/*

  *  Copyright 2009-2013 Stephen Colebourne

  *

  *  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 org.joda.money;

 import java.io.BufferedReader;

 import java.io.FileNotFoundException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 /**

  * Provider for available currencies using a file.

  * <p>

  * This reads currencies from two files.

  * Firstly it reads the mandatory resource named {@code /org/joda/money/MoneyData.csv}.

  * Then it reads the optional resource named {@code /org/joda/money/MoneyDataExtension.csv}.

  * Both will be read as the first found on the classpath.

  * The second file may replace entries in the first file.

  */

 class DefaultCurrencyUnitDataProvider extends CurrencyUnitDataProvider {

     /** Regex format for the csv line. */

     private static final Pattern REGEX_LINE = Pattern.compile("([A-Z]{3}),(-1|[0-9]{1,3}),(-1|[0-9]),([A-Z]*)#?.*");

     /**

      * Registers all the currencies known by this provider.

      * 

      * @throws Exception if an error occurs

      */ 

     @Override

     protected void registerCurrencies() throws Exception {

         loadCurrenciesFromFile("/org/joda/money/MoneyData.csv", true);

         loadCurrenciesFromFile("/org/joda/money/MoneyDataExtension.csv", false);

     }

     /**

      * Loads Currencies from a file

      *  

      * @param fileName  the file to load, not null

      * @param isNecessary  whether or not the file is necessary

      * @throws Exception if a necessary file is not found

      */

     private void loadCurrenciesFromFile(String fileName, boolean isNecessary) throws Exception {

         InputStream in = getClass().getResourceAsStream(fileName);

         if (in == null && isNecessary) {

             throw new FileNotFoundException("Data file " + fileName + " not found");

         } else if (in == null && !isNecessary) {

             return; // no extension file found, no problem. just return

         }

         BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));

         String line;

         while ((line = reader.readLine()) != null) {

             Matcher matcher = REGEX_LINE.matcher(line);

             if (matcher.matches()) {

                 List<String> countryCodes = new ArrayList<String>();

                 String codeStr = matcher.group(4);

                 String currencyCode = matcher.group(1);

                 if (codeStr.length() % 2 == 1) {

                     continue;  // invalid line

                 }

                 for (int i = 0; i < codeStr.length(); i += 2) {

                     countryCodes.add(codeStr.substring(i, i + 2));

                 }

                 int numericCode = Integer.parseInt(matcher.group(2));

                 int digits = Integer.parseInt(matcher.group(3));

                 registerCurrency(currencyCode, numericCode, digits, countryCodes);

             }

         }

     }

 }