package com.checkfree.cc.cap; 

import java.lang.reflect.*;
import java.util.*;
import java.net.*;
import java.text.*;

/**
 * This class builds a list of <option> HTML elements given a data object,
 * typically a GAPI output object, and a list of accessor method names.  
 * <p>
 * <b>Usage:</b><pre>
 *   // Create the bank account list select
 *   RBBankAcctList2Input acctIn = new RBBankAcctList2Input();
 *   initApiHeader(acctIn.getHeader(),sessInfo);
 *   ArrayList accts = new ArrayList();
 *   getBankAccounts(acctIn,accts);
 *   
 *   String ol = OptionList.createListHtmlFromApi(accts.toArray(),
 *                                   new String[]{"getBankAcctNbr","getBankRtgNbr","getBankAcctTyp"},
 *                                   new String[]{"getBankAcctNbr"},
 *                                   new MessageFormat("{0}"),
 *                                   Integer.parseInt(acctIndex));
 * 
 * </pre>
 * @author Rich Price
 */
class OptionList
{
    private static final String OPTION_PATTERN = "<option value=\"{0}\" {1}>{2}</option>";
    private static final Object[] GETTER_ARGS = new Object[0];
    private static final Class[] GETTER_ARG_TYPES = new Class[0];
    private static final String DELIM = "&";
    
    /**
     * Parses the value string and returns a HashMap of name/value pairs
     * @return A HashMap of name/value pairs. 
     * @see createListHtmlFromApi
     */
    public static HashMap getSelectedValues(String optionListValueString)
    {
        HashMap map = new HashMap();
        if ( optionListValueString != null )
        {
            StringTokenizer lex = new StringTokenizer(optionListValueString,DELIM + "=",false);
            while ( lex.hasMoreTokens() )
                map.put(lex.nextToken(),URLDecoder.decode(lex.nextToken()));
        }
        return map;            
    }
    
    /**
     * This method creates a String of HTML &lt;option&gt; elements in the following
     * format:<p>
     * <pre>
     * &lt;option value="valueName1=value1^valueName2=value2"&gt; optionValues &lt;option&gt;
     * </pre>
     * @param api An array of Objects, typically a GAPI output object, from which data
     * will be retrieved by name(s).
     * @param valueNames An array of method names declared in <code>api</code>. Only
     * public methods taking zero arguments can be used.  Each non-null value
     * is used to create a value string for the particular HTML option element in the form:
     * valueName1=value1^valueName2=value2...where valueName[n] is the method name.
     * For convenience, the getValues() method will return a HashMap of these name/value
     * pairs.
     * @param optionNames An array of method names declared in <code>api</code>. Only
     * public methods taking zero arguments can be listed.  Each non-null value
     * is used to create a parameter list to pass to a supplied MessageFormat object.
     * Each value retrieved from the api object will be substituted using the MessageFormat
     * object, the resulting String is used to create the optionValues string that is
     * displayed to the user.
     * @param selectedIndex The index of the option that should be selected. If -1, nothing
     * will be selected.
     * 
     */
    public static String createListHtmlFromApi(Object[] api, 
                                    String[] valueNames,
                                    String[] optionNames,
                                    MessageFormat optionFormat,
                                    int selectedIndex )
    {
        StringBuffer html = new StringBuffer();
        for ( int apiIndex = 0; apiIndex < api.length; apiIndex++ )
        {
            final String[] messageArgs = new String[3];        
            // for each valueName, use reflection to look up data from the api
            StringBuffer buf = new StringBuffer();
            for ( int i = 0; i < valueNames.length; i++ )
            {
                try
                {
                    Method m = api[apiIndex].getClass().getMethod(valueNames[i], GETTER_ARG_TYPES);
                    String value = m.invoke(api[apiIndex],GETTER_ARGS).toString();

                    if ( value != null && value.length() > 0 )
                    {
                        if ( buf.length() > 0 )
                            buf.append(DELIM);
                        buf.append(valueNames[i]).append("=").append(URLEncoder.encode(value));
                    }    
                }
                catch (Exception e) {}
            }
            // set the first and second value arguments for the pattern
            messageArgs[0] = buf.toString();
            if ( apiIndex == selectedIndex )
                messageArgs[1] = "selected";
            else
                messageArgs[1] = "";
                        
            // now, handle the option part
            buf.setLength(0);
            String[] optionFormatArgs = new String[optionNames.length];
            for ( int i = 0; i < optionNames.length; i++ )
            {
                try
                {
                    optionFormatArgs[i] = "";    
                    Method m = api[apiIndex].getClass().getMethod(optionNames[i],GETTER_ARG_TYPES);
                    String value = m.invoke(api[apiIndex],GETTER_ARGS).toString();
                    if ( value != null )
                        optionFormatArgs[i] = value;
                }
                catch(Exception e) {}
            }
            
            messageArgs[2] = optionFormat.format(optionFormatArgs,buf,new FieldPosition(0)).toString();
            html.append(MessageFormat.format(OPTION_PATTERN,messageArgs));
        }
        return html.toString();
    }
    
    public static void main(String[] args) throws Exception
    {
        OptionList.createListHtmlFromApi(new Object[]{new String()},new String[]{"getFoo"},new String[]{"getFoo"},new MessageFormat("{0}"),-1);
    }
    
}