// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.container.plugin.bundle;

import com.yahoo.container.plugin.osgi.ExportPackageParser;
import com.yahoo.container.plugin.osgi.ExportPackages.Export;
import com.yahoo.container.plugin.util.JarFiles;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.jar.Manifest;
import java.util.stream.Collectors;

/**
 * Static utilities for analyzing jar files.
 *
 * @author Tony Vaagenes
 * @author ollivir
 * @author gjoranv
 */
public class AnalyzeBundle {

    public static List<Export> exportedPackagesAggregated(Collection<File> jarFiles) {
        List<Export> exports = new ArrayList<>();

        for (File jarFile : jarFiles) {
            var exported = exportedPackages(jarFile);
            exports.addAll(exported);
        }
        return exports;
    }

    static List<Export> exportedPackages(File jarFile) {
        try {
            Optional<Manifest> jarManifest = JarFiles.getManifest(jarFile);
            if (jarManifest.isPresent()) {
                Manifest manifest = jarManifest.get();
                if (isOsgiManifest(manifest)) {
                    return parseExports(manifest);
                }
            }
            return Collections.emptyList();
        } catch (Exception e) {
            throw new RuntimeException(String.format("Invalid manifest in bundle '%s'", jarFile.getPath()), e);
        }
    }

    public static Optional<String> bundleSymbolicName(File jarFile) {
        return JarFiles.getManifest(jarFile).flatMap(AnalyzeBundle::getBundleSymbolicName);
    }

    private static List<Export> parseExports(Manifest jarManifest) {
        return getMainAttributeValue(jarManifest, "Export-Package")
                .map(ExportPackageParser::parseExports)
                .orElseGet(ArrayList::new);
    }

    private static Optional<String> getMainAttributeValue(Manifest manifest, String attributeName) {
        return Optional.ofNullable(manifest.getMainAttributes().getValue(attributeName));
    }

    private static boolean isOsgiManifest(Manifest mf) {
        return getBundleSymbolicName(mf).isPresent();
    }

    private static Optional<String> getBundleSymbolicName(Manifest mf) {
        return getMainAttributeValue(mf, "Bundle-SymbolicName");
    }
}