japod@25: package org.apidesign.apifest08.currency;
japod@25: 
japod@49: import java.util.ArrayList;
japod@49: import java.util.Collection;
japod@49: import java.util.Collections;
japod@49: import java.util.HashSet;
japod@49: import java.util.List;
japod@49: import java.util.Set;
japod@49: 
japod@25: /** This is the skeleton class for your API. You need to make it public, so
japod@25:  * it is accessible to your client code (currently in Task1Test.java) file.
japod@25:  * <p>
japod@25:  * Feel free to create additional classes or rename this one, just keep all
japod@25:  * the API and its implementation in this package. Do not spread it outside
japod@25:  * to other packages.
japod@25:  */
japod@25: public final class Convertor {
japod@49:     //version 1 fields
japod@49: 
japod@49:     private String currency1 = null;
japod@49:     private String currency2 = null;
japod@49:     private Rate rate = null;
japod@49: 
japod@49:     //version 2 field
japod@49:     private List<CurrencyRate> currencyRates = null;
japod@49: 
japod@49:     //version - for compatible mode
japod@49:     private int instanceVersion = 0; //compatible mode because of problem with empty currency and CZE -> CZE (1:2) rate
japod@49: 
japod@25:     Convertor(String currency1, String currency2, Rate rate) {
japod@49:         instanceVersion = 1;
japod@49:         if ((currency1 == null) || (currency2 == null) || (rate == null)) {
japod@25:             throw new IllegalArgumentException("All arguments have to be non-null.");
japod@25:         }
japod@25:         this.currency1 = currency1;
japod@25:         this.currency2 = currency2;
japod@25:         this.rate = rate;
japod@25:     }
japod@25: 
japod@49:     Convertor(final CurrencyRate ... currencyRate) {
japod@49:         instanceVersion = 2;
japod@49: 
japod@49:         if (currencyRate == null) {
japod@49:             throw new IllegalArgumentException("Parameter cannot be null.");
japod@49:         }
japod@49:         if (currencyRate.length == 0) {
japod@49:             throw new IllegalArgumentException("CurrencyRates cannot be empty.");
japod@49:         }
japod@49:         Set<Pair<String,String>> currencies = new HashSet<Pair<String,String>>();
japod@49:         List<CurrencyRate> curRates = new ArrayList<CurrencyRate>();
japod@49:         for (int i = 0; i < currencyRate.length; i++) {
japod@49:             CurrencyRate curRat = currencyRate[i];
japod@49:             if (curRat == null) {
japod@49:                 throw new IllegalArgumentException("Parameter cannot be null.");
japod@49:             }
japod@49:             //check that currencyRate is not defined twice
japod@49:             Pair<String, String> curPair= new Pair<String, String>(curRat.getCurrency1(), curRat.getCurrency2());
japod@49:             if (currencies.contains(curPair)) {
japod@49:                 throw new IllegalArgumentException("Pair of currencies in a currency rate cannot be defined twice");
japod@49:             }
japod@49:             currencies.add(curPair);
japod@49:             
japod@49:             curRates.add(curRat);
japod@49:         }
japod@49:         this.currencyRates = Collections.unmodifiableList(curRates);
japod@49:     }
japod@49: 
japod@25:     public double convert(String fromCurrency, String toCurrency, int amount) {
japod@49:         if (instanceVersion == 1) {
japod@49:             if ((fromCurrency == null) || (toCurrency == null)) {
japod@49:                 throw new IllegalArgumentException("All arguments have to be non-null.");
japod@49:             }
japod@49: 
japod@49:             if (currency1.equals(fromCurrency) && currency2.equals(toCurrency)) {
japod@49:                 return rate.convertAtoB(amount);
japod@49:             } else if (currency2.equals(fromCurrency) && currency1.equals(toCurrency)) {
japod@49:                 return rate.convertBtoA(amount);
japod@49:             } else {
japod@49:                 throw new IllegalArgumentException("Convertor " + this.toString() +
japod@49:                         " cannot work with currencies " + fromCurrency + " and " + toCurrency + ".");
japod@49:             }
japod@54:         } else { //instanceVersion >= 2
japod@49:             //find suitable convertor
japod@49:             for (CurrencyRate curRate : currencyRates) {
japod@49:                 if ((curRate.getCurrency1().equals(fromCurrency))&& 
japod@49:                         (curRate.getCurrency2().equals(toCurrency))) 
japod@49:                 {
japod@49:                     return curRate.getRate().convertAtoB(amount);
japod@49:                 }
japod@49:             }
japod@49:             //suitable convertor not found, try to find inverse convertor
japod@49:             for (CurrencyRate curRate : currencyRates) {
japod@49:                 if ((curRate.getCurrency2().equals(fromCurrency))&&
japod@49:                         (curRate.getCurrency1().equals(toCurrency)))
japod@49:                 {
japod@49:                     return curRate.getRate().convertBtoA(amount);
japod@49:                 }
japod@49:             }            
japod@49:             //even inverse convertor not found
