/*

 * Copyright (c) 2011, 2015, 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.javac.tree;

import java.text.BreakIterator;

import java.util.ArrayList;

import java.util.Collection;

import java.util.EnumSet;

import java.util.ListIterator;

import com.sun.source.doctree.AttributeTree.ValueKind;

import com.sun.source.doctree.DocTree;

import com.sun.source.doctree.DocTree.Kind;

import com.sun.source.doctree.EndElementTree;

import com.sun.source.doctree.StartElementTree;

import com.sun.source.doctree.TextTree;

import com.sun.tools.doclint.HtmlTag;

import com.sun.tools.javac.api.JavacTrees;

import com.sun.tools.javac.parser.Tokens.Comment;

import com.sun.tools.javac.tree.DCTree.DCAttribute;

import com.sun.tools.javac.tree.DCTree.DCAuthor;

import com.sun.tools.javac.tree.DCTree.DCComment;

import com.sun.tools.javac.tree.DCTree.DCDeprecated;

import com.sun.tools.javac.tree.DCTree.DCDocComment;

import com.sun.tools.javac.tree.DCTree.DCDocRoot;

import com.sun.tools.javac.tree.DCTree.DCEndElement;

import com.sun.tools.javac.tree.DCTree.DCEntity;

import com.sun.tools.javac.tree.DCTree.DCErroneous;

import com.sun.tools.javac.tree.DCTree.DCIdentifier;

import com.sun.tools.javac.tree.DCTree.DCInheritDoc;

import com.sun.tools.javac.tree.DCTree.DCLink;

import com.sun.tools.javac.tree.DCTree.DCLiteral;

import com.sun.tools.javac.tree.DCTree.DCParam;

import com.sun.tools.javac.tree.DCTree.DCReference;

import com.sun.tools.javac.tree.DCTree.DCReturn;

import com.sun.tools.javac.tree.DCTree.DCSee;

import com.sun.tools.javac.tree.DCTree.DCSerial;

import com.sun.tools.javac.tree.DCTree.DCSerialData;

import com.sun.tools.javac.tree.DCTree.DCSerialField;

import com.sun.tools.javac.tree.DCTree.DCSince;

import com.sun.tools.javac.tree.DCTree.DCStartElement;

import com.sun.tools.javac.tree.DCTree.DCText;

import com.sun.tools.javac.tree.DCTree.DCThrows;

import com.sun.tools.javac.tree.DCTree.DCUnknownBlockTag;

import com.sun.tools.javac.tree.DCTree.DCUnknownInlineTag;

import com.sun.tools.javac.tree.DCTree.DCValue;

import com.sun.tools.javac.tree.DCTree.DCVersion;

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

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

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

import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

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

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

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

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

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

import static com.sun.tools.doclint.HtmlTag.*;

/**

 *

 *  <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>

 */

public class DocTreeMaker {

    /** The context key for the tree factory. */

    protected static final Context.Key<DocTreeMaker> treeMakerKey = new Context.Key<>();

    // A subset of block tags, which acts as sentence breakers, appearing

    // anywhere but the zero'th position in the first sentence.

    final EnumSet<HtmlTag> sentenceBreakTags;

    /** Get the TreeMaker instance. */

    public static DocTreeMaker instance(Context context) {

        DocTreeMaker instance = context.get(treeMakerKey);

        if (instance == null)

            instance = new DocTreeMaker(context);

        return instance;

    }

    /** The position at which subsequent trees will be created.

     */

    public int pos = Position.NOPOS;

    /** Access to diag factory for ErroneousTrees. */

    private final JCDiagnostic.Factory diags;

    private final JavacTrees trees;

    /** Create a tree maker with NOPOS as initial position.

     */

    protected DocTreeMaker(Context context) {

        context.put(treeMakerKey, this);

        diags = JCDiagnostic.Factory.instance(context);

        this.pos = Position.NOPOS;

        trees = JavacTrees.instance(context);

        sentenceBreakTags = EnumSet.of(H1, H2, H3, H4, H5, H6, PRE, P);

    }

    /** Reassign current position.

