package org.smallmind.license;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.plugins.annotations.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.project.MavenProject;

// Installs license files for inclusion in distribution artifacts
@Mojo(name = "install-license-files", defaultPhase = LifecyclePhase.PREPARE_PACKAGE, threadSafe = true)
public class TargetLicenseMojo extends AbstractMojo {

  @Parameter(readonly = true, property = "project")
  private MavenProject project;
  @Parameter
  private Root root;
  @Parameter
  private Rule[] rules;
  @Parameter
  private String[] licenses;
  @Parameter(defaultValue = "false")
  private boolean verbose;

  @Override
  public void execute ()
    throws MojoExecutionException, MojoFailureException {

    if ((new File(project.getBuild().getOutputDirectory())).exists()) {

      MavenProject rootProject = project;
      byte[] buffer = new byte[8192];

      while ((root == null) ? !(rootProject.getParent() == null) : !(root.getGroupId().equals(rootProject.getGroupId()) && root.getArtifactId().equals(rootProject.getArtifactId()))) {
        rootProject = rootProject.getParent();
      }

      for (String license : licenses) {

        File licenseFile;
        File copyFile;
        FileInputStream inputStream;
        FileOutputStream outputStream;
        int bytesRead;

        if (!(licenseFile = new File(license)).isAbsolute()) {
          licenseFile = new File(rootProject.getBasedir() + System.getProperty("file.separator") + licenseFile.getPath());
        }

        if (!licenseFile.exists()) {
          getLog().warn(String.format("Unable to acquire the license file(%s), skipping license copying...", licenseFile.getAbsolutePath()));
        }
        else {
          if (verbose) {
            getLog().info(String.format("Copying license(%s)...", licenseFile.getName()));
          }

          copyFile = new File(project.getBuild().getOutputDirectory() + System.getProperty("file.separator") + licenseFile.getName());

          try {
            outputStream = new FileOutputStream(copyFile);
          }
          catch (IOException ioException) {
            throw new MojoExecutionException("Unable to create output license file (" + copyFile.getAbsolutePath() + ")", ioException);
          }

          try {
            inputStream = new FileInputStream(licenseFile);

            while ((bytesRead = inputStream.read(buffer)) >= 0) {
              outputStream.write(buffer, 0, bytesRead);
            }

            inputStream.close();
          }
          catch (IOException ioException) {
            copyFile.delete();
            throw new MojoExecutionException("Problem in copying output license file (" + copyFile.getAbsolutePath() + ")", ioException);
          }

          try {
            outputStream.close();
          }
          catch (IOException ioException) {
            throw new MojoExecutionException("Problem in closing license file (" + licenseFile.getAbsolutePath() + ")", ioException);
          }
        }
      }
    }
  }
}