japod@49:             throw new IllegalArgumentException("Cannot work with selected currencies.");
japod@25:         }
japod@25:     }
japod@25: 
japod@25:     public double convert(String fromCurrency, String toCurrency, double amount) {
japod@49:         if (instanceVersion == 1) {
japod@49:             if ((fromCurrency == null) || (toCurrency == null)) {
japod@49:                 throw new IllegalArgumentException("All arguments have to be non-null.");
japod@49:             }
japod@49: 
japod@49:             if (currency1.equals(fromCurrency) && currency2.equals(toCurrency)) {
japod@49:                 return rate.convertAtoB(amount);
japod@49:             } else if (currency2.equals(fromCurrency) && currency1.equals(toCurrency)) {
japod@49:                 return rate.convertBtoA(amount);
japod@49:             } else {
japod@49:                 throw new IllegalArgumentException("Convertor " + this.toString() +
japod@49:                         " cannot work with currencies " + fromCurrency + " and " + toCurrency + ".");
japod@49:             }
japod@54:         } else { //instanceVersion >= 2
japod@49:             //find suitable convertor
japod@49:             for (CurrencyRate curRate : currencyRates) {
japod@49:                 if ((curRate.getCurrency1().equals(fromCurrency))&& 
japod@49:                         (curRate.getCurrency2().equals(toCurrency))) 
japod@49:                 {
japod@49:                     return curRate.getRate().convertAtoB(amount);
japod@49:                 }
japod@49:             }
japod@49:             //suitable convertor not found, try to find inverse convertor
japod@49:             for (CurrencyRate curRate : currencyRates) {
japod@49:                 if ((curRate.getCurrency2().equals(fromCurrency))&&
japod@49:                         (curRate.getCurrency1().equals(toCurrency)))
japod@49:                 {
japod@49:                     return curRate.getRate().convertBtoA(amount);
japod@49:                 }
japod@49:             }            
japod@49:             //even inverse convertor not found
japod@49:             throw new IllegalArgumentException("Cannot work with selected currencies.");
japod@25:         }
japod@25:     }
japod@49: 
japod@49:     /**
japod@49:      * Returns currency rates. If instantiated with constructor from vesion 1
japod@49:      * it creates new collection with one CurrencyRate.
japod@49:      * Note, it can cause exception because of empty currencies or same currencies.
japod@49:      */
japod@49:     public Collection<CurrencyRate> getCurrencyRates() {
japod@49:         if (instanceVersion == 1) {
japod@49:             List<CurrencyRate> ret = new ArrayList<CurrencyRate>();
japod@54:             ret.add(new CurrencyRateImpl(currency1, currency2, rate)); //here it checks that currency rate is not nonsense
japod@49:             return Collections.unmodifiableCollection(ret);
japod@54:         } else { //instanceVersion >= 2
japod@49:             return currencyRates;
japod@49:         }
japod@49:     }
japod@49: 
japod@25:     @Override
japod@25:     public String toString() {
japod@49:         if (instanceVersion == 1) {
japod@49:             return currency1 + currency2;
japod@49:         } else { //instanceVersion == 2
japod@49:             return super.toString(); //better be compatible in future :-)
japod@49:         }
japod@25:     }
japod@49: 
japod@25:     @Override
japod@25:     public boolean equals(Object obj) {
japod@49:         if (instanceVersion == 1) {
japod@49:             if (obj == null) {
japod@49:                 return false;
japod@49:             }
japod@49:             if (getClass() != obj.getClass()) {
japod@49:                 return false;
japod@49:             }
japod@49:             final Convertor other = (Convertor) obj;
japod@49:             if (this.currency1 != other.currency1 && (this.currency1 == null || !this.currency1.equals(other.currency1))) {
japod@49:                 return false;
japod@49:             }
japod@49:             if (this.currency2 != other.currency2 && (this.currency2 == null || !this.currency2.equals(other.currency2))) {
japod@49:                 return false;
japod@49:             }
japod@49:             if (this.rate != other.rate && (this.rate == null || !this.rate.equals(other.rate))) {
japod@49:                 return false;
japod@49:             }
japod@49:             return true;
japod@49:         } else { //instanceVersion == 2
japod@49:             return super.equals(obj); //better be compatible in future :-)
japod@25:         }
japod@25:     }
japod@25: 
japod@25:     @Override
japod@25:     public int hashCode() {
japod@49:         if (instanceVersion == 1) {
japod@49:             int hash = 5;
japod@49:             hash = 67 * hash + (this.currency1 != null ? this.currency1.hashCode() : 0);
japod@49:             hash = 67 * hash + (this.currency2 != null ? this.currency2.hashCode() : 0);
japod@49:             hash = 67 * hash + (this.rate != null ? this.rate.hashCode() : 0);
japod@25:         return hash;
japod@49:         } else { //instanceVersion == 2
japod@49:             return super.hashCode(); //better be compatible in future :-)
japod@49:         }
japod@25:     }
japod@25: }