package org.vamsas.client.simpleclient;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarInputStream;
import java.util.jar.JarOutputStream;
/**
 * Basic methods for accessing an existing Vamsas Archive, 
 * and Jar entry names for creating new vamsas archives.
 * 
 * @author jimp
 *
 */
public class VamsasArchiveReader {
  JarFile jfile;
  public VamsasArchiveReader(File vamsasfile) {
    jfile=null;
    if (vamsasfile.exists()) {
      try {
        jfile=new JarFile(vamsasfile);
      }
      catch (Exception e) {
        jfile=null;
      }
    }
    
  }
  
  /**
   * name of the jarEntry containing a well formatted vamsas XML Document
   */
  
  final public static String VAMSASDOC="vamsasDocument.xml";
  
  /**
   * name of the jarEntry containing a root VAMSAS element, and containing a 
   * random sequence of VAMSAS DataSet elements 
   */
  
  final public static String VAMSASXML="vamsas.xml";
  
  /**
   * 
   * @return JarEntry for VamsasArchiveReader.VAMSASDOC
   */
  protected JarEntry getVamsasDocumentEntry() {
    if (jfile!=null)
      return jfile.getJarEntry(VAMSASDOC);
    return null;
  }
  /**
   * 
   * @return JarEntry for VamsasArchiveReader.VAMSASXML
   */
  protected JarEntry getVamsasXmlEntry() {
    if (jfile!=null)
      return jfile.getJarEntry(VAMSASXML);
    return null;
  }
  /**
   * Test for valid vamsas document archive
   * @return true if getVamsasDocumentStream will return a stream likely to contain valid XML
   */
  public boolean isValid() {
    if (jfile!=null)
      // TODO: check if VAMSASDOC is well formed, follows www.vamsas.ac.uk/schemas/vamsasDocument.xsd, and all appData references are resolvable - preferably as jar entries
      return (getVamsasDocumentEntry()!=null);
    return false;   
  }

  /**
   * get the VamsasDocument input stream, if it exists.
   * @return null or valid input stream
   */
  public InputStream getVamsasDocumentStream() {
    InputStream vdoc;
    if (jfile==null || !isValid())
      return null;
    try {
      vdoc = jfile.getInputStream(getVamsasDocumentEntry());
    } catch (IOException e) {
      e.printStackTrace(System.err);
      vdoc=null;
    }
    return vdoc;
  }
  
  /**
   * get the VamsasXML input stream, if it exists.
   * Note: Deprecated beyond our prealpha testing.
   * @return null or valid input stream.
   */
  
  public InputStream getVamsasXmlStream() {
    JarEntry xmle=getVamsasXmlEntry();
    InputStream vdoc;
    if (xmle==null)
      return null;
    try {
      vdoc = jfile.getInputStream(xmle);
    } catch (IOException e) {
      e.printStackTrace(System.err);
      vdoc=null;
    }
    return vdoc;
  }
  
  /**
   * silently close the jar file.
   *
   */
  public void close() {
    if (jfile!=null) {
      try {
        jfile.close();
      } catch (IOException e) {
        e.printStackTrace(System.err);
      }
    }
  }
}