/*******************************************************************************
 * Copyright (c) 2004, 2006 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/

module dwtx.jface.bindings.keys.KeySequence;

import dwtx.jface.bindings.keys.KeyStroke;

import tango.util.collection.ArraySeq;
import tango.util.collection.model.Seq;
import tango.util.collection.model.SeqView;

import dwtx.jface.bindings.TriggerSequence;
import dwtx.jface.bindings.keys.formatting.KeyFormatterFactory;

import dwtx.jface.util.Util;

import dwt.dwthelper.utils;
static import tango.text.Util;
/**
 * <p>
 * A <code>KeySequence</code> is defined as a list of zero or more
 * <code>KeyStrokes</code>, with the stipulation that all
 * <code>KeyStroke</code> objects must be complete, save for the last one,
 * whose completeness is optional. A <code>KeySequence</code> is said to be
 * complete if all of its <code>KeyStroke</code> objects are complete.
 * </p>
 * <p>
 * All <code>KeySequence</code> objects have a formal string representation
 * available via the <code>toString()</code> method. There are a number of
 * methods to get instances of <code>KeySequence</code> objects, including one
 * which can parse this formal string representation.
 * </p>
 * <p>
 * All <code>KeySequence</code> objects, via the <code>format()</code>
 * method, provide a version of their formal string representation translated by
 * platform and locale, suitable for display to a user.
 * </p>
 * <p>
 * <code>KeySequence</code> objects are immutable. Clients are not permitted
 * to extend this class.
 * </p>
 *
 * @since 3.1
 */
public final class KeySequence : TriggerSequence, Comparable {

    /**
     * An empty key sequence instance for use by everyone.
     */
    private const static KeySequence EMPTY_KEY_SEQUENCE;

    static this(){
        EMPTY_KEY_SEQUENCE = new KeySequence(null);
    }

    /**
     * The delimiter between multiple key strokes in a single key sequence --
     * expressed in the formal key stroke grammar. This is not to be displayed
     * to the user. It is only intended as an internal representation.
     */
    public const static String KEY_STROKE_DELIMITER = "\u0020"; //$NON-NLS-1$

    /**
     * The set of delimiters for <code>KeyStroke</code> objects allowed during
     * parsing of the formal string representation.
     */
    public const static String KEY_STROKE_DELIMITERS = KEY_STROKE_DELIMITER
            ~ "\b\r\u007F\u001B\f\n\0\t\u000B"; //$NON-NLS-1$

    /**
     * Gets an instance of <code>KeySequence</code>.
     *
     * @return a key sequence. This key sequence will have no key strokes.
     *         Guaranteed not to be <code>null</code>.
     */
    public static final KeySequence getInstance() {
        return EMPTY_KEY_SEQUENCE;
    }

    /**
     * Creates an instance of <code>KeySequence</code> given a key sequence
     * and a key stroke.
     *
     * @param keySequence
     *            a key sequence. Must not be <code>null</code>.
     * @param keyStroke
     *            a key stroke. Must not be <code>null</code>.
     * @return a key sequence that is equal to the given key sequence with the
     *         given key stroke appended to the end. Guaranteed not to be
     *         <code>null</code>.
     */
    public static final KeySequence getInstance(KeySequence keySequence,
            KeyStroke keyStroke) {
        if (keySequence is null || keyStroke is null) {
            throw new NullPointerException();
        }

        KeyStroke[] oldKeyStrokes = keySequence.getKeyStrokes();
        int oldKeyStrokeLength = oldKeyStrokes.length;
        KeyStroke[] newKeyStrokes = new KeyStroke[oldKeyStrokeLength + 1];
        System.arraycopy(oldKeyStrokes, 0, newKeyStrokes, 0,
                        oldKeyStrokeLength);
        newKeyStrokes[oldKeyStrokeLength] = keyStroke;
        return new KeySequence(newKeyStrokes);
    }

    /**
     * Creates an instance of <code>KeySequence</code> given a single key
     * stroke.
     *
     * @param keyStroke
     *            a single key stroke. Must not be <code>null</code>.
     * @return a key sequence. Guaranteed not to be <code>null</code>.
     */
    public static final KeySequence getInstance(KeyStroke keyStroke) {
        return new KeySequence([ keyStroke ]);
    }

    /**
     * Creates an instance of <code>KeySequence</code> given an array of key
     * strokes.
     *
     * @param keyStrokes
     *            the array of key strokes. This array may be empty, but it must
     *            not be <code>null</code>. This array must not contain
     *            <code>null</code> elements.
     * @return a key sequence. Guaranteed not to be <code>null</code>.
     */
    public static final KeySequence getInstance(KeyStroke[] keyStrokes) {
        return new KeySequence(keyStrokes);
    }

    /**
     * Creates an instance of <code>KeySequence</code> given a list of key
     * strokes.
     *
     * @param keyStrokes
     *            the list of key strokes. This list may be empty, but it must
     *            not be <code>null</code>. If this list is not empty, it
     *            must only contain instances of <code>KeyStroke</code>.
     * @return a key sequence. Guaranteed not to be <code>null</code>.
     */
    public static final KeySequence getInstance(SeqView!(KeyStroke) keyStrokes) {
        return new KeySequence(keyStrokes.toArray());
    }

    /**
     * Creates an instance of <code>KeySequence</code> by parsing a given
     * formal string representation.
     *
     * @param string
     *            the formal string representation to parse.
     * @return a key sequence. Guaranteed not to be <code>null</code>.
     * @throws ParseException
     *             if the given formal string representation could not be parsed
     *             to a valid key sequence.
     */
    public static final KeySequence getInstance(String string) {
        if (string is null) {
            throw new NullPointerException();
        }

        auto keyStrokes = new ArraySeq!(KeyStroke);

        try {
            auto tokens = tango.text.Util.delimit( string, KEY_STROKE_DELIMITERS );
            KeyStroke[] keyStrokeArray = new KeyStroke[ tokens.length ];
            foreach( idx, tok; tokens ){
                keyStrokeArray[idx] = KeyStroke.getInstance(tok);
            }
            return new KeySequence(keyStrokeArray);
        } catch (IllegalArgumentException e) {
            throw new ParseException(
                    "Could not construct key sequence with these key strokes: " //$NON-NLS-1$
                            /+~ keyStrokes+/);
        } catch (NullPointerException e) {
            throw new ParseException(
                    "Could not construct key sequence with these key strokes: " //$NON-NLS-1$
                            /+~ keyStrokes+/);
        }
    }

    /**
     * Constructs an instance of <code>KeySequence</code> given a list of key
     * strokes.
     *
     * @param keyStrokes
     *            the list of key strokes. This list may be empty, but it must
     *            not be <code>null</code>. If this list is not empty, it
     *            must only contain instances of <code>KeyStroke</code>.
     */
    protected this(KeyStroke[] keyStrokes) {
        super(keyStrokes);

        for (int i = 0; i < cast(int)triggers.length - 1; i++) {
            KeyStroke keyStroke = cast(KeyStroke) triggers[i];

            if (!keyStroke.isComplete()) {
                throw new IllegalArgumentException(null);
            }
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#compareTo(java.lang.Object)
     */
    public final int compareTo(Object object) {
        KeySequence castedObject = cast(KeySequence) object;
        return Util.compare( arraycast!(Comparable)(triggers), arraycast!(Comparable)(castedObject.triggers));
    }

    /**
     * Formats this key sequence into the current default look.
     *
     * @return A string representation for this key sequence using the default
     *         look; never <code>null</code>.
     */
    public override final String format() {
        return KeyFormatterFactory.getDefault().format(this);
    }

    /**
     * Returns the list of key strokes for this key sequence.
     *
     * @return the list of key strokes keys. This list may be empty, but is
     *         guaranteed not to be <code>null</code>. If this list is not
     *         empty, it is guaranteed to only contain instances of
     *         <code>KeyStroke</code>.
     */
    public final KeyStroke[] getKeyStrokes() {
        int triggerLength = triggers.length;
        KeyStroke[] keyStrokes = new KeyStroke[triggerLength];
        System.arraycopy(triggers, 0, keyStrokes, 0, triggerLength);
        return keyStrokes;
    }

    /*
     * (non-Javadoc)
     *
     * @see dwtx.jface.bindings.TriggerSequence#getPrefixes()
     */
    public override final TriggerSequence[] getPrefixes() {
        int numberOfPrefixes = triggers.length;
        TriggerSequence[] prefixes = new TriggerSequence[numberOfPrefixes];
        prefixes[0] = KeySequence.getInstance();
        for (int i = 0; i < numberOfPrefixes - 1; i++) {
            final KeyStroke[] prefixKeyStrokes = new KeyStroke[i + 1];
            System.arraycopy(triggers, 0, prefixKeyStrokes, 0, i + 1);
            prefixes[i + 1] = KeySequence.getInstance(prefixKeyStrokes);
        }

        return prefixes;
    }

    /**
     * Returns whether or not this key sequence is complete. Key sequences are
     * complete iff all of their key strokes are complete.
     *
     * @return <code>true</code>, iff the key sequence is complete.
     */
    public final bool isComplete() {
        int triggersLength = triggers.length;
        for (int i = 0; i < triggersLength; i++) {
            if (!(cast(KeyStroke) triggers[i]).isComplete()) {
                return false;
            }
        }

        return true;
    }

    /**
     * Returns the formal string representation for this key sequence.
     *
     * @return The formal string representation for this key sequence.
     *         Guaranteed not to be <code>null</code>.
     * @see java.lang.Object#toString()
     */
    public override final String toString() {
        return KeyFormatterFactory.getFormalKeyFormatter().format(this);
    }
}