     */

    public DocTreeMaker at(int pos) {

        this.pos = pos;

        return this;

    }

    /** Reassign current position.

     */

    public DocTreeMaker at(DiagnosticPosition pos) {

        this.pos = (pos == null ? Position.NOPOS : pos.getStartPosition());

        return this;

    }

    public DCAttribute Attribute(Name name, ValueKind vkind, List<DCTree> value) {

        DCAttribute tree = new DCAttribute(name, vkind, value);

        tree.pos = pos;

        return tree;

    }

    public DCAuthor Author(List<DCTree> name) {

        DCAuthor tree = new DCAuthor(name);

        tree.pos = pos;

        return tree;

    }

    public DCLiteral Code(DCText text) {

        DCLiteral tree = new DCLiteral(Kind.CODE, text);

        tree.pos = pos;

        return tree;

    }

    public DCComment Comment(String text) {

        DCComment tree = new DCComment(text);

        tree.pos = pos;

        return tree;

    }

    public DCDeprecated Deprecated(List<DCTree> text) {

        DCDeprecated tree = new DCDeprecated(text);

        tree.pos = pos;

        return tree;

    }

    public DCDocComment DocComment(Comment comment, List<DCTree> fullBody, List<DCTree> tags) {

        Pair<List<DCTree>, List<DCTree>> pair = splitBody(fullBody);

        DCDocComment tree = new DCDocComment(comment, fullBody, pair.fst, pair.snd, tags);

        tree.pos = pos;

        return tree;

    }

    /*

     * Primarily to produce a DocCommenTree when given a

     * first sentence and a body, this is useful, in cases

     * where the trees are being synthesized by a tool.

     */

    public DCDocComment DocComment(List<DCTree> firstSentence, List<DCTree> body, List<DCTree> tags) {

        ListBuffer<DCTree> lb = new ListBuffer<>();

        lb.addAll(firstSentence);

        lb.addAll(body);

        List<DCTree> fullBody = lb.toList();

        DCDocComment tree = new DCDocComment(null, fullBody, firstSentence, body, tags);

        return tree;

    }

    public DCDocRoot DocRoot() {

        DCDocRoot tree = new DCDocRoot();

        tree.pos = pos;

        return tree;

    }

    public DCEndElement EndElement(Name name) {

        DCEndElement tree = new DCEndElement(name);

        tree.pos = pos;

        return tree;

    }

    public DCEntity Entity(Name name) {

        DCEntity tree = new DCEntity(name);

        tree.pos = pos;

        return tree;

    }

    public DCErroneous Erroneous(String text, DiagnosticSource diagSource, String code, Object... args) {

        DCErroneous tree = new DCErroneous(text, diags, diagSource, code, args);

        tree.pos = pos;

        return tree;

    }

    public DCThrows Exception(DCReference name, List<DCTree> description) {

        DCThrows tree = new DCThrows(Kind.EXCEPTION, name, description);

        tree.pos = pos;

        return tree;

    }

    public DCIdentifier Identifier(Name name) {

        DCIdentifier tree = new DCIdentifier(name);

        tree.pos = pos;

        return tree;

    }

    public DCInheritDoc InheritDoc() {

        DCInheritDoc tree = new DCInheritDoc();

        tree.pos = pos;

        return tree;

    }

    public DCLink Link(DCReference ref, List<DCTree> label) {

        DCLink tree = new DCLink(Kind.LINK, ref, label);

        tree.pos = pos;

        return tree;

    }

    public DCLink LinkPlain(DCReference ref, List<DCTree> label) {

        DCLink tree = new DCLink(Kind.LINK_PLAIN, ref, label);

        tree.pos = pos;

        return tree;

    }

    public DCLiteral Literal(DCText text) {

        DCLiteral tree = new DCLiteral(Kind.LITERAL, text);

        tree.pos = pos;

        return tree;

    }

    public DCParam Param(boolean isTypeParameter, DCIdentifier name, List<DCTree> description) {

        DCParam tree = new DCParam(isTypeParameter, name, description);

        tree.pos = pos;

        return tree;

