package vtk;

import java.io.File;

/**
 * Enum used to load native library more easily. If you don't want to set the
 * specific environment variable you can provide the path of the directory that
 * contains the VTK library through a Java Property. Like in the following
 * command line:
 *
 * > java -cp vtk.jar -Dvtk.lib.dir=.../vtk-libs vtk.sample.SimpleVTK
 *
 * The directory .../vtk-libs must contain the so/dll/dylib + the jnilib files
 *
 * @author sebastien jourdain - sebastien.jourdain@kitware.com
 */
public enum vtkNativeLibrary {

@VTK_JAVA_NATIVE_LIBRARIES@

  /**
   * Try to load all library
   *
   * @return true if all library have been successfully loaded
   */
  public static boolean LoadAllNativeLibraries() {
    boolean isEveryThingLoaded = true;
    for (vtkNativeLibrary lib : values()) {
      try {
        if(lib.IsBuilt()) {
          lib.LoadLibrary();
        }
      } catch (UnsatisfiedLinkError e) {
        isEveryThingLoaded = false;
        e.printStackTrace();
      }
    }

    return isEveryThingLoaded;
  }

  /**
   * Load the set of given library and trows runtime exception if any given
   * library failed in the loading process
   *
   * @param nativeLibraries
   */
  public static void LoadNativeLibraries(vtkNativeLibrary... nativeLibraries) {
    for (vtkNativeLibrary lib : nativeLibraries) {
      lib.LoadLibrary();
    }
  }

  /**
   * Disable the pop-in vtkErrorWindow by writing the error to a log file.
   * If the provided logFile is null the default "vtkError.txt" file will be
   * used.
   *
   * @param logFile
   */
  public static void DisableOutputWindow(File logFile) {
    if(logFile == null) {
      logFile = new File("vtkError.txt");
    }
    vtkFileOutputWindow outputError = new vtkFileOutputWindow();
    outputError.SetFileName(logFile.getAbsolutePath());
    outputError.SetInstance(outputError);
  }

  private vtkNativeLibrary(String nativeLibraryName, boolean built) {
    this.nativeLibraryName = nativeLibraryName;
    this.loaded = false;
    this.built = built;
  }

  /**
   * Load the library and throws runtime exception if the library failed in
   * the loading process
   */
  public void LoadLibrary() throws UnsatisfiedLinkError {
    if (!loaded) {
      if (System.getProperty("vtk.lib.dir") != null) {
        File dir = new File(System.getProperty("vtk.lib.dir"));
        patchJavaLibraryPath(dir.getAbsolutePath());
        File libPath = new File(dir, System.mapLibraryName(nativeLibraryName));
        if (libPath.exists()) {
          try {
            Runtime.getRuntime().load(libPath.getAbsolutePath());
            loaded = true;
            return;
          } catch (UnsatisfiedLinkError e) {
            e.printStackTrace();
          }
        }
      }
      System.loadLibrary(nativeLibraryName);
    }
    loaded = true;
  }

  /**
   * @return true if the library has already been successfully loaded
   */
  public boolean IsLoaded() {
    return loaded;
  }

  /**
   * @return true if the module was enabled and therefore build
   */
  public boolean IsBuilt() {
    return built;
  }

  /**
   * @return the library name
   */
  public String GetLibraryName() {
    return nativeLibraryName;
  }

  private static void patchJavaLibraryPath(String vtkLibDir) {
    if (vtkLibDir != null) {
      String path_separator = System.getProperty("path.separator");
      String s = System.getProperty("java.library.path");
      if (!s.contains(vtkLibDir)) {
        s = s + path_separator + vtkLibDir;
        System.setProperty("java.library.path", s);
      }
    }
  }

  private String nativeLibraryName;
  private boolean loaded;
  private boolean built;
}