/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2022 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.devops.conga.plugins.aem.maven.model;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Collection;
  import java.util.LinkedHashSet;
  import java.util.Set;
  
  import org.jetbrains.annotations.NotNull;
  
  import com.google.common.hash.HashCode;
  import com.google.common.hash.Hashing;
  import com.google.common.io.Files;
  
  import io.wcm.devops.conga.generator.util.FileUtil;
  
  /**
   * Describes an installable file with a set of run modes and (lazily evaluated) hash code.
   */
  public abstract class AbstractInstallableFile implements InstallableFile {
  
    private final File file;
    private final Set<String> variants;
    private HashCode hashCode;
  
    protected AbstractInstallableFile(File file, Collection<String> variants) {
      this.file = file;
      this.variants = new LinkedHashSet<>(variants);
    }
  
    @Override
    @NotNull
    public File getFile() {
      return file;
    }
  
    @Override
    @NotNull
    public Set<String> getVariants() {
      return variants;
    }
  
    @Override
    @NotNull
    public HashCode getHashCode() {
      if (this.hashCode == null) {
        this.hashCode = getHashCode(file);
      }
      return this.hashCode;
    }
  
    @Override
    public String toString() {
      return file.toString();
    }
  
    private static HashCode getHashCode(File file) {
      try {
        return Files.asByteSource(file).hash(Hashing.sha256());
      }
      catch (IOException ex) {
        throw new IllegalArgumentException("Unable to get hashcode for " + FileUtil.getCanonicalPath(file), ex);
      }
    }
  
  }