/*

 * Copyright (c) 2005, 2012, 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.api;

import java.io.File;

import java.io.IOException;

import java.nio.CharBuffer;

import java.util.*;

import java.util.concurrent.atomic.AtomicBoolean;

import javax.annotation.processing.Processor;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.lang.model.type.TypeMirror;

import javax.tools.*;

import com.sun.source.tree.*;

import com.sun.source.util.*;

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

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

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

import com.sun.tools.javac.file.JavacFileManager;

import com.sun.tools.javac.main.*;

import com.sun.tools.javac.main.JavaCompiler;

import com.sun.tools.javac.model.*;

import com.sun.tools.javac.parser.Parser;

import com.sun.tools.javac.parser.ParserFactory;

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

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

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

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

/**

 * Provides access to functionality specific to the JDK Java Compiler, javac.

 *

 * <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></p>

 *

 * @author Peter von der Ahé

 * @author Jonathan Gibbons

 */

public class JavacTaskImpl extends BasicJavacTask {

    private ClientCodeWrapper ccw;

    private Main compilerMain;

    private JavaCompiler compiler;

    private Locale locale;

    private String[] args;

    private String[] classNames;

    private List<JavaFileObject> fileObjects;

    private Map<JavaFileObject, JCCompilationUnit> notYetEntered;

    private ListBuffer<Env<AttrContext>> genList;

    private final AtomicBoolean used = new AtomicBoolean();

    private Iterable<? extends Processor> processors;

    private Main.Result result = null;

    JavacTaskImpl(Main compilerMain,

                String[] args,

                String[] classNames,

                Context context,

                List<JavaFileObject> fileObjects) {

        super(null, false);

        this.ccw = ClientCodeWrapper.instance(context);

        this.compilerMain = compilerMain;

        this.args = args;

        this.classNames = classNames;

        this.context = context;

        this.fileObjects = fileObjects;

        setLocale(Locale.getDefault());

        // null checks

        compilerMain.getClass();

        args.getClass();

        fileObjects.getClass();

    }

    JavacTaskImpl(Main compilerMain,

                Iterable<String> args,

                Context context,

                Iterable<String> classes,

                Iterable<? extends JavaFileObject> fileObjects) {

        this(compilerMain, toArray(args), toArray(classes), context, toList(fileObjects));

    }

    static private String[] toArray(Iterable<String> iter) {

        ListBuffer<String> result = new ListBuffer<String>();

        if (iter != null)

            for (String s : iter)

                result.append(s);

        return result.toArray(new String[result.length()]);

    }

    static private List<JavaFileObject> toList(Iterable<? extends JavaFileObject> fileObjects) {

        if (fileObjects == null)

            return List.nil();

        ListBuffer<JavaFileObject> result = new ListBuffer<JavaFileObject>();

        for (JavaFileObject fo : fileObjects)

            result.append(fo);

        return result.toList();

    }

    public Boolean call() {

        if (!used.getAndSet(true)) {

            initContext();

            notYetEntered = new HashMap<JavaFileObject, JCCompilationUnit>();

            compilerMain.setAPIMode(true);

            result = compilerMain.compile(args, classNames, context, fileObjects, processors);

            cleanup();

            return result.isOK();

        } else {

            throw new IllegalStateException("multiple calls to method 'call'");

        }

    }

    public void setProcessors(Iterable<? extends Processor> processors) {

        processors.getClass(); // null check

        // not mt-safe

        if (used.get())

            throw new IllegalStateException();

        this.processors = processors;

    }

    public void setLocale(Locale locale) {

        if (used.get())

            throw new IllegalStateException();

        this.locale = locale;

    }

    private void prepareCompiler() throws IOException {

        if (used.getAndSet(true)) {

            if (compiler == null)

                throw new IllegalStateException();

        } else {

            initContext();

            compilerMain.setOptions(Options.instance(context));

            compilerMain.filenames = new LinkedHashSet<File>();

            Collection<File> filenames = compilerMain.processArgs(CommandLine.parse(args), classNames);

            if (!filenames.isEmpty())

                throw new IllegalArgumentException("Malformed arguments " + toString(filenames, " "));

            compiler = JavaCompiler.instance(context);

            compiler.keepComments = true;

            compiler.genEndPos = true;

            // NOTE: this value will be updated after annotation processing

            compiler.initProcessAnnotations(processors);

            notYetEntered = new HashMap<JavaFileObject, JCCompilationUnit>();

            for (JavaFileObject file: fileObjects)

                notYetEntered.put(file, null);

            genList = new ListBuffer<Env<AttrContext>>();

            // endContext will be called when all classes have been generated

            // TODO: should handle the case after each phase if errors have occurred

            args = null;

            classNames = null;

        }

    }

    <T> String toString(Iterable<T> items, String sep) {

        String currSep = "";

        StringBuilder sb = new StringBuilder();

        for (T item: items) {

            sb.append(currSep);

            sb.append(item.toString());

            currSep = sep;

        }

        return sb.toString();

    }

    private void initContext() {

        context.put(JavacTask.class, this);

        //initialize compiler's default locale

        context.put(Locale.class, locale);

    }

    void cleanup() {

        if (compiler != null)

            compiler.close();

        compiler = null;

        compilerMain = null;

        args = null;

        classNames = null;

        context = null;

        fileObjects = null;

        notYetEntered = null;

    }

    /**

     * Construct a JavaFileObject from the given file.

