/*
 * Copyright 2016-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.onlab.osgiwrap;

import aQute.bnd.header.Attrs;
import aQute.bnd.header.Parameters;
import aQute.bnd.osgi.Analyzer;
import aQute.bnd.osgi.Builder;
import aQute.bnd.osgi.FileResource;
import aQute.bnd.osgi.Jar;
import aQute.bnd.osgi.Resource;
import com.google.common.base.Joiner;
import com.google.common.base.MoreObjects;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.google.common.io.ByteStreams;
import org.apache.felix.scrplugin.bnd.SCRDescriptorBndPlugin;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.jar.Manifest;

import static com.google.common.io.Files.createParentDirs;
import static com.google.common.io.Files.write;
import static java.nio.file.Files.walkFileTree;

/**
 * BND-based wrapper to convert Buck JARs to OSGi-compatible JARs.
 */
public class OSGiWrapper {
    private static final String NONE = "NONE";

    private String inputJar;
    private String outputJar;
    private List<String> classpath;

    private String bundleName;
    private String groupId;
    private String bundleSymbolicName;
    private String bundleVersion;

    private String importPackages;
    private String dynamicimportPackages;

    private String exportPackages;
    private String includeResources;
    private Set<String> includedResources = Sets.newHashSet();

    private String bundleDescription;
    private String bundleLicense;

    private String webContext;
    private String webXmlRoot;
    private String destdir;

    private String bundleClasspath;

    // FIXME should consider using Commons CLI, etc.
    public static void main(String[] args) {
        if (args.length < 14) {
            System.err.println("Not enough args");
            System.exit(1);
        }

        String jar = args[0];
        String output = args[1];
        String cp = args[2];
        String name = args[3];
        String group = args[4];
        String version = args[5];
        String license = args[6];
        String importPackages = args[7];
        String exportPackages = args[8];
        String includeResources = args[9];
        String webContext = args[10];
        String webXmlRoot = args[11];
        String dynamicimportPackages = args[12];
        String destdir = args[13];
        String bundleClasspath = args[14];
        String desc = Joiner.on(' ').join(Arrays.copyOfRange(args, 12, args.length));

        OSGiWrapper wrapper = new OSGiWrapper(jar, output, cp,
                name, group,
                version, license,
                importPackages, exportPackages,
                includeResources,
                webContext,
                webXmlRoot,
                dynamicimportPackages,
                desc,
                destdir,
                bundleClasspath);
        wrapper.log(wrapper + "\n");
        if (!wrapper.execute()) {
            System.err.printf("Error generating %s\n", name);
            System.exit(2);
        }
    }


    public OSGiWrapper(String inputJar,
                       String outputJar,
                       String classpath,
                       String bundleName,
                       String groupId,
                       String bundleVersion,
                       String bundleLicense,
                       String importPackages,
                       String exportPackages,
                       String includeResources,
                       String webContext,
                       String webXmlRoot,
                       String dynamicimportPackages,
                       String bundleDescription,
                       String destdir,
                       String bundleClasspath) {
        this.inputJar = inputJar;
        this.classpath = Lists.newArrayList(classpath.split(":"));
        if (!this.classpath.contains(inputJar)) {
            this.classpath.add(0, inputJar);
        }
        this.outputJar = outputJar;

        this.bundleName = bundleName;
        this.groupId = groupId;
        this.bundleSymbolicName = String.format("%s.%s", groupId, bundleName);

        this.bundleVersion = bundleVersion;
        this.bundleLicense = bundleLicense;
        this.bundleDescription = bundleDescription;

        this.importPackages = importPackages;
        this.dynamicimportPackages = dynamicimportPackages;
        if (Objects.equals(dynamicimportPackages, "''")) {
            this.dynamicimportPackages = null;
        }
        this.exportPackages = exportPackages;
        if (!Objects.equals(includeResources, NONE)) {
            this.includeResources = includeResources;
        }

        this.webContext = webContext;
        this.webXmlRoot = webXmlRoot;
        this.destdir = destdir;

        this.bundleClasspath = bundleClasspath;
    }

    private void setProperties(Analyzer analyzer) {
        analyzer.setProperty(Analyzer.BUNDLE_NAME, bundleName);
        analyzer.setProperty(Analyzer.BUNDLE_SYMBOLICNAME, bundleSymbolicName);
        analyzer.setProperty(Analyzer.BUNDLE_VERSION, bundleVersion.replace('-', '.'));

        analyzer.setProperty(Analyzer.BUNDLE_DESCRIPTION, bundleDescription);
        analyzer.setProperty(Analyzer.BUNDLE_LICENSE, bundleLicense);

