/*
    * MoneyWise: Finance Application
    * Copyright 2012-2026. Tony Washer
    *
    * Licensed under the Apache License, Version 2.0 (the "License"); you may not
    * use this file except in compliance with the License.  You may obtain a copy
    * of the License at
    *
    *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations under
   * the License.
   */
  package io.github.tonywasher.joceanus.moneywise.tax.uk;
  
  import io.github.tonywasher.joceanus.metis.field.MetisFieldSet;
  import io.github.tonywasher.joceanus.moneywise.data.statics.MoneyWiseTaxClass;
  import io.github.tonywasher.joceanus.moneywise.tax.MoneyWiseTaxBandSet.MoneyWiseTaxBand;
  import io.github.tonywasher.joceanus.moneywise.tax.MoneyWiseTaxResource;
  import io.github.tonywasher.joceanus.oceanus.decimal.OceanusMoney;
  import io.github.tonywasher.joceanus.oceanus.decimal.OceanusRate;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  /**
   * Interest Tax Scheme.
   */
  public abstract class MoneyWiseUKInterestScheme
          extends MoneyWiseUKIncomeScheme {
      /*
       * Local Report fields.
       */
      static {
          MetisFieldSet.newFieldSet(MoneyWiseUKInterestScheme.class);
      }
  
      /**
       * Constructor.
       */
      protected MoneyWiseUKInterestScheme() {
      }
  
      /**
       * Obtain theTaxCredit rate for interest.
       *
       * @param pTaxYear the taxYear
       * @return the taxCredit rate
       */
      protected abstract OceanusRate getTaxCreditRate(MoneyWiseUKTaxYear pTaxYear);
  
      @Override
      protected OceanusMoney adjustAllowances(final MoneyWiseUKTaxConfig pConfig,
                                              final OceanusMoney pAmount) {
          /* Adjust against the basic allowance */
          final OceanusMoney myRemaining = super.adjustAllowances(pConfig, pAmount);
  
          /* If we have any interest left */
          if (myRemaining.isNonZero()) {
              /* Adjust the savings allowance noting that it still counts against the taxBand */
              final OceanusMoney myInterest = adjustForAllowance(pConfig.getSavingsAllowance(), myRemaining);
  
              /* Adjust any loSavings band noting that it still counts against the taxBand */
              adjustForAllowance(pConfig.getLoSavingsBand().getAmount(), myInterest);
          }
  
          /* Return unallocated income */
          return myRemaining;
      }
  
      @Override
      protected OceanusMoney getAmountInAllowance(final MoneyWiseUKTaxConfig pConfig,
                                                  final OceanusMoney pAmount) {
          /* Obtain the amount covered by the basic allowance */
          OceanusMoney myAmount = super.getAmountInAllowance(pConfig, pAmount);
  
          /* If we have income left over */
          if (myAmount.compareTo(pAmount) < 0) {
              /* Calculate remaining amount */
              final OceanusMoney myRemaining = new OceanusMoney(pAmount);
              myRemaining.subtractAmount(myAmount);
  
              /* Calculate the amount covered by savings allowance */
              final OceanusMoney myXtra = getAmountInBand(pConfig.getSavingsAllowance(), myRemaining);
  
              /* Determine the total amount covered by the allowance */
              myAmount = new OceanusMoney(myAmount);
              myAmount.addAmount(myXtra);
          }
  
          /* return the amount */
          return myAmount;
      }
  
      /**
      * Obtain the base rate.
      *
      * @return the base rate
      */
     protected OceanusRate getBaseRate() {
         return null;
     }
 
     @Override
     protected Iterator<MoneyWiseTaxBand> taxBandIterator(final MoneyWiseUKTaxConfig pConfig,
                                                          final MoneyWiseTaxClass pBasis) {
         /* Obtain the loSavingsBand and the basicRate */
         final MoneyWiseTaxBand myLoBand = pConfig.getLoSavingsBand();
         final OceanusMoney myLoAmount = myLoBand.getAmount();
         OceanusRate myRate = getBaseRate();
 
         /* Create a new List */
         final List<MoneyWiseTaxBand> myList = new ArrayList<>();
 
         /* Access underlying iterator and obtain first band */
         final Iterator<MoneyWiseTaxBand> myIterator = super.taxBandIterator(pConfig, pBasis);
         MoneyWiseTaxBand myBasicBand = myIterator.next();
         OceanusMoney myAmount = myBasicBand.getAmount();
 
