/*
 * Copyright 2017-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 com.facebook.buck.util.function.ThrowingSupplier;
import com.facebook.buck.zip.CustomZipEntry;
import com.facebook.buck.zip.JarBuilder;
import com.facebook.buck.zip.JarEntrySupplier;
import com.google.common.base.Preconditions;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Path;

/** A {@link StubJarWriter} that writes to a file through {@link ProjectFilesystem}. */
class FilesystemStubJarWriter implements StubJarWriter {
  private final Path outputPath;
  private final JarBuilder jarBuilder;
  private boolean closed = false;

  public FilesystemStubJarWriter(ProjectFilesystem filesystem, Path outputPath) throws IOException {
    Preconditions.checkState(
        !filesystem.exists(outputPath), "Output file already exists: %s)", outputPath);

    if (outputPath.getParent() != null && !filesystem.exists(outputPath.getParent())) {
      filesystem.createParentDirs(outputPath);
    }

    this.outputPath = filesystem.resolve(outputPath);
    jarBuilder = new JarBuilder().setShouldHashEntries(true);
  }

  @Override
  public void writeEntry(
      Path relativePath, ThrowingSupplier<InputStream, IOException> streamSupplier)
      throws IOException {
    jarBuilder.addEntry(
        new JarEntrySupplier(
            new CustomZipEntry(MorePaths.pathWithUnixSeparators(relativePath)),
            outputPath.toString(),
            streamSupplier));
  }

  @Override
  public void close() throws IOException {
    if (!closed) {
      jarBuilder.createJarFile(outputPath);
    }
    closed = true;
  }
}