/*
    * Copyright (C) 2013 4th Line GmbH, Switzerland
    *
    * The contents of this file are subject to the terms of either the GNU
    * Lesser General Public License Version 2 or later ("LGPL") or the
    * Common Development and Distribution License Version 1 or later
    * ("CDDL") (collectively, the "License"). You may not use this file
    * except in compliance with the License. See LICENSE.txt for more
    * information.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   */
  
  package org.fourthline.cling.model.types.csv;
  
  import org.fourthline.cling.model.types.Datatype;
  import org.fourthline.cling.model.types.InvalidValueException;
  import org.fourthline.cling.model.ModelUtil;
  import org.seamless.util.Reflections;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Transforms a state variable value from/to strings of comma-separated elements.
   * <p>
   * A concrete implementation of this interface knows how to transform values of the
   * declared type into a string of comma-separated list of elements, and how to read
   * such strings back into individual values.
   * </p>
   * <p>
   * Your action method returns a <code>CSV<...></code> instance as an output argument. It can
   * also accept a concrecte subclass of this type as an input argument, e.g. <code>CSVString</code>.
   * This type extends a regular <code>List</code>, so within your action method you can
   * handle the elements as usual.
   * </p>
   *
   * @author Christian Bauer
   */
  public abstract class CSV<T> extends ArrayList<T> {
  
      protected final Datatype.Builtin datatype;
  
      public CSV() {
          datatype = getBuiltinDatatype();
      }
  
      public CSV(String s) throws InvalidValueException {
          datatype = getBuiltinDatatype();
          addAll(parseString(s));
      }
  
      protected List parseString(String s) throws InvalidValueException {
          String[] strings = ModelUtil.fromCommaSeparatedList(s);
          List values = new ArrayList<>();
          for (String string : strings) {
              values.add(datatype.getDatatype().valueOf(string));
          }
          return values;
      }
  
      protected Datatype.Builtin getBuiltinDatatype() throws InvalidValueException {
          Class csvType = Reflections.getTypeArguments(ArrayList.class, getClass()).get(0);
          Datatype.Default defaultType = Datatype.Default.getByJavaType(csvType);
          if (defaultType == null) {
              throw new InvalidValueException("No built-in UPnP datatype for Java type of CSV: " + csvType);
          }
          return defaultType.getBuiltinType();
      }
  
      @Override
      public String toString() {
          List<String> stringValues = new ArrayList<>();
          for (T t : this) {
              stringValues.add(datatype.getDatatype().getString(t));
          }
          return ModelUtil.toCommaSeparatedList(stringValues.toArray(new Object[stringValues.size()]));
      }
  }