        //TODO consider using stricter version policy
        //analyzer.setProperty("-provider-policy", "${range;[===,==+)}");
        //analyzer.setProperty("-consumer-policy", "${range;[===,==+)}");

        analyzer.setProperty(Analyzer.DYNAMICIMPORT_PACKAGE, dynamicimportPackages);

        // TODO include version in export, but not in import
        analyzer.setProperty(Analyzer.EXPORT_PACKAGE, exportPackages);

        // TODO we may need INCLUDE_RESOURCE, or that might be done by Buck
        if (includeResources != null) {
            analyzer.setProperty(Analyzer.INCLUDE_RESOURCE, includeResources);
        }

        // There are no good defaults so make sure you set the Import-Package
        analyzer.setProperty(Analyzer.IMPORT_PACKAGE, importPackages);

        if (isWab()) {
            analyzer.setProperty(Analyzer.WAB, webXmlRoot);
            analyzer.setProperty("Web-ContextPath", webContext);
            analyzer.setProperty(Analyzer.IMPORT_PACKAGE, importPackages +
                    ",org.glassfish.jersey.servlet,org.jvnet.mimepull\n");
        }
    }

    public boolean execute() {
        Analyzer analyzer = new Builder();
        try {
            // Extract the input jar contents into the specified output directory
            expandJar(inputJar, new File(destdir));

            Jar jar = new Jar(new File(inputJar));  // where our data is
            analyzer.setJar(jar);                   // give bnd the contents

            // You can provide additional class path entries to allow
            // bnd to pickup export version from the packageinfo file,
            // Version annotation, or their manifests.
            analyzer.addClasspath(classpath);

            setProperties(analyzer);

            // ------------- let's begin... -------------------------

            // Analyze the target JAR first
            analyzer.analyze();

            // Scan the JAR for Felix SCR annotations and generate XML files
            Map<String, String> properties = Maps.newHashMap();
            // destdir hack
            properties.put("destdir", destdir);
            SCRDescriptorBndPlugin scrDescriptorBndPlugin = new SCRDescriptorBndPlugin();
            scrDescriptorBndPlugin.setProperties(properties);
            scrDescriptorBndPlugin.setReporter(analyzer);
            scrDescriptorBndPlugin.analyzeJar(analyzer);

            if (includeResources != null) {
                doIncludeResources(analyzer);
            }

            // Repack the JAR as a WAR
            doWabStaging(analyzer);

            // Calculate the manifest
            Manifest manifest = analyzer.calcManifest();

            if (analyzer.isOk()) {
                analyzer.getJar().setManifest(manifest);
                if (analyzer.save(new File(outputJar), true)) {
                    log("Saved!\n");
                } else {
                    warn("Failed to create jar \n");
                    return false;
                }
            } else {
                warn("Analyzer Errors:\n%s\n", analyzer.getErrors());
                return false;
            }

            analyzer.close();

            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    // Expands the specified jar file into the given directory
    private void expandJar(String inputJar, File intoDir) throws IOException {
        try (JarInputStream jis = new JarInputStream(new FileInputStream(inputJar))) {
            JarEntry entry;
            while ((entry = jis.getNextJarEntry()) != null) {
                if (!entry.isDirectory()) {
                    byte[] data = ByteStreams.toByteArray(jis);
                    jis.closeEntry();
                    if (!entry.getName().contains("..")) {
                        File file = new File(intoDir, entry.getName());
                        createParentDirs(file);
                        write(data, file);
                    } else {
                        throw new IOException("Corrupt jar file");
                    }
                }
            }
        }
    }

    private boolean isWab() {
        return !Objects.equals(webContext, NONE);
    }

    private void doWabStaging(Analyzer analyzer) throws Exception {
        if (!isWab()) {
            return;
        }
        String wab = analyzer.getProperty(analyzer.WAB);
        Jar dot = analyzer.getJar();

        log("wab %s", wab);

