/*
 * Copyright (C) 2001-2004 Red Hat Inc. All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
package com.arsdigita.bebop.form;


import com.arsdigita.bebop.event.PageEvent;
import com.arsdigita.bebop.event.PrintEvent;
import com.arsdigita.bebop.event.PrintListener;
import com.arsdigita.bebop.event.SearchAndSelectListener;
import com.arsdigita.bebop.event.SearchAndSelectModel;
import com.arsdigita.bebop.event.FormValidationListener;
import com.arsdigita.bebop.event.FormSectionEvent;
import com.arsdigita.bebop.FormSection;
import com.arsdigita.bebop.FormData;
import com.arsdigita.bebop.PageState;
import com.arsdigita.bebop.SimpleContainer;
import com.arsdigita.bebop.parameters.StringParameter;
import com.arsdigita.bebop.parameters.ArrayParameter;
import com.arsdigita.bebop.parameters.ParameterData;
// This interface contains the XML element name of this class
// in a constant which is used when generating XML
import com.arsdigita.bebop.util.BebopConstants;
import com.arsdigita.xml.Element;
import java.util.TooManyListenersException;
import org.apache.log4j.Logger;

/**
 * Search and select Bebop widget.  This widget is used to allow a user to
 * search for a particular item over a potentially very large set.  Depending
 * on the size of the dataset, the user will either see a search box or a
 * selection box (with all valid items).  The search box will then change to
 * a selection box once the user submits the form, allowing them then to
 * choose the items they desire.
 * <p>
 * The datasource for SearchAndSelect is provided by an implentation of the
 * SearchAndSelectModel interface.  SAMPLE IMPLEMENTATION GOES HERE
 *
 * @author Patrick McNeill
 * @version $Id: SearchAndSelect.java 287 2005-02-22 00:29:02Z sskracic $
 * @since 4.5
 */
public class SearchAndSelect extends FormSection
    implements BebopConstants, PrintListener {

    public static final String versionId = "$Id: SearchAndSelect.java 287 2005-02-22 00:29:02Z sskracic $ by $Author: sskracic $, $DateTime: 2004/08/16 18:10:38 $";
    private static final Logger s_cat =
        Logger.getLogger(SearchAndSelect.class);

    protected String m_name;
    // name of this super-widget

    protected String m_value = "";
    // current value of the widget

    protected String m_query = "";
    // the query to search for this go round.  set by the form validation
    // listener.

    protected int m_maxViewableResults = 10;
    // number of hits before the search widget pops up, eventually should be
    // a system parameter

    protected SearchAndSelectModel m_results = null;
    // interface to the dataset

    protected SearchAndSelectListener m_listener = null;

    protected boolean m_isMultiple = false;
    // multiselect?

    protected boolean m_useCheckboxes = false;
    // use checkboxes or multiple-select for the multiple case

    protected boolean m_isOptional = true;
    // optional?

    protected Object m_this = this;
    // so "this" will work in my anonymous inner classes

    protected TextField  m_outputTextWidget;
    protected Widget m_outputSelectWidget;
    // internal widgets used render either a text box, a checkbox, or a select

    protected Hidden m_oldValueWidget;
    // internal Hidden widget used to save the previous search

    protected String m_oldValue = "";
    // the contents of the oldValueWidget, set by the validation listener

    protected boolean m_isSearchLocked = false;
    // true if the user has already seen a checkbox group or select box,
    // false otherwise.  determines if the user is still refining his/her search

    /*
     * Creates the output widgets and adds them all to the form
     */
    private void initializeOutputWidget () {
        m_oldValueWidget = new Hidden(getName() + ".oldvalue");
        add(m_oldValueWidget);

        m_outputTextWidget = new TextField(getName() + ".text");
        add(m_outputTextWidget);

        if ( m_isMultiple ) {
            if ( m_useCheckboxes ) {
                m_outputSelectWidget = new CheckboxGroup(getName() + ".select");
            } else {
                m_outputSelectWidget =
                    new MultipleSelect(getName() + ".select");
            }
        } else {
            m_outputSelectWidget = new SingleSelect(getName() + ".select");
        }
        add(m_outputSelectWidget);

        try {
            m_outputSelectWidget.addPrintListener(this);
        } catch (TooManyListenersException e) {
            s_cat.error("Could not add print listener", e);
        } catch (IllegalArgumentException e) {
            s_cat.error("Could not add print listener", e);
        }
    }

    public void prepare(PrintEvent e) {
        if ( m_results == null ) {
            m_results = m_listener.getModel(new PageEvent(this, e.getPageState()));
        }

        if ( m_results == null ) {
            return;
        }

        m_results.setQuery ( m_query );

        if ( m_isSearchLocked ||
             ( ( ( ! m_oldValue.equals("") &&
                   m_oldValue.equals(m_value) ) ||
                 ( m_maxViewableResults >= m_results.resultsCount() ) ) &&
               ( m_results.resultsCount() > 0 ) ) ) {

