/*
 * Copyright (c) 2015, 2019, 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.
 */

 A utility class.
 
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.
/**
 *  A utility class.
 *
 *  <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>
 */

package jdk.javadoc.internal.doclets.toolkit;

import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.Name;
import javax.lang.model.element.PackageElement;
import javax.lang.model.element.RecordComponentElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.util.Elements;
import javax.tools.FileObject;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;

import com.sun.source.doctree.AttributeTree;
import com.sun.source.doctree.DocCommentTree;
import com.sun.source.doctree.DocTree;
import com.sun.source.doctree.IdentifierTree;
import com.sun.source.doctree.ParamTree;
import com.sun.source.doctree.ReferenceTree;
import com.sun.source.doctree.TextTree;
import com.sun.source.util.DocTreeFactory;
import com.sun.source.util.DocTreePath;
import com.sun.source.util.DocTrees;
import com.sun.source.util.TreePath;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
import jdk.javadoc.internal.doclets.toolkit.util.Utils;

public class CommentUtils {

    final BaseConfiguration configuration;
    final Utils utils;
    final Resources resources;
    final DocTreeFactory treeFactory;
    final HashMap<Element, DocCommentDuo> dcTreesMap = new HashMap<>();
    final DocTrees trees;
    final Elements elementUtils;

    protected CommentUtils(BaseConfiguration configuration) {
        this.configuration = configuration;
        utils = configuration.utils;
        resources = configuration.getResources();
        trees = configuration.docEnv.getDocTrees();
        treeFactory = trees.getDocTreeFactory();
        elementUtils = configuration.docEnv.getElementUtils();
    }

    public List<? extends DocTree> makePropertyDescriptionTree(List<? extends DocTree> content) {
        List<DocTree> out = new ArrayList<>();
        Name name = elementUtils.getName("propertyDescription");
        out.add(treeFactory.newUnknownBlockTagTree(name, content));
        return out;
    }

    public List<? extends DocTree> makePropertyDescriptionTree(String content) {
        List<DocTree> inlist = new ArrayList<>();
        inlist.add(treeFactory.newCommentTree(content));
        List<DocTree> out = new ArrayList<>();
        Name name = elementUtils.getName("propertyDescription");
        out.add(treeFactory.newUnknownBlockTagTree(name, inlist));
        return out;
    }

    public List<? extends DocTree> makeFirstSentenceTree(String content) {
        List<DocTree> out = new ArrayList<>();
        out.add(treeFactory.newTextTree(content));
        return out;
    }

    public DocTree makeSeeTree(String sig, Element e) {
        List<DocTree> list = new ArrayList<>();
        list.add(treeFactory.newReferenceTree(sig));
        return treeFactory.newSeeTree(list);
    }

    public TextTree makeTextTree(String content) {
        return treeFactory.newTextTree(content);
    }

    public TextTree makeTextTreeForResource(String key) {
        return treeFactory.newTextTree(resources.getText(key));
    }

    public void setEnumValuesTree(ExecutableElement ee) {
        List<DocTree> fullBody = new ArrayList<>();
        fullBody.add(treeFactory.newTextTree(resources.getText("doclet.enum_values_doc.fullbody")));

        List<DocTree> descriptions = new ArrayList<>();
        descriptions.add(treeFactory.newTextTree(resources.getText("doclet.enum_values_doc.return")));

        List<DocTree> tags = new ArrayList<>();
        tags.add(treeFactory.newReturnTree(descriptions));
        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, tags);
        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    public void setEnumValueOfTree(ExecutableElement ee) {
        List<DocTree> fullBody = new ArrayList<>();
        fullBody.add(treeFactory.newTextTree(resources.getText("doclet.enum_valueof_doc.fullbody")));

        List<DocTree> tags = new ArrayList<>();

        List<DocTree> paramDescs = new ArrayList<>();
        paramDescs.add(treeFactory.newTextTree(resources.getText("doclet.enum_valueof_doc.param_name")));
        java.util.List<? extends VariableElement> parameters = ee.getParameters();
        VariableElement param = parameters.get(0);
        IdentifierTree id = treeFactory.newIdentifierTree(elementUtils.getName(param.getSimpleName().toString()));
        tags.add(treeFactory.newParamTree(false, id, paramDescs));

        List<DocTree> returnDescs = new ArrayList<>();
        returnDescs.add(treeFactory.newTextTree(resources.getText("doclet.enum_valueof_doc.return")));
        tags.add(treeFactory.newReturnTree(returnDescs));

