/*

 * Copyright (c) 2001, 2017, 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.tool;

import java.io.File;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import com.sun.tools.javac.code.ClassFinder;

import com.sun.tools.javac.code.Symbol.Completer;

import com.sun.tools.javac.code.Symbol.CompletionFailure;

import com.sun.tools.javac.comp.Enter;

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

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

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

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

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

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

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

import jdk.javadoc.doclet.DocletEnvironment;

import static jdk.javadoc.internal.tool.Main.Result.*;

/**

 *  This class could be the main entry point for Javadoc when Javadoc is used as a

 *  component in a larger software system. It provides operations to

 *  construct a new javadoc processor, and to run it on a set of source

 *  files.

 *

 *  <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 Neal Gafter

 */

public class JavadocTool extends com.sun.tools.javac.main.JavaCompiler {

    ToolEnvironment toolEnv;

    final Messager messager;

    final ClassFinder javadocFinder;

    final Enter javadocEnter;

    final Set<JavaFileObject> uniquefiles;

    /**

     * Construct a new JavaCompiler processor, using appropriately

     * extended phases of the underlying compiler.

     */

    protected JavadocTool(Context context) {

        super(context);

        messager = Messager.instance0(context);

        javadocFinder = JavadocClassFinder.instance(context);

        javadocEnter = JavadocEnter.instance(context);

        uniquefiles = new HashSet<>();

    }

    /**

     * For javadoc, the parser needs to keep comments. Overrides method from JavaCompiler.

     */

    @Override

    protected boolean keepComments() {

        return true;

    }

    /**

     *  Construct a new javadoc tool.

     */

    public static JavadocTool make0(Context context) {

        Messager messager = null;

        try {

            // force the use of Javadoc's class finder

            JavadocClassFinder.preRegister(context);

            // force the use of Javadoc's own enter phase

            JavadocEnter.preRegister(context);

            // force the use of Javadoc's own member enter phase

            JavadocMemberEnter.preRegister(context);

            // force the use of Javadoc's own todo phase

            JavadocTodo.preRegister(context);

            // force the use of Messager as a Log

            messager = Messager.instance0(context);

            return new JavadocTool(context);

        } catch (CompletionFailure ex) {

            messager.error(Position.NOPOS, ex.getMessage());

            return null;

        }

    }

    public DocletEnvironment getEnvironment(Map<ToolOption,

            Object> jdtoolOpts,

            List<String> javaNames,

            Iterable<? extends JavaFileObject> fileObjects) throws ToolException {

        toolEnv = ToolEnvironment.instance(context);

        toolEnv.initialize(jdtoolOpts);

        ElementsTable etable = new ElementsTable(context, jdtoolOpts);

        javadocFinder.sourceCompleter = etable.xclasses

                ? Completer.NULL_COMPLETER

                : sourceCompleter;

        if (etable.xclasses) {

            // If -Xclasses is set, the args should be a list of class names

            for (String arg: javaNames) {

                if (!isValidPackageName(arg)) { // checks

                    String text = messager.getText("main.illegal_class_name", arg);

                    throw new ToolException(CMDERR, text);

                }

            }

            if (messager.hasErrors()) {

                return null;

            }

            etable.setClassArgList(javaNames);

            // prepare, force the data structures to be analyzed

            etable.analyze();

            return new DocEnvImpl(toolEnv, etable);

        }

        ListBuffer<JCCompilationUnit> classTrees = new ListBuffer<>();

        try {

            StandardJavaFileManager fm = toolEnv.fileManager instanceof StandardJavaFileManager

                    ? (StandardJavaFileManager) toolEnv.fileManager

                    : null;

            Set<String> packageNames = new LinkedHashSet<>();

            // Normally, the args should be a series of package names or file names.

            // Parse the files and collect the package names.

            for (String arg: javaNames) {

                if (fm != null && arg.endsWith(".java") && new File(arg).exists()) {

                    parse(fm.getJavaFileObjects(arg), classTrees, true);

                } else if (isValidPackageName(arg)) {

                    packageNames.add(arg);

                } else if (arg.endsWith(".java")) {

                    if (fm == null) {

                        String text = messager.getText("main.assertion.error", "fm == null");

                        throw new ToolException(ABNORMAL, text);

                    } else {

                        String text = messager.getText("main.file_not_found", arg);

                        throw new ToolException(ERROR, text);