    }

    public DCReference Reference(String signature,

            JCTree qualExpr, Name member, List<JCTree> paramTypes) {

        DCReference tree = new DCReference(signature, qualExpr, member, paramTypes);

        tree.pos = pos;

        return tree;

    }

    public DCReturn Return(List<DCTree> description) {

        DCReturn tree = new DCReturn(description);

        tree.pos = pos;

        return tree;

    }

    public DCSee See(List<DCTree> reference) {

        DCSee tree = new DCSee(reference);

        tree.pos = pos;

        return tree;

    }

    public DCSerial Serial(List<DCTree> description) {

        DCSerial tree = new DCSerial(description);

        tree.pos = pos;

        return tree;

    }

    public DCSerialData SerialData(List<DCTree> description) {

        DCSerialData tree = new DCSerialData(description);

        tree.pos = pos;

        return tree;

    }

    public DCSerialField SerialField(DCIdentifier name, DCReference type, List<DCTree> description) {

        DCSerialField tree = new DCSerialField(name, type, description);

        tree.pos = pos;

        return tree;

    }

    public DCSince Since(List<DCTree> text) {

        DCSince tree = new DCSince(text);

        tree.pos = pos;

        return tree;

    }

    public DCStartElement StartElement(Name name, List<DCTree> attrs, boolean selfClosing) {

        DCStartElement tree = new DCStartElement(name, attrs, selfClosing);

        tree.pos = pos;

        return tree;

    }

    public DCText Text(String text) {

        DCText tree = new DCText(text);

        tree.pos = pos;

        return tree;

    }

    public DCThrows Throws(DCReference name, List<DCTree> description) {

        DCThrows tree = new DCThrows(Kind.THROWS, name, description);

        tree.pos = pos;

        return tree;

    }

    public DCUnknownBlockTag UnknownBlockTag(Name name, List<DCTree> content) {

        DCUnknownBlockTag tree = new DCUnknownBlockTag(name, content);

        tree.pos = pos;

        return tree;

    }

    public DCUnknownInlineTag UnknownInlineTag(Name name, List<DCTree> content) {

        DCUnknownInlineTag tree = new DCUnknownInlineTag(name, content);

        tree.pos = pos;

        return tree;

    }

    public DCValue Value(DCReference ref) {

        DCValue tree = new DCValue(ref);

        tree.pos = pos;

        return tree;

    }

    public DCVersion Version(List<DCTree> text) {

        DCVersion tree = new DCVersion(text);

        tree.pos = pos;

        return tree;

    }

    public java.util.List<DocTree> getFirstSentence(java.util.List<? extends DocTree> list) {

        Pair<List<DCTree>, List<DCTree>> pair = splitBody(list);

        return new ArrayList<>(pair.fst);

    }

    /*

     * Breaks up the body tags into the first sentence and its successors.

     * The first sentence is determined with the presence of a period,

     * block tag, or a sentence break, as returned by the BreakIterator.

     * Trailing whitespaces are trimmed.

     */

    private Pair<List<DCTree>, List<DCTree>> splitBody(Collection<? extends DocTree> list) {

        // pos is modified as we create trees, therefore

        // we save the pos and restore it later.

        final int savedpos = this.pos;

        try {

            ListBuffer<DCTree> body = new ListBuffer<>();

            // split body into first sentence and body

            ListBuffer<DCTree> fs = new ListBuffer<>();

            if (list.isEmpty()) {

                return new Pair<>(fs.toList(), body.toList());

            }

            boolean foundFirstSentence = false;

            ArrayList<DocTree> alist = new ArrayList<>(list);

            ListIterator<DocTree> itr = alist.listIterator();

            while (itr.hasNext()) {

                boolean isFirst = !itr.hasPrevious();

                DocTree dt = itr.next();

                int spos = ((DCTree) dt).pos;

                if (foundFirstSentence) {

                    body.add((DCTree) dt);

                    continue;

                }

                switch (dt.getKind()) {

                    case TEXT:

                        DCText tt = (DCText) dt;

                        String s = tt.getBody();