         /* If we are a LoBase instance */
         if (this instanceof MoneyWiseUKInterestLoBaseRateScheme) {
             /* Add the first band as is */
             myList.add(myBasicBand);
 
             /* Access the true basic band */
             myBasicBand = myIterator.next();
             myAmount = myBasicBand.getAmount();
 
             /* Add low band if required */
         } else if (myLoAmount.isNonZero()) {
             myList.add(myLoBand);
             myAmount = new OceanusMoney(myAmount);
             myAmount.subtract(myLoAmount);
         }
 
         /* Add the basic band */
         if (myRate == null) {
             myRate = myBasicBand.getRate();
         }
         myList.add(new MoneyWiseTaxBand(myAmount, myRate));
 
         /* Loop through remaining tax bands */
         while (myIterator.hasNext()) {
             final MoneyWiseTaxBand myBand = myIterator.next();
             myList.add(myBand);
         }
 
         /* Return the iterator */
         return myList.iterator();
     }
 
     /**
      * As Income Scheme.
      */
     public static class MoneyWiseUKInterestAsIncomeScheme
             extends MoneyWiseUKInterestScheme {
         /**
          * Local Report fields.
          */
         private static final MetisFieldSet<MoneyWiseUKInterestAsIncomeScheme> FIELD_DEFS = MetisFieldSet.newFieldSet(MoneyWiseUKInterestAsIncomeScheme.class);
 
         /**
          * Default constructor.
          */
         MoneyWiseUKInterestAsIncomeScheme() {
             /* NoOp */
         }
 
         @Override
         protected OceanusRate getTaxCreditRate(final MoneyWiseUKTaxYear pTaxYear) {
             return pTaxYear.getTaxBands().getBasicTaxRate();
         }
 
         @Override
         public MetisFieldSet<MoneyWiseUKInterestAsIncomeScheme> getDataFieldSet() {
             return FIELD_DEFS;
         }
     }
 
     /**
      * Base Rate Scheme.
      */
     public static class MoneyWiseUKInterestBaseRateScheme
             extends MoneyWiseUKInterestScheme {
         /**
          * Local Report fields.
          */
         private static final MetisFieldSet<MoneyWiseUKInterestBaseRateScheme> FIELD_DEFS = MetisFieldSet.newFieldSet(MoneyWiseUKInterestBaseRateScheme.class);
 
         /*
          * Declare Fields.
          */
         static {
             FIELD_DEFS.declareLocalField(MoneyWiseTaxResource.SCHEME_BASE_RATE, MoneyWiseUKInterestBaseRateScheme::getBaseRate);
         }
 
         /**
          * The Base Rate.
          */
         private final OceanusRate theBaseRate;
 
         /**
          * Constructor.
          *
          * @param pRate the base rate
          */
         protected MoneyWiseUKInterestBaseRateScheme(final OceanusRate pRate) {
             theBaseRate = pRate;
         }
 
         @Override
         protected OceanusRate getBaseRate() {
             return theBaseRate;
         }
 
         @Override
         protected OceanusRate getTaxCreditRate(final MoneyWiseUKTaxYear pTaxYear) {
             return theBaseRate;
         }
 
         @Override
         public MetisFieldSet<? extends MoneyWiseUKInterestBaseRateScheme> getDataFieldSet() {
             return FIELD_DEFS;
         }
     }
 
     /**
      * LoBase Rate Scheme.
      */
     public static class MoneyWiseUKInterestLoBaseRateScheme
             extends MoneyWiseUKInterestBaseRateScheme {
         /**
          * Local Report fields.
          */
         private static final MetisFieldSet<MoneyWiseUKInterestLoBaseRateScheme> FIELD_DEFS = MetisFieldSet.newFieldSet(MoneyWiseUKInterestLoBaseRateScheme.class);
 
         /**
          * Constructor.
          *
          * @param pRate the base rate
          */
         protected MoneyWiseUKInterestLoBaseRateScheme(final OceanusRate pRate) {
             super(pRate);
         }
 
         @Override
         public MetisFieldSet<MoneyWiseUKInterestLoBaseRateScheme> getDataFieldSet() {
             return FIELD_DEFS;
         }
     }
 }