/*
 * Copyright 2014-present Facebook, Inc.
 *
 * 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.facebook.buck.jvm.java.abi;

import com.facebook.buck.io.MorePaths;
import com.facebook.buck.io.ProjectFilesystem;
import java.io.IOException;
import java.nio.file.Path;
import java.util.Comparator;
import java.util.List;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.Elements;
import javax.tools.JavaFileManager;

public class StubJar {
  private final Supplier<LibraryReader> libraryReaderSupplier;
  private boolean sourceAbiCompatible;

  public StubJar(Path toMirror) {
    libraryReaderSupplier = () -> LibraryReader.of(toMirror);
  }

  /**
   * @param targetVersion the class file version to output, expressed as the corresponding Java
   *     source version
   */
  public StubJar(
      SourceVersion targetVersion, Elements elements, Iterable<TypeElement> topLevelTypes) {
    libraryReaderSupplier = () -> LibraryReader.of(targetVersion, elements, topLevelTypes);
  }

  /**
   * Filters the stub jar through {@link SourceAbiCompatibleVisitor}. See that class for details.
   */
  public StubJar setSourceAbiCompatible(boolean sourceAbiCompatible) {
    this.sourceAbiCompatible = sourceAbiCompatible;
    return this;
  }

  public void writeTo(ProjectFilesystem filesystem, Path path) throws IOException {
    try (StubJarWriter writer = new FilesystemStubJarWriter(filesystem, path)) {
      writeTo(writer);
    }
  }

  public void writeTo(JavaFileManager fileManager) throws IOException {
    try (StubJarWriter writer = new JavaFileManagerStubJarWriter(fileManager)) {
      writeTo(writer);
    }
  }

  private void writeTo(StubJarWriter writer) throws IOException {
    try (LibraryReader input = libraryReaderSupplier.get()) {
      List<Path> paths =
          input
              .getRelativePaths()
              .stream()
              .sorted(Comparator.comparing(MorePaths::pathWithUnixSeparators))
              .collect(Collectors.toList());

      for (Path path : paths) {
        StubJarEntry entry = StubJarEntry.of(input, path);
        if (entry == null) {
          continue;
        } else if (entry instanceof StubJarClassEntry) {
          ((StubJarClassEntry) entry).setSourceAbiCompatible(sourceAbiCompatible);
        }
        entry.write(writer);
      }
    }
  }
}