/*

 * To change this template, choose Tools | Templates

 * and open the template in the editor.

 */

package org.apidesign.bck2brwsr.dew;

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.nio.charset.Charset;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Locale;

import java.util.Map;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

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.JavaCompiler;

import javax.tools.JavaCompiler.CompilationTask;

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;

/**

 *

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

 */

final class Compile implements JavaFileManager, DiagnosticListener<JavaFileObject> {

    private final JFO jfo;

    private final String pkg;

    private StandardJavaFileManager delegate;

    private List<Diagnostic<? extends JavaFileObject>> errors = new ArrayList<>();

    public Compile(String pkg, JFO jfo) {

        this.pkg = pkg;

        this.jfo = jfo;

    }

    /*

    public static Map<String,byte[]> compile(String html, String java) throws IOException {

        JavaCompiler jc = javax.tools.ToolProvider.getSystemJavaCompiler();

        String pkg = findPkg(java);

        String cls = findCls(java);

        JFO jfo = new JFO(java, pkg.replace('.', '/') + '/' + cls + ".java");

        final Compile cmp = new Compile(pkg, jfo);

        cmp.delegate = jc.getStandardFileManager(cmp, Locale.ENGLISH, Charset.forName("UTF-8"));

        Set<String> toCmp = Collections.singleton(pkg + '.' + cls);

        Set<JFO> unit = Collections.singleton(jfo);

        CompilationTask task = jc.getTask(null, cmp, cmp, null, null, unit);

        if (task.call() != true) {

            throw new IOException("Compilation failed: " + cmp.errors);

        }

        return Collections.emptyMap();

    }

    */

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

        final String pkg = findPkg(code);

//        String cls = findCls(code);

        DiagnosticListener<JavaFileObject> devNull = new DiagnosticListener<JavaFileObject>() {

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

                System.err.println("diagnostic=" + diagnostic);

            }

        };

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

//        sjfm.setLocation(StandardLocation.PLATFORM_CLASS_PATH, toFiles(boot));

//        sjfm.setLocation(StandardLocation.CLASS_PATH, toFiles(compile));

        final Map<String, ByteArrayOutputStream> 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) {

                    return new SimpleJavaFileObject(scratch/*sibling.toUri()*/, kind) {

                        private final ByteArrayOutputStream data = new ByteArrayOutputStream();

                        @Override

                        public OutputStream openOutputStream() throws IOException {

                            return data;

                        }

                        @Override

                        public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {

                            data.close();

                            return new String(data.toByteArray());

                        }

                    };

                }

                throw new IllegalStateException();

            }

//            @Override

//            public Iterable<JavaFileObject> list(Location location, String packageName, Set<Kind> kinds, boolean recurse) throws IOException {

//                if (location == StandardLocation.PLATFORM_CLASS_PATH) {

//                    return super.list(location, packageName, kinds, recurse);

//                }

//                if (location == StandardLocation.CLASS_PATH) {

//                    return super.list(location, packageName, kinds, recurse);

//                }

//                if (location == StandardLocation.SOURCE_PATH) {

//                    System.out.println("src path for " + packageName + " kinds: " + kinds);

//                    if (packageName.equals(pkg) && kinds.contains(Kind.OTHER)) {

//                        return Collections.<JavaFileObject>singleton(htmlFile);

//                    }

//                    return Collections.emptyList();

//                }

//                throw new UnsupportedOperationException("Loc: " + location + " pkg: " + packageName + " kinds: " + kinds + " rec: " + recurse);

//            }

            @Override

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

                if (location == StandardLocation.SOURCE_PATH) {

//                    System.out.println("src path for " + packageName + " kinds: " + kinds);

                    if (packageName.equals(pkg)) {

                        return htmlFile;

                    }

                }

                return null;

            }

        };

        ToolProvider.getSystemJavaCompiler().getTask(null, jfm, devNull, /*XXX:*/Arrays.asList("-source", "1.7", "-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 ClassLoader getClassLoader(Location location) {

        return null;//Compile.class.getClassLoader();

    }

    @Override

    public Iterable<JavaFileObject> list(Location location, String packageName, Set<Kind> kinds, boolean recurse) throws IOException {

        if (location == StandardLocation.PLATFORM_CLASS_PATH) {

            return delegate.list(location, packageName, kinds, recurse);

        }

        if (location == StandardLocation.CLASS_PATH) {

            return delegate.list(location, packageName, kinds, recurse);

        }

        if (location == StandardLocation.SOURCE_PATH) {

            if (packageName.equals(pkg)) {

                return Collections.<JavaFileObject>singleton(jfo);

            }

            return Collections.emptyList();

        }

        throw new UnsupportedOperationException("Loc: " + location + " pkg: " + packageName + " kinds: " + kinds + " rec: " + recurse);

    }

    @Override

    public String inferBinaryName(Location location, JavaFileObject file) {

        if (file == jfo) {

            return pkg + "." + file.getName();

        }

        return delegate.inferBinaryName(location, file);

    }

    @Override

    public boolean isSameFile(FileObject a, FileObject b) {

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

    public boolean handleOption(String current, Iterator<String> remaining) {

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

    public boolean hasLocation(Location location) {

        return true;

    }

    @Override

    public JavaFileObject getJavaFileForInput(Location location, String className, Kind kind) throws IOException {

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

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

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

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

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

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

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

    public void flush() throws IOException {

    }

    @Override

    public void close() throws IOException {

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

    public int isSupportedOption(String option) {

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @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;

    }

}