hazelcast-master/hazelcast-build-utils/src/main/java/com/hazelcast/buildutils/HazelcastManifestTransformer.java
/*
 * Copyright (c) 2008-2023, Hazelcast, Inc. All Rights Reserved.
 *
 * 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 com.hazelcast.buildutils;

import aQute.lib.osgi.Instruction;
import com.hazelcast.logging.ILogger;
import com.hazelcast.logging.Logger;
import org.apache.maven.plugins.shade.relocation.Relocator;
import org.apache.maven.plugins.shade.resource.ManifestResourceTransformer;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.jar.Attributes;
import java.util.jar.Attributes.Name;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;

import static java.util.Arrays.asList;
import static java.util.Collections.emptySet;
import static org.codehaus.plexus.util.IOUtil.close;
import static org.codehaus.plexus.util.StringUtils.join;

/**
 * This transformer implementation is used to merge MANIFEST and OSGi
 * bundle metadata in conjunction with the Maven Shade plugin when
 * integrating multiple dependencies into one output JAR.
 */
public class HazelcastManifestTransformer extends ManifestResourceTransformer {

    private static final ILogger LOGGER = Logger.getLogger(HazelcastManifestTransformer.class);

    private static final String VERSION_PREFIX = "version=";
    private static final String RESOLUTION_PREFIX = "resolution:=";
    private static final String USES_PREFIX = "uses:=";

    private static final int VERSION_OFFSET = 8;
    private static final int USES_OFFSET = 7;

    private static final String IMPORT_PACKAGE = "Import-Package";
    private static final String EXPORT_PACKAGE = "Export-Package";

    private static final Name AUTOMATIC_MODULE_NAME = new Name("Automatic-Module-Name");

    // configuration
    private String mainClass;
    private Map<String, Object> manifestEntries;
    private Map<String, String> overrideInstructions;

    private final Map<String, PackageDefinition> importedPackages = new HashMap<>();
    private final Map<String, PackageDefinition> exportedPackages = new HashMap<>();
    private final List<InstructionDefinition> importOverrideInstructions = new ArrayList<>();
    private final List<InstructionDefinition> exportOverrideInstructions = new ArrayList<>();

    private Manifest shadedManifest;

    @Override
    public void setMainClass(String mainClass) {
        this.mainClass = mainClass;
        super.setMainClass(mainClass);
    }

    @Override
    public void setManifestEntries(Map<String, Object> manifestEntries) {
        this.manifestEntries = manifestEntries;
        super.setManifestEntries(manifestEntries);
    }

    public void setOverrideInstructions(Map<String, String> overrideInstructions) {
        this.overrideInstructions = overrideInstructions;
    }

    @Override
    public boolean canTransformResource(String resource) {
        return JarFile.MANIFEST_NAME.equals(resource.toUpperCase(Locale.ROOT));
    }

    @Override
    public void processResource(String resource, InputStream inputStream, List<Relocator> relocators, long time)
            throws IOException {
        Attributes attributes;
        if (shadedManifest == null) {
            shadedManifest = new Manifest(inputStream);
            attributes = shadedManifest.getMainAttributes();
        } else {
            Manifest manifest = new Manifest(inputStream);
            attributes = manifest.getMainAttributes();
        }

        String importPackages = attributes.getValue(IMPORT_PACKAGE);
        if (importPackages != null) {
            List<String> definitions = ElementParser.parseDelimitedString(importPackages, ',', true);
            for (String definition : definitions) {
                PackageDefinition packageDefinition = new PackageDefinition(definition);

                String packageName = packageDefinition.packageName;
                PackageDefinition oldPackageDefinition = importedPackages.get(packageName);
                importedPackages.put(packageName, findStrongerDefinition(packageDefinition, oldPackageDefinition));
            }
        }

        String exportPackages = attributes.getValue(EXPORT_PACKAGE);
        if (exportPackages != null) {
            List<String> definitions = ElementParser.parseDelimitedString(exportPackages, ',', true);
            for (String definition : definitions) {
                PackageDefinition packageDefinition = new PackageDefinition(definition);

                String packageName = packageDefinition.packageName;
                PackageDefinition oldPackageDefinition = exportedPackages.get(packageName);
                exportedPackages.put(packageName, mergeExportUsesConstraint(packageDefinition, oldPackageDefinition));
            }
        }

        close(inputStream);
    }

    private PackageDefinition findStrongerDefinition(PackageDefinition packageDefinition,
                                                     PackageDefinition oldPackageDefinition) {
        // if the override is a remove instruction skip all other tests
        if (packageDefinition.removeImport) {
            return packageDefinition;
        }

