DateUtil.java

package org.ei.drishti.common.util;

import org.joda.time.DateTime;
import org.joda.time.LocalDate;
import org.joda.time.LocalTime;
import org.joda.time.Period;

import static org.motechproject.util.DateUtil.inRange;

public class DateUtil {
    private static DateUtility dateUtility = new RealDate();

    public static void fakeIt(LocalDate fakeDayAsToday) {
        dateUtility = new MockDate(fakeDayAsToday);
    }

    public static LocalDate today() {
        return dateUtility.today();
    }

    public static long millis() {
        return dateUtility.millis();
    }

    public static boolean isDateWithinGivenPeriodBeforeToday(LocalDate referenceDateForSchedule, Period period) {
        return inRange(toTime(referenceDateForSchedule), toTime(today().minus(period)), toTime(today()));
    }

    private static DateTime toTime(LocalDate referenceDateForSchedule) {
        return referenceDateForSchedule.toDateTime(new LocalTime(0, 0));
    }

    public static LocalDate tryParse(String value, LocalDate defaultValue) {
        try {
            return LocalDate.parse(value);
        } catch (Exception e) {
            return defaultValue;
        }
    }
}

interface DateUtility {
    LocalDate today();

    long millis();
}

class RealDate implements DateUtility {
    @Override
    public LocalDate today() {
        return LocalDate.now();
    }

    @Override
    public long millis() {
        return DateTime.now().getMillis();
    }
}

class MockDate implements DateUtility {
    private DateTime fakeDay;

    MockDate(LocalDate fakeDay) {
        this.fakeDay = fakeDay.toDateTimeAtStartOfDay();
    }

    @Override
    public LocalDate today() {
        return fakeDay.toLocalDate();
    }

    @Override
    public long millis() {
        return fakeDay.getMillis();
    }
}