     *

     * <p><b>TODO: this method is useless here</b></p>

     *

     * @param file a file

     * @return a JavaFileObject from the standard file manager.

     */

    public JavaFileObject asJavaFileObject(File file) {

        JavacFileManager fm = (JavacFileManager)context.get(JavaFileManager.class);

        return fm.getRegularFile(file);

    }

    /**

     * Parse the specified files returning a list of abstract syntax trees.

     *

     * @throws java.io.IOException TODO

     * @return a list of abstract syntax trees

     */

    public Iterable<? extends CompilationUnitTree> parse() throws IOException {

        try {

            prepareCompiler();

            List<JCCompilationUnit> units = compiler.parseFiles(fileObjects);

            for (JCCompilationUnit unit: units) {

                JavaFileObject file = unit.getSourceFile();

                if (notYetEntered.containsKey(file))

                    notYetEntered.put(file, unit);

            }

            return units;

        }

        finally {

            parsed = true;

            if (compiler != null && compiler.log != null)

                compiler.log.flush();

        }

    }

    private boolean parsed = false;

    /**

     * Translate all the abstract syntax trees to elements.

     *

     * @throws IOException TODO

     * @return a list of elements corresponding to the top level

     * classes in the abstract syntax trees

     */

    public Iterable<? extends TypeElement> enter() throws IOException {

        return enter(null);

    }

    /**

     * Translate the given abstract syntax trees to elements.

     *

     * @param trees a list of abstract syntax trees.

     * @throws java.io.IOException TODO

     * @return a list of elements corresponding to the top level

     * classes in the abstract syntax trees

     */

    public Iterable<? extends TypeElement> enter(Iterable<? extends CompilationUnitTree> trees)

        throws IOException

    {

        if (trees == null && notYetEntered != null && notYetEntered.isEmpty())

            return List.nil();

        prepareCompiler();

        ListBuffer<JCCompilationUnit> roots = null;

        if (trees == null) {

            // If there are still files which were specified to be compiled

            // (i.e. in fileObjects) but which have not yet been entered,

            // then we make sure they have been parsed and add them to the

            // list to be entered.

            if (notYetEntered.size() > 0) {

                if (!parsed)

                    parse(); // TODO would be nice to specify files needed to be parsed

                for (JavaFileObject file: fileObjects) {

                    JCCompilationUnit unit = notYetEntered.remove(file);

                    if (unit != null) {

                        if (roots == null)

                            roots = new ListBuffer<JCCompilationUnit>();

                        roots.append(unit);

                    }

                }

                notYetEntered.clear();

            }

        }

        else {

            for (CompilationUnitTree cu : trees) {

                if (cu instanceof JCCompilationUnit) {

                    if (roots == null)

                        roots = new ListBuffer<JCCompilationUnit>();

                    roots.append((JCCompilationUnit)cu);

                    notYetEntered.remove(cu.getSourceFile());

                }

                else

                    throw new IllegalArgumentException(cu.toString());

            }

        }

        if (roots == null)

            return List.nil();

        try {

            List<JCCompilationUnit> units = compiler.enterTrees(roots.toList());

            if (notYetEntered.isEmpty())

                compiler = compiler.processAnnotations(units);

            ListBuffer<TypeElement> elements = new ListBuffer<TypeElement>();

            for (JCCompilationUnit unit : units) {

                for (JCTree node : unit.defs) {

                    if (node.hasTag(JCTree.Tag.CLASSDEF)) {

                        JCClassDecl cdef = (JCClassDecl) node;

                        if (cdef.sym != null) // maybe null if errors in anno processing

                            elements.append(cdef.sym);

                    }

                }

            }

            return elements.toList();

        }

        finally {

            compiler.log.flush();

        }

    }

    /**

     * Complete all analysis.

     * @throws IOException TODO

     */

    @Override

    public Iterable<? extends Element> analyze() throws IOException {

        return analyze(null);

    }

    /**

     * Complete all analysis on the given classes.

     * This can be used to ensure that all compile time errors are reported.

     * The classes must have previously been returned from {@link #enter}.

     * If null is specified, all outstanding classes will be analyzed.

     *

     * @param classes a list of class elements

     */

    // This implementation requires that we open up privileges on JavaCompiler.