        String specifiedClasspath = this.bundleClasspath;
        String bundleClasspath = "WEB-INF/classes";
        if (specifiedClasspath != null) {
            bundleClasspath += "," + specifiedClasspath;
        }
        analyzer.setBundleClasspath(bundleClasspath);

        Set<String> paths = new HashSet<>(dot.getResources().keySet());

        for (String path : paths) {
            if (path.indexOf('/') > 0 && !Character.isUpperCase(path.charAt(0))) {
                log("wab: moving: %s", path);
                dot.rename(path, "WEB-INF/classes/" + path);
            }
        }

        Path wabRoot = Paths.get(wab);
        log("wab root " + wabRoot.toString());
        includeFiles(dot, null, wabRoot.toString());
    }

    /**
     * Parse the Bundle-Includes header. Files in the bundles Include header are
     * included in the jar. The source can be a directory or a file.
     *
     * @throws Exception
     */
    private void doIncludeResources(Analyzer analyzer) throws Exception {
        String includes = analyzer.getProperty(Analyzer.INCLUDE_RESOURCE);
        if (includes == null) {
            return;
        }
        Parameters clauses = analyzer.parseHeader(includes);
        Jar jar = analyzer.getJar();

        for (Map.Entry<String, Attrs> entry : clauses.entrySet()) {
            String name = entry.getKey();
            Map<String, String> extra = entry.getValue();
            // TODO consider doing something with extras

            String[] parts = name.split("\\s*=\\s*");
            String source = parts[0];
            String destination = parts[0];
            if (parts.length == 2) {
                source = parts[1];
            }

            includeFiles(jar, destination, source);
        }
    }

    private void includeFiles(Jar jar, String destinationRoot, String sourceRoot)
            throws IOException {
        Path sourceRootPath = Paths.get(sourceRoot);
        // iterate through sources
        // put each source on the jar
        FileVisitor<Path> visitor = new SimpleFileVisitor<Path>() {
            @Override
            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                Path relativePath = sourceRootPath.relativize(file);
                String destination = destinationRoot != null ?
                        destinationRoot + "/" + relativePath.toString() : //TODO
                        relativePath.toString();

                addFileToJar(jar, destination, file.toAbsolutePath().toString());
                return FileVisitResult.CONTINUE;
            }
        };
        File dir = new File(sourceRoot);
        if (dir.isFile()) {
            addFileToJar(jar, destinationRoot, dir.getAbsolutePath());
        } else if (dir.isDirectory()) {
            walkFileTree(sourceRootPath, visitor);
        } else {
            warn("Skipping resource in bundle %s: %s (File Not Found)\n",
                    bundleSymbolicName, sourceRoot);
        }
    }

    private boolean addFileToJar(Jar jar, String destination, String sourceAbsPath) throws IOException {
        if (includedResources.contains(sourceAbsPath)) {
            log("Skipping already included resource: %s\n", sourceAbsPath);
            return false;
        }
        File file = new File(sourceAbsPath);
        if (!file.isFile()) {
            throw new RuntimeException(
                    String.format("Skipping non-existent file: %s\n", sourceAbsPath));
        }
        Resource resource = new FileResource(file);
        if (jar.getResource(destination) != null) {
            warn("Skipping duplicate resource: %s\n", destination);
            return false;
        }
        jar.putResource(destination, resource);
        includedResources.add(sourceAbsPath);
        log("Adding resource: %s\n", destination);
        return true;
    }

    private void log(String format, Object... objects) {
        //System.err.printf(format, objects);
    }

    private void warn(String format, Object... objects) {
        System.err.printf(format, objects);
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
                .add("inputJar", inputJar)
                .add("outputJar", outputJar)
                .add("classpath", classpath)
                .add("bundleName", bundleName)
                .add("groupId", groupId)
                .add("bundleSymbolicName", bundleSymbolicName)
                .add("bundleVersion", bundleVersion)
                .add("bundleDescription", bundleDescription)
                .add("bundleLicense", bundleLicense)
                .add("bundleClassPath", bundleClasspath)
                .toString();

    }
}