EDIT

// $Id$

/**

 * Copyright (C) 2013 EDIT

 * European Distributed Institute of Taxonomy

 * http://www.e-taxonomy.eu

 *

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

package eu.etaxonomy.taxeditor.ui.campanula;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import org.eclipse.jface.util.PropertyChangeEvent;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.DisposeEvent;

import org.eclipse.swt.events.DisposeListener;

import org.eclipse.swt.events.SelectionEvent;

import org.eclipse.swt.events.SelectionListener;

import org.eclipse.swt.graphics.Color;

import org.eclipse.swt.widgets.Combo;

import org.eclipse.swt.widgets.Listener;

import eu.etaxonomy.cdm.model.common.DefinedTermBase;

import eu.etaxonomy.taxeditor.preference.PreferencesUtil;

import eu.etaxonomy.taxeditor.preference.Resources;

import eu.etaxonomy.taxeditor.store.CdmStore;

import eu.etaxonomy.taxeditor.store.StoreUtil;

import eu.etaxonomy.taxeditor.store.TermManager;

import eu.etaxonomy.taxeditor.ui.element.AbstractCdmFormElement;

import eu.etaxonomy.taxeditor.ui.element.CdmFormFactory;

import eu.etaxonomy.taxeditor.ui.element.CdmPropertyChangeEvent;

import eu.etaxonomy.taxeditor.ui.element.IEnableableFormElement;

import eu.etaxonomy.taxeditor.ui.element.ISelectable;

import eu.etaxonomy.taxeditor.ui.section.campanula.compatibility.ICdmFormElement;

/**

 * @author pplitzner

 * @date 15.08.2013

 *

 */

public class TermComboFieldController<T extends DefinedTermBase> extends AbstractCdmFormElement implements SelectionListener, DisposeListener, IEnableableFormElement, ISelectable {

    private static final int DEFAULT_VISIBLE_ITEMS = 10;

    private T selection;

    private T emptyElement;

    private static String EMPTY_ELEMENT_LABEL = "";

//    protected Label label;

    private Combo combo;

    private ArrayList<T> terms;

    private Comparator<T> termComparator;

    private Class<T> termClass;

    private List<T> customPreferredTerms;

    /**

     * <p>

     * Constructor for AbstractTermComboElement.

     * </p>

     *

     * @param parentElement

     *            a {@link eu.etaxonomy.taxeditor.ui.element.ICdmFormElement}

     *            object.

     * @param style

     *            a int.

     * @param formFactory

     *            a {@link eu.etaxonomy.taxeditor.ui.element.CdmFormFactory}

     *            object.

     * @param labelString

     *            a {@link java.lang.String} object.

     * @param selection

     *            a T object.

     * @param visibleItems

     *            a int.

     * @param <T>

     *            a T object.

     */

    public TermComboFieldController(Combo combo, CdmFormFactory formFactory, ICdmFormElement parentElement, Class<T> termClass, T selection, int style) {

        super(formFactory, parentElement);

        this.termClass = termClass;

        setPropertyChangeListeners(formFactory.getPropertyChangeListeners());

        formFactory.addPropertyChangeListener(this);

//        if (labelString != null) {

//            label = formFactory.createLabel(getLayoutComposite(), labelString);

//            addControl(label);

//        }

        // create combo

        this.combo = combo;//new Combo(getLayoutComposite(), SWT.BORDER | SWT.READ_ONLY);

        addControl(combo);

//        combo.setLayoutData(LayoutConstants.FILL_HORIZONTALLY());

        combo.setVisibleItemCount(DEFAULT_VISIBLE_ITEMS);

        populateTerms(getPreferredTerms());

        combo.addSelectionListener(this);

        combo.addDisposeListener(this);

        PreferencesUtil.getPreferenceStore().addPropertyChangeListener(this);

        if (selection != null) {

            setSelection(selection);

        }

    }

    /**

     * <p>

     * Getter for the field <code>selection</code>.

     * </p>

     *

     * @return a T object.

     */

    public T getSelection() {

        return selection;

    }

    /**

     * <p>

     * Sets the selection of the combo to the given T object.

     * </p>

     * <p>

     * Passing <code>null</code> to this method will set the selection to the

     * empty element and effectively clear the selection

     * </p>

     *

     * @param selection

     *            a T object or <code>null</code> to clear the selection

     */

    public void setSelection(T selection) {

        this.selection = selection;

        this.selection = selection;

        Listener[] listeners = combo.getListeners(SWT.Selection);

        for (Listener listener : listeners) {

            combo.removeListener(SWT.Selection, listener);

        }

        int selectedIndex;

        if (selection == null) {

            // set selection to the emptyElement

            selectedIndex = 0;

        } else {

            selectedIndex = terms.indexOf(selection);

            if (selectedIndex == -1) {

                createTermNotInPreferredTerms(selection);

                selectedIndex = terms.indexOf(selection);

            }

        }

        combo.select(selectedIndex);

        for (Listener listener : listeners) {

            combo.addListener(SWT.Selection, listener);

        }

    }

    /**

     * Fills the combo with elements and sets up the convenience functions for

     * selection index

     *

     * @param preferredTerms

     */

    private void populateTerms(List<T> preferredTerms) {

        combo.removeAll();

        terms = new ArrayList<T>();

        int i = 1;

        int index = 0;