        List<DocTree> throwsDescs = new ArrayList<>();
        throwsDescs.add(treeFactory.newTextTree(resources.getText("doclet.enum_valueof_doc.throws_ila")));

        ReferenceTree ref = treeFactory.newReferenceTree("java.lang.IllegalArgumentException");
        tags.add(treeFactory.newThrowsTree(ref, throwsDescs));

        throwsDescs = new ArrayList<>();
        throwsDescs.add(treeFactory.newTextTree(resources.getText("doclet.enum_valueof_doc.throws_npe")));

        ref = treeFactory.newReferenceTree("java.lang.NullPointerException");
        tags.add(treeFactory.newThrowsTree(ref, throwsDescs));

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, tags);

        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    
Generates the description for the canonical constructor for a record.
Params:
ee – the constructor/**
     * Generates the description for the canonical constructor for a record.
     * @param ee the constructor
     */
    public void setRecordConstructorTree(ExecutableElement ee) {
        TypeElement te = utils.getEnclosingTypeElement(ee);

        List<DocTree> fullBody =
                makeDescriptionWithName("doclet.record_constructor_doc.fullbody", te.getSimpleName());

        List<DocTree> tags = new ArrayList<>();
        java.util.List<? extends VariableElement> parameters = ee.getParameters();
        for (VariableElement param : ee.getParameters()) {
            Name name = param.getSimpleName();
            IdentifierTree id = treeFactory.newIdentifierTree(name);
            tags.add(treeFactory.newParamTree(false, id,
                    makeDescriptionWithComponent("doclet.record_constructor_doc.param_name", te, name)));
        }

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, tags);
        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    
Generates the description for the standard equals method for a record. 
Params:
ee – the equals method/**
     * Generates the description for the standard {@code equals} method for a record.
     * @param ee the {@code equals} method
     */
    @SuppressWarnings("preview")
    public void setRecordEqualsTree(ExecutableElement ee) {
        List<DocTree> fullBody = new ArrayList<>();
        add(fullBody, "doclet.record_equals_doc.fullbody.head");
        fullBody.add(treeFactory.newTextTree(" "));

        List<? extends RecordComponentElement> comps = ((TypeElement) ee.getEnclosingElement()).getRecordComponents();
        boolean hasPrimitiveComponents =
                comps.stream().anyMatch(e -> e.asType().getKind().isPrimitive());
        boolean hasReferenceComponents =
                comps.stream().anyMatch(e -> !e.asType().getKind().isPrimitive());
        if (hasPrimitiveComponents && hasReferenceComponents) {
            add(fullBody, "doclet.record_equals_doc.fullbody.tail.both");
        } else if (hasPrimitiveComponents) {
            add(fullBody, "doclet.record_equals_doc.fullbody.tail.primitive");
        } else if (hasReferenceComponents) {
            add(fullBody, "doclet.record_equals_doc.fullbody.tail.reference");
        }
        Name paramName = ee.getParameters().get(0).getSimpleName();
        IdentifierTree id = treeFactory.newIdentifierTree(paramName);
        List<DocTree> paramDesc =
                makeDescriptionWithName("doclet.record_equals_doc.param_name", paramName);
        DocTree paramTree = treeFactory.newParamTree(false, id, paramDesc);

        DocTree returnTree = treeFactory.newReturnTree(
                makeDescriptionWithName("doclet.record_equals_doc.return", paramName));

        TreePath treePath = utils.getTreePath(ee.getEnclosingElement());
        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, List.of(paramTree, returnTree));
        dcTreesMap.put(ee, new DocCommentDuo(treePath, docTree));
    }

    private void add(List<DocTree> contents, String resourceKey) {
        // Special case to allow '{@link ...}' to appear in the string.
        // A less general case would be to detect literal use of Object.equals
        // A more general case would be to allow access to DocCommentParser somehow
        String body = resources.getText(resourceKey);
        Pattern p = Pattern.compile("\\{@link (\\S*)(.*)}");
        Matcher m = p.matcher(body);
        int start = 0;
        while (m.find(start)) {
            if (m.start() > start) {
                contents.add(treeFactory.newTextTree(body.substring(start, m.start())));
            }
            ReferenceTree refTree = treeFactory.newReferenceTree(m.group(1));
            List<DocTree> descr = List.of(treeFactory.newTextTree(m.group(2).trim())) ;
            contents.add(treeFactory.newLinkTree(refTree, descr));
            start = m.end();
        }
        if (start < body.length()) {
            contents.add(treeFactory.newTextTree(body.substring(start)));
        }
    }

