/*
 * Copyright (C) 2020 The Dagger Authors.
 *
 * 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.
 */

import java.util.jar.Manifest;
import com.github.jengelman.gradle.plugins.shadow.transformers.Transformer
import com.github.jengelman.gradle.plugins.shadow.transformers.TransformerContext
import shadow.org.apache.tools.zip.ZipOutputStream
import shadow.org.apache.tools.zip.ZipEntry

plugins {
  id 'java-library'
  // Use shadow version >= 7.1.1 to get log4j vulnerability patches:
  //   https://github.com/johnrengelman/shadow/releases/tag/7.1.1
  id 'com.github.johnrengelman.shadow' version '7.1.1'
}

repositories {
  mavenCentral()
  mavenLocal()
}

java {
    // This can be Java 8 because this is non-Android and so isn't required to
    // be Java 11 by AGP.
    sourceCompatibility = JavaVersion.VERSION_1_8
}

// This transformation makes sure the input jar's MANIFEST.MF properties,
// such as "Created-by:" get merged into the final artifact jar (although it's
// not clear how necessary this is).
/** A transform that merges in the MANIFEST.MF files from the inputJar.  */
class ManifestMerger implements Transformer {
    private static final String MANIFEST_MF = "META-INF/MANIFEST.MF";

    private Manifest manifest;

    @Override
    boolean canTransformResource(FileTreeElement element) {
        return MANIFEST_MF.equalsIgnoreCase(element.relativePath.pathString);
    }

    @Override
    void transform(TransformerContext context) {
        if (manifest == null) {
            manifest = new Manifest(context.is);
        } else {
            Manifest toMerge = new Manifest(context.is);
            manifest.getMainAttributes()
                .putAll(toMerge.getMainAttributes().entrySet());
            manifest.getEntries().putAll(toMerge.getEntries().entrySet());
        }
    }

    @Override
    boolean hasTransformedResource() { true }

    @Override
    void modifyOutputStream(
            ZipOutputStream os, boolean preserveFileTimestamps) {
        os.putNextEntry(new ZipEntry(MANIFEST_MF));
        if (manifest != null) {
            ByteArrayOutputStream content = new ByteArrayOutputStream();
            manifest.write(content);
            os.write(content.toByteArray());
        }
    }
}

configurations {
    shaded
}

shadowJar {
    // This transform is needed so that services get relocated/shaded as well.
    mergeServiceFiles()

    archiveClassifier = "" // postfix for output jar
    configurations = [project.configurations.shaded]
    transform(ManifestMerger.class)

    // Add a 'relocate' declaration for each shaded rule.
    //   Format: "key1,value1;key2,value2;key3,value3"
    def rules = project.getProperty("shadedRules").split(";")
    for (def i = 0; i < rules.size(); i++) {
        def rule = rules[i].split(",")
        relocate "${rule[0]}", "${rule[1]}"
    }
}

dependencies {
    shaded files(project.getProperty("inputJar"))
}