        // Add an empty element for when nothing was selected yet

        combo.add(EMPTY_ELEMENT_LABEL);

        terms.add(emptyElement);

        if (termComparator != null) {

            Collections.sort(preferredTerms, termComparator);

        }

        for (T term : preferredTerms) {

            String label = getLabel(term);

            if (label == null) {

                if (term.getTitleCache() != null) {

                    label = term.getTitleCache();

                    StoreUtil.warn(getClass(), "Term does not have a representation: " + term + ", " + term.getUuid());

                } else {

                    label = "Unknown";

                    StoreUtil.warn(getClass(), "Representation Label and TitleCache empty for term: " + term + ", " + term.getUuid());

                }

            }

            combo.add(label);

            terms.add(term);

            i++;

            if (selection != null) {

                if (selection.equals(term)) {

                    index = i;

                }

            }

        }

        if (selection != null && index == 0) {

            createTermNotInPreferredTerms(selection);

        }

        combo.select(index);

    }

    /*

     * (non-Javadoc)

     *

     * @see

     * eu.etaxonomy.taxeditor.forms.IEnableableFormElement#setEnabled(boolean)

     */

    /** {@inheritDoc} */

    @Override

    public void setEnabled(boolean enabled) {

        combo.setEnabled(enabled);

    }

    /**

     * <p>

     * preferredTerms

     * </p>

     *

     * @return a {@link java.util.List} object.

     */

    protected List<T> getPreferredTerms() {

        if (customPreferredTerms != null) {

            return customPreferredTerms;

        }

        return getTermManager().getPreferredTerms(termClass);

    }

    /**

     * May be overridden by derived classes if the desired label string does not

     * reside in term.getLabel();

     *

     * @param term

     *            a T object.

     * @return a {@link java.lang.String} object.

     */

    protected String getLabel(T term) {

        return term.getLabel(CdmStore.getDefaultLanguage());

    }

    /**

     *

     *

     * @param term

     */

    private void createTermNotInPreferredTerms(T term) {

        List<T> preferredTerms = getPreferredTerms();

        preferredTerms.add(term);

        populateTerms(preferredTerms);

    }

    /**

     * <p>

     * addSelectionListener

     * </p>

     *

     * @param listener

     *            a {@link org.eclipse.swt.events.SelectionListener} object.

     */

    public void addSelectionListener(SelectionListener listener) {

        combo.addSelectionListener(listener);

    }

    /**

     * <p>

     * removeSelectionListener

     * </p>

     *

     * @param listener

     *            a {@link org.eclipse.swt.events.SelectionListener} object.

     */

    public void removeSelectionListener(SelectionListener listener) {

        combo.removeSelectionListener(listener);

    }

    /*

     * (non-Javadoc)

     *

     * @see

     * org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt

     * .events.SelectionEvent)

     */

    /** {@inheritDoc} */

    @Override

    public void widgetSelected(SelectionEvent e) {

        selection = terms.get(combo.getSelectionIndex());

        firePropertyChangeEvent(new CdmPropertyChangeEvent(this, e));

    }

    /*

     * (non-Javadoc)

     *

     * @see java.beans.PropertyChangeListener#propertyChange(java.beans.

     * PropertyChangeEvent)

     */

    /** {@inheritDoc} */

    @Override

    public void propertyChange(PropertyChangeEvent event) {

        super.propertyChange(event);

        if (event != null && PreferencesUtil.PREFERRED_TERMS_CHANGE.equals(event.getProperty())) {

            populateTerms(getPreferredTerms());

        }

    }

    /** {@inheritDoc} */

    @Override

    public void setSelected(boolean selected) {

        setBackground(selected ? SELECTED : getPersistentBackground());

    }

    /** {@inheritDoc} */

    @Override

    public void widgetDisposed(DisposeEvent e) {

        PreferencesUtil.getPreferenceStore().removePropertyChangeListener(this);

    }

    // not used

    /** {@inheritDoc} */

    @Override

    public void widgetDefaultSelected(SelectionEvent e) {

    }

    /** {@inheritDoc} */

    @Override

    public void setIrrelevant(boolean irrelevant) {

        String colorId = irrelevant ? Resources.COLOR_COMPOSITE_IRRELEVANT : Resources.COLOR_COMPOSITE_BACKGROUND;

        Color color = StoreUtil.getColor(colorId);

        combo.setBackground(color);

    }

//    /** {@inheritDoc} */

//    @Override

//    public void setBackground(Color color) {

//        if (label != null)

//            label.setBackground(color);

//    }

    /**

*

*/

    protected TermManager getTermManager() {

        return CdmStore.getTermManager();

    }

    /**

     *

     * @return

     */

    public int getVisibleItemCount() {

        return combo.getVisibleItemCount();

    }

    /**

     *

     * @param count

     */

    public void setVisibleItemCount(int count) {

        combo.setVisibleItemCount(count);

    }

    /**

     * <p>

     * A {@link List} of term objects may be passed to this combo box. In this

     * case, the default behaviour of displaying the preferred terms for the T

     * type will be overridden and the combo will only display the given terms.

     * Also, any previous selection will be reseted.

     * </p>

     *

     * <p>

     * To return to the default of displaying the preferred terms, simply pass

     * <code>null</code>.

     * </p>

     *

     * @param terms

     *            a {@link List} of T objects or <code>null</code> for default

     *            preferred terms

     */

    public void setTerms(List<T> terms) {

        setSelection(null);

        customPreferredTerms = terms;

        populateTerms(customPreferredTerms);

    }

}