/*
 This file is part of the software framework JStatCom, 
 a library for building applications for data based analysis.

 Copyright (C) 2000-2005  Markus Kraetzig

 This library is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as
 published by the Free Software Foundation; either version 2.1 of the
 License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 USA
 */

package com.jstatcom.ts;

import org.apache.log4j.Logger;

import com.jstatcom.component.IValTextField;

/**
 * Component for display and selection of a single TSDate. It
 * takes an input string and validates it against a parser and a defined range.
 * This component can be costumized by setting an overall range that must
 * enclose the date that is selected. This is ensured by the validation
 * mechanism.
 * 

 * This class fires a "TSDate" property change, if a new date was set.
 * 
 * @see com.jstatcom.ts.TSDate
 * @see com.jstatcom.parser.TSDateParser
 * @author Markus Kraetzig
 */
public final class TSDateSelector extends IValTextField {
    private static final Logger log = Logger.getLogger(TSDateSelector.class);

    /**
     * Range that the input must be in with.
     */
    private TSDateRange range = null;

    /**
     * Currently displayed date.
     */
    private TSDate tSDate = null;

    /**
     * TSDateSelector default constructor sets range to
     * [1960 q1,1982 q4] and displayed date to
     * 1960 q1.
     */
    public TSDateSelector() {
        super();

        TSDate t1 = TSDate.valueOf("1960 q1");
        TSDate t2 = TSDate.valueOf("1982 q4");

        range = new TSDateRange(t1, t2);
        setTSDate(t1);
        setSize(39, getHeight());
    }

    /**
     * Returns the currently displayed date as an index relative to the lower
     * bound of the defined range, starting from 0.
     * 
     * @return index that is >= 0 and < than the number of observations within
     *         the allowed range
     */
    public int getDateAsIndex() {
        return range.indexForDate(tSDate);
    }

    /**
     * Gets the range that the selected date must be in with.
     * 
     * @return the bounding range
     */
    public TSDateRange getRange() {
        return range;
    }

    /**
     * Gets the currently displayed date.
     * 
     * @return the selected date
     */
    public TSDate getTSDate() {
        return tSDate;
    }

    /**
     * Error handling routine if validation failed. Displays error message and
     * sets back date value to the last valid one..
     * 
     * @param msg
     *            an error message
     */
    public void handleError(String msg) {
        super.handleError(msg + "\nThe previous value {" + tSDate
                + "} is restored.");
        setTSDate(tSDate);
    }

    /**
     * Sets the range that the selected date must be in with by setting an
     * initial date and the desired number of available periods within the
     * range.
     * 
     * @param newStart
     *            the new start for the bounding range
     * @param numberOfPeriods >
     *            0 to define the end of the bounding range
     */
    public void setEnclosingRange(TSDate newStart, int numberOfPeriods) {
        setEnclosingRange(new TSDateRange(newStart, newStart
                .addPeriods(numberOfPeriods - 1)));
    }

    /**
     * Sets the range that the selected date must be in with. The selected date
     * is not changed unless it violates the new range setting. In that case it
     * is set to the start date of the new range.
     * 
     * @param newOverallRange
     *            the new bounding range that the date has to be in with
     * @throws IllegalArgumentException
     *             if (newOverallRange == null)
     */
    public void setEnclosingRange(TSDateRange newOverallRange) {
        if (newOverallRange == null)
            throw new IllegalArgumentException("Range cannot be null.");
        range = newOverallRange;
        if (range.encloses(tSDate) != null)
            setTSDate(range.lowerBound());
    }

    /**
     * Sets the currently displayed date if it conforms to the specified range.
     * This method fires a "TSDate" property change with the old value and the
     * changed value if a new date was set.
     * 
     * @param newTSDate
     *            the date to be displayed
     * @throws IllegalArgumentException
     *             if newTSDate is not enclosed in range
     */
    public void setTSDate(TSDate newTSDate) {
        String msg;
        if ((msg = range.encloses(newTSDate)) != null)
            throw new IllegalArgumentException(msg);

        TSDate oldDate = tSDate;
        tSDate = newTSDate;

        setTextCarefully(tSDate.toString());

        // fire property change
        if (oldDate != null && !oldDate.equals(tSDate))
            firePropertyChange("TSDate", oldDate, tSDate);
    }

    /**
     * Validates input against the TSDateParser and the specified
     * TSDateRange.
     * 
     * @return error message if failure, null if ok
     */
    public String validateInput() {

        TSDate tmpDate = null;
        String inputString = getText();
        try {
            tmpDate = TSDate.valueOf(inputString);
        } catch (Throwable ex) {
            String msg = "Input \"" + inputString + "\" is not a valid date.";
            log.warn(msg, ex);
            return msg;
        }
        String error = range.encloses(tmpDate);
        if (error == null)
            setTSDate(tmpDate);
        return error;

    }
}