTag=" + isValidInheritDocTag

                    + ", tagList=" + tagList + '}';

        }

    }

    /**

     * Search for the requested comments in the given element.  If it does not

     * have comments, return documentation from the overridden element if possible.

     * If the overridden element does not exist or does not have documentation to

     * inherit, search for documentation to inherit from implemented methods.

     *

     * @param input the input object used to perform the search.

     *

     * @return an Output object representing the documentation that was found.

     */

    public static Output search(Configuration configuration, Input input) {

        Output output = new Output();

        Utils utils = configuration.utils;

        if (input.isInheritDocTag) {

            //Do nothing because "element" does not have any documentation.

            //All it has is {@inheritDoc}.

        } else if (input.taglet == null) {

            //We want overall documentation.

            output.inlineTags = input.isFirstSentence

                    ? utils.getFirstSentenceTrees(input.element)

            output.holder = input.element;

        } else {

            input.taglet.inherit(input, output);

        }

        if (output.inlineTags != null && !output.inlineTags.isEmpty()) {

            return output;

        }

        output.isValidInheritDocTag = false;

        Input inheritedSearchInput = input.copy(configuration.utils);

        inheritedSearchInput.isInheritDocTag = false;

        if (utils.isMethod(input.element)) {

            ExecutableElement overriddenMethod = utils.overriddenMethod((ExecutableElement) input.element);

            if (overriddenMethod != null) {

                inheritedSearchInput.element = overriddenMethod;

                output = search(configuration, inheritedSearchInput);

                output.isValidInheritDocTag = true;

                if (!output.inlineTags.isEmpty()) {

                    return output;

                }

            }

            //NOTE:  When we fix the bug where ClassDoc.interfaceTypes() does

            //       not pass all implemented interfaces, we will use the

            //       appropriate element here.

            ImplementedMethods implMethods

                    = new ImplementedMethods((ExecutableElement) input.element, configuration);

            List<ExecutableElement> implementedMethods = implMethods.build();

            for (ExecutableElement implementedMethod : implementedMethods) {

                inheritedSearchInput.element = implementedMethod;

                output = search(configuration, inheritedSearchInput);

                output.isValidInheritDocTag = true;

                if (!output.inlineTags.isEmpty()) {

                    return output;

                }

            }

        } else if (utils.isTypeElement(input.element)) {

            TypeMirror t = ((TypeElement) input.element).getSuperclass();

            Element superclass = utils.asTypeElement(t);

            if (superclass != null) {

                inheritedSearchInput.element = superclass;

                output = search(configuration, inheritedSearchInput);

                output.isValidInheritDocTag = true;

                if (!output.inlineTags.isEmpty()) {

                    return output;

                }

            }

        }

        return output;

    }

}