/// <summary>
/// Determines whether the add instruction operand has a valid value.
/// </summary>
/// <param name="value">The string used to check whether the add instruction operand has a valid value. </param>
/// <returns>True if the add instruction operand has a valid value; otherwise, false. </returns>
/// <remarks>
/// The test performed is not dependent on the current setting of <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.DateType">DateType</see>.
/// This means true is returned if the operand is valid, even if <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.DateType">DateType</see> is not Exact or Approximate.
/// </remarks>
public static bool IsAddValid(string value)
{
if (value == null)
{
throw new ArgumentNullException("value");
}
Regex shortcut = new Regex(NhsDate.ResolveAddInstructionRegExTokens(), RegexOptions.IgnoreCase);
Match match = shortcut.Match(value.Replace(" ", string.Empty));
return(match.Success);
}
/// <summary>
/// Adds a number of months, weeks, days or years to a date.
/// </summary>
/// <param name="sourceDate">The date to be added to. </param>
/// <param name="instruction">Add instructions such as +2w to add 2 weeks or -3m to subtract 3 months. </param>
/// <remarks>
/// The operand can be positive or negative; if the operand is not included, it is assumed to be positive.
/// </remarks>
/// <exception cref="System.ArgumentNullException">If either argument is null.
/// </exception>
/// <exception cref="System.InvalidOperationException">If <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.DateType">DateType</see>
/// is null. </exception>
/// <exception cref="System.ArgumentException">If <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.DateType">DateType</see>
/// is <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.Year">Year</see> and the unit in the instruction is
/// not DateArithmeticResources.YearsUnit. Or if <see cref="P:NhsCui.Toolkit.DateAndTime.NhsDate.DateType">DateType</see>
/// is YearMonth and the unit in the instruction is
/// not DateArithmeticResources.YearsUnit or DateArithmeticResources.MonthsUnit. Or if the instruction is not
/// of the expected format.</exception>
/// <exception cref="NhsCui.Toolkit.DateAndTime.InvalidArithmeticSetException">If the set of letters in
/// the DateArithmeticResources is not unique or if values are not each a single character long.
/// </exception>
/// <returns>A new NhsDate object. </returns>
public static NhsDate Add(NhsDate sourceDate, string instruction)
{
if (instruction == null)
{
throw new ArgumentNullException("instruction");
}
if (sourceDate == null)
{
throw new ArgumentNullException("sourceDate");
}
// check the set of resource strings used by this method are
// valid
if (!CheckArithmeticSetResources())
{
throw new InvalidArithmeticSetException(Resources.NhsDateResources.ArithmeticSetInvalidResources);
}
if (sourceDate.DateType == DateType.NullIndex)
{
throw new InvalidOperationException(Resources.NhsDateResources.AddNotAllowedForDateType);
}
if (NhsDate.IsAddValid(instruction) == false)
{
throw new ArgumentException(Resources.NhsDateResources.AddInstructionInvalidFormat, "instruction");
}
Regex shortcut = new Regex(NhsDate.ResolveAddInstructionRegExTokens(), RegexOptions.IgnoreCase);
Match match = shortcut.Match(instruction.Replace(" ", string.Empty));
if (match.Success == true)
{
// We need to skip the first group because with this RegEx it is always the complete string
int groupNumber = 0;
foreach (Group g in match.Groups)
{
if (groupNumber > 0) // Skip first group
{
foreach (Capture c in g.Captures)
{
int increment;
if (int.TryParse(c.Value.Substring(0, c.Value.Length - 1), out increment))
{
if (c.Value.EndsWith(Resources.NhsDateResources.MonthsUnit, StringComparison.OrdinalIgnoreCase) == true)
{
if (sourceDate.DateType == DateType.Exact || sourceDate.DateType == DateType.Approximate)
{
sourceDate.DateValue = sourceDate.DateValue.AddMonths(increment);
}
else if (sourceDate.DateType == DateType.YearMonth)
{
sourceDate.Year += increment / 12;
sourceDate.Month += increment % 12;
}
else
{
throw new ArgumentException(
string.Format(CultureInfo.CurrentCulture, Resources.NhsDateResources.AddInstructionNotAllowedForDateType, "Month", sourceDate.DateType),
"instruction");
}
}
else if (c.Value.EndsWith(Resources.NhsDateResources.WeeksUnit, StringComparison.OrdinalIgnoreCase) == true)
{
if (sourceDate.DateType == DateType.Exact || sourceDate.DateType == DateType.Approximate)
{
// Add weeks using AddDays and multiplying number of weeks to add by 7
sourceDate.DateValue = sourceDate.DateValue.AddDays(increment * 7);
}
else
{
throw new ArgumentException(
string.Format(CultureInfo.CurrentCulture, Resources.NhsDateResources.AddInstructionNotAllowedForDateType, "Week", sourceDate.DateType),
"instruction");
}
}
else if (c.Value.EndsWith(Resources.NhsDateResources.DaysUnit, StringComparison.OrdinalIgnoreCase) == true)
{
if (sourceDate.DateType == DateType.Exact || sourceDate.DateType == DateType.Approximate)
{
sourceDate.DateValue = sourceDate.DateValue.AddDays(increment);
}
else
{
throw new ArgumentException(
string.Format(CultureInfo.CurrentCulture, Resources.NhsDateResources.AddInstructionNotAllowedForDateType, "Day", sourceDate.DateType),
"instruction");
}
}
else if (c.Value.EndsWith(Resources.NhsDateResources.YearsUnit, StringComparison.OrdinalIgnoreCase) == true)
{
if (sourceDate.DateType == DateType.Exact || sourceDate.DateType == DateType.Approximate)
{
sourceDate.DateValue = sourceDate.DateValue.AddYears(increment);
}
else if (sourceDate.DateType == DateType.Year || sourceDate.DateType == DateType.YearMonth)
{
sourceDate.Year += increment;
}
else
{
throw new ArgumentException(
string.Format(CultureInfo.CurrentCulture, Resources.NhsDateResources.AddInstructionNotAllowedForDateType, "Year", sourceDate.DateType),
"instruction");
}
}
}
}
}
groupNumber++;
}
}
return(sourceDate);
}