            OptionGroup outputWidget = (OptionGroup)e.getTarget();

            if ( m_isOptional && ! m_isMultiple ) {
                outputWidget.addOption( new Option ( "", "None" ) );
            }

            for ( int i = 0; i < m_results.resultsCount(); i++ ) {
                outputWidget.addOption(
                                       new Option ( m_results.getID(i), m_results.getLabel(i) ) );

                s_cat.debug("    " + m_results.getID(i));
            }
        }
    }

    /**
     * Create a new SearchAndSelect widget to select a single value.
     *
     * @param name the name of the widget
     */
    public SearchAndSelect ( String name ) {
        this( name, false, false );
    }

    /**
     * Create a new SearchAndSelect widget with the specified name and
     * SearchAndSelectModel.
     *
     * @param name the name of the widget
     * @param isMultiple whether or not the widget accepts multiple values
     * @param useCheckboxes use checkboxes or a multiselect
     */
    public SearchAndSelect ( String name,
                             boolean isMultiple ) {
        this( name, isMultiple, false );
    }

    /**
     * Create a new SearchAndSelect widget with the specified name and
     * SearchAndSelectModel.
     *
     * @param name the name of the widget
     * @param isMultiple whether or not the widget accepts multiple values
     * @param useCheckboxes use checkboxes or a multiselect
     */
    public SearchAndSelect ( String name,
                             boolean isMultiple,
                             boolean useCheckboxes ) {

        super(new SimpleContainer());

        m_isMultiple = isMultiple;
        m_useCheckboxes = useCheckboxes;
        m_name = name;

        initializeOutputWidget();

        /*
         * Add a form validation listener so that we can determine whether
         * or not the form is valid.  This is required because this widget
         * needs an arbitrary number of page loads to succeed.  Also note
         * that the error messages generated here are not displayed to the
         * user as the error field is also used as a help field.
         */
        super.addValidationListener ( new FormValidationListener() {
                public void validate ( FormSectionEvent e ) {
                    FormData data = e.getFormData();

                    m_results = m_listener.getModel(
                                                    new PageEvent(m_this, e.getPageState()));

                    if ( m_results == null ) {
                        return;
                    }

                    m_oldValue = data.getString( getName() + ".oldvalue");

                    m_value = data.getString( getName() + ".text");

                    /*
                     * Determine what stage in the process we're at.  If .text
                     * is null, then check what the select/checkbox shows.
                     */
                    if ( m_value == null ) {
                        m_isSearchLocked = true;
                        m_query = m_oldValue;

                        if ( m_isMultiple ) {
                            String[] tmpArray = (String[])data
                                .get( getName() + ".select" );
                            if ( tmpArray == null ) {
                                m_value = "";
                            } else {
                                m_value = tmpArray[0];
                            }
                        } else {
                            m_value = data.getString( getName() + ".select");
                        }
                    } else {
                        m_query = m_value;
                    }

                    /*
                     * If optional and nothing selected, we're done
                     */
                    if ( m_value.equals("") && m_isOptional ) {
                        return;
                    }

                    String oldQuery = m_results.getQuery();

                    m_results.setQuery(m_query);

                    /*
                     * If search returns only one hit and is a non-optional single
                     * select, it's done.
                     */
                    if ( ! m_isOptional &&
                         ! m_isMultiple &&
                         ( m_results.resultsCount() == 1 ) ) {
                        m_isSearchLocked = true;
                        m_value = m_results.getID(0);
                    }

                    /*
                     * If we're in the results phase, determine what the user
                     * chose
                     */
                    if ( m_isSearchLocked ) {
                        if ( !m_isMultiple ) {
                            StringParameter param =
                                new StringParameter( getName() );

                            data.setParameter( getName(),
                                               new ParameterData(param, m_value) );
                        } else {
                            ArrayParameter param =
                                new ArrayParameter( getName() );
                            String[] tmpArray = (String[])data
                                .get( getName() + ".select" );

                            if ( tmpArray == null ) {
                                tmpArray = new String[0];
                            }

                            data.setParameter( getName(),
                                               new ParameterData(param, tmpArray ));
                        }