    // An alternative implementation would be to move this code to JavaCompiler and

    // wrap it here

    public Iterable<? extends Element> analyze(Iterable<? extends TypeElement> classes) throws IOException {

        enter(null);  // ensure all classes have been entered

        final ListBuffer<Element> results = new ListBuffer<Element>();

        try {

            if (classes == null) {

                handleFlowResults(compiler.flow(compiler.attribute(compiler.todo)), results);

            } else {

                Filter f = new Filter() {

                    public void process(Env<AttrContext> env) {

                        handleFlowResults(compiler.flow(compiler.attribute(env)), results);

                    }

                };

                f.run(compiler.todo, classes);

            }

        } finally {

            compiler.log.flush();

        }

        return results;

    }

    // where

        private void handleFlowResults(Queue<Env<AttrContext>> queue, ListBuffer<Element> elems) {

            for (Env<AttrContext> env: queue) {

                switch (env.tree.getTag()) {

                    case CLASSDEF:

                        JCClassDecl cdef = (JCClassDecl) env.tree;

                        if (cdef.sym != null)

                            elems.append(cdef.sym);

                        break;

                    case TOPLEVEL:

                        JCCompilationUnit unit = (JCCompilationUnit) env.tree;

                        if (unit.packge != null)

                            elems.append(unit.packge);

                        break;

                }

            }

            genList.addAll(queue);

        }

    /**

     * Generate code.

     * @throws IOException TODO

     */

    @Override

    public Iterable<? extends JavaFileObject> generate() throws IOException {

        return generate(null);

    }

    /**

     * Generate code corresponding to the given classes.

     * The classes must have previously been returned from {@link #enter}.

     * If there are classes outstanding to be analyzed, that will be done before

     * any classes are generated.

     * If null is specified, code will be generated for all outstanding classes.

     *

     * @param classes a list of class elements

     */

    public Iterable<? extends JavaFileObject> generate(Iterable<? extends TypeElement> classes) throws IOException {

        final ListBuffer<JavaFileObject> results = new ListBuffer<JavaFileObject>();

        try {

            analyze(null);  // ensure all classes have been parsed, entered, and analyzed

            if (classes == null) {

                compiler.generate(compiler.desugar(genList), results);

                genList.clear();

            }

            else {

                Filter f = new Filter() {

                        public void process(Env<AttrContext> env) {

                            compiler.generate(compiler.desugar(ListBuffer.of(env)), results);

                        }

                    };

                f.run(genList, classes);

            }

            if (genList.isEmpty()) {

                compiler.reportDeferredDiagnostics();

                cleanup();

            }

        }

        finally {

            if (compiler != null)

                compiler.log.flush();

        }

        return results;

    }

    public TypeMirror getTypeMirror(Iterable<? extends Tree> path) {

        // TODO: Should complete attribution if necessary

        Tree last = null;

        for (Tree node : path)

            last = node;

        return ((JCTree)last).type;

    }

    public JavacElements getElements() {

        if (context == null)

            throw new IllegalStateException();

        return JavacElements.instance(context);

    }

    public JavacTypes getTypes() {

        if (context == null)

            throw new IllegalStateException();

        return JavacTypes.instance(context);

    }

    public Iterable<? extends Tree> pathFor(CompilationUnitTree unit, Tree node) {

        return TreeInfo.pathFor((JCTree) node, (JCTree.JCCompilationUnit) unit).reverse();

    }

    abstract class Filter {

        void run(Queue<Env<AttrContext>> list, Iterable<? extends TypeElement> classes) {

            Set<TypeElement> set = new HashSet<TypeElement>();

            for (TypeElement item: classes)

                set.add(item);

            ListBuffer<Env<AttrContext>> defer = ListBuffer.<Env<AttrContext>>lb();

            while (list.peek() != null) {

                Env<AttrContext> env = list.remove();

                ClassSymbol csym = env.enclClass.sym;

                if (csym != null && set.contains(csym.outermostClass()))

                    process(env);

                else

                    defer = defer.append(env);

            }

            list.addAll(defer);

        }

        abstract void process(Env<AttrContext> env);

    }

    /**

     * For internal use only.  This method will be

     * removed without warning.

     */

    public Type parseType(String expr, TypeElement scope) {

        if (expr == null || expr.equals(""))

            throw new IllegalArgumentException();

        compiler = JavaCompiler.instance(context);

        JavaFileObject prev = compiler.log.useSource(null);

        ParserFactory parserFactory = ParserFactory.instance(context);

        Attr attr = Attr.instance(context);

        try {

            CharBuffer buf = CharBuffer.wrap((expr+"\u0000").toCharArray(), 0, expr.length());

            Parser parser = parserFactory.newParser(buf, false, false, false);

            JCTree tree = parser.parseType();

            return attr.attribType(tree, (Symbol.TypeSymbol)scope);

        } finally {

            compiler.log.useSource(prev);

        }

    }

}