                        DocTree peekedNext = itr.hasNext()

                                ? alist.get(itr.nextIndex())

                                : null;

                        int sbreak = getSentenceBreak(s, peekedNext);

                        if (sbreak > 0) {

                            s = removeTrailingWhitespace(s.substring(0, sbreak));

                            DCText text = this.at(spos).Text(s);

                            fs.add(text);

                            foundFirstSentence = true;

                            int nwPos = skipWhiteSpace(tt.getBody(), sbreak);

                            if (nwPos > 0) {

                                DCText text2 = this.at(spos + nwPos).Text(tt.getBody().substring(nwPos));

                                body.add(text2);

                            }

                            continue;

                        } else if (itr.hasNext()) {

                            // if the next doctree is a break, remove trailing spaces

                            peekedNext = alist.get(itr.nextIndex());

                            boolean sbrk = isSentenceBreak(peekedNext, false);

                            if (sbrk) {

                                DocTree next = itr.next();

                                s = removeTrailingWhitespace(s);

                                DCText text = this.at(spos).Text(s);

                                fs.add(text);

                                body.add((DCTree) next);

                                foundFirstSentence = true;

                                continue;

                            }

                        }

                        break;

                    default:

                        if (isSentenceBreak(dt, isFirst)) {

                            body.add((DCTree) dt);

                            foundFirstSentence = true;

                            continue;

                        }

                        break;

                }

                fs.add((DCTree) dt);

            }

            return new Pair<>(fs.toList(), body.toList());

        } finally {

            this.pos = savedpos;

        }

    }

    private boolean isTextTree(DocTree tree) {

        return tree.getKind() == Kind.TEXT;

    }

    /*

     * Computes the first sentence break, a simple dot-space algorithm.

     */

    int defaultSentenceBreak(String s) {

        // scan for period followed by whitespace

        int period = -1;

        for (int i = 0; i < s.length(); i++) {

            switch (s.charAt(i)) {

                case '.':

                    period = i;

                    break;

                case ' ':

                case '\f':

                case '\n':

                case '\r':

                case '\t':

                    if (period >= 0) {

                        return i;

                    }

                    break;

                default:

                    period = -1;

                    break;

            }

        }

        return -1;

    }

    /*

     * Computes the first sentence, if using a default breaker,

     * the break is returned, if not then a -1, indicating that

     * more doctree elements are required to be examined.

     *

     * BreakIterator.next points to the the start of the following sentence,

     * and does not provide an easy way to disambiguate between "sentence break",

     * "possible sentence break" and "not a sentence break" at the end of the input.

     * For example, BreakIterator.next returns the index for the end

     * of the string for all of these examples,

     * using vertical bars to delimit the bounds of the example text

     * |Abc|        (not a valid end of sentence break, if followed by more text)

     * |Abc.|       (maybe a valid end of sentence break, depending on the following text)

     * |Abc. |      (maybe a valid end of sentence break, depending on the following text)

     * |"Abc." |    (maybe a valid end of sentence break, depending on the following text)

     * |Abc.  |     (definitely a valid end of sentence break)

     * |"Abc."  |   (definitely a valid end of sentence break)

     * Therefore, we have to probe further to determine whether

     * there really is a sentence break or not at the end of this run of text.

     */

    int getSentenceBreak(String s, DocTree dt) {

        BreakIterator breakIterator = trees.getBreakIterator();

        if (breakIterator == null) {

            return defaultSentenceBreak(s);

        }

        breakIterator.setText(s);

        final int sbrk = breakIterator.next();

        // This is the last doctree, found the droid we are looking for

        if (dt == null) {

            return sbrk;

        }

        // If the break is well within the span of the string ie. not

        // at EOL, then we have a clear break.

        if (sbrk < s.length() - 1) {

            return sbrk;

        }

        if (isTextTree(dt)) {

            // Two adjacent text trees, a corner case, perhaps

            // produced by a tool synthesizing a doctree. In

            // this case, does the break lie within the first span,

            // then we have the droid, otherwise allow the callers

            // logic to handle the break in the adjacent doctree.