package jaxcent.yui;

import jaxcent.*;
import java.util.*;

/**
  * Class Tree encapsulates the YUI Tree component.
  * Objects of this class must be initialized with the id for the DIV where
  * the tree is to be placed.  After that, nodes can be added/removed to the
  * tree, and other operations can be performed.
  */

public class Tree extends JaxcentPage {

    String treeVarName;                        // Internal JS name for tree

    Hashtable nodeList = new Hashtable();      // List of tree nodes

    boolean dateCreated = false;               // Variables for date formatting
    char dateSep = '/';
    boolean dateMonthFirst = true;

    /**
      * To create the tree on the page, init must be called with the
      * id for a DIV where the tree is to be drawn.
      */
    public void init( String treeDivId ) throws Jaxception
    {
        treeVarName = getJSVar();
        execJavaScriptCode( treeVarName + " = new YAHOO.widget.TreeView( '" + treeDivId + "');" );
        execJavaScriptCode( treeVarName + ".subscribe('clickEvent', yuiTreeClickHandler );" );
        draw();
    }


    // Called in node constructor to add nodes to nodeList
    void nodeAdded( TreeNode node )
    {
        nodeList.put( node.getVarName(), node );
    }

    /**
      * The draw method updates the tree.
      */
    public void draw() throws Jaxception
    {
        execJavaScriptCode( treeVarName + ".draw();" );
    }

    // Quote JavaScript strings.
    String quote( String str )
    {
        if ( str.indexOf( '\'' ) < 0 )
            return str;
        StringBuffer sb = new StringBuffer();
        for ( int i = 0; i < str.length(); i++ ) {
            char ch = str.charAt( i );
            sb.append( ch );
            if ( ch == '\'' )
                sb.append( ch );
        }
        return sb.toString();
    }


    // Internal method for adding a text node to the tree
    TreeNode addTextNode( String text, boolean editable, String parent ) throws Jaxception
    {
        TreeNode node = new TreeNode( this, editable, false );
        String varname = node.getVarName();
        if ( parent == null )
            parent = treeVarName + ".getRoot()";
        String str = varname + " = new YAHOO.widget.TextNode('" + quote( text ) + "', " + parent + ", true)";
        execJavaScriptCode( str );
        execJavaScriptCode( varname + ".varname = '" + varname + "'" );
        if ( editable )
            execJavaScriptCode( varname + ".editable = true" );
        draw();
        return node;
    }

    /** Add a non-editable text node to the tree root
      */
    public TreeNode addTextNode( String text ) throws Jaxception
    {
        return addTextNode( text, false, null );
    }

    /** Add an editable text node to the tree root
      */
    public TreeNode addEditableTextNode( String text ) throws Jaxception
    {
        return addTextNode( text, true, null );
    }

    /** Sets the format for displaying the date in date nodes.
      * sep is the character to use to separate parts of the date.
      * monthFirst is false if month comes after date, true if month comes first.
      */
    public void setDateFormat( char sep, boolean monthFirst ) throws Jaxception
    {
        if ( dateCreated )
            throw new Jaxception( "Dates have already been created, cannot change separator" );
        if ( sep == '\'' || sep == '"' ) throw new Jaxception( "Invalid date separator" );
        dateSep = sep;
        dateMonthFirst = monthFirst;
    }

    // Internal method to add date node
    TreeNode addDateNode( java.util.Date date, boolean editable, String parent ) throws Jaxception
    {
        TreeNode node = new TreeNode( this, editable, true );
        String varname = node.getVarName();
        java.util.Calendar cal = java.util.Calendar.getInstance();
        cal.setTime( date );
        String datestr = "";
        dateCreated = true;
        if ( dateMonthFirst ) {
            datestr += 1 + cal.get( cal.MONTH );
            datestr += dateSep;
            datestr += cal.get( cal.DAY_OF_MONTH );
        } else {
            datestr += cal.get( cal.DAY_OF_MONTH );
            datestr += dateSep;
            datestr += 1 + cal.get( cal.MONTH );
        }
        datestr += dateSep;
        datestr += cal.get( cal.YEAR );
        String str = varname + " = new YAHOO.widget.DateNode({type:'DateNode',label:'" + datestr + "',";
        if ( editable ) {
            str += "editable:true,";
        } else
            str += "editable:false,";
        str += "calendarConfig: { DATE_FIELD_DELIMITER:'" + dateSep + "',";
        if ( dateMonthFirst )
            str += "MDY_MONTH_POSITION:1,MDY_DAY_POSITION:2,MDY_YEAR_POSITION:3";
        else
            str += "MDY_DAY_POSITION:1,MDY_MONTH_POSITION:2,MDY_YEAR_POSITION:3";
        str += "}}, ";
        if ( parent == null )
            parent = treeVarName + ".getRoot()";
        str += parent;
        str += ", true )";
        execJavaScriptCode( str );
        execJavaScriptCode( varname + ".varname = '" + varname + "'" );
        draw();
        return node;
    }

    /** Add a non-editable date node to the tree root
      */
    public TreeNode addDateNode( java.util.Date date ) throws Jaxception
    {
        return addDateNode( date, false, null );
    }

    /** Add an editable date node to the tree root
      */
    public TreeNode addEditableDateNode( java.util.Date date ) throws Jaxception
    {
        return addDateNode( date, true, null );
    }


    /** Expand the entire tree.
      */
    public void expandAll() throws Jaxception
    {
        execJavaScriptCode( treeVarName + ".expandAll();" );
    }

    /** Collapse the entire tree.
      */
    public void collapseAll() throws Jaxception
    {
        execJavaScriptCode( treeVarName + ".collapseAll();" );
    }


    // Delete a node
    void deleteNode( String nodeVarName ) throws Jaxception
    {
        execJavaScriptCode( treeVarName + ".removeNode( " + nodeVarName + ", true );" );
        draw();
    }

    /**
      * Over-ridable method for receiving click events on tree nodes.
      */
    protected void onClick( TreeNode node )
    {
    }

    protected void onJavaScriptRequest(java.lang.String cmd,
                                       java.lang.String[] args)
    {
        if ( cmd.equals( "YuiTreeOnClick" )) {
            onClick( (TreeNode) nodeList.get( args[0] ));
        }
    }

    // Internal method for generating JavaScript variable names.

    static int varNumber = 1;

    synchronized static String getJSVar()
    {
        return "Jaxcent__YUI_InternalVar__" + varNumber++;
    }

}