/*******************************************************************************
 * Copyright (c) 2007, 2012 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.browsing.ui.swt.contentassist;

import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import java.util.TreeMap;

import org.eclipse.jface.fieldassist.IContentProposal;
import org.eclipse.jface.fieldassist.IContentProposalListener;
import org.eclipse.jface.fieldassist.TextContentAdapter;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.layout.GridLayoutFactory;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;


/**
 * @author Tuukka Lehtonen
 *
 * @param <T>
 */
public class ContentAssistTextField extends Composite {

    private static final boolean DEBUG = false;
    
    Text text;
    INamedObject acceptedProposal;
    INamedObject result;
    OpenableContentAssistCommandAdapter contentAssist;

    public <T extends INamedObject> ContentAssistTextField(final Composite parent, T initialValue, final T[] allowedValues, int style) {
        this(parent, initialValue, Arrays.asList(allowedValues), style);
    }

    public <T extends INamedObject> ContentAssistTextField(final Composite parent, T initialValue, final Collection<T> allowedValues, int style) {
        super(parent, style);
        this.result = initialValue;

        GridLayoutFactory.fillDefaults().applyTo(this);

        text = new Text(this, style);
        text.setText(initialValue == null ? "" : initialValue.getName());
        GridDataFactory.fillDefaults().grab(true, true).applyTo(text);

        final Map<String, INamedObject> valueMap = new TreeMap<String, INamedObject>(String.CASE_INSENSITIVE_ORDER);
        for (T t : allowedValues) {
            valueMap.put(t.getName(), t);
        }

        contentAssist = new OpenableContentAssistCommandAdapter(text,
                new TextContentAdapter(),
                new NamedObjectContentProposalProvider<T>(allowedValues),
                (String) null,
                (char[]) null,
                true
        );
        contentAssist.addContentProposalListener(new IContentProposalListener() {
            @Override
            public void proposalAccepted(IContentProposal proposal) {
                if (DEBUG)
                    System.out.println("accepted: " + proposal);
                acceptedProposal = ((INamedObjectContentProposal) proposal).getNamedObject();
                ContentAssistTextField.this.result = acceptedProposal;
                text.setText(acceptedProposal.getName());
                text.setSelection(acceptedProposal.getName().length());
                //text.selectAll();
            }
        });

        text.addModifyListener(new ModifyListener() {
            @Override
            public void modifyText(ModifyEvent e) {
                String t = text.getText();
                if (DEBUG) {
                    System.out.println("text: " + t);
                    System.out.println("value set: " + valueMap);
                }
                INamedObject obj = valueMap.get(t);
                if (obj == null) {
                    result = null;
                    if (DEBUG)
                        System.out.println("no result");
                    contentAssist.open();
                } else {
                    result = obj;
                    if (DEBUG)
                        System.out.println("result: " + result);
                }
            }
        });
        text.addKeyListener(new KeyAdapter() {

            @Override
            public void keyPressed(KeyEvent e) {
                if(e.keyCode == SWT.CR) {
                    String name = text.getText();
                    if (DEBUG)
                        System.out.println("CR: " + name);
                    if(name.isEmpty()) {
                        return;
                    }
                    if(acceptedProposal == null)
                        acceptedProposal = FindExactMatch.exec(name, allowedValues);
                    if(acceptedProposal == null)
                        contentAssist.open();
                    else {
                        ContentAssistTextField.this.result = acceptedProposal;
                        //text.setText(acceptedProposal.getName());
                        //text.traverse(SWT.TRAVERSE_TAB_NEXT);
                        //text.traverse(SWT.TRAVERSE_RETURN);
                    }
                }
            }

        });
        text.addFocusListener(new FocusListener() {

            TraverseListener listener = new TraverseListener() {
                @Override
                public void keyTraversed(TraverseEvent e) {
//                    System.out.println("CA TraverseListener PARENT TRAVERSE: " + e.detail);
                    if (e.detail == SWT.TRAVERSE_RETURN) {
                        e.doit = false;
                    }
                }
            };

            @Override
            public void focusLost(FocusEvent e) {
                parent.removeTraverseListener(listener);
            }

            @Override
            public void focusGained(FocusEvent e) {
                parent.addTraverseListener(listener);
            }
        });

        contentAssist.setPropagateKeys(true);
    }

    public INamedObject getResult() {
        return result;
    }

    public Text getControl() {
        return text;
    }

    public void openAssist() {
        contentAssist.open();
    }

}