        // if no old definition or new definition is required import we take the new one
        if (oldPackageDefinition == null
                || oldPackageDefinition.resolutionOptional && !packageDefinition.resolutionOptional) {
            return packageDefinition;
        }

        // if old definition was required import but new isn't we take the old one
        if (!oldPackageDefinition.resolutionOptional && packageDefinition.resolutionOptional) {
            return oldPackageDefinition;
        }

        if (oldPackageDefinition.version == null && packageDefinition.version != null) {
            return packageDefinition;
        }

        if (oldPackageDefinition.version != null && packageDefinition.version == null) {
            return oldPackageDefinition;
        }

        return oldPackageDefinition;
    }

    private PackageDefinition mergeExportUsesConstraint(PackageDefinition packageDefinition,
                                                        PackageDefinition oldPackageDefinition) {
        Set<String> uses = new LinkedHashSet<>();
        if (oldPackageDefinition != null) {
            uses.addAll(oldPackageDefinition.uses);
        }
        uses.addAll(packageDefinition.uses);

        String packageName = packageDefinition.packageName;
        boolean resolutionOptional = packageDefinition.resolutionOptional;
        String version = packageDefinition.version;
        return new PackageDefinition(packageName, resolutionOptional, version, uses);
    }

    @Override
    public boolean hasTransformedResource() {
        return true;
    }

    @Override
    public void modifyOutputStream(JarOutputStream jarOutputStream) throws IOException {
        if (shadedManifest == null) {
            shadedManifest = new Manifest();
        }

        Attributes attributes = shadedManifest.getMainAttributes();

        if (overrideInstructions != null) {
            precompileOverrideInstructions();
            attributes.putValue(IMPORT_PACKAGE, join(shadeImports().iterator(), ","));
            attributes.putValue(EXPORT_PACKAGE, join(shadeExports().iterator(), ","));
        }

        attributes.putValue("Created-By", "HazelcastManifestTransformer through Shade Plugin");

        if (mainClass != null) {
            attributes.put(Attributes.Name.MAIN_CLASS, mainClass);
        }

        if (manifestEntries != null) {
            for (Map.Entry<String, Object> entry : manifestEntries.entrySet()) {
                attributes.put(new Attributes.Name(entry.getKey()), entry.getValue());
            }
        }

        // the Manifest in hazelcast uberjar won't have the Automatic-Module-Name
        attributes.remove(AUTOMATIC_MODULE_NAME);

        jarOutputStream.putNextEntry(new JarEntry(JarFile.MANIFEST_NAME));
        shadedManifest.write(jarOutputStream);
        jarOutputStream.flush();
    }

    private void precompileOverrideInstructions() {
        String importPackageInstructions = overrideInstructions.get(IMPORT_PACKAGE);
        if (importPackageInstructions != null) {
            List<String> packageInstructions = ElementParser.parseDelimitedString(importPackageInstructions, ',', true);
            for (String packageInstruction : packageInstructions) {
                PackageDefinition packageDefinition = new PackageDefinition(packageInstruction);
                Instruction instruction = Instruction.getPattern(packageDefinition.packageName);
                LOGGER.fine("Compiled import instruction '" + packageInstruction + "' -> " + instruction);
                importOverrideInstructions.add(new InstructionDefinition(packageDefinition, instruction));
            }
        }
        String exportPackageInstructions = overrideInstructions.get(EXPORT_PACKAGE);
        if (exportPackageInstructions != null) {
            List<String> packageInstructions = ElementParser.parseDelimitedString(exportPackageInstructions, ',', true);
            for (String packageInstruction : packageInstructions) {
                PackageDefinition packageDefinition = new PackageDefinition(packageInstruction);
                Instruction instruction = Instruction.getPattern(packageDefinition.packageName);
                LOGGER.fine("Compiled export instruction '" + packageInstruction + "' -> " + instruction);
                exportOverrideInstructions.add(new InstructionDefinition(packageDefinition, instruction));
            }
        }
    }

    private Set<String> shadeExports() {
        Set<String> exports = new LinkedHashSet<>();
        for (Map.Entry<String, PackageDefinition> entry : exportedPackages.entrySet()) {
            String definition = entry.getValue().buildDefinition(false);
            exports.add(definition);
            LOGGER.fine("Adding shaded export -> " + definition);
        }
        return exports;
    }

