// Copyright (c) 2021, Fr.Terrot. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file. 

package io.gitea.model;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.OffsetDateTime;
import java.util.Date;

/** Handles Gitea to Mylyn date conversions */
public class GiteaDateTimeUtils {
    private static final String dateFormat_from_LocalDateTime = "yyyy-MM-dd'T'HH:mm:ss"; //$NON-NLS-1$
    private static final String dateFormat_from_Offset = "yyyy-MM-dd'T'HH:mm:ssX"; //$NON-NLS-1$
    private static final String dateFormat_1 = "yyyy-MM-dd HH:mm:ss"; //$NON-NLS-1$

    private static final String dateFormat_2 = "yyyy-MM-dd HH:mm"; //$NON-NLS-1$

    private static final String dateFormat_3 = "yyyy-MM-dd"; //$NON-NLS-1$

    private static final String dateFormat_1_TimeZone = "yyyy-MM-dd HH:mm:ss Z"; //$NON-NLS-1$

    private static final String dateFormat_2_TimeZone = "yyyy-MM-dd HH:mm z"; //$NON-NLS-1$

    private static final String dateFormat_3_TimeZone = "yyyy-MM-dd z"; //$NON-NLS-1$
    // Order is significant
    private static final String[] dateFormats = { dateFormat_from_Offset, dateFormat_from_LocalDateTime,
            dateFormat_1_TimeZone, dateFormat_1, dateFormat_2_TimeZone, dateFormat_2, dateFormat_3_TimeZone,
            dateFormat_3 };

    /**
     * Note: Date formatter constructed within method for thread safety
     */
    public static final Date parseDate(String dateString) {
        for (String format : dateFormats) {
            try {
                SimpleDateFormat simpleFormatter = new SimpleDateFormat(format);
                return simpleFormatter.parse(dateString);
            } catch (ParseException e) {
            } catch (NumberFormatException e) {
            }
        }
        return null;
    }

    /** Convert OffsetDateTime to Date */
    public static final Date toDate(OffsetDateTime offset) {
    	return parseDate(offset.toString()); // FIXME: use better Offset to date convertion
    }
}