/// <summary>
/// Determines if this <b>Interval</b> is an integer multiple of another.
/// </summary>
/// <remarks>The calculation recognises that a week is seven days and that
/// a year is twelve months. It also allows 1T to match any time period
/// longer than a day and for any time period to be a multiple of 1 day.</remarks>
/// <param name="other">The other <b>Interval</b> instance.</param>
/// <returns><c>true</c> if this instance is an integer multiple of the
/// other <b>Interval</b>, <c>false</c> otherwise.</returns>
public bool IsMultipleOf(Interval other)
{
int value = 0;
// 1T is a positive integer multiple (>= 1) of any frequency
if ((multiplier == 1) && (period == Period.TERM) && (other.multiplier >= 1))
return (true);
// Any period > 0 is a multiple of 1D
if ((multiplier > 0) && (other.multiplier == 1) && (other.period == Period.DAY))
return (true);
// Handle 1W = 7D and 1Y = 12M or multiples thereof
if (period == other.Period)
value = multiplier;
else if ((period == Period.WEEK) && (other.Period == Period.DAY))
value = 7 * multiplier;
else if ((period == Period.YEAR) && (other.Period == Period.MONTH))
value = 12 * multiplier;
return (((value / other.Multiplier) >= 1) &&
((value % other.Multiplier) == 0));
}
/// <summary>
/// Calculates the result of adding another <b>Interval</b> to this
/// one.
/// </summary>
/// <param name="other">The <b>Interval</b> to add.</param>
/// <returns>A new <b>Interval</b> representing the combined time
/// period.</returns>
/// <exception cref="ArgumentException">If the two time periods
/// cannot be combined.</exception>
public Interval Plus(Interval other)
{
// One of the Intervals is zero length?
if (multiplier == 0) return (other);
if (other.multiplier == 0) return (this);
// Both Intervals have the same unit?
if (period == other.period)
return (new Interval (multiplier + other.multiplier, period));
// Otherwise check for equivalences
if ((period == Period.YEAR) && (other.period == Period.MONTH))
return (new Interval (12 * multiplier + other.multiplier, Period.MONTH));
if ((period == Period.MONTH) && (other.period == Period.YEAR))
return (new Interval (multiplier + 12 * other.multiplier, Period.MONTH));
if ((period == Period.WEEK) && (other.period == Period.DAY))
return (new Interval (7 * multiplier + other.multiplier, Period.DAY));
if ((period == Period.DAY) && (other.period == Period.WEEK))
return (new Interval (multiplier + 7 * other.multiplier, Period.DAY));
throw new ArgumentException ("Intervals cannot be combined");
}
/// <summary>
/// Compares two <b>Interval</b> instance to see if they contain the
/// same information.
/// </summary>
/// <remarks>This routine takes into account the equivalence of certain
/// time intervals (e.g. 1Y = 12M and 1W = 7D).</remarks>
/// <param name="other">The other <b>Interval</b> instance.</param>
/// <returns>A <see cref="bool"/> value indicating equality.</returns>
public bool Equals(Interval other)
{
if (period == other.period)
return (multiplier == other.multiplier);
// Handle 1Y == 12M equivalence
if (period == Period.YEAR) {
if (other.period == Period.MONTH)
return ((multiplier * 12) == other.multiplier);
return (false);
}
if (period == Period.MONTH) {
if (other.period == Period.YEAR)
return (multiplier == (other.multiplier * 12));
return (false);
}
// Handle 1W == 7D equivalence
if (period == Period.WEEK) {
if (other.period == Period.DAY)
return ((multiplier * 7) == other.multiplier);
return (false);
}
if (period == Period.DAY) {
if (other.period == Period.WEEK)
return (multiplier == (other.multiplier * 7));
return (false);
}
return (false);
}
/// <summary>
/// Creates a new <b>DateValue</b> based on the current instance and a given
/// <see cref="Interval"/>.
/// </summary>
/// <param name="interval">The time <see cref="Interval"/>.</param>
/// <returns>The adjusted date.</returns>
public DateValue Plus(Interval interval)
{
int multiplier = interval.Multiplier;
Period period = interval.Period;
if (period == Period.DAY)
return (PlusDays (multiplier));
else if (period == Period.WEEK)
return (PlusWeeks (multiplier));
else if (period == Period.MONTH)
return (PlusMonths (multiplier));
else if (period == Period.YEAR)
return (PlusYears (multiplier));
else
return (null);
}
/// <summary>
/// Creates a new <b>Date</b> based on the current instance and a given
/// <see cref="Interval"/>.
/// </summary>
/// <param name="interval">The time <see cref="Interval"/>.</param>
/// <returns>The adjusted date.</returns>
public Date Plus(Interval interval)
{
return (new Date (dateValue.Plus (interval), timeZone));
}
// --------------------------------------------------------------------
/// <summary>
/// Generates a set of dates according to schedule defined by a start date,
/// an end date, an interval, roll convention and a calendar.
/// </summary>
/// <param name="start">The start date.</param>
/// <param name="end">The end date.</param>
/// <param name="frequency">The frequency of the schedule (e.g. 6M).</param>
/// <param name="roll">The date roll convention or <c>null</c>.</param>
/// <param name="calendar">The holiday calendar or <c>null</c>.</param>
/// <returns>An array of calculated and adjusted dates.</returns>
private static Date[] GenerateSchedule(Date start, Date end,
Interval frequency, DateRoll roll, Calendar calendar)
{
Date current = start;
ArrayList found = new ArrayList ();
Date [] dates;
while (Less (current, end)) {
Date adjusted;
if (roll != null)
adjusted = roll.Adjust (calendar, current);
else
adjusted = current;
if (!found.Contains (adjusted))
found.Add (adjusted);
if (frequency.Period == Period.TERM) {
if (Equal (current, start))
current = end;
else
break;
}
else
current = current.Plus (frequency);
}
found.CopyTo (dates = new Date [found.Count]);
return (dates);
}
/// <summary>
/// Tests if the payment date falls on a calculated date.
/// </summary>
/// <param name="paymentDate">The payment date.</param>
/// <param name="startDate">The calculation period start date.</param>
/// <param name="endDate">The calculation perion end date.</param>
/// <param name="freq"> The period frequency.</param>
/// <returns><c>true</c> if the payment date falls on a calculated date.</returns>
private static bool IsUnadjustedCalculationPeriodDate(Date paymentDate, Date startDate, Date endDate, Interval freq)
{
Interval step = new Interval (0, Period.DAY);
for (;;) {
Date targetDate = startDate.Plus (step);
if (targetDate.CompareTo (endDate) > 0) return (false);
if (targetDate.Equals (paymentDate)) return (true);
step = step.Plus (freq);
}
}