    private Set<String> shadeImports() {
        for (String export : exportedPackages.keySet()) {
            PackageDefinition definition = new PackageDefinition(export);
            importedPackages.remove(definition.packageName);
        }
        Set<String> imports = new LinkedHashSet<>();
        for (Map.Entry<String, PackageDefinition> entry : importedPackages.entrySet()) {
            PackageDefinition original = entry.getValue();
            PackageDefinition overridden = overridePackageDefinitionResolution(original);
            if (overridden != null) {
                String definition = overridden.buildDefinition(true);
                imports.add(definition);
                LOGGER.fine("Adding shaded import -> " + definition);
            } else {
                LOGGER.fine("Removing shaded import -> " + entry.getValue().packageName);
            }
        }
        return imports;
    }

    private PackageDefinition overridePackageDefinitionResolution(PackageDefinition packageDefinition) {
        for (InstructionDefinition instructionDefinition : importOverrideInstructions) {
            Instruction instruction = instructionDefinition.instruction;
            if (instruction.matches(packageDefinition.packageName)) {
                // is remove instruction?
                if (instruction.isNegated()) {
                    LOGGER.fine("Instruction '" + instruction + "' -> package '" + packageDefinition.packageName + "'");
                    return null;
                }

                LOGGER.fine("Instruction '" + instruction + "' -> package '" + packageDefinition.packageName + "'");

                PackageDefinition override = instructionDefinition.packageDefinition;
                String packageName = packageDefinition.packageName;
                String version = packageDefinition.version;
                Set<String> uses = packageDefinition.uses;
                return new PackageDefinition(packageName, override.resolutionOptional, version, uses);
            }
        }

        return packageDefinition;
    }

    static final class PackageDefinition {

        private final boolean removeImport;
        private final String packageName;
        private final boolean resolutionOptional;
        private final String version;
        private final Set<String> uses;

        PackageDefinition(String definition) {
            String[] tokens = definition.split(";");
            this.removeImport = tokens[0].startsWith("!");
            this.packageName = tokens[0];
            this.resolutionOptional = findResolutionConstraint(tokens);
            this.version = findVersionConstraint(tokens);
            this.uses = findUsesConstraint(tokens);
        }

        PackageDefinition(String packageName, boolean resolutionOptional, String version, Set<String> uses) {
            this.removeImport = packageName.startsWith("!");
            this.packageName = packageName;
            this.resolutionOptional = resolutionOptional;
            this.version = version;
            this.uses = new LinkedHashSet<>(uses);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            PackageDefinition that = (PackageDefinition) o;
            return Objects.equals(packageName, that.packageName);
        }

        @Override
        public int hashCode() {
            return packageName != null ? packageName.hashCode() : 0;
        }

        @Override
        public String toString() {
            return "PackageDefinition{"
                    + "packageName='" + packageName + '\''
                    + ", resolutionOptional=" + resolutionOptional
                    + ", version='" + version + '\''
                    + ", uses=" + uses + '}';
        }

        String buildDefinition(boolean addResolutionConstraint) {
            StringBuilder sb = new StringBuilder(packageName);
            if (addResolutionConstraint && resolutionOptional) {
                sb.append(";").append(RESOLUTION_PREFIX).append("optional");
            }
            if (version != null) {
                sb.append(";").append(VERSION_PREFIX).append(version);
            }
            if (uses != null && !uses.isEmpty()) {
                sb.append(";").append(USES_PREFIX).append('"').append(join(uses.iterator(), ",")).append('"');
            }
            return sb.toString();
        }

        private String findVersionConstraint(String[] tokens) {
            for (String token : tokens) {
                if (token.startsWith(VERSION_PREFIX)) {
                    return token.substring(VERSION_OFFSET);
                }
            }
            return null;
        }

        private boolean findResolutionConstraint(String[] tokens) {
            for (String token : tokens) {
                if (token.startsWith(RESOLUTION_PREFIX)) {
                    return token.toLowerCase(Locale.ROOT).equals("resolution:=optional");
                }
            }
            return false;
        }

        private Set<String> findUsesConstraint(String[] tokens) {
            for (String token : tokens) {
                if (token.startsWith(USES_PREFIX)) {
                    String packages = token.substring(USES_OFFSET, token.length() - 1);
                    String[] sepPackages = packages.split(",");
                    return new LinkedHashSet<>(asList(sepPackages));
                }
            }
            return emptySet();
        }
    }

    static final class InstructionDefinition {

        private final PackageDefinition packageDefinition;
        private final Instruction instruction;

        InstructionDefinition(PackageDefinition packageDefinition, Instruction instruction) {
            this.packageDefinition = packageDefinition;
            this.instruction = instruction;
        }

        @Override
        public String toString() {
            return "InstructionDefinition{"
                    + "packageDefinition=" + packageDefinition
                    + ", instruction=" + instruction + '}';
        }
    }
}
