AppsheetEpplus/FormulaParsing/Excel/Functions/DateTime/Networkdays.cs

using System.Collections.Generic;
using System.Linq;

namespace AppsheetEpplus;

public class Networkdays : ExcelFunction {
  public override CompileResult Execute(
      IEnumerable<FunctionArgument> arguments,
      ParsingContext context) {
    var functionArguments = arguments as FunctionArgument[] ?? arguments.ToArray();
    ValidateArguments(functionArguments, 2);
    var startDate = System.DateTime.FromOADate(ArgToInt(functionArguments, 0));
    var endDate = System.DateTime.FromOADate(ArgToInt(functionArguments, 1));
    var calculator = new WorkdayCalculator();
    var result = calculator.CalculateNumberOfWorkdays(startDate, endDate);
    if (functionArguments.Length > 2) {
      result = calculator.ReduceWorkdaysWithHolidays(result, functionArguments[2]);
    }

    return new(result.NumberOfWorkdays, DataType.Integer);
  }
}