                    }

                } else {

                    String text = messager.getText("main.illegal_package_name", arg);

                    throw new ToolException(CMDERR, text);

                }

            }

            // Parse file objects provide via the DocumentationTool API

            parse(fileObjects, classTrees, true);

            etable.packages(packageNames)

                    .classTrees(classTrees.toList())

                    .scanSpecifiedItems();

            // abort, if errors were encountered during modules initialization

            if (messager.hasErrors()) {

                return null;

            }

            // Parse the files in the packages and subpackages to be documented

            ListBuffer<JCCompilationUnit> packageTrees = new ListBuffer<>();

            parse(etable.getFilesToParse(), packageTrees, false);

            modules.enter(packageTrees.toList(), null);

            if (messager.hasErrors()) {

                return null;

            }

            // Enter symbols for all files

            toolEnv.notice("main.Building_tree");

            javadocEnter.main(classTrees.toList().appendList(packageTrees));

            if (messager.hasErrors()) {

                return null;

            }

            etable.setClassDeclList(listClasses(classTrees.toList()));

            etable.analyze();

        } catch (CompletionFailure cf) {

            throw new ToolException(ABNORMAL, cf.getMessage(), cf);

        } catch (Abort abort) {

            if (messager.hasErrors()) {

                // presumably a message has been emitted, keep silent

                throw new ToolException(ABNORMAL, "", abort);

            } else {

                String text = messager.getText("main.internal.error");

                Throwable t = abort.getCause() == null ? abort : abort.getCause();

                throw new ToolException(ABNORMAL, text, t);

            }

        }

        if (messager.hasErrors())

            return null;

        toolEnv.docEnv = new DocEnvImpl(toolEnv, etable);

        return toolEnv.docEnv;

    }

    /** Is the given string a valid package name? */

    boolean isValidPackageName(String s) {

        if (s.contains("/")) {

            String[] a = s.split("/");

            if (a.length == 2) {

                 return isValidPackageName0(a[0]) && isValidPackageName0(a[1]);

            }

            return false;

        }

        return isValidPackageName0(s);

    }

    private boolean isValidPackageName0(String s) {

        for (int index = s.indexOf('.') ; index != -1; index = s.indexOf('.')) {

            if (!isValidClassName(s.substring(0, index))) {

                return false;

            }

            s = s.substring(index + 1);

        }

        return isValidClassName(s);

    }

    private void parse(Iterable<? extends JavaFileObject> files, ListBuffer<JCCompilationUnit> trees,

                       boolean trace) {

        for (JavaFileObject fo: files) {

            if (uniquefiles.add(fo)) { // ignore duplicates

                if (trace)

                    toolEnv.notice("main.Loading_source_file", fo.getName());

                trees.append(parse(fo));

            }

        }

    }

    /** Are surrogates supported? */

    final static boolean surrogatesSupported = surrogatesSupported();

    private static boolean surrogatesSupported() {

        try {

            boolean b = Character.isHighSurrogate('a');

            return true;

        } catch (NoSuchMethodError ex) {

            return false;

        }

    }

    /**

     * Return true if given file name is a valid class name

     * (including "package-info").

     * @param s the name of the class to check.

     * @return true if given class name is a valid class name

     * and false otherwise.

     */

    public static boolean isValidClassName(String s) {

        if (s.length() < 1) return false;

        if (s.equals("package-info")) return true;

        if (surrogatesSupported) {

            int cp = s.codePointAt(0);

            if (!Character.isJavaIdentifierStart(cp))

                return false;

            for (int j = Character.charCount(cp); j < s.length(); j += Character.charCount(cp)) {

                cp = s.codePointAt(j);

                if (!Character.isJavaIdentifierPart(cp))

                    return false;

            }

        } else {

            if (!Character.isJavaIdentifierStart(s.charAt(0)))

                return false;

            for (int j = 1; j < s.length(); j++)

                if (!Character.isJavaIdentifierPart(s.charAt(j)))

                    return false;

        }

        return true;

    }

    /**

     * From a list of top level trees, return the list of contained class definitions

     */

    List<JCClassDecl> listClasses(List<JCCompilationUnit> trees) {

        List<JCClassDecl> result = new ArrayList<>();

        for (JCCompilationUnit t : trees) {

            for (JCTree def : t.defs) {

                if (def.hasTag(JCTree.Tag.CLASSDEF))

                    result.add((JCClassDecl)def);

            }

        }

        return result;

    }

}