/**
 * PO_DBDialog
 *
 * A custom dialog for browsing the database
 * User can also extend this class for specific application capabilities
 *
 * @version 1.2 April 1997
 * @author  Francis Chan <fchan@iceecs.berkeley.edu>
 */

import java.awt.*;
import java.util.*;
import java.lang.*;
import java.io.*;

public class PO_DBDialog extends Frame{

  public static final int OPEN = 0;
  public static final int SAVE = 1;

  private List m_dirs;
  private List m_files;
  protected Vector dirVec;
  protected Vector fileVec;
  private TextField m_filter;
  private TextField m_selection;
  private String m_fileSelected;
  private String m_dirSelected;
  private Vector contentsVec;
  private String title;
  private String user;
  private DirObject rootDir;
  private int mode = OPEN;
  private PersistentObject pObj;

  /**
   * Constructor for PO_DBDialog
   * 
   * @param title        Title for the dialog box
   * @param contentsVec  Initial Contents of the dialog box      
   */
  public PO_DBDialog(String title, Vector contentsVec) {

    super(title);
    this.title = title;
    this.dirVec = contentsVec;
    fileVec = new Vector();

    setup();
  }

  /**
   * Constructor for PO_DBDialog
   * 
   * @param user         User name
   */
  public PO_DBDialog(String user) {

    setTitle("DB Browser");
    this.user = user;
    contentsVec = new Vector();
    fileVec = new Vector();
    setup();
  }

  /**
   * Constructor for PO_DBDialog
   * 
   * @param user         User name
   * @param mode         SAVE or OPEN
   * @param pObj         Persistent Object to be saved (if any)
   */
  public PO_DBDialog(String user, int mode, PersistentObject pObj) {

    setTitle("DB Browser");
    this.user = user;
    this.mode = mode;
    this.pObj = pObj;
    contentsVec = new Vector();
    fileVec = new Vector();
    setup();
  }

  private void setup(){

    dirVec = new Vector();

    GridBagLayout gridbag = new GridBagLayout();
    GridBagConstraints c = new GridBagConstraints();
    setFont(new Font("Courier", Font.PLAIN, 14));
    setLayout(gridbag);
    c.fill = GridBagConstraints.BOTH;
    c.weightx = 1.0;
    c.anchor = GridBagConstraints.WEST;
    c.gridwidth = GridBagConstraints.REMAINDER; //end row
    makeLabel("Filter", gridbag, c);
    c.anchor = GridBagConstraints.CENTER;
    //m_filter = new TextField("/", 80);
    m_filter = new TextField(80);
    makeTextField(m_filter, gridbag, c);

    c.anchor = GridBagConstraints.WEST;
    c.gridwidth = GridBagConstraints.RELATIVE;
    makeLabel("Directory", gridbag, c);
    c.gridwidth = GridBagConstraints.REMAINDER; //end row
    makeLabel("Contents", gridbag, c);
    
    c.weighty = 1.0;
    c.gridheight = 10;
    c.anchor = GridBagConstraints.CENTER;
    c.gridwidth = GridBagConstraints.RELATIVE;
    m_dirs = new List();
    m_files = new List();
    makeList(m_dirs, gridbag, c);
    c.gridwidth = GridBagConstraints.REMAINDER; //end row
    makeList(m_files, gridbag, c);

    c.gridheight = 1;
    c.weighty = 0.0;
    c.anchor = GridBagConstraints.WEST;
    c.gridwidth = GridBagConstraints.REMAINDER; //end row
    makeLabel("Entry", gridbag, c);
    c.anchor = GridBagConstraints.CENTER;
    m_selection = new TextField(80);
    //m_selection = new TextField("/", 80);
    makeTextField(m_selection, gridbag, c);
    
    MyPanel p = new MyPanel();
    //p.setLayout(new GridLayout(1,3,15,15));
    p.setLayout(new GridLayout(1,3,15,15));
    p.insets();
    p.add(new Button("Open"));
    if (mode == SAVE)
      p.add(new Button("Save"));
    //p.add(new Button("Up"));
    p.add(new Button("Cancel"));
    c.gridheight = 20;
    c.gridwidth = GridBagConstraints.REMAINDER; //end row
    makePanel(p, gridbag, c);

    resize(350, 380);
    
    init();
    show();
  }

  private void init(){

    rootDir = new DirObject();
    rootDir.getRoot();

    PO_ObjectInfo rootDir = new PO_ObjectInfo("DirObject", "root", 11);
    dirVec.addElement(rootDir);
    m_dirs.addItem("root/");
    m_files.addItem("");
  }

  /**
   * Assesses the information in dirVec and fileVec
   * to update the m_dirs and m_files list
   */
  private void updateInfo(){

    int i;
    PO_ObjectInfo info;

    m_dirs.clear();
    m_files.clear();

    for (i=0; i<dirVec.size(); i++){
      info = (PO_ObjectInfo) dirVec.elementAt(i);
      if (info.className.compareTo("DirObject") == 0)
	m_dirs.addItem(info.contentName + "/");
      else m_dirs.addItem(info.contentName);
    }

    for (i=0; i<fileVec.size(); i++){
      info = (PO_ObjectInfo) fileVec.elementAt(i);
      if (info.className.compareTo("DirObject") == 0)
	m_files.addItem(info.contentName + "/");
      else m_files.addItem(info.contentName);

    }

    repaint();
  }

  private void openContent(String dir, Vector vec){

    PO_ObjectInfo info;

    if (dir.compareTo("root/") == 0){
      fileVec = rootDir.getContext();

      updateInfo();
      return;
    }
      
    for (int i=0; i<vec.size(); i++){
      info = (PO_ObjectInfo) vec.elementAt(i);

