package com.onaro.util.jfc;

import java.awt.Component;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JSeparator;
import javax.swing.ListCellRenderer;

import com.onaro.commons.lang.CommonStringUtils;
import com.onaro.util.enumeration.EnumPresentation;

/**
 * Enables selection of one of the values of an enum or value in the table 
 */
public class EnumJComboBox extends JComboBox<Object> {
    private static final long serialVersionUID = 1L;
    /**
     * Used as an indicator for painting a separator in the combobox. Selection of this value will be ignored
     */
    private Object SEPARATER_VALUE = new Object();
    private Object[] attributes;

    /**
     * the user should later call to {@link #setValues(List, Set, Object)}
     */
    public EnumJComboBox() {
        //Set key selection manager so text with HTML markup (such as "<i>Empty</i>") can be easily selected.
        setKeySelectionManager(new HtmlAwareKeySelectionManager());
    }

    // Note unchecked types must be used because Jide's AutoCompletionComboBox is not a generic type.
    public void setValues(List<EnumPresentation.Attributes> enumAttributes, Set<Object> nonEnumValuesInQuery, Object initialSelectionValue) {
        this.attributes = createObjectsList(enumAttributes,nonEnumValuesInQuery);
        setModel(new EnumComboBoxModel(SEPARATER_VALUE));

        //if initialSelectionValue is provided, select the right entry in the combo box
        setSelectedValue(initialSelectionValue);

        final ListCellRenderer<? super Object> cellRenderer = getRenderer();
        //set the renders to show the enum name and icon
        setRenderer(new EnumCellRenderer(cellRenderer, SEPARATER_VALUE));
    }

    private Object[] createObjectsList(List<EnumPresentation.Attributes> enumAttributes, Set<Object> nonEnumValuesInQuery) {
        LinkedList<Object> list = new LinkedList<Object>(enumAttributes);
        if(nonEnumValuesInQuery != null && nonEnumValuesInQuery.size() > 0) {
            list.add(SEPARATER_VALUE);
            list.addAll(nonEnumValuesInQuery);
        }
        return list.toArray(new Object[list.size()]);
    }

    private void setSelectedValue(Object selectedEnum) {
        if (selectedEnum != null) {
            for (int i = 0; i < attributes.length; i++) {
                if (selectedEnum.equals(attributes[i])) {
                    setSelectedIndex(i);
                    return;
                }
            }
        }
    }



    public Object getSelectedValue() {
        return getSelectedItem();
    }

    private class EnumComboBoxModel extends DefaultComboBoxModel<Object> {
        private static final long serialVersionUID = 1L;
        /**
         * This value will be ignored if selected. This is being used for values that are merely indicators for rendering of something like a separator
         */
        private Object ignoreIfSelected;

        public EnumComboBoxModel(Object ignoreIfSelected) {
            super(EnumJComboBox.this.attributes);
            this.ignoreIfSelected = ignoreIfSelected;
        }

        public void setSelectedItem(Object selection) {
            if (!ignoreIfSelected.equals(selection)) {
                super.setSelectedItem(selection);
            }
        }
    }

    private static class EnumCellRenderer implements ListCellRenderer<Object> {
        private final ListCellRenderer<? super Object> renderer;

        /**
         * Used as an indicator for painting a separator in the combobox. Selection of this value will be ignored
         */
        private Object separaterValue;
        private JSeparator separator;

        /**
         *
         * @param renderer the original renderer of the combo box. the call is delegated to it
         * @param separaterValue Used as an indicator for painting a separator in the combobox. Selection of this value will be ignored
         */
        public EnumCellRenderer(ListCellRenderer<? super Object> renderer, Object separaterValue) {
            this.renderer = renderer;
            this.separaterValue = separaterValue;
            separator = new JSeparator(JSeparator.HORIZONTAL);
        }

        public Component getListCellRendererComponent(JList<?> list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
            if (!isSeparator(value)) {
                boolean isEnumValue = value instanceof EnumPresentation.Attributes;
                Object valueToRender = isEnumValue ? ((EnumPresentation.Attributes) value).name : value;

                //call the super to arrange all the fonts, colors etc.
                renderer.getListCellRendererComponent(list, valueToRender, index, isSelected, cellHasFocus);

                if (isEnumValue) {
                    //calling super.getListCellRendererComponent() nulls the icon since the value is a text
                    //so we're setting the icon later
                    ((JLabel) renderer).setIcon(((EnumPresentation.Attributes) value).smallIcon);
                }

                return (Component) renderer;
            }else {
                //the value is merely an indicator to the separator. so {@link JSeparator} is returned
                return separator;
            }
        }

        private boolean isSeparator(Object value) {
            return separaterValue.equals(value);
        }
    }
    
    /**
     * A {@link KeySelectionManager} that is the same as {@link JComboBox.DefaultKeySelectionManager}
     * except that it ignores HTML markup and SEPARATOR values. This allows the user to, i.e., select
     * "<i>Empty</i>" by typing the letter 'e'.
     */
    private class HtmlAwareKeySelectionManager implements KeySelectionManager {
        @Override
        public int selectionForKey(char aKey,ComboBoxModel aModel) {
            int i,c;
            int currentSelection = -1;
            Object selectedItem = aModel.getSelectedItem();
            String v;
            String pattern;

            if ( selectedItem != null ) {
                for ( i=0,c=aModel.getSize();i<c;i++ ) {
                    if ( selectedItem == aModel.getElementAt(i) ) {
                        currentSelection  =  i;
                        break;
                    }
                }
            }

            pattern = ("" + aKey).toLowerCase(); //$NON-NLS-1$
            aKey = pattern.charAt(0);

            for ( i = ++currentSelection, c = aModel.getSize() ; i < c ; i++ ) {
                Object elem = aModel.getElementAt(i);
                // Ignore separator value.
                if (SEPARATER_VALUE.equals(elem)) {
                    continue;
                }
                if (elem != null && elem.toString() != null) {
                    // Strip HTML from text before comparison.
                    v = CommonStringUtils.getTextFromHtml(elem.toString()).toLowerCase();
                    if ( v.length() > 0 && v.charAt(0) == aKey )
                        return i;
                }
            }

            for ( i = 0 ; i < currentSelection ; i ++ ) {
                Object elem = aModel.getElementAt(i);
                // Ignore separator value.
                if (SEPARATER_VALUE.equals(elem)) {
                    continue;
                }
                if (elem != null && elem.toString() != null) {
                    // Strip HTML from text before comparison.
                    v = CommonStringUtils.getTextFromHtml(elem.toString()).toLowerCase();
                    if ( v.length() > 0 && v.charAt(0) == aKey )
                        return i;
                }
            }
            return -1;
        }
    }
}