    
Generates the description for the standard hashCode method for a record. 
Params:
ee – the hashCode method/**
     * Generates the description for the standard {@code hashCode} method for a record.
     * @param ee the {@code hashCode} method
     */
    public void setRecordHashCodeTree(ExecutableElement ee) {
        List<DocTree> fullBody = List.of(makeTextTreeForResource("doclet.record_hashCode_doc.fullbody"));

        DocTree returnTree = treeFactory.newReturnTree(
                List.of(makeTextTreeForResource("doclet.record_hashCode_doc.return")));

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, List.of(returnTree));
        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    
Generates the description for the standard toString method for a record. 
Params:
ee – the toString method/**
     * Generates the description for the standard {@code toString} method for a record.
     * @param ee the {@code toString} method
     */
    public void setRecordToStringTree(ExecutableElement ee) {
        List<DocTree> fullBody = List.of(
                treeFactory.newTextTree(resources.getText("doclet.record_toString_doc.fullbody")));

        DocTree returnTree = treeFactory.newReturnTree(List.of(
                treeFactory.newTextTree(resources.getText("doclet.record_toString_doc.return"))));

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, List.of(returnTree));
        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    
Generates the description for the accessor method for a state component of a record.
Params:
ee – the accessor method/**
     * Generates the description for the accessor method for a state component of a record.
     * @param ee the accessor method
     */
    public void setRecordAccessorTree(ExecutableElement ee) {
        TypeElement te = utils.getEnclosingTypeElement(ee);

        List<DocTree> fullBody =
                makeDescriptionWithComponent("doclet.record_accessor_doc.fullbody", te, ee.getSimpleName());

        DocTree returnTree = treeFactory.newReturnTree(
                    makeDescriptionWithComponent("doclet.record_accessor_doc.return", te, ee.getSimpleName()));

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, List.of(returnTree));
        dcTreesMap.put(ee, new DocCommentDuo(null, docTree));
    }

    
Generates the description for the field for a state component of a record.
Params:
ve – the field/**
     * Generates the description for the field for a state component of a record.
     * @param ve the field
     */
    public void setRecordFieldTree(VariableElement ve) {
        TypeElement te = utils.getEnclosingTypeElement(ve);

        List<DocTree> fullBody =
            makeDescriptionWithComponent("doclet.record_field_doc.fullbody", te, ve.getSimpleName());

        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, List.of());
        dcTreesMap.put(ve, new DocCommentDuo(null, docTree));
    }

    
Creates a description that contains a reference to a state component of a record. The description is looked up as a resource, and should contain {0} where the reference to the component is to be inserted. The reference will be a link if the doc comment for the record has a @param tag for the component. 
Params:
key – the resource key for the description
elem – the record element
component – the name of the component
Returns:
the description/**
     * Creates a description that contains a reference to a state component of a record.
     * The description is looked up as a resource, and should contain {@code {0}} where the
     * reference to the component is to be inserted. The reference will be a link if the
     * doc comment for the record has a {@code @param} tag for the component.
     * @param key the resource key for the description
     * @param elem the record element
     * @param component the name of the component
     * @return the description
     */
    private List<DocTree> makeDescriptionWithComponent(String key, TypeElement elem, Name component) {
        List<DocTree> result = new ArrayList<>();
        String text = resources.getText(key);
        int index = text.indexOf("{0}");
        result.add(treeFactory.newTextTree(text.substring(0, index)));
        Name A = elementUtils.getName("a");
        Name CODE = elementUtils.getName("code");
        Name HREF = elementUtils.getName("href");
        List<DocTree> code = List.of(
                treeFactory.newStartElementTree(CODE, List.of(), false),
                treeFactory.newTextTree(component.toString()),
                treeFactory.newEndElementTree(CODE));
        if (hasParamForComponent(elem, component)) {
            DocTree href = treeFactory.newAttributeTree(HREF,
                    AttributeTree.ValueKind.DOUBLE,
                    List.of(treeFactory.newTextTree("#param-" + component)));
            result.add(treeFactory.newStartElementTree(A, List.of(href), false));
            result.addAll(code);
            result.add(treeFactory.newEndElementTree(A));
        } else {
            result.addAll(code);
        }
        result.add(treeFactory.newTextTree(text.substring(index + 3)));
        return result;
    }

