/**
//
// flexibleRetirementPlanner Source Code Module.
//
// Copyright 2006-2008  by Jim Richmond
// You may not use, distribute, or modify this code without the consent of the copyright holder.
//
// for more information, visit: http://www.flexibleRetirementPlanner.com
//
//
// The attached is a partial listing of source code provided for example only.  This code is
// not intended to be useable in its current form.  Although this example was reflective of the
// actual code at the time it was copied, the actual source code used by the planner may differ.
//

 */

package retirementsim;


public class SimCalc {

// Method: ComputeFundingUsingConservativePolicy()
//
// Computes the percentage of expenses that will be funded for the next year
// using the CONSERVATIVE spending policy.
//
// The general idea of this policy is to skip COLAs (cost of living adjustments) on
// the spending during periods of poor portfolio performance to save cash.
// The code implements this by subtracting out the current period's inflation rate
// from the percent of expenses that will be funded.
// In real life, the retiree's withdrawal wouldn't be reduced, be would be frozen at
// the same level as it was in the year prior to when the conservation action kicked in.
//
// Finally, notice that with this method, if the portfolio is doing well, ie. growing and
// worth more than at retirement start, previously missed COLA's can be partly made up.
// However, the percentage can never be greater than 100% of the desired amount
  public static double ComputeFundingUsingConservativePolicy(
      double currentBalance, double previousBalance, double startBalance,
      double previousFundingPercent, double adjustmentRate,
      double spendingPercentFloor, double spendingPercentCeiling) {

    double percentOfExpensesToFund;

    // if portfolio is not doing well so the retiree doesn't get a cost of living increase
    if ( (currentBalance < previousBalance) && (currentBalance < startBalance)) {
      // Protect from turning the percent negative.
      if (adjustmentRate > 1.0)
         adjustmentRate = 0.99;

      //  Need to subtract percent by inflation rate to reduce purchasing power.
      percentOfExpensesToFund = previousFundingPercent * (1 - adjustmentRate);
    }
    else if ( (currentBalance > startBalance) && (previousFundingPercent < 1.0)) {
      // Portfolio is bigger than starting value, so add some purchasing power back
      percentOfExpensesToFund = previousFundingPercent * (1 + adjustmentRate);
      if (percentOfExpensesToFund > 1.0) {
        percentOfExpensesToFund = 1.0;
      }
    }
    else {
      // The portfolio is doing ok so the retiree gets a standard COLA based on the
      // inflation rate.
      percentOfExpensesToFund = previousFundingPercent;
    }
    if (percentOfExpensesToFund > spendingPercentCeiling)
      percentOfExpensesToFund = spendingPercentCeiling;
    else if (percentOfExpensesToFund < spendingPercentFloor)
      percentOfExpensesToFund = spendingPercentFloor;
    return percentOfExpensesToFund;
  }

// Method: ComputeFundingUsingFlexiblePolicy()
//
// Computes the funding percent for the next year using the FLEXIBLE policy.
//
// Same as Conservative policy in the lean years, but this policy allows funding
// percent to increase to more than 100% if the portfolio is doing really
// well.  The extra increase in any year can be as high as the inflation rate
// (which is like applying a double COLA) if the portfolio has doubled in value
// since the start.  If the portfolio is above the starting value, but hasn't doubled,
// the extra increase is one forth of the inflation rate.
  public static double ComputeFundingUsingFlexiblePolicy(
      double currentBalance, double previousBalance, double startBalance,
      double previousFundingPercent, double adjustmentRate,
      double spendingPercentFloor, double spendingPercentCeiling) {

    double percentOfExpensesToFund;

    if ( (currentBalance < previousBalance) && (currentBalance < startBalance)) {
      // Protect from turning the percent negative.
      if (adjustmentRate > 1.0)
          adjustmentRate = 0.99;
      // Portfolio Value is shrinking, no COLA this year (reduce withdrawal by inflation rate)
      percentOfExpensesToFund = previousFundingPercent * (1 - (adjustmentRate));
    }
    else {
      if (currentBalance > startBalance) {
        // if portfolio balance is ok, then add some extra purchasing power
        // by increasing withdrawal by the inflation rate, this increase
        // results in the retiree getting a double COLA for the year
        if (currentBalance > (2 * startBalance)) {
          // Portfolio has doubled in size, increase withdrawal by inflation rate twice
          // (note: if
          percentOfExpensesToFund = previousFundingPercent * (1 + adjustmentRate);
        }
        else {
          // Portfolio is above the start value, but not doubled, give a smaller increase.
          percentOfExpensesToFund = previousFundingPercent *
              (1 + (adjustmentRate / 4));
        }
      }
      else {
        // Not a bad year, but portfolio isn't growing much so just give a normal COLA
        percentOfExpensesToFund = previousFundingPercent;
      }
    }
    if (percentOfExpensesToFund > spendingPercentCeiling)
      percentOfExpensesToFund = spendingPercentCeiling;
    else if (percentOfExpensesToFund < spendingPercentFloor)
      percentOfExpensesToFund = spendingPercentFloor;
    return percentOfExpensesToFund;
  }

}