                        return;
                    } else {
                        data.addError("Search not complete yet.");
                    }

                    m_results.setQuery(oldQuery);
                }
            });
    }

    public final void setSearchAndSelectListener
        (SearchAndSelectListener listener) {
        m_listener = listener;
    }

    /**
     * Get the name of the widget.
     *
     * @return the name of the widget
     */
    public final String getName () {
        return m_name;
    }

    /*
     * Internal function to retrieve a single text value for the widget.
     */
    private String getTextValue ( PageState state ) {
        if ( m_value != null ) {
            return m_value;
        }

        if ( m_isSearchLocked ) {
            if ( m_isMultiple ) {
                return ((String[])m_outputSelectWidget.getValue(state))[0];
            } else {
                return (String)m_outputSelectWidget.getValue(state);
            }
        } else {
            return (String)m_outputTextWidget.getValue(state);
        }
    }

    /**
     * Determine the type of HTML form element to create.
     * This will not necessarily be accurate until generateWidget is called
     * as the query will be unavailable until that point.
     *
     * @return "text" or "select" depending on the result size
     */
    public String getType () {
        if ( m_isSearchLocked ) {
            return m_outputSelectWidget.getType();
        } else {
            return "text";
        }
    }

    /**
     * Determine if this is a multiple select widget, or single select.
     *
     * @return boolean -- true for multiple, false for single
     */
    public final boolean isMultiple () {
        return m_isMultiple;
    }

    /**
     * Determine if this is an optional widget
     *
     * @return true for optional, false otherwise
     */
    public final boolean isOptional () {
        return m_isOptional;
    }

    /**
     * Specify whether or not the widget is optional.
     *
     * @param isOptional true for optional, false for required
     */
    public SearchAndSelect setOptional ( boolean isOptional ) {
        m_isOptional = isOptional;

        return this;
    }

    /**
     * Indicates if the widget is composed of multiple HTML elements.
     * Always returns true, as the widget makes use of a hidden element and
     * another element.
     *
     * @return true
     */
    public boolean isCompound () {
        return true;
    }

    /**
     * Generates the XML datastructure for this widget.  Adds a hidden,
     * a textbox, checkbox group, or select, and possibly some number of
     * formErrors.
     *
     * @param state the state of the page
     * @param parent the parent widget
     */
    public void generateXML( PageState state, Element parent ) {
        if ( m_results == null ) {
            m_results = m_listener.getModel(new PageEvent(this, state));
        }

        if ( m_results == null ) {
            return;
        }

        if ( m_isSearchLocked ||
             ( ( ( ! m_oldValue.equals("") &&
                   m_oldValue.equals(m_value) ) ||
                 ( m_maxViewableResults >= m_results.resultsCount() ) ) &&
               ( m_results.resultsCount() > 0 ) ) ) {
            m_outputSelectWidget.generateXML ( state, parent );
        } else {
            m_outputTextWidget.generateXML ( state, parent );
        }

        m_oldValueWidget.setValue ( state, m_query );

        m_oldValueWidget.generateXML ( state, parent );

        generateErrors ( state, parent );
    }

    /**
     * Generate the error messages for this widget.  This widget has some
     * specialized error messages, so it is necessary to override the
     * default error generator.  Basically, the m_results field won't be
     * available outside this class, so this needs to be internal.
     *
     * @param state the state of the page
     * @param parent the parent widget
     */
    protected void generateErrors ( PageState state, Element parent ) {
        String curValue = getTextValue(state);

        if ( m_results == null ) {
            return;
        }

        if ( m_results.resultsCount() > m_maxViewableResults ) {

            Element error = parent.newChildElement("bebop:formErrors", BEBOP_XML_NS);

            if ( ( curValue == null ) || ( curValue.equals("") ) ) {
                error.addAttribute("message",
                                   "Please enter a comma-delimited search");
            } else if ( ( ! m_oldValue.equals( curValue ) ) &&
                        ! m_isSearchLocked ) {
                error.addAttribute("message",
                                   "Your search returned " +
                                   m_results.resultsCount() +" matches.  " +
                                   "Please refine your search or leave the " +
                                   "search as it is to see all results.");
            }
        }

        if ( m_results.resultsCount() == 0 ) {
            if ( !curValue.equals("") ) {
                Element error = parent.newChildElement("bebop:formErrors", BEBOP_XML_NS);
                error.addAttribute("message",
                                   "Your search returned no matches.  Please " +
                                   "try again");
            } else {
                Element error = parent.newChildElement("bebop:formErrors", BEBOP_XML_NS);
                error.addAttribute("message", "WARNING -- NO DATA FOUND");
            }
        }
    }

}