    
Returns whether or not the doc comment for a record contains an @param} for a state component of the record. 
Params:
elem – the record element
component – the name of the component
Returns:
whether or not there is a @param} for the component/**
     * Returns whether or not the doc comment for a record contains an {@code @param}}
     * for a state component of the record.
     * @param elem the record element
     * @param component the name of the component
     * @return whether or not there is a {@code @param}} for the component
     */
    private boolean hasParamForComponent(TypeElement elem, Name component) {
        DocCommentTree elemComment = utils.getDocCommentTree(elem);
        if (elemComment == null) {
            return false;
        }

        for (DocTree t : elemComment.getBlockTags()) {
            if (t instanceof ParamTree && ((ParamTree) t).getName().getName() == component) {
                return true;
            }
        }

        return false;
    }

    
Creates a description that contains the simple name of a program element The description is looked up as a resource, and should contain {0} where the name is to be inserted. 
Params:
key – the resource key for the description
name – the name
Returns:
the description/**
     * Creates a description that contains the simple name of a program element
     * The description is looked up as a resource, and should contain {@code {0}} where the
     * name is to be inserted.
     * @param key the resource key for the description
     * @param name the name
     * @return the description
     */
    private List<DocTree> makeDescriptionWithName(String key, Name name) {
        String text = resources.getText(key);
        int index = text.indexOf("{0}");
        if (index == -1) {
            return List.of(treeFactory.newTextTree(text));
        } else {
            Name CODE = elementUtils.getName("code");
            return List.of(
                    treeFactory.newTextTree(text.substring(0, index)),
                    treeFactory.newStartElementTree(CODE, List.of(), false),
                    treeFactory.newTextTree(name.toString()),
                    treeFactory.newEndElementTree(CODE),
                    treeFactory.newTextTree(text.substring(index + 3))
            );
        }
    }

    /*
     * Returns the TreePath/DocCommentTree duo for synthesized element.
     */
    public DocCommentDuo getSyntheticCommentDuo(Element e) {
        return dcTreesMap.get(e);
    }

    /*
     * Returns the TreePath/DocCommentTree duo for html sources.
     */
    public DocCommentDuo getHtmlCommentDuo(Element e) {
        FileObject fo = null;
        PackageElement pe = null;
        switch (e.getKind()) {
            case OTHER:
                if (e instanceof DocletElement) {
                    DocletElement de = (DocletElement)e;
                    fo = de.getFileObject();
                    pe = de.getPackageElement();
                }
                break;
            case PACKAGE:
                fo = configuration.workArounds.getJavaFileObject((PackageElement)e);
                pe = (PackageElement)e;
                break;
            default:
                return null;
        }
        if (fo == null) {
            return null;
        }

        DocCommentTree dcTree = trees.getDocCommentTree(fo);
        if (dcTree == null) {
            return null;
        }
        DocTreePath treePath = trees.getDocTreePath(fo, pe);
        return new DocCommentDuo(treePath.getTreePath(), dcTree);
    }

    public DocCommentTree parse(URI uri, String text) {
        return trees.getDocCommentTree(new SimpleJavaFileObject(
                uri, JavaFileObject.Kind.SOURCE) {
            @Override @DefinedBy(Api.COMPILER)
            public CharSequence getCharContent(boolean ignoreEncoding) {
                return text;
            }
        });
    }

    public void setDocCommentTree(Element element, List<? extends DocTree> fullBody,
                                  List<? extends DocTree> blockTags) {
        DocCommentTree docTree = treeFactory.newDocCommentTree(fullBody, blockTags);
        dcTreesMap.put(element, new DocCommentDuo(null, docTree));
        // A method having null comment (no comment) that might need to be replaced
        // with a synthetic comment, remove such a comment from the cache.
        utils.removeCommentHelper(element);
    }

    
A simplistic container to transport a TreePath, DocCommentTree pair.
Here is why we need this:
a. not desirable to add javac's pair.
b. DocTreePath is not a viable  option either, as a null TreePath is required
to represent synthetic comments for Enum.values, valuesOf, javafx properties.
/**
     * A simplistic container to transport a TreePath, DocCommentTree pair.
     * Here is why we need this:
     * a. not desirable to add javac's pair.
     * b. DocTreePath is not a viable  option either, as a null TreePath is required
     * to represent synthetic comments for Enum.values, valuesOf, javafx properties.
     */
    public static class DocCommentDuo {
        public final TreePath treePath;
        public final DocCommentTree dcTree;

        public DocCommentDuo(TreePath treePath, DocCommentTree dcTree) {
            this.treePath = treePath;
            this.dcTree = dcTree;
        }
    }
}