bflows-bandi-be/src/main/java/net/gepafin/tendermanagement/util/DateTimeUtil.java

package net.gepafin.tendermanagement.util;

import net.gepafin.tendermanagement.web.rest.api.errors.CustomValidationException;
import net.gepafin.tendermanagement.web.rest.api.errors.Status;
import org.springframework.stereotype.Component;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Calendar;
import java.util.Date;
import java.util.regex.Pattern;

@Component
public class DateTimeUtil {

	private static final Pattern TIME_PATTERN = Pattern.compile(
			"^((([01]?\\d|2[0-3]):([0-5]\\d)(:[0-5]\\d)?(\\s?[AP]M)?)|((0?[1-9]|1[0-2]):([0-5]\\d)(:[0-5]\\d)?\\s?[AP]M))$");


	public static LocalDateTime DateServerToUTC(LocalDateTime systemDate) {

		ZonedDateTime ldtZoned = systemDate.atZone(ZoneId.systemDefault());
		LocalDateTime localDatetime = ldtZoned.withZoneSameInstant(ZoneId.of("Europe/Rome")).toLocalDateTime();
		return localDatetime;
	}

	public static LocalTime LocalTimeServerToEurope(LocalTime systemTime) {
	    ZonedDateTime zonedDateTime = systemTime.atDate(LocalDate.now()).atZone(ZoneId.systemDefault());
	    return zonedDateTime.withZoneSameInstant(ZoneId.of("Europe/Rome")).toLocalTime();
	}

	public static LocalDateTime getPreviousMonthDate(int month) {
		Calendar c = Calendar.getInstance();
		c.add(Calendar.MONTH, -month);
		LocalDateTime conv = LocalDateTime.ofInstant(c.getTime().toInstant(), ZoneId.systemDefault());
		return conv;
	}
	
	public static Date getDateWithoutTime(LocalDateTime systemDate) {
		ZonedDateTime zdt = systemDate.atZone(ZoneId.systemDefault());
		Date date = Date.from(zdt.toInstant());
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		calendar.set(Calendar.HOUR_OF_DAY, 0);
		calendar.set(Calendar.MINUTE, 0);
		calendar.set(Calendar.SECOND, 0);
		calendar.set(Calendar.MILLISECOND, 0);
		return calendar.getTime();
	}
	
	public static LocalDateTime convertDateToLocalDateTime(Date date) {
		LocalDateTime ldt = LocalDateTime.ofInstant(date.toInstant(),
                ZoneId.systemDefault());
		return ldt;
	}

	
    public static Date convertLocalDateTimeToDateUsingInstant(LocalDateTime localDateTime) {
        return Date
          .from(localDateTime.atZone(ZoneId.systemDefault())
          .toInstant());
    }

	public static LocalTime parseTime(String timeString) throws DateTimeParseException {
		DateTimeFormatter formatter;
		if(timeString==null) {
			return null;
		}
		if (!TIME_PATTERN.matcher(timeString).matches()) {
			throw new CustomValidationException(Status.BAD_REQUEST,"Invalid time format: " + timeString);
		}
		// Try to parse using default formats if no format is provided
		String[] defaultFormats = {"HH:mm:ss", "HH:mm", "HH:mm:ss a", "hh:mm a"};
		for (String defaultFormat : defaultFormats) {
			formatter = DateTimeFormatter.ofPattern(defaultFormat);
			try {
				return LocalTime.parse(timeString, formatter);
			} catch (DateTimeParseException e) {
				// Continue to the next format
			}
		}

		// If all parsing attempts fail, throw an exception
		throw new CustomValidationException(Status.BAD_REQUEST,"Failed to parse time: " + timeString);
	}

	public static String formatLocalDateTime(LocalDateTime dateTime, String pattern) {
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return dateTime.format(formatter);
	}

	public static LocalDateTime parseStringToLocalDateTime(String dateTimeStr, String pattern) {
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
		return LocalDateTime.parse(dateTimeStr, formatter);
	}
	public static LocalDateTime parseStringToLocalDateTime(String dateStr) {
		if (dateStr == null || dateStr.isEmpty()) return null;

		try {
			return LocalDateTime.parse(dateStr, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		} catch (Exception e) {
			try {
				return LocalDateTime.parse(dateStr, DateTimeFormatter.ISO_DATE_TIME); // fallback
			} catch (Exception ignored) {
			}
		}
		return null;
	}
	public static String parseLocalTimeToString(LocalTime time, String format) {
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern(format);
        return time.format(formatter);
    }

    // Method 2: Convert String and format to LocalTime
    public static LocalTime parseStringToLocalTime(String timeString, String format) {
        try {
            DateTimeFormatter formatter = DateTimeFormatter.ofPattern(format);
            return LocalTime.parse(timeString, formatter);
        } catch (DateTimeParseException e) {
            System.out.println("Invalid time format: " + e.getMessage());
            return null;
        }
    }
	public static String formatCreatedDate(LocalDateTime createdDate) {

		if (createdDate == null) {
			return "";
		}
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy");
		return createdDate.format(formatter);
	}
}