      //System.out.println("info content = " + info.className + 
      //info.contentName + info.id);

      String str = info.contentName + "/";
      if (str.compareTo(dir) == 0){
      
	if ((info.className).compareTo("DirObject") == 0){
	  DirObject dObj = new DirObject();
	  dObj.load(info.id);

	  // dirVec take old fileVec if content side if selected
	  // fileVec takes in new values 

	  if (m_dirSelected == null){
	    dirVec = new Vector();
	    for (int j=0; j<fileVec.size(); j++){
	      dirVec.addElement(fileVec.elementAt(j));
	    }
	  }

	  fileVec = new Vector();   
	  fileVec = dObj.getContext();
	  updateInfo();
	  return;
	}      
      }

      else if ((info.contentName).compareTo(dir) == 0){

	accessContent(dir, vec);
      }
    }
  }

  /**
   * Action taken when a user opens/accesses a particular object
   * (Can/should be overloaded by user/application developer)
   *
   * @param name     Name of the item selected by the user
   * @param vec      Vector of contents in the selected column
   */
  protected void accessContent(String name, Vector vec){

    System.out.println("Opening " + name + " not supported in this app.");
  }

  public boolean handleEvent(Event evt){
    if(evt.target instanceof List){
      if (mode != SAVE){
	String filename = ((List)evt.target).getSelectedItem();
	((TextComponent)m_selection).setText(filename);
	return true;
      }
      return true;
    }
    else
      return super.handleEvent(evt);
  }

  public boolean action(Event e, Object arg) {
    if(e.target instanceof Button) {
      String label = ((Button)e.target).getLabel();
      m_fileSelected = m_files.getSelectedItem();
      m_dirSelected = m_dirs.getSelectedItem();

      if(label.equals("Open")) {
	if (m_dirSelected != null)
	  openContent(m_dirSelected, dirVec);
	else if (m_fileSelected != null)
	  openContent(m_fileSelected, fileVec);
	else {
	  //System.out.println("nothing selected");
	  return true;
	}
      }
      else if(label.equals("Save")) {

	String nameStr = m_selection.getText();
	
	if (nameStr.trim().length() == 0){
	  System.out.println("Have to provide file name for save");
	  return false;
	}
	DirObject dObj = null;

	if (m_dirSelected != null){
	  dObj = getDirObj(m_dirSelected, dirVec);
	}
	else if (m_fileSelected != null){
	  dObj = getDirObj(m_fileSelected, fileVec);
	}
	else {
	  System.out.println("Should choose a Directory Object to save to");
	  return false;
	}
	if (dObj == null){
	  System.out.println("Should save to a Directory Object");
	  return false;
	} 
	else {
	  saveEntry(nameStr, dObj);
	} 
      }
      else if(label.equals("Up")) {

	//!! do some initGenContainers...

	System.out.println("Traversing upwards");
      }
      else if(label.equals("Cancel")) {
	dispose();
      }
      return true;
    }
    else return false;
  }


  /**
   * Action to be taken by a save 
   * (can/should be overloaded by users)
   * (Right now, for illustration purposes, it connects a DataObject 
   *  with the user input parameter to the DataObject specified)
   *
   * @param nameStr  Name of the item to be saved
   * @param dObj     DataObject that the item is to be attached to
   */
  protected void saveEntry(String nameStr, DirObject dObj){

    // This is to attach the persistent object passed in
    // to the DataObject the user highlighted in the window
    //dObj.attach(pObj);
    //dObj.save();

    DataObject dtObj = new DataObject(nameStr, "some data");
    dObj.attach(dtObj);
    dObj.save();
  }

  private DirObject getDirObj(String str, Vector vec){

    PO_ObjectInfo info;

    if (str.charAt(str.length()-1) != '/'){
      System.out.println("Should choose Directory Object to save to");
      return null;
    }

    System.out.println("getDirObj: Directory chosen");

    for (int i=0; i<vec.size(); i++){
      info = (PO_ObjectInfo) vec.elementAt(i);

      //System.out.println("info content = " + info.className + 
      //info.contentName + info.id);

      String name = info.contentName + "/";
      if (name.compareTo(str) == 0){

	DirObject dObj = new DirObject();
	dObj.load(info.id);
	return dObj;
      }
    }
    return null;
  }

  public Insets insets(){
    return new Insets(30,20,10,20);
  }

  protected void makeLabel(String name,
			   GridBagLayout gridbag,
			   GridBagConstraints c) {
    Label l = new Label(name);
    gridbag.setConstraints(l, c);
    add(l);
  }

  protected void makeTextField(TextField tf,
			       GridBagLayout gridbag,
			       GridBagConstraints c) {
    gridbag.setConstraints(tf, c);
    add(tf);
  }

  protected void makeList(List l,
			  GridBagLayout gridbag,
			  GridBagConstraints c) {
    gridbag.setConstraints(l, c);
    add(l);
  }

  protected void makePanel(Panel p,
			   GridBagLayout gridbag,
			   GridBagConstraints c) {
    gridbag.setConstraints(p, c);
    add(p);
  }
}// end DBDialog


class MyPanel extends Panel{
    Insets m_insets = null;

    public MyPanel(){
        super();
    }

    public void setInsets(Insets i) {
        m_insets = i;
    }

    public Insets insets() {
        if(m_insets == null)
            return new Insets(15,20,20,10);
        else
            return m_insets;
    }

}//end MyPanel