/*
 * Copyright (c) 2015, 2020, 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.Objects;
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 DocTrees trees;
    final Elements elementUtils;

    
A map for storing automatically generated comments for various
elements, such as mandated elements (Enum.values, Enum.valueOf, etc)
and JavaFX properties.
See Also:
dcTreeCache.dcTreeCache/**
     * A map for storing automatically generated comments for various
     * elements, such as mandated elements (Enum.values, Enum.valueOf, etc)
     * and JavaFX properties.
     *
     * @see Utils#dcTreeCache
     */
    final HashMap<Element, DocCommentInfo> dcInfoMap = new HashMap<>();

    protected CommentUtils(BaseConfiguration configuration) {
        this.configuration = configuration;
        utils = configuration.utils;
        resources = configuration.getDocResources();
        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);
        dcInfoMap.put(ee, new DocCommentInfo(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);

        dcInfoMap.put(ee, new DocCommentInfo(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);
        dcInfoMap.put(ee, new DocCommentInfo(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));
        dcInfoMap.put(ee, new DocCommentInfo(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));
        dcInfoMap.put(ee, new DocCommentInfo(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));
        dcInfoMap.put(ee, new DocCommentInfo(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));
        dcInfoMap.put(ee, new DocCommentInfo(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());
        dcInfoMap.put(ve, new DocCommentInfo(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 info that has been generated for an element.
     * @param e the element
     * @return the info object containing the tree path and doc comment
     */
    // "synthetic" is not the best word here, and should not be confused with synthetic elements
    public DocCommentInfo getSyntheticCommentInfo(Element e) {
        return dcInfoMap.get(e);
    }

    /*
     * Returns the TreePath/DocCommentTree info for HTML sources.
     */
    public DocCommentInfo getHtmlCommentInfo(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 DocCommentInfo(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);
        dcInfoMap.put(element, new DocCommentInfo(null, docTree));
        // A method having null comment (no comment) that might need to be replaced
        // with a generated comment, remove such a comment from the cache.
        utils.removeCommentHelper(element);
    }

    
Info about a doc comment: the position in the enclosing AST, and the parsed doc comment itself. The position in the AST is null for automatically generated comments, such as for Enum.values, Enum.valuesOf, and JavaFX properties. /**
     * Info about a doc comment:
     *   the position in the enclosing AST, and
     *   the parsed doc comment itself.
     *
     * The position in the AST is {@code null} for automatically generated comments,
     * such as for {@code Enum.values}, {@code Enum.valuesOf}, and JavaFX properties.
     */
    public static class DocCommentInfo {
        
The position of the comment in the enclosing AST, or null for automatically generated comments. /**
         * The position of the comment in the enclosing AST, or {@code null}
         * for automatically generated comments.
         */
        public final TreePath treePath;

        
The doc comment tree that is the root node of a parsed doc comment, or null if there is no comment. /**
         * The doc comment tree that is the root node of a parsed doc comment,
         * or {@code null} if there is no comment.
         */
        public final DocCommentTree dcTree;

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