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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

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 * The contents of this file are subject to the terms of either the GNU

 * General Public License Version 2 only ("GPL") or the Common

 * Development and Distribution License("CDDL") (collectively, the

 * "License"). You may not use this file except in compliance with the

 * License. You can obtain a copy of the License at

 * http://www.netbeans.org/cddl-gplv2.html

 * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the

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 * particular file as subject to the "Classpath" exception as provided

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 * The Original Software is NetBeans. The Initial Developer of the Original

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package net.java.html.json;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashMap;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import javax.tools.Diagnostic;

import javax.tools.DiagnosticListener;

import javax.tools.FileObject;

import javax.tools.ForwardingJavaFileManager;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.JavaFileObject.Kind;

import javax.tools.SimpleJavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardLocation;

import javax.tools.ToolProvider;

import static org.testng.Assert.assertFalse;

import static org.testng.Assert.fail;

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

final class Compile implements DiagnosticListener<JavaFileObject> {

    private final List<Diagnostic<? extends JavaFileObject>> errors = 

            new ArrayList<Diagnostic<? extends JavaFileObject>>();

    private final Map<String, byte[]> classes;

    private final String pkg;

    private final String cls;

    private final String html;

    private final String sourceLevel;

    private Compile(String html, String code, String sl) throws IOException {

        this.pkg = findPkg(code);

        this.cls = findCls(code);

        this.html = html;

        this.sourceLevel = sl;

        classes = compile(html, code);

    }

    /** Performs compilation of given HTML page and associated Java code

     */

    public static Compile create(String html, String code) throws IOException {

        return create(html, code, "1.7");

    }

    static Compile create(String html, String code, String sourceLevel) throws IOException {

        return new Compile(html, code, sourceLevel);

    }

    /** Checks for given class among compiled resources */

    public byte[] get(String res) {

        return classes.get(res);

    }

    /** Obtains errors created during compilation.

     */

    public List<Diagnostic<? extends JavaFileObject>> getErrors() {

        List<Diagnostic<? extends JavaFileObject>> err;

        err = new ArrayList<Diagnostic<? extends JavaFileObject>>();

        for (Diagnostic<? extends JavaFileObject> diagnostic : errors) {

            if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {

                err.add(diagnostic);

            }

        }

        return err;

    }

    private Map<String, byte[]> compile(final String html, final String code) throws IOException {

        StandardJavaFileManager sjfm = ToolProvider.getSystemJavaCompiler().getStandardFileManager(this, null, null);

        final Map<String, ByteArrayOutputStream> class2BAOS;

        class2BAOS = new HashMap<String, ByteArrayOutputStream>();

        JavaFileObject file = new SimpleJavaFileObject(URI.create("mem://mem"), Kind.SOURCE) {

            @Override

            public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {

                return code;

            }

        };

        final JavaFileObject htmlFile = new SimpleJavaFileObject(URI.create("mem://mem2"), Kind.OTHER) {

            @Override

            public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {

                return html;

            }

            @Override

            public InputStream openInputStream() throws IOException {

                return new ByteArrayInputStream(html.getBytes());

            }

        };

        final URI scratch;

        try {

            scratch = new URI("mem://mem3");

        } catch (URISyntaxException ex) {

            throw new IOException(ex);

        }

        JavaFileManager jfm = new ForwardingJavaFileManager<JavaFileManager>(sjfm) {

            @Override

            public JavaFileObject getJavaFileForOutput(Location location, String className, Kind kind, FileObject sibling) throws IOException {

                if (kind  == Kind.CLASS) {

                    final ByteArrayOutputStream buffer = new ByteArrayOutputStream();

                    class2BAOS.put(className.replace('.', '/') + ".class", buffer);

                    return new SimpleJavaFileObject(sibling.toUri(), kind) {

                        @Override

                        public OutputStream openOutputStream() throws IOException {

                            return buffer;

                        }

                    };

                }

                if (kind == Kind.SOURCE) {

                    final String n = className.replace('.', '/') + ".java";

                    final URI un;

                    try {

                        un = new URI("mem://" + n);

                    } catch (URISyntaxException ex) {

                        throw new IOException(ex);

                    }

                    return new VirtFO(un/*sibling.toUri()*/, kind, n);

                }

                throw new IllegalStateException();

            }

            @Override

            public FileObject getFileForInput(Location location, String packageName, String relativeName) throws IOException {

                if (location == StandardLocation.SOURCE_PATH) {

                    if (packageName.equals(pkg)) {

                        return htmlFile;

                    }

                }

                return null;

            }

            @Override

            public boolean isSameFile(FileObject a, FileObject b) {

                if (a instanceof VirtFO && b instanceof VirtFO) {

                    return ((VirtFO)a).getName().equals(((VirtFO)b).getName());

                }

                return super.isSameFile(a, b);

            }

            class VirtFO extends SimpleJavaFileObject {

                private final String n;

                public VirtFO(URI uri, Kind kind, String n) {

                    super(uri, kind);

                    this.n = n;

                }

                private final ByteArrayOutputStream data = new ByteArrayOutputStream();

                @Override

                public OutputStream openOutputStream() throws IOException {

                    return data;

                }

                @Override

                public String getName() {

                    return n;

                }

                @Override

                public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {

                    data.close();

                    return new String(data.toByteArray());

                }

            }

        };

        ToolProvider.getSystemJavaCompiler().getTask(null, jfm, this, /*XXX:*/Arrays.asList("-source", sourceLevel, "-target", "1.7"), null, Arrays.asList(file)).call();

        Map<String, byte[]> result = new HashMap<String, byte[]>();

        for (Map.Entry<String, ByteArrayOutputStream> e : class2BAOS.entrySet()) {

            result.put(e.getKey(), e.getValue().toByteArray());

        }

        return result;

    }

    @Override

    public void report(Diagnostic<? extends JavaFileObject> diagnostic) {

        errors.add(diagnostic);

    }

    private static String findPkg(String java) throws IOException {

        Pattern p = Pattern.compile("package\\p{javaWhitespace}*([\\p{Alnum}\\.]+)\\p{javaWhitespace}*;", Pattern.MULTILINE);

        Matcher m = p.matcher(java);

        if (!m.find()) {

            throw new IOException("Can't find package declaration in the java file");

        }

        String pkg = m.group(1);

        return pkg;

    }

    private static String findCls(String java) throws IOException {

        Pattern p = Pattern.compile("class\\p{javaWhitespace}*([\\p{Alnum}\\.]+)\\p{javaWhitespace}", Pattern.MULTILINE);

        Matcher m = p.matcher(java);

        if (!m.find()) {

            throw new IOException("Can't find package declaration in the java file");

        }

        String cls = m.group(1);

        return cls;

    }

    String getHtml() {

        String fqn = "'" + pkg + '.' + cls + "'";

        return html.replace("'${fqn}'", fqn);

    }

    void assertErrors() {

        assertFalse(getErrors().isEmpty(), "There are supposed to be some errors");

    }

    void assertError(String expMsg) {

        StringBuilder sb = new StringBuilder();

        sb.append("Can't find ").append(expMsg).append(" among:");

        for (Diagnostic<? extends JavaFileObject> e : errors) {

            String msg = e.getMessage(Locale.US);

            if (msg.contains(expMsg)) {

                return;

            }

            sb.append("\n");

            sb.append(msg);

        }

        fail(sb.toString());

    }

}