/* 
 * Copyright (c) 2006 Stiftung Deutsches Elektronen-Synchroton, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
package org.csstudio.sds.model;

import java.util.regex.Pattern;

import org.eclipse.swt.SWT;

/**
 * An enum for the available text types.
 * 
 * @author Kai Meyer
 * 
 */
public enum TextTypeEnum {
    /**
     * text type.
     */
    TEXT(0, "Text Value"),
    /**
     * double type.
     */
    DOUBLE(1, "Double Value"),
    /**
     * aliases type.
     */
    ALIAS(2, "Alias Value"),
    /**
     * hex type.
     */
    HEX(3, "Hex Value"),
    /**
     * expo Exp Value.
     */
    EXP(4, "Exp Value");
    /**
     * The ID for the <i>text</i> type.
     */
    public static final int TYPE_TEXT = 0;
    /**
     * The ID for the <i>double</i> type.
     */
    public static final int TYPE_DOUBLE = 1;
    /**
     * The ID for the <i>alias</i> type.
     */
    public static final int TYPE_ALIAS = 2;
    /**
     * The ID for the <i>alias</i> type.
     */
    public static final int TYPE_HEX = 3;
    /**
     * The ID for the <i>exponet</i> type.
     */
    public static final int TYPE_EXP = 4;

    /**
     * The index of his enum.
     */
    private int _index;
    /**
     * The display name of this enum.
     */
    private String _displayName;

    /**
     * Constructor.
     * 
     * @param index
     *            The index of this value
     * @param displayName
     *            The name of this value
     */
    private TextTypeEnum(final int index, final String displayName) {
        _index = index;
        _displayName = displayName;
    }

    /**
     * Returns the index of this {@link BorderStyleEnum}.
     * 
     * @return The index
     */
    public int getIndex() {
        return _index;
    }

    /**
     * Returns the display name of this {@link BorderStyleEnum}.
     * 
     * @return The display name
     */
    public String getDisplayName() {
        return _displayName;
    }

    /**
     * Returns the display names of the all text types.
     * 
     * @return The display names
     */
    public static String[] getDisplayNames() {
        TextTypeEnum[] textTypeEnums = TextTypeEnum.values();
        String[] result = new String[textTypeEnums.length];
        for (int i = 0; i < textTypeEnums.length; i++) {
            result[i] = textTypeEnums[i].getDisplayName();
        }
        return result;
    }

    /**
     * Checks the Format of new Input Value.
     * 
     * @param value
     *            the new Input Value.
     * @return only true if new value has a valid format.
     */
    public boolean isValidFormat(String value) {
        try {
            switch (this) {
                case HEX:
                case EXP:
                case DOUBLE:
                    // Erlaubte Zeichen: + - digi .
                    if (value.toString().matches("(-)?0[xX].*")) {
                        Long.parseLong(value.replaceFirst("0[xX]", ""), 16);
                    } else {
                        Double.parseDouble(value);
                    }
                    break;
                default:
                    break;
            }
        } catch (NumberFormatException nfe) {
            return false;
        }
        return true;
    }

    /**
     * Check if new input Character belongs to value format.
     * 
     * @param chars
     *            The new input characters.
     * @param pos
     *            position of new input character.
     * @return only true if new value belongs to value format.
     */
    public boolean isValidChars(char character, CharSequence chars, int pos) {
        TextTypeEnum propertyValue = this;
        if (character == SWT.CR || character == SWT.KEYPAD_CR || character == SWT.DEL
                || character == SWT.BS 
                || ((pos == 1 || pos == 2) && (character == 'X' || character == 'x'))) {
            return true;
        }
        Pattern pattern;
        switch (propertyValue) {
            case HEX:
            case EXP:
            case DOUBLE:
                pattern = Pattern.compile("[\\.\\p{XDigit}eE-]*");
                return pattern.matcher(chars).matches();
            default:
                return true;
        }
    }

    /**
     * Returns the corresponding {@link TextTypeEnum} to the given index or <code>null</code> if the
     * index is unknown.
     * 
     * @param index
     *            The index of the enum
     * @return The corresponding {@link TextTypeEnum} or <code>null</code> if the index is unknown
     */
    public static TextTypeEnum getEnumForIndex(final int index) {
        for (TextTypeEnum ttenum : TextTypeEnum.values()) {
            if (ttenum.getIndex() == index) {
                return ttenum;
            }
